Tag Archives: hydrogène

Molecular Hydrogen CANCER treatment

Gas signaling molecules (GSMs), composed of oxygen, carbon monoxide, nitric oxide, hydrogen sulfide, etc., play critical roles in regulating signal transduction and cellular homeostasis. Interestingly, through various administrations, these molecules also exhibit potential in cancer treatment. Recently, hydrogen gas (formula: H2) emerges as another GSM which possesses multiple bioactivities, including anti-inflammation, anti-reactive oxygen species, and anti-cancer. Growing evidence has shown that hydrogen gas can either alleviate the side effects caused by conventional chemotherapeutics, or suppress the growth of cancer cells and xenograft tumor, suggesting its broad potent application in clinical therapy. In the current review, we summarize these studies and discuss the underlying mechanisms. The application of hydrogen gas in cancer treatment is still in its nascent stage, further mechanistic study and the development of portable instruments are warranted.

Introduction

Gaseous signaling molecules (GSMs) refer to a group of gaseous molecules, such as oxygen (1), nitric oxide (2), carbon monoxide (3), hydrogen sulfide (4), sulfur dioxide (56), ethylene (78), etc. These gaseous molecules possess multiple critical functions in regulating cell biology in vivo via signal transduction (9). More importantly, certain GSMs could serve as therapeutic agents in primary cancer, as well as in multidrug-resistant cancer treatment when used by directly or certain pharmaceutical formulations (913). In addition, some of these GSMs can be generated in body via different bacteria or enzymes, such as nitric oxide, hydrogen sulfide, indicating that they are more compatible molecules that may exhibit less adverse effects compared with conventional chemotherapeutics (91415). Recently, hydrogen gas has been recognized as another important GSM in biology, exhibiting appealing potential in health care for its role in preventing cell injury from various attacking (1619).

With the formula of H2, hydrogen gas is the lightest molecule in the nature which only accounts for about 0.5 parts per million (ppm) of all the gas. Naturally, hydrogen gas is a colorless, odorless, tasteless, non-toxic, highly combustible gas which may form explosive mixtures with air in concentrations from 4 to 74% that can be triggered by spark, heat, or sunlight. Hydrogen gas can be generated in small amount by hydrogenase of certain members of the human gastrointestinal tract microbiota from unabsorbed carbohydrates in the intestine through degradation and metabolism (2021), which then is partially diffused into blood flow and released and detected in exhaled breath (20), indicating its potential to serve as a biomarker.

As the lightest molecule in natural, hydrogen gas exhibits appealing penetration property, as it can rapidly diffuse through cell membranes (2223). Study in animal model showed that, after orally administration of hydrogen super-rich water (HSRW) and intra-peritoneal administration of hydrogen super-rich saline (HSRS), the hydrogen concentration reached the peak at 5 min; while it took 1 min by intravenous administration of HSRS (23). Another in vivo study tested the distribution of hydrogen in brain, liver, kidney, mesentery fat, and thigh muscle in rat upon inhalation of 3% hydrogen gas (24). The concentration order of hydrogen gas, when reached saturated status, was liver, brain, mesentery, muscle, kidney, indicating various distributions among organs in rats. Except the thigh muscle required a longer time to saturate, the other organs need 5–10 min to reach Cmax (maximum hydrogen concentration). Meanwhile, the liver had the highest Cmax (24). The information may direct the future clinical application of hydrogen gas.

Although hydrogen gas was studied as a therapy in a skin squamous carcinoma mouse model back in 1975 (25), its potential in medical application has not been vastly explored until 2007, when Oshawa et al. reported that hydrogen could ameliorate cerebral ischemia-reperfusion injury by selectively reducing cytotoxic reactive oxygen species (ROS), including hydroxyl radical (•OH) and peroxynitrite (ONOO-) (26), which then provoked a worldwide attention. Upon various administrative formulations, hydrogen gas has been served as a therapeutic agent for a variety of illnesses, such as Parkinson’s disease (2728), rheumatoid arthritis (29), brain injury (30), ischemic reperfusion injury (3132), and diabetes (3334), etc.

More importantly, hydrogen has been shown to improve clinical end-points and surrogate markers, from metabolic diseases to chronic systemic inflammatory disorders to cancer (17). A clinical study in 2016 showed that inhalation of hydrogen gas was safe in patients with post-cardiac arrest syndrome (35), its further therapeutic application in other diseases became even more appealing.

In the current review, we take a spot on its application in cancer treatment. Typically, hydrogen gas may exert its bio-functions via regulating ROS, inflammation and apoptosis events.

Hydrogen Gas Selectively Scavenges Hydroxyl Radical and Peroxynitrite, and Regulates Certain Antioxidant Enzymes

By far, many studies have indicated that hydrogen gas doesn’t target specific proteins, but regulate several key players in cancer, including ROS, and certain antioxidant enzymes (36).

ROS refers to a series of unstable molecules that contain oxygen, including singlet oxygen (O2•), hydrogen peroxide (H2O2), hydroxyl radical (•OH), superoxide (O2•O2-), nitric oxide (NO•), and peroxynitrite (ONOO), etc. (3738). Once generated in vivo, due to their high reactivity, ROS may attack proteins, DNA/RNA and lipids in cells, eliciting distinct damage that may lead to apoptosis. The presence of ROS can produce cellular stress and damage that may produce cell death, via a mechanism known as oxidative stress (3940). Normally, under physical condition, cells including cancer cells maintain a balance between generation and elimination of ROS, which is of paramount importance for their survival (4142). The over-produced ROS, resulted from imbalance regulatory system or outer chemical attack (including chemotherapy/radiotherapy), may initiate inner apoptosis cascade, causing severely toxic effects (4345).

Hydrogen gas may act as a ROS modulator. First, as shown in Ohsawa et al.’s study, hydrogen gas could selectively scavenge the most cytotoxic ROS, •OH, as tested in an acute rat model of cerebral ischemia and reperfusion (26). Another study also confirmed that hydrogen gas might reduce the oxygen toxicity resulted from hyperbaric oxygen via effectively reducing •OH (46).

Second, hydrogen may induce the expression of some antioxidant enzymes that can eliminate ROS, and it plays key roles in regulating redox homeostasis of cancer cells (4247). Studies have indicated that upon hydrogen gas treatment, the expression of superoxide dismutase (SOD) (48), heme oxyganase-1 (HO-1) (49), as well as nuclear factor erythroid 2-related factor 2 (Nrf2) (50), increased significantly, strengthening its potential in eliminating ROS.

By regulating ROS, hydrogen gas may act as an adjuvant regimen to reduce the adverse effects in cancer treatment while at the same time doesn’t abrogate the cytotoxicity of other therapy, such as radiotherapy and chemotherapy (4851). Interestingly, due the over-produced ROS in cancer cells (38), the administration of hydrogen gas may lower the ROS level at the beginning, but it provokes much more ROS production as a result of compensation effect, leading to the killing of cancer cells (52).

Hydrogen Gas Suppresses Inflammatory Cytokines

Inflammatory cytokines are a series of signal molecules that mediate the innate immune response, whose dys-regulation may contribute in many diseases, including cancer (5355). Typical inflammatory cytokines include interleukins (ILs) excreted by white blood cells, tumor necrosis factors (TNFs) excreted by macrophages, both of which have shown close linkage to cancer initiation and progression (5659), and both of ILs and TNFs can be suppressed by hydrogen gas (6061).

Inflammation induced by chemotherapy in cancer patients not only causes severely adverse effects (6263), but also leads to cancer metastasis, and treatment failure (6465). By regulating inflammation, hydrogen gas can prevent tumor formation, progression, as well as reduce the side effects caused by chemotherapy/radiotherapy (66).

Hydrogen Gas Inhibits/Induces Apoptosis

Apoptosis, also termed as programed cell death, can be triggered by extrinsic or intrinsic signals and executed by different molecular pathways, which serve as one efficient strategy for cancer treatment (6768). Generally, apoptosis can be induced by (1) provoking the death receptors of cell surface (such as Fas, TNF receptors, or TNF-related apoptosis-inducing ligand), (2) suppressing the survival signaling (such as epidermal growth factor receptor, mitogen-activated protein kinase, or phosphoinositide 3-kinases), and (3) activating the pro-apoptotic B-cell lymphoma-2 (Bcl-2) family proteins, or down-regulating anti-apoptosis proteins (such as X-linked inhibitor of apoptosis protein, surviving, and the inhibitor of apoptosis) (6970).

Hydrogen gas can regulate intracellular apoptosis by impacting the expression of apoptosis-related enzymes. At certain concentration, it can either serve as apoptosis-inhibiting agent via inhibiting the pro-apoptotic B-cell lymphoma-2-associated X protein (Bax), caspase-3, 8, 12, and enhancing the anti-apoptotic B-cell lymphoma-2 (Bcl-2) (71), or as apoptosis-inducing agent via the contrast mechanisms (72), suggesting its potential in protecting normal cells from anti-cancer drugs or in suppressing cancer cells.

Hydrogen Gas Exhibits Potential in Cancer Treatment

Hydrogen Gas Relieves the Adverse Effects Related to Chemotherapy/Radiotherapy

Chemotherapy and radiotherapy remain the leading strategies to treat cancer (7374). However, cancer patients receiving these treatments often experience fatigue and impaired quality of life (7577). The skyrocketed generation of ROS during the treatment is believed to contribute in the adverse effects, resulting in remarkable oxidative stress, and inflammation (414278). Therefore, benefited from its anti-oxidant and anti-inflammatory and other cell protective properties, hydrogen gas can be adopted as an adjuvant therapeutic regimen to suppress these adverse effects.

Under treatment of epidermal growth factor receptor inhibitor gefitinib, patients with non-small cell lung cancer often suffer with severe acute interstitial pneumonia (79). In a mice model treated with oral administration of gefitinib and intraperitoneal injection of naphthalene which induced severely lung injury due to oxidative stress, hydrogen-rich water treatment significantly reduced the inflammatory cytokines, such as IL-6 and TNFα in the bronchoalveolar lavage fluid, leading to a relieve of lung inflammation. More importantly, hydrogen-rich water didn’t impair the overall anti-tumor effects of gefitinib both in vitro and in vivo, while in contrast, it antagonized the weight loss induced by gefitinib and naphthalene, and enhanced the overall survival rate, suggesting hydrogen gas to be a promising adjuvant agent that has potential to be applied in clinical practice to improve quality of life of cancer patients (80).

Doxorubicin, an anthracycline antibiotic, is an effective anticancer agent in the treatment of various cancers, but its application is limited for the fatal dilated cardiomyopathy and hepatotoxicity (8182). One in vivo study showed that intraperitoneal injection of hydrogen-rich saline ameliorated the mortality, and cardiac dysfunction caused by doxorubicin. This treatment also attenuated histopathological changes in serum of rats, such as the serum brain natriuretic peptide (BNP), aspartate transaminase (AST), alanine transaminase (ALT), albumin and malondialdehyde (MDA) levels. Mechanistically, hydrogen-rich saline significantly lowered the ROS level, as well as inflammatory cytokines TNF-α, IL-1β, and IL-6 in cardiac and hepatic tissue. Hydrogen-rich saline also induced less expression of apoptotic Bax, cleaved caspase-3, and higher anti-apoptotic Bcl-2, resulting in less apoptosis in both tissues (71). This study suggested that hydrogen-rich saline treatment exerted its protective effects via inhibiting the inflammatory TNF-α/IL-6 pathway, increasing the cleaved C8 expression and Bcl-2/Bax ratio, and attenuating cell apoptosis in both heart and liver tissue (71).

Hydrogen-rich water also showed renal protective effect against cisplatin-induced nephrotoxicity in rats. In the studies, blood oxygenation level-dependent (BOLD) contrast magnetic resonance images (MRI) acquired in different treated group showed that the creatinine and blood urea nitrogen (BUN) levels, two parameters that related to nephrotoxicity, were significantly higher in cisplatin treated group than those in the control group. Hydrogen-rich water treatment could significantly reverse the toxic effects, and it showed much higher transverse relaxation rate by eliminating oxygen radicals (8384).

Another study showed that both inhaling hydrogen gas (1% hydrogen in air) and drinking hydrogen-rich water (0.8 mM hydrogen in water) could reverse the mortality, and body-weight loss caused by cisplatin via its anti-oxidant property. Both treatments improved the metamorphosis, accompanied with decreased apoptosis in the kidney, and nephrotoxicity as assessed by serum creatinine and BUN levels. More importantly, hydrogen didn’t impair the anti-tumor activity of cisplatin against cancer cell lines in vitro and in tumor-bearing mice (85). Similar results were also observed in Meng et al.’s study, as they showed that hydrogen-rich saline could attenuate the follicle-stimulating hormone release, elevate the level of estrogen, improve the development of follicles, and reduce the damage to the ovarian cortex induced by cisplatin. In the study, cisplatin treatment induced higher level of oxidation products, suppressed the antioxidant enzyme activity. The hydrogen-rich saline administration could reverse these toxic effects by reducing MDA and restoring the activity of superoxide dismutase (SOD), catalase (CAT), two important anti-oxidant enzymes. Furthermore, hydrogen-rich saline stimulated the Nrf2 pathway in rats with ovarian damage (86).

The mFOLFOX6 regimen, composed with folinic acid, 5-fluorouracil, and oxaliplatin, is used as first-line treatment for metastatic colorectal cancer, but it also confers toxic effects to liver, leading to bad quality of life of patient (8788). A clinical study was conducted in China by investing the protective effect of hydrogen-rich water on hepatic function of colorectal cancer patients (144 patients were enrolled and 136 of them were include in the final analysis) treated with mFOLFOX6 chemotherapy. The results showed that the placebo group exhibited damaging effects caused by mFOLFOX6 chemotherapy as measured by the elevated levels of ALT, AST and indirect bilirubin (IBIL), while the hydrogen-rich water combinational treatment group exhibited no differences in liver function during the treatment, probably due to its antioxidant activity, indicating it a promising protective agent to alleviate the mFOLFOX6-related liver injury (51).

Most of the ionizing radiation-induced adverse effects to normal cells are induced by hydroxyl radicals. The combination of radiotherapy with certain forms of hydrogen gas may be beneficial to alleviate these side effects (89). Indeed, several studies found that hydrogen could protect cells and mice from radiation (4890).

As tested in a rat model of skin damage established by using a 44 Gy electronic beam, the treated group by hydrogen-rich water exhibited higher lever of SOD activity and lower MDA and IL-6 in the wounded tissues than the control group and the distilled water group. Furthermore, hydrogen-rich water shortened the healing time and increased the healing rate of skin injury (48).

Gastrointestinal toxicity is a common side effect induced by radiotherapy, which impairs the life quality of cancer patients (91). As shown in Xiao et al.’s study in mice model, hydrogen-water administration via oral gavage increased the survival rate and body weight of mice which were exposed to total abdominal irradiation, accompanied with an improvement in gastrointestinal tract function and the epithelial integrity of the small intestine. Further microarray analysis revealed that hydrogen-water treatment up-regulated miR-1968-5p, which then up-regulated its target myeloid differentiation primary response gene 88 (MyD88, a mediator in immunopathology, and gut microbiota dynamics of certain intestinal diseases involving toll-like receptors 9) expression in the small intestine after total abdominal irradiation (92).

Another study conducted in clinical patients with malignant liver tumors showed that the consumption of hydrogen-rich water for 6 weeks reduced the level of reactive oxygen metabolite, hydroperoxide, and maintained the biologic antioxidant activity in the blood. Importantly, scores of quality of life during radiotherapy were significantly improved in hydrogen-rich water group compared to the placebo water group. Both groups exhibited similar tumor response to radiotherapy, indicating that the consumption of hydrogen-rich water reduced the radiation-induced oxidative stress while at the same time didn’t compromise anti-tumor effect of radiotherapy (93).

Hydrogen Gas Acts Synergistically With Thermal Therapy

Recently, one study found that hydrogen might enhance the effect of photothermal therapy. Zhao et al. designed the hydrogenated Pd nanocrystals (named as PdH0.2) as multifunctional hydrogen carrier to allow the tumor-targeted delivery (due to 30 nm cubic Pd nanocrystal) and controlled release of bio-reductive hydrogen (due to the hydrogen incorporated into the lattice of Pd). As shown in this study, hydrogen release could be adjusted by the power and duration of near-infrared (NIR) irradiation. Treatment of PdH0.2 nanocrystals plus NIR irradiation lead to higher initial ROS loss in cancer cells, and the subsequent ROS rebound was also much higher than that in normal cells, resulting in more apoptosis, and severely mitochondrial metabolism inhibition in cancer cells but not in normal cells. The combination of PdH0.2 nanocrystals with NIR irradiation significantly enhanced the anticancer efficacies of thermal therapy, achieving a synergetic anticancer effect. In vivo safety evaluation showed that the injection dose of 10 mg kg−1 PdH0.2 nanocrystals caused no death, no changes of several blood indicators, and no affected functions of liver and kidney. In 4T1 murine breast cancer tumor model and B16-F10 melanoma tumor model, the combined PdH0.2 nanocrystals and NIR irradiation therapy exhibited a synergetic anticancer effect, leading to remarkable tumor inhibition when compared with thermal therapy. Meanwhile, the combination group showed no visible damage to heart, liver, spleen, lung, and kidney, indicating suitable tissue safety and compatibility (52).

Hydrogen Gas Suppresses Tumor Formation

Li et al. reported that the consumption of hydrogen-rich water alleviated renal injury caused by Ferric nitrilotriacetate (Fe-NTA) in rats, evidenced by decreased levels of serum creatinine and BUN. Hydrogen-rich water suppressed the Fe-NTA-induced oxidative stress by lowering lipid peroxidation, ONOO, and inhibiting the activities of NADPH oxidase and xanthine oxidase, as well as by up-regulating antioxidant catalase, and restoring mitochondrial function in kidneys. Consequently, Fe-NTA-induced inflammatory cytokines, such as NF-κB, IL-6, and monocyte chemoattractant protein-1 were significantly alleviated by hydrogen treatment. More importantly, hydrogen-rich water consumption inhibited several cancer-related proteins expression, including vascular endothelial growth factor (VEGF), signal transducer and activator of transcription 3 (STAT3) phosphorylation, and proliferating cell nuclear antigen (PCNA) in rats, resulting in lower incidence of renal cell carcinoma and the suppression of tumor growth. This work suggested that hydrogen-rich water was a promising regimen to attenuate Fe-NTA-induced renal injury and suppress early tumor events (66).

Non-alcoholic steatohepatitis (NASH) due to oxidative stress induced by various stimuli, is one of the reasons that cause hepatocarcinogenesis (9495). In a mouse model, hydrogen-rich water administration lowered the hepatic cholesterol, peroxisome proliferator-activated receptor-α (PPARα) expression, and increased the anti-oxidative effects in the liver when compared with control and pioglitazone treated group (96). Hydrogen-rich water exhibited strong inhibitory effects to inflammatory cytokines TNF-α and IL-6, oxidative stress and apoptosis biomarker. As shown in NASH-related hepatocarcinogenesis model, in the group of hydrogen-rich water treatment, tumor incidence was lower and the tumor volumes were smaller than control and pioglitazone treated group. The above findings indicated that hydrogen-rich water had potential in liver protection and liver cancer treatment (96).

Hydrogen Gas Suppresses Tumor Growth

Not only working as an adjuvant therapy, hydrogen gas can also suppress tumor and tumor cells growth.

As shown in Wang et al.’s study, on lung cancer cell lines A549 and H1975 cells, hydrogen gas inhibited the cell proliferation, migration, and invasion, and induced remarkable apoptosis as tested by CCK-8, wound healing, transwell assays and flow cytometry. Hydrogen gas arrested the cell cycle at G2/M stage on both cell lines via inhibiting the expression of several cell cycle regulating proteins, including Cyclin D1, CDK4, and CDK6. Chromosomes 3 (SMC3), a complex required for chromosome cohesion during the cell cycle (97), was suppressed by hydrogen gas via ubiquitinating effects. Importantly, in vivo study showed that under hydrogen gas treatment, tumor growth was significantly inhibited, as well as the expression of Ki-67, VEGF and SMC3. These data suggested that hydrogen gas could serve as a new method for the treatment of lung cancer (98).

Due to its physicochemical characteristics, the use of hydrogen gas has been strictly limited in hospital and medical facilities and laboratories. Li et al. designed a solidified hydrogen-occluding-silica (H2-silica) that could stably release molecular hydrogen into cell culture medium. H2-silica could concentration-dependently inhibit the cell viability of human esophageal squamous cell carcinoma (KYSE-70) cells, while it need higher dose to suppress normal human esophageal epithelial cells (HEEpiCs), indicating its selective profile. This effect was further confirmed by apoptosis and cell migration assay in these two cell lines. Mechanistic study revealed that H2-silica exerted its anticancer via inducing H2O2 accumulation, cell cycle arrest, and apoptosis induction mediated by mitochondrial apoptotic pathways (72).

Recently, hydrogen gas was found to inhibit cancer stem cells (CSCs). Hydrogen gas reduced the colony formation and sphere formation of human ovarian cancer cell lines Hs38.T and PA-1 cells via inhibiting the proliferation marker Ki67, stem cell markers CD34, and angiogenesis. Hydrogen gas treatment significantly inhibited the proliferation, invasion, migration of both Hs38.T and PA-1 cells. More important, inhalation of hydrogen gas inhibited the tumor volume significantly as shown in the Hs38.T xenografted BALB/c nude mice model (99).

Another recent study also confirmed the effects of hydrogen gas in suppressing glioblastoma (GBM), the most common malignant brain tumor. In vitro study indicated that hydrogen gas inhibited several markers involved in stemness, resulting in the suppression of sphere formation, cell migration, invasion, and colony formation of glioma cells. By inhaling hydrogen gas (67%) 1 h, 2 times per day, the GBM growth was significantly inhibited, and the survival rate was improved in a rat orthotopic glioma model, suggesting that hydrogen might be a promising agent in the treatment of GBM (100).

Discussion

Hydrogen gas has been recognized as one medical gas that has potential in the treatment of cardiovascular disease, inflammatory disease, neurodegenerative disorders, and cancer (1760). As a hydroxyl radical and peroxynitrite scavenger, and due to its anti-inflammatory effects, hydrogen gas may work to prevent/relieve the adverse effects caused by chemotherapy and radiotherapy without compromise their anti-cancer potential (as summarized in Table 1 and Figure 1). Hydrogen gas may also work alone or synergistically with other therapy to suppress tumor growth via inducing apoptosis, inhibiting CSCs-related and cell cycle-related factors, etc. (summarized in Table 1).

TABLE 1

www.frontiersin.orgTable 1. The Summary of various formulation, application, mechanisms of H2 in cancer treatment.

FIGURE 1

www.frontiersin.orgFigure 1. Hydrogen in cancer treatment.

More importantly, in most of the research, hydrogen gas has demonstrated safety profile and certain selectivity property to cancer cells over normal cells, which is quite pivotal to clinical trials. One clinical trials (NCT03818347) is now undergoing to study the hydrogen gas in cancer rehabilitation in China.

By far, several delivery methods have proved to be available and convenient, including inhalation, drinking hydrogen-dissolved water, injection with hydrogen-saturated saline and taking a hydrogen bath (101). Hydrogen-rich water is non-toxic, inexpensive, easily administered, and can readily diffuse into tissues and cells (102), cross the blood-brain barrier (103), suggesting its potential in the treatment of brain tumor. Further portable devices that are well-designed and safe enough will be needed.

However, regarding its medicinal properties, such as dosage and administration, or possible adverse reactions and use in specific populations, less information is available. Its mechanism, target, indications are also not clear, further study are warranted.

NOTE:

Molecular hydrogen-rich water generally shows a more prominent effect than molecular hydrogen gas, although the amount of hydrogen taken up by hydrogen water is ~100 times less than that given by hydrogen gas [11].

We have showed that drinking molecular hydrogen water, but not continuous molecular hydrogen gas exposure, prevented development of 6-hydorxydopamine-induced Parkinson’s disease in rats [11].

https://water-ionizers.info/en/2017/09/05/modalities-of-molecular-hydrogen-administrationin-water-gas-or-saline-to-animals-humans-and-plants/

 

SEE ALL WATER IONIZERS – MOLECULAR HYDROGEN GENERATORS

REVIEW ARTICLE

Front. Oncol., 06 August 2019 | https://doi.org/10.3389/fonc.2019.00696

Hydrogen Gas in Cancer Treatment
Sai Li1Rongrong Liao2Xiaoyan Sheng2Xiaojun Luo3Xin Zhang1Xiaomin Wen3Jin Zhou2* and Kang Peng1,3*
  • 1Department of Pharmacy, Integrated Hospital of Traditional Chinese Medicine, Southern Medical University, Guangzhou, China
  • 2Nursing Department, Integrated Hospital of Traditional Chinese Medicine, Southern Medical University, Guangzhou, China
  • 3The Centre of Preventive Treatment of Disease, Integrated Hospital of Traditional Chinese Medicine, Southern Medical University, Guangzhou, China

Author Contributions

SL, XW, JZ, and KP: conceptualization. SL, RL, XS, XL, XZ, JZ, and KP: writing. SL, RL, and XS: revising.

Funding

This work was supported in part by grants from the Natural Science Foundation of Guangdong Province (2018A030313987) and Traditional Chinese Medicine Bureau of Guangdong Province (20164015 and 20183009) and Science and Technology Planning Project of Guangdong Province (2016ZC0059).

Conflict of Interest Statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Acknowledgments

We thank Miss Ryma Iftikhar, Dhiviya Samuel, Mahnoor Shamsi (St. John’s University), and Mr. Muaz Sadeia for editing and revising the manuscript.

References

1. De Bels D, Corazza F, Germonpre P, Balestra C. The normobaric oxygen paradox: a novel way to administer oxygen as an adjuvant treatment for cancer? Med Hypotheses. (2011) 76:467–70. doi: 10.1016/j.mehy.2010.11.022

PubMed Abstract | CrossRef Full Text | Google Scholar

2. Oliveira C, Benfeito S, Fernandes C, Cagide F, Silva T, Borges F. NO and HNO donors, nitrones, and nitroxides: past, present, and future. Med Res Rev. (2018) 38:1159–87. doi: 10.1002/med.21461

PubMed Abstract | CrossRef Full Text | Google Scholar

3. Vitek L, Gbelcova H, Muchova L, Vanova K, Zelenka J, Konickova R, et al. Antiproliferative effects of carbon monoxide on pancreatic cancer. Dig Liver Dis. (2014) 46:369–75. doi: 10.1016/j.dld.2013.12.007

PubMed Abstract | CrossRef Full Text | Google Scholar

4. Flannigan KL, Wallace JL. Hydrogen sulfide-based anti-inflammatory and chemopreventive therapies: an experimental approach. Curr Pharm Des. (2015) 21:3012–22. doi: 10.2174/1381612821666150514105413

PubMed Abstract | CrossRef Full Text | Google Scholar

5. Li Z, Huang Y, Du J, Liu AD, Tang C, Qi Y, et al. Endogenous sulfur dioxide inhibits vascular calcification in association with the TGF-beta/Smad signaling pathway. Int J Mol Sci. (2016) 17:266. doi: 10.3390/ijms17030266

PubMed Abstract | CrossRef Full Text | Google Scholar

6. Jin H, Liu AD, Holmberg L, Zhao M, Chen S, Yang J, et al. The role of sulfur dioxide in the regulation of mitochondrion-related cardiomyocyte apoptosis in rats with isopropylarterenol-induced myocardial injury. Int J Mol Sci. (2013) 14:10465–82. doi: 10.3390/ijms140510465

PubMed Abstract | CrossRef Full Text | Google Scholar

7. Jiroutova P, Oklestkova J, Strnad M. Crosstalk between brassinosteroids and ethylene during plant growth and under abiotic stress conditions. Int J Mol Sci. (2018) 19:3283. doi: 10.3390/ijms19103283

PubMed Abstract | CrossRef Full Text | Google Scholar

8. Paardekooper LM, van den Bogaart G, Kox M, Dingjan I, Neerincx AH, Bendix MB, et al. Ethylene, an early marker of systemic inflammation in humans. Sci Rep. (2017) 7:6889. doi: 10.1038/s41598-017-05930-9

PubMed Abstract | CrossRef Full Text | Google Scholar

9. Cui Q, Yang Y, Ji N, Wang JQ, Ren L, Yang DH, et al. Gaseous signaling molecules and their application in resistant cancer treatment: from invisible to visible. Future Med Chem. (2019) 11:323–6. doi: 10.4155/fmc-2018-0403

CrossRef Full Text | Google Scholar

10. Huang Z, Fu J, Zhang Y. Nitric oxide donor-based cancer therapy: advances and prospects. J Med Chem. (2017) 60:7617–35. doi: 10.1021/acs.jmedchem.6b01672

PubMed Abstract | CrossRef Full Text | Google Scholar

11. Ma Y, Yan Z, Deng X, Guo J, Hu J, Yu Y, et al. Anticancer effect of exogenous hydrogen sulfide in cisplatinresistant A549/DDP cells. Oncol Rep. (2018) 39:2969–77. doi: 10.3892/or.2018.6362

PubMed Abstract | CrossRef Full Text | Google Scholar

12. Zheng DW, Li B, Li CX, Xu L, Fan JX, Lei Q, et al. Photocatalyzing CO2 to CO for enhanced cancer therapy. Adv Mater. (2017) 29:1703822. doi: 10.1002/adma.201703822

PubMed Abstract | CrossRef Full Text | Google Scholar

13. Chen J, Luo H, Liu Y, Zhang W, Li H, Luo T, et al. Oxygen-self-produced nanoplatform for relieving hypoxia and breaking resistance to sonodynamic treatment of pancreatic cancer. Acs Nano. (2017) 11:12849–62. doi: 10.1021/acsnano.7b08225

PubMed Abstract | CrossRef Full Text | Google Scholar

14. Stuehr DJ, Vasquez-Vivar J. Nitric oxide synthases-from genes to function. Nitric Oxide. (2017) 63:29. doi: 10.1016/j.niox.2017.01.005

PubMed Abstract | CrossRef Full Text | Google Scholar

15. Cao X, Ding L, Xie ZZ, Yang Y, Whiteman M, Moore PK, et al. A review of hydrogen sulfide synthesis, metabolism, and measurement: is modulation of hydrogen sulfide a novel therapeutic for cancer? Antioxid Redox Signal. (2018) 31:1–38. doi: 10.1089/ars.2017.7058

PubMed Abstract | CrossRef Full Text | Google Scholar

16. Zhai X, Chen X, Ohta S, Sun X. Review and prospect of the biomedical effects of hydrogen. Med Gas Res. (2014) 4:19. doi: 10.1186/s13618-014-0019-6

PubMed Abstract | CrossRef Full Text | Google Scholar

17. Ostojic SM. Molecular hydrogen: an inert gas turns clinically effective. Ann Med. (2015) 47:301–4. doi: 10.3109/07853890.2015.1034765

PubMed Abstract | CrossRef Full Text | Google Scholar

18. LeBaron TW, Laher I, Kura B, Slezak J. Hydrogen gas: from clinical medicine to an emerging ergogenic molecule for sports athletes. Can J Physiol Pharmacol. (2019) 10:1–11. doi: 10.1139/cjpp-2019-0067

CrossRef Full Text | Google Scholar

19. Guan P, Sun ZM, Luo LF, Zhao YS, Yang SC, Yu FY, et al. Hydrogen gas alleviates chronic intermittent hypoxia-induced renal injury through reducing iron overload. Molecules. (2019) 24: 24:E1184. doi: 10.3390/molecules24061184

PubMed Abstract | CrossRef Full Text | Google Scholar

20. Sakai D, Hirooka Y, Kawashima H, Ohno E, Ishikawa T, Suhara H, et al. Increase in breath hydrogen concentration was correlated with the main pancreatic duct stenosis. J Breath Res. (2018) 12:36004. doi: 10.1088/1752-7163/aaaf77

PubMed Abstract | CrossRef Full Text | Google Scholar

21. Smith NW, Shorten PR, Altermann EH, Roy NC, McNabb WC. Hydrogen cross-feeders of the human gastrointestinal tract. Gut Microbes. (2018) 10:1–9. doi: 10.1080/19490976.2018.1546522

PubMed Abstract | CrossRef Full Text | Google Scholar

22. Fukuda K, Asoh S, Ishikawa M, Yamamoto Y, Ohsawa I, Ohta S. Inhalation of hydrogen gas suppresses hepatic injury caused by ischemia/reperfusion through reducing oxidative stress. Biochem Biophys Res Commun. (2007) 361:670–4. doi: 10.1016/j.bbrc.2007.07.088

PubMed Abstract | CrossRef Full Text | Google Scholar

23. Liu C, Kurokawa R, Fujino M, Hirano S, Sato B, Li XK. Estimation of the hydrogen concentration in rat tissue using an airtight tube following the administration of hydrogen via various routes. Sci Rep. (2014) 4:5485. doi: 10.1038/srep05485

PubMed Abstract | CrossRef Full Text | Google Scholar

24. Yamamoto R, Homma K, Suzuki S, Sano M, Sasaki J. Hydrogen gas distribution in organs after inhalation: real-time monitoring of tissue hydrogen concentration in rat. Sci Rep. (2019) 9:1255. doi: 10.1038/s41598-018-38180-4

PubMed Abstract | CrossRef Full Text | Google Scholar

25. Dole M, Wilson FR, Fife WP. Hyperbaric hydrogen therapy: a possible treatment for cancer. Science. (1975) 190:152–4. doi: 10.1126/science.1166304

PubMed Abstract | CrossRef Full Text | Google Scholar

26. Ohsawa I, Ishikawa M, Takahashi K, Watanabe M, Nishimaki K, Yamagata K, et al. Hydrogen acts as a therapeutic antioxidant by selectively reducing cytotoxic oxygen radicals. Nat Med. (2007) 13:688–94. doi: 10.1038/nm1577

PubMed Abstract | CrossRef Full Text | Google Scholar

27. Ostojic SM. Inadequate production of H2 by gut microbiota and Parkinson disease. Trends Endocrinol Metab. (2018) 29:286–8. doi: 10.1016/j.tem.2018.02.006

PubMed Abstract | CrossRef Full Text | Google Scholar

28. Hirayama M, Ito M, Minato T, Yoritaka A, LeBaron TW, Ohno K. Inhalation of hydrogen gas elevates urinary 8-hydroxy-2′-deoxyguanine in Parkinson’s disease. Med Gas Res. (2018) 8:144–9. doi: 10.4103/2045-9912.248264

PubMed Abstract | CrossRef Full Text | Google Scholar

29. Meng J, Yu P, Jiang H, Yuan T, Liu N, Tong J, et al. Molecular hydrogen decelerates rheumatoid arthritis progression through inhibition of oxidative stress. Am J Transl Res. (2016) 8:4472–7.

PubMed Abstract | Google Scholar

30. Shao A, Wu H, Hong Y, Tu S, Sun X, Wu Q, et al. Hydrogen-rich saline attenuated subarachnoid hemorrhage-induced early brain injury in rats by suppressing inflammatory response: possible involvement of NF-kappaB pathway and NLRP3 inflammasome. Mol Neurobiol. (2016) 53:3462–76. doi: 10.1007/s12035-015-9242-y

PubMed Abstract | CrossRef Full Text | Google Scholar

31. Gao Y, Yang H, Chi J, Xu Q, Zhao L, Yang W, et al. Hydrogen gas attenuates myocardial ischemia reperfusion injury independent of postconditioning in rats by attenuating endoplasmic reticulum stress-induced autophagy. Cell Physiol Biochem. (2017) 43:1503–4. doi: 10.1159/000481974

PubMed Abstract | CrossRef Full Text | Google Scholar

32. Dozen M, Enosawa S, Tada Y, Hirasawa K. Inhibition of hepatic ischemic reperfusion injury using saline exposed to electron discharge in a rat model. Cell Med. (2013) 5:83–7. doi: 10.3727/215517913X666486

PubMed Abstract | CrossRef Full Text | Google Scholar

33. Fan M, Xu X, He X, Chen L, Qian L, Liu J, et al. Protective effects of hydrogen-rich saline against erectile dysfunction in a streptozotocin induced diabetic rat model. J Urol. (2013) 190:350–6. doi: 10.1016/j.juro.2012.12.001

PubMed Abstract | CrossRef Full Text | Google Scholar

34. Zhang X, Liu J, Jin K, Xu H, Wang C, Zhang Z, et al. Subcutaneous injection of hydrogen gas is a novel effective treatment for type 2 diabetes. J Diabetes Investig. (2018) 9:83–90. doi: 10.1111/jdi.12674

PubMed Abstract | CrossRef Full Text | Google Scholar

35. Tamura T, Hayashida K, Sano M, Suzuki M, Shibusawa T, Yoshizawa J, et al. Feasibility and safety of hydrogen gas inhalation for post-cardiac arrest syndrome- first-in-human pilot study. Circ J. (2016) 80:1870–3. doi: 10.1253/circj.CJ-16-0127

PubMed Abstract | CrossRef Full Text | Google Scholar

36. Ge L, Yang M, Yang NN, Yin XX, Song WG. Molecular hydrogen: a preventive and therapeutic medical gas for various diseases. Oncotarget. (2017) 8:102653–73. doi: 10.18632/oncotarget.21130

PubMed Abstract | CrossRef Full Text | Google Scholar

37. Ray PD, Huang BW, Tsuji Y. Reactive oxygen species (ROS) homeostasis and redox regulation in cellular signaling. Cell Signal. (2012) 24:981–90. doi: 10.1016/j.cellsig.2012.01.008

PubMed Abstract | CrossRef Full Text | Google Scholar

38. Kumari S, Badana AK, G MM, G S, Malla R. Reactive oxygen species: a key constituent in cancer survival. Biomark Insights. (2018) 13:91914689. doi: 10.1177/1177271918755391

PubMed Abstract | CrossRef Full Text | Google Scholar

39. Nita M, Grzybowski A. The role of the reactive oxygen species and oxidative stress in the pathomechanism of the age-related ocular diseases and other pathologies of the anterior and posterior eye segments in adults. Oxid Med Cell Longev. (2016) 2016:3164734. doi: 10.1155/2016/3164734

PubMed Abstract | CrossRef Full Text | Google Scholar

40. Pelicano H, Carney D, Huang P. ROS stress in cancer cells and therapeutic implications. Drug Resist Updat. (2004) 7:97–110. doi: 10.1016/j.drup.2004.01.004

PubMed Abstract | CrossRef Full Text | Google Scholar

41. Liou GY, Storz P. Reactive oxygen species in cancer. Free Radic Res. (2010) 44:479–96. doi: 10.3109/10715761003667554

PubMed Abstract | CrossRef Full Text | Google Scholar

42. Cui Q, Wang JQ, Assaraf YG, Ren L, Gupta P, Wei L, et al. Modulating ROS to overcome multidrug resistance in cancer. Drug Resist Updat. (2018) 41:1–25. doi: 10.1016/j.drup.2018.11.001

PubMed Abstract | CrossRef Full Text | Google Scholar

43. Zhao Y, Hu X, Liu Y, Dong S, Wen Z, He W, et al. ROS signaling under metabolic stress: cross-talk between AMPK and AKT pathway. Mol Cancer. (2017) 16:79. doi: 10.1186/s12943-017-0648-1

PubMed Abstract | CrossRef Full Text | Google Scholar

44. Zha J, Chen F, Dong H, Shi P, Yao Y, Zhang Y, et al. Disulfiram targeting lymphoid malignant cell lines via ROS-JNK activation as well as Nrf2 and NF-kB pathway inhibition. J Transl Med. (2014) 12:163. doi: 10.1186/1479-5876-12-163

PubMed Abstract | CrossRef Full Text | Google Scholar

45. Gorrini C, Harris IS, Mak TW. Modulation of oxidative stress as an anticancer strategy. Nat Rev Drug Discov. (2013) 12:931–47. doi: 10.1038/nrd4002

PubMed Abstract | CrossRef Full Text | Google Scholar

46. Yu J, Yu Q, Liu Y, Zhang R, Xue L. Hydrogen gas alleviates oxygen toxicity by reducing hydroxyl radical levels in PC12 cells. PLoS ONE. (2017) 12:e173645. doi: 10.1371/journal.pone.0173645

PubMed Abstract | CrossRef Full Text | Google Scholar

47. Li Y, Li Q, Chen H, Wang T, Liu L, Wang G, et al. Hydrogen gas alleviates the intestinal injury caused by severe sepsis in mice by increasing the expression of heme oxygenase-1. Shock. (2015) 44:90–8. doi: 10.1097/SHK.0000000000000382

PubMed Abstract | CrossRef Full Text | Google Scholar

48. Zhou P, Lin B, Wang P, Pan T, Wang S, Chen W, et al. The healing effect of hydrogen-rich water on acute radiation-induced skin injury in rats. J Radiat Res. (2019) 60:17–22. doi: 10.1093/jrr/rry074

PubMed Abstract | CrossRef Full Text | Google Scholar

49. Iketani M, Ohshiro J, Urushibara T, Takahashi M, Arai T, Kawaguchi H, et al. Preadministration of hydrogen-rich water protects against lipopolysaccharide-induced sepsis and attenuates liver injury. Shock. (2017) 48:85–93. doi: 10.1097/SHK.0000000000000810

PubMed Abstract | CrossRef Full Text | Google Scholar

50. Dong A, Yu Y, Wang Y, Li C, Chen H, Bian Y, et al. Protective effects of hydrogen gas against sepsis-induced acute lung injury via regulation of mitochondrial function and dynamics. Int Immunopharmacol. (2018) 65:366–72. doi: 10.1016/j.intimp.2018.10.012

PubMed Abstract | CrossRef Full Text | Google Scholar

51. Yang Q, Ji G, Pan R, Zhao Y, Yan P. Protective effect of hydrogen-rich water on liver function of colorectal cancer patients treated with mFOLFOX6 chemotherapy. Mol Clin Oncol. (2017) 7:891–6. doi: 10.3892/mco.2017.1409

PubMed Abstract | CrossRef Full Text | Google Scholar

52. Zhao P, Jin Z, Chen Q, Yang T, Chen D, Meng J, et al. Local generation of hydrogen for enhanced photothermal therapy. Nat Commun. (2018) 9:4241. doi: 10.1038/s41467-018-06630-2

PubMed Abstract | CrossRef Full Text | Google Scholar

53. Antonioli L, Blandizzi C, Pacher P, Hasko G. Immunity, inflammation and cancer: a leading role for adenosine. Nat Rev Cancer. (2013) 13:842–57. doi: 10.1038/nrc3613

PubMed Abstract | CrossRef Full Text | Google Scholar

54. Dermond O, Ruegg C. Inhibition of tumor angiogenesis by non-steroidal anti-inflammatory drugs: emerging mechanisms and therapeutic perspectives. Drug Resist Updat. (2001) 4:314–21. doi: 10.1054/drup.2001.0219

PubMed Abstract | CrossRef Full Text | Google Scholar

55. Shakola F, Suri P, Ruggiu M. Splicing regulation of pro-inflammatory cytokines and chemokines: at the interface of the neuroendocrine and immune systems. Biomolecules. (2015) 5:2073–100. doi: 10.3390/biom5032073

PubMed Abstract | CrossRef Full Text | Google Scholar

56. Bottazzi B, Riboli E, Mantovani A. Aging, inflammation, and cancer. Semin Immunol. (2018) 40:74–82. doi: 10.1016/j.smim.2018.10.011

PubMed Abstract | CrossRef Full Text | Google Scholar

57. Zitvogel L, Pietrocola F, Kroemer G. Nutrition, inflammation, and cancer. Nat Immunol. (2017) 18:843–50. doi: 10.1038/ni.3754

PubMed Abstract | CrossRef Full Text | Google Scholar

58. Liu K, Lu X, Zhu YS, Le N, Kim H, Poh CF. Plasma-derived inflammatory proteins predict oral squamous cell carcinoma. Front Oncol. (2018) 8:585. doi: 10.3389/fonc.2018.00585

PubMed Abstract | CrossRef Full Text | Google Scholar

59. Mager LF, Wasmer MH, Rau TT, Krebs P. Cytokine-induced modulation of colorectal cancer. Front Oncol. (2016) 6:96. doi: 10.3389/fonc.2016.00096

PubMed Abstract | CrossRef Full Text | Google Scholar

60. Ning K, Liu WW, Huang JL, Lu HT, Sun XJ. Effects of hydrogen on polarization of macrophages and microglia in a stroke model. Med Gas Res. (2018) 8:154–9. doi: 10.4103/2045-9912.248266

PubMed Abstract | CrossRef Full Text | Google Scholar

61. Zhang N, Deng C, Zhang X, Zhang J, Bai C. Inhalation of hydrogen gas attenuates airway inflammation and oxidative stress in allergic asthmatic mice. Asthma Res Pract. (2018) 4:3. doi: 10.1186/s40733-018-0040-y

PubMed Abstract | CrossRef Full Text | Google Scholar

62. Wardill HR, Mander KA, Van Sebille YZ, Gibson RJ, Logan RM, Bowen JM, et al. Cytokine-mediated blood brain barrier disruption as a conduit for cancer/chemotherapy-associated neurotoxicity and cognitive dysfunction. Int J Cancer. (2016) 139:2635–45. doi: 10.1002/ijc.30252

PubMed Abstract | CrossRef Full Text | Google Scholar

63. Cheung YT, Ng T, Shwe M, Ho HK, Foo KM, Cham MT, et al. Association of proinflammatory cytokines and chemotherapy-associated cognitive impairment in breast cancer patients: a multi-centered, prospective, cohort study. Ann Oncol. (2015) 26:1446–51. doi: 10.1093/annonc/mdv206

PubMed Abstract | CrossRef Full Text | Google Scholar

64. Vyas D, Laput G, Vyas AK. Chemotherapy-enhanced inflammation may lead to the failure of therapy and metastasis. Onco Targets Ther. (2014) 7:1015–23. doi: 10.2147/OTT.S60114

PubMed Abstract | CrossRef Full Text | Google Scholar

65. Padoan A, Plebani M, Basso D. Inflammation and pancreatic cancer: focus on metabolism, cytokines, and immunity. Int J Mol Sci. (2019) 20:E676. doi: 10.3390/ijms20030676

PubMed Abstract | CrossRef Full Text | Google Scholar

66. Li FY, Zhu SX, Wang ZP, Wang H, Zhao Y, Chen GP. Consumption of hydrogen-rich water protects against ferric nitrilotriacetate-induced nephrotoxicity and early tumor promotional events in rats. Food Chem Toxicol. (2013) 61:248–54. doi: 10.1016/j.fct.2013.10.004

PubMed Abstract | CrossRef Full Text | Google Scholar

67. Huang D, Ichikawa K. Drug discovery targeting apoptosis. Nat Rev Drug Discov. (2008) 7:1041. doi: 10.1038/nrd2765

PubMed Abstract | CrossRef Full Text | Google Scholar

68. Pfeffer CM, Singh A. Apoptosis: a target for anticancer therapy. Int J Mol Sci. (2018) 19:E448. doi: 10.3390/ijms19020448

PubMed Abstract | CrossRef Full Text | Google Scholar

69. Qiao L, Wong BC. Targeting apoptosis as an approach for gastrointestinal cancer therapy. Drug Resist Updat. (2009) 12:55–64. doi: 10.1016/j.drup.2009.02.002

PubMed Abstract | CrossRef Full Text | Google Scholar

70. Kumar S. Caspase 2 in apoptosis, the DNA damage response and tumour suppression: enigma no more? Nat Rev Cancer. (2009) 9:897–903. doi: 10.1038/nrc2745

PubMed Abstract | CrossRef Full Text | Google Scholar

71. Gao Y, Yang H, Fan Y, Li L, Fang J, Yang W. Hydrogen-rich saline attenuates cardiac and hepatic injury in doxorubicin rat model by inhibiting inflammation and apoptosis. Mediators Inflamm. (2016) 2016:1320365. doi: 10.1155/2016/1320365

PubMed Abstract | CrossRef Full Text | Google Scholar

72. Li Q, Tanaka Y, Miwa N. Influence of hydrogen-occluding-silica on migration and apoptosis in human esophageal cells in vitroMed Gas Res. (2017) 7:76–85. doi: 10.4103/2045-9912.208510

PubMed Abstract | CrossRef Full Text | Google Scholar

73. Wang FH, Shen L, Li J, Zhou ZW, Liang H, Zhang XT, et al. The chinese society of clinical oncology (CSCO): clinical guidelines for the diagnosis and treatment of gastric cancer. Cancer Commun. (2019) 39:10. doi: 10.1186/s40880-019-0349-9

PubMed Abstract | CrossRef Full Text | Google Scholar

74. Verheij M, Vens C, van Triest B. Novel therapeutics in combination with radiotherapy to improve cancer treatment: rationale, mechanisms of action and clinical perspective. Drug Resist Updat. (2010) 13:29–43. doi: 10.1016/j.drup.2010.01.002

PubMed Abstract | CrossRef Full Text | Google Scholar

75. Sun YJ, Hu YJ, Jin D, Li JW, Yu B. Health-related quality of life after treatment for malignant bone tumors: a follow-up study in China. Asian Pac J Cancer Prev. (2012) 13:3099–102. doi: 10.7314/APJCP.2012.13.7.3099

PubMed Abstract | CrossRef Full Text | Google Scholar

76. Susanne K, Michael F, Thomas S, Peter E, Andreas H. Predictors of fatigue in cancer patients: a longitudinal study. Support Care Cancer. (2019) 120:425–32. doi: 10.1007/s00520-019-4660-4

CrossRef Full Text | Google Scholar

77. Razzaghdoust A, Mofid B, Peyghambarlou P. Predictors of chemotherapy-induced severe anemia in cancer patients receiving chemotherapy. Support Care Cancer. (2019). doi: 10.1007/s00520-019-04780-7. [Epub ahead of print].

PubMed Abstract | CrossRef Full Text | Google Scholar

78. Schumacker PT. Reactive oxygen species in cancer cells: live by the sword, die by the sword. Cancer Cell. (2006) 10:175–6. doi: 10.1016/j.ccr.2006.08.015

PubMed Abstract | CrossRef Full Text | Google Scholar

79. Inoue A, Saijo Y, Maemondo M, Gomi K, Tokue Y, Kimura Y, et al. Severe acute interstitial pneumonia and gefitinib. Lancet. (2003) 361:137–9. doi: 10.1016/S0140-6736(03)12190-3

PubMed Abstract | CrossRef Full Text | Google Scholar

80. Terasaki Y, Suzuki T, Tonaki K, Terasaki M, Kuwahara N, Ohsiro J, et al. Molecular hydrogen attenuates gefitinib-induced exacerbation of naphthalene-evoked acute lung injury through a reduction in oxidative stress and inflammation. Lab Invest. (2019) 99:793–806. doi: 10.1038/s41374-019-0187-z

PubMed Abstract | CrossRef Full Text | Google Scholar

81. Luo W, Wen G, Yang L, Tang J, Wang J, Wang J, et al. Dual-targeted and pH-sensitive doxorubicin prodrug-microbubble complex with ultrasound for tumor treatment. Theranostics. (2017) 7:452–65. doi: 10.7150/thno.16677

PubMed Abstract | CrossRef Full Text | Google Scholar

82. Shen BY, Chen C, Xu YF, Shen JJ, Guo HM, Li HF, et al. Is the combinational administration of doxorubicin and glutathione a reasonable proposal? Acta Pharmacol Sin. (2019) 40:699–709. doi: 10.1038/s41401-018-0158-8

PubMed Abstract | CrossRef Full Text | Google Scholar

83. Matsushita T, Kusakabe Y, Kitamura A, Okada S, Murase K. Investigation of protective effect of hydrogen-rich water against cisplatin-induced nephrotoxicity in rats using blood oxygenation level-dependent magnetic resonance imaging. Jpn J Radiol. (2011) 29:503–12. doi: 10.1007/s11604-011-0588-4

PubMed Abstract | CrossRef Full Text | Google Scholar

84. Kitamura A, Kobayashi S, Matsushita T, Fujinawa H, Murase K. Experimental verification of protective effect of hydrogen-rich water against cisplatin-induced nephrotoxicity in rats using dynamic contrast-enhanced CT. Br J Radiol. (2010) 83:509–14. doi: 10.1259/bjr/25604811

PubMed Abstract | CrossRef Full Text | Google Scholar

85. Nakashima-Kamimura N, Mori T, Ohsawa I, Asoh S, Ohta S. Molecular hydrogen alleviates nephrotoxicity induced by an anti-cancer drug cisplatin without compromising anti-tumor activity in mice. Cancer Chemother Pharmacol. (2009) 64:753–61. doi: 10.1007/s00280-008-0924-2

PubMed Abstract | CrossRef Full Text | Google Scholar

86. Meng X, Chen H, Wang G, Yu Y, Xie K. Hydrogen-rich saline attenuates chemotherapy-induced ovarian injury via regulation of oxidative stress. Exp Ther Med. (2015) 10:2277–82. doi: 10.3892/etm.2015.2787

PubMed Abstract | CrossRef Full Text | Google Scholar

87. Marco MR, Zhou L, Patil S, Marcet JE, Varma MG, Oommen S, et al. Consolidation mFOLFOX6 chemotherapy after chemoradiotherapy improves survival in patients with locally advanced rectal cancer: final results of a multicenter phase II trial. Dis Colon Rectum. (2018) 61:1146–55. doi: 10.1097/DCR.0000000000001207

PubMed Abstract | CrossRef Full Text | Google Scholar

88. Horimatsu T, Nakayama N, Moriwaki T, Hirashima Y, Fujita M, Asayama M, et al. A phase II study of 5-fluorouracil/L-leucovorin/oxaliplatin. (mFOLFOX6) in Japanese patients with metastatic or unresectable small bowel adenocarcinoma. Int J Clin Oncol. (2017) 22:905–12. doi: 10.1007/s10147-017-1138-6

CrossRef Full Text | Google Scholar

89. Chuai Y, Zhao L, Ni J, Sun D, Cui J, Li B, et al. A possible prevention strategy of radiation pneumonitis: combine radiotherapy with aerosol inhalation of hydrogen-rich solution. Med Sci Monit. (2011) 17:Y1–4. doi: 10.12659/MSM.881698

PubMed Abstract | CrossRef Full Text | Google Scholar

90. Mei K, Zhao S, Qian L, Li B, Ni J, Cai J. Hydrogen protects rats from dermatitis caused by local radiation. J Dermatolog Treat. (2014) 25:182–8. doi: 10.3109/09546634.2012.762639

PubMed Abstract | CrossRef Full Text | Google Scholar

91. Rodriguez ML, Martin MM, Padellano LC, Palomo AM, Puebla YI. Gastrointestinal toxicity associated to radiation therapy. Clin Transl Oncol. (2010) 12:554–61. doi: 10.1007/s12094-010-0553-1

PubMed Abstract | CrossRef Full Text | Google Scholar

92. Xiao HW, Li Y, Luo D, Dong JL, Zhou LX, Zhao SY, et al. Hydrogen-water ameliorates radiation-induced gastrointestinal toxicity via MyD88’s effects on the gut microbiota. Exp Mol Med. (2018) 50:e433. doi: 10.1038/emm.2017.246

PubMed Abstract | CrossRef Full Text | Google Scholar

93. Kang KM, Kang YN, Choi IB, Gu Y, Kawamura T, Toyoda Y, et al. Effects of drinking hydrogen-rich water on the quality of life of patients treated with radiotherapy for liver tumors. Med Gas Res. (2011) 1:11. doi: 10.1186/2045-9912-1-11

PubMed Abstract | CrossRef Full Text | Google Scholar

94. Phan J, Ng V, Sheinbaum A, French S, Choi G, El KM, et al. Hyperlipidemia and nonalcoholic steatohepatitis predispose to hepatocellular carcinoma development without cirrhosis. J Clin Gastroenterol. (2019) 53:309–13. doi: 10.1097/MCG.0000000000001062

PubMed Abstract | CrossRef Full Text | Google Scholar

95. Ma C, Zhang Q, Greten TF. Non-alcoholic fatty liver disease promotes hepatocellular carcinoma through direct and indirect effects on hepatocytes. Febs J. (2018) 285:752–62. doi: 10.1111/febs.14209

CrossRef Full Text | Google Scholar

96. Kawai D, Takaki A, Nakatsuka A, Wada J, Tamaki N, Yasunaka T, et al. Hydrogen-rich water prevents progression of non-alcoholic steatohepatitis and accompanying hepatocarcinogenesis in mice. Hepatology. (2012) 56:912–21. doi: 10.1002/hep.25782

CrossRef Full Text | Google Scholar

97. Kissebah AH, Sonnenberg GE, Myklebust J, Goldstein M, Broman K, James RG, et al. Quantitative trait loci on chromosomes 3 and 17 influence phenotypes of the metabolic syndrome. Proc Natl Acad Sci USA. (2000) 97:14478–83. doi: 10.1073/pnas.97.26.14478

PubMed Abstract | CrossRef Full Text | Google Scholar

98. Wang D, Wang L, Zhang Y, Zhao Y, Chen G. Hydrogen gas inhibits lung cancer progression through targeting SMC3. Biomed Pharmacother. (2018) 104:788–97. doi: 10.1016/j.biopha.2018.05.055

PubMed Abstract | CrossRef Full Text | Google Scholar

99. Shang L, Xie F, Li J, Zhang Y, Liu M, Zhao P, et al. Therapeutic potential of molecular hydrogen in ovarian cancer. Transl Cancer Res. (2018) 7:988–95. doi: 10.21037/tcr.2018.07.09

CrossRef Full Text | Google Scholar

100. Liu MY, Xie F, Zhang Y, Wang TT, Ma SN, Zhao PX, et al. Molecular hydrogen suppresses glioblastoma growth via inducing the glioma stem-like cell differentiation. Stem Cell Res Ther. (2019) 10:145. doi: 10.1186/s13287-019-1241-x

PubMed Abstract | CrossRef Full Text | Google Scholar

101. Zhang JY, Liu C, Zhou L, Qu K, Wang R, Tai MH, et al. A review of hydrogen as a new medical therapy. Hepatogastroenterology. (2012) 59:1026–32. doi: 10.5754/hge11883

PubMed Abstract | CrossRef Full Text | Google Scholar

102. Ohta S. Recent progress toward hydrogen medicine: potential of molecular hydrogen for preventive and therapeutic applications. Curr Pharm Des. (2011) 17:2241–52. doi: 10.2174/138161211797052664

PubMed Abstract | CrossRef Full Text | Google Scholar

103. Dixon BJ, Tang J, Zhang JH. The evolution of molecular hydrogen: a noteworthy potential therapy with clinical significance. Med Gas Res. (2013) 3:10. doi: 10.1186/2045-9912-3-10

PubMed Abstract | CrossRef Full Text | Google Scholar

 

Citation: Li S, Liao R, Sheng X, Luo X, Zhang X, Wen X, Zhou J and Peng K (2019) Hydrogen Gas in Cancer Treatment. Front. Oncol. 9:696. doi: 10.3389/fonc.2019.00696

Received: 02 May 2019; Accepted: 15 July 2019;
Published: 06 August 2019.

Edited by:

Nelson Shu-Sang Yee, Penn State Milton S. Hershey Medical Center, United States

Reviewed by:

Leo E. Otterbein, Beth Israelv Deaconess Medical Center and Harvard Medical School, United States
Paolo Armando Gagliardi, University of Bern, Switzerland

Copyright © 2019 Li, Liao, Sheng, Luo, Zhang, Wen, Zhou and Peng. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

*Correspondence: Jin Zhou, zhou-jin-2008@163.com; Kang Peng, kds978@163.com

These authors share co-first authorship

Molecular hydrogen (water) in the treatment of acute and chronic neurological conditions(Alzheimer’s, Parkinson’s,etc): mechanisms of protection and routes of administration

Molecular hydrogen (water) in the treatment of acute and chronic neurological conditions(i.e Alzheimer’s, Parkinson’s, etc. ): mechanisms of protection and routes of administration

 
 
We review the effects of molecular hydrogen water therapy in acute neuronal conditions and neurodegenerative diseases.
Molecular hydrogen water therapy /drinking water with dissolved molecular hydrogen may be useful for the prevention of neurodegenerative diseases and for reducing the symptoms of acute neuronal conditions.
 
Recently, the neuroprotective effects of treatment with molecular hydrogen (water) have been reported in both basic and clinical settings-as you will see below, we have examined the effects of molecular hydrogen H2  (water) treatment on acute central nervous system diseases and on chronic neurodegenerative diseases. We have also examined the various mechanism by which molecular hydrogen H2 exerts its neuroprotective effects .
Molecular hydrogen  H2 acts as a scavenger for OH and ONOO, affects neuroinflammation, preserves mitochondrial energy production, and possesses neuroprotective properties.
 
Unlike more conventional drugs, molecular hydrogen  H2 treatment, particularly the consumption of  molecular hydrogen  H2-rich water, has no known serious side effects and is effective for preventing the onset of neurodegenerative disease and aggravation of acute neuronal conditions – i.e.:
 

Molecular hydrogen water & Parkinson’s disease (PD)

Parkinson’s disease PD is a disorder that presents with extrapyramidal symptoms caused by the degeneration and loss of dopamine-producing cells in substantia nigra. Oxidative stress is known to be involved in the clinical condition of PD.() Moreover, the involvement of mitochondrial dysfunction in PD has been reported.()

The effects of molecular hydrogen  H2 on Parkinson’s disease PD have been reported in animal models of PD as well as in clinical studies.()

In 2009, Fujita et al.() and Fu et al.() reported that consuming  molecular hydrogen H2-rich water inhibits oxidative stress on the nigrostriatal pathway and prevents the loss of dopamine cells in a PD animal model. With the consumption of molecular hydrogen H2-rich-water-drinking, oxidative stress in the nigrostriatal pathway was inhibited and loss of dopamine cells was decreased. These results suggest that consuming molecular hydrogen H2-rich water could affect the onset of Parkinson’s Disease PD.

In recent years, the results of a clinical trial on the effects of consuming molecular hydrogen H2-rich water for Parkinson’s Disease PD have been reported.() A randomized double-blind study showed that consuming molecular hydrogen H2-rich water (1,000 ml/day) for 48 weeks significantly improved the total Unified Parkinson’s Disease Rating Scale (UPDRS) score of Parkinson’s disease PD patients treated with levodopa. A double-blind multi-center trial of molecular hydrogen H2 water is currently underway (Table 1).()

 

Molecular hydrogen water &  Alzheimer’s disease (AD)

Alzheimer Disease AD, an age-related neurodegenerative disease, is the most common cause of dementia.(,) Pathologically, it is characterized by the deposition of Aβ protein outside nerve cells and the accumulation of phosphorylated tau protein inside nerve cells. There is also a marked loss of nervous cells in the cerebral cortex.() In recent years, oxidative stress and neuroinflammation have been reported to be involved in Alzheimer’s disease AD.(,) To date, reports have centered on the involvement of oxidative stress in brain parenchyma.(,,)The accumulation of Aβ protein is strongly associated with the failure of Aβ clearance that is closely related to the pathogenesis of Alzheimer’s Disease AD.() It is known that low-density lipoprotein receptor-related protein 1 (LRP1) is involved in Aβ protein elimination. LRP dysfunction caused by oxidative stress and neuroinflammation is involved in the onset of Alzheimer’s Disease AD.() The regulation of oxidative stress and neuroinflammation may prevent the onset or progression of Alzheimer’s Disease AD. A number of reports have investigated the effects of molecular hydrogen H2 for the prevention of Alzheimer’s Disease AD onset.(,)

In a rat Alzheimer’s Disease AD model, it has been reported that the administration of molecular H2-rich saline (5 ml/kg, i.p., daily) inhibited oxidative stress, cytokine production, and nuclear factor-κB (NF-κB) production in the hippocampus and cerebral cortex, and improved impaired memory.(,)

It has  been reported that consuming molecular hydrogen H2-rich water inhibits age-related brain alterations and spatial memory decline.()

 

The therapeutic effect of molecular hydrogen H2-rich water following Traumatic brain injury (TBI) and in posttraumatic onset of Alzheimer’s disease (AD) was investigated by Dohi et al. in 2014,() who investigated whether the consumption of molecular hydrogen  H2-rich water 24 h prior to trauma can inhibit neuronal damage in a controlled cortical injury model using mice. The authors found that the expression of the phosphorylated tau proteins AT8 and Alz50 in the hippocampus and cortex was blocked in mice that consumed molecular hydrogen  H2-rich water. Moreover, the activity of astrocytes and microglia were inhibited in mice Traumatic Brain Injury model consuming molecular hydrogen H2-rich water. The expression of genes induced by Traumatic Brain Injury, particularly those that are involved in oxidation/carbohydrate metabolism, cytokine release, leukocyte or cell migration, cytokine transport, and adenosine triphosphate (ATP) and nucleotide binding, was inhibited by consuming molecular hydrogen  H2-rich water.

Dohi et al.() specifically reviewed the role of molecular hydrogen H2-rich water in neuroinflammation following brain trauma. The consumption of molecular hydrogen H2-rich water influenced the production of cytokines and chemokines in the damaged brain and inhibited the production of hypoxia inducible factor-1 (HIF-1), MMP-9, and cyclophilin A. However,molecular hydrogen  H2-rich water did not affect the production of amyloid precursor protein (APP), Aβ-40, or Aβ-42. They also investigated the relationship between molecular hydrogen H2 and ATP production and reported that molecular hydrogen H2 increased basal respiration, reserve capacity, and nonmitochondrial respiration but did not increase aerobic ATP production. It has thus been demonstrated that the inhibitory effects of molecular hydrogen H2 on nerve damage are not solely due to its simple function as a free radical scavenger (Fig. 1 and and22).

 
Molecular hydrogen is well characterized as a selective scavenger of hydroxyl radicals and peroxynitrite.

Oxidative stress caused by reactive oxygen species is considered a major mediator of tissue and cell injuries in various neuronal conditions, including neurological emergencies and neurodegenerative diseases.

 

Oxidative stress caused by reactive oxygen species (ROS) is a major mediator of tissue and cellular injuries in various neuronal conditions, including neurological emergencies and neurodegenerative diseases.()

Control of oxidative stress is a major therapeutic strategy for various neuronal conditions.(,,) There are many methods for controlling oxidative stress with the use of free radical scavengers being the most common approach.(,) Evidence from animal experiments support the notion that free radical scavengers and antioxidants dramatically reduce cerebral damage.() Edaravone (MCI-186), a novel free radical scavenger, was developed to prevent lipid peroxidation in pathological neurological conditions.(,)Edaravone is currently the only antioxidant drug approved for treating cerebral infarction that improves the functional outcome of ischemic stroke.() Brain hypothermia therapy (targeted temperature management) can also effectively control oxidative stress. Brain hypothermia therapy is effective in patients with various acute neuronal diseases.(,,)

In 2007, Ohsawa et al.() reported that molecular hydrogen (H2) can act as an antioxidant to prevent and treat middle cerebral artery occlusion–reperfusion injury in rats. This effect has been supported by additional reports. Recently, the beneficial effect of molecular H2 has been reported in many other organs, including the brain.() The first major therapeutic effect of molecular hydrogen H2 was that of an antioxidant, combining with hydroxyl ions to produce water.() Recently, other biological mechanisms of molecular hydrogen H2 (anti-inflammatory, anti-apoptosis, anti-cytokine, DNA expression, and energy metabolism) have been proposed (Fig. 1 and and22).()Therefore, the biology of molecular hydrogen H2 is not simple. In this review, we discuss the role of molecular H2 in various neuronal conditions.

Fig. 1

Beneficial effects of molecular hydrogen in pathophysiology of various acute neuronal conditions. ATP, adenosine triphosphate; miR-200, microRNA-200; ROS, reactive oxygen species.

Fig. 2

Effect of consumption of molecular hydrogen-rich water as functional water in pathophysiology of neurodegenerative diseases. ATP, adenosine triphosphate; miR-200, microRNA-200; ROS, reactive oxygen species.

Method and Route of Administration in Molecular hydrogen H2 Therapy

As a small (2 Da), uncharged molecule of hydrogen H2, would be expected to readily distribute throughout the body, including being able to easily penetrate cell membranes, However we are unable to determine the distribution of moleclar hydrogen H2 among organs and its concentrations in each organ and serum based on the administration methods and dosage. This problem was investigated in 2014.() A comparative review was conducted on the consumption of molecular hydrogen H2-rich water, i.p. or intravenous administration of molecular hydrogen  H2-rich saline, and inhalation of molecular hydrogen H2 gas. The results showed that the highest concentrations are reached 1 min after intravenous administration and 5 min after oral administration. The highest concentration was reached 30 min after the inhalation of molecular hydrogen H2 gas and was maintained for some time. Although molecular hydrogen H2 concentrations in the brain tend to be high after either intravenous administration or inhalation, no significant differences have been observed in comparison with the concentrations after the consumption of molecular hydrogen  H2-rich water and i.p. administration of molecular hydrogen H2-rich saline. Thus, although there have been variations based on the administration method, all methods have been found to result in the presence of molecular hydrogen H2 in the serum and brain tissue. Liu et al.() measured molecular hydrogen  H2 levels in the arteries, veins, and brain tissues after the inhalation of 2% molecular hydrogen H2 gas. They found that arterial molecular hydrogen H2 peaked at 30 min after administration, whereas venous and brain tissue molecular hydrogen H2 peaked at 45 min after administration. They reported that molecular hydrogen  H2 levels were similar in arteries and brain tissues.

This demonstrated that molecular hydrogen  H2 migrates to the brain tissue regardless of the method of administration(Thus, the studies below might as well have been performed using molecular hydrogen water instead of molecular hydrogen gas or molecular hydrogen saline).

These results suggest that the consumption of molecular hydrogen  H2-rich water prevents neurodegenerative disease and that molecular hydrogen H2-rich drinking water could be used to treat acute brain disorders (Fig. 1 and and22).

 
 
 
 

Molecular Hydrogen & Neurological Diseases

Molecular hydrogen & Ischemic brain injury

It has been reported that molecular hydrogen H2 prevents ischemic brain damage in animal experiments.(,) Ohsawa et al.() reported that inhalation of 2% molecular hydrogen H2 gas strongly suppressed infarct volume after middle cerebral artery ischemia–reperfusion in rats. In an electron spin resonance (ESR) study, they showed that molecular hydrogen  H2 had hydroxyl radical scavenging activity. Hydroxynonenal (HNE) and 8-hydroxy-2′-deoxyguanosine (8-OHdG) immunoreactivity was suppressed in the damaged brain after treatment with 2% molecular hydrogen H2. molecular hydrogen H2 inhalation reduced ischemic damage and hemorrhagic volume after transient middle crebral artery occlusion (MCAO) ischemia.() Free radical generation after ischemia induces matrix metalloproteinase (MMP) expression.(,) MMP-9 promotes hemorrhagic infarction by disrupting cerebral vessels.() molecular hydrogen H2 inhalation has been found to reduce MMP-9 expression in an MCAO rat model. molecular hydrogen H2 also has a neuroprotective effect against global ischemia. Ji et al.() reported that molecular hydrogen H2-rich saline injection [5 ml/kg intra-peritoneal (i.p.) administration] after global ischemia reduced neuronal cell death in hippocampal Cornet d’Ammon 1 (CA1) lesions in rats. Cerebral hypoxia–ischemia and neonatal asphyxia are major causes of brain damage in neonates. molecular hydrogen H2 gas inhalation and molecular hydrogen H2-rich saline injection provide early neuroprotection from neonatal neurological damage.() Nagatani et al.() reported that that an molecular hydrogen H2-enriched intravenous solution is safe for patients with acute cerebral infarction, including patients treated with tissue plasminogen activator (t-PA) therapy.

Metabolic syndrome is a strong risk factor of stroke. It has been reported that molecular hydrogen H2 therapy can improve metabolic syndrome in basic and clinical settings.() molecular hydrogen H2 therapy may reduce stroke in patients with metabolic syndrome involving diabetes mellitus.

Molecular hydrogen & Hemorrhagic stroke

Hemorrhagic stroke involving intracerebral hemorrhage (ICH) and subarachnoid hemorrhage (SAH) is a critical neuronal condition, and the mortality rate of hemorrhagic stroke is still high.() Manaenko et al.() reported a neuroprotective effect of molecular hydrogen H2 gas inhalation using an experimental ICH animal model.molecular hydrogen H2 gas inhalation suppresses redox stress and blood brain barrier (BBB) disruption by reducing mast cell activation and degranulation. Brain edema and neurological deficits were also suppressed. In SAH, there are several studies demonstrating the neuroprotective effect of molecular hydrogen  H2 treatment.() A clinical trial has started in patients with SAH (Table 1).()

Table 1

Clinical trials of molecular hydrogen in central nervous system (CNS) diseases

Molecular hydrogen & Traumatic brain injury (TBI)

The efficacy of molecular hydrogen H2 for treating TBI has been investigated in several studies.(,,) Ji et al.() reported that in a rat TBI model,molecular hydrogen H2 gas inhalation has been found to protect BBB permeability and regulate posttraumatic brain edema, thereby inhibiting brain damage. molecular hydrogen H2 gas inhalation also inhibits the decrease in superoxide dismutase (SOD) activity and catalase (CAT) activity. These are antioxidant enzymes in posttraumatic brains that inhibit the production of malondialdehyde (MDA) and 8-iso-prostaglandin F2α (8-iso-PGF2α). Eckermann et al.() reported that in a surgical trauma mouse model involving right frontal lobectomy, molecular hydrogen H2 gas inhalation has been found to inhibit postoperative brain edema and improve the postoperative neurobehavioral score. The same report also showed that lipid peroxidation and the production of oxidative stress substances were not inhibited by molecular hydrogen  H2 gas inhalation.() 

Molecular Hydrogen & Spinal cord injury

Chen et al.() reviewed the effects of molecular hydrogen H2-rich saline administration (i.p.) in a rat traumatic spinal cord injury model. They found that posttraumatic neurological symptoms were improved by molecular hydrogen H2-rich saline treatment. Furthermore, molecular hydrogen H2-rich saline treatment has been found to reduce inflammatory cell infiltration, TdT-mediated dUTP nick and labeling (TUNEL)-positive cells, and hemorrhage. In addition, oxidative stress was inhibited and the expression of brain derived neurotrophic factor (BDNF) was increased.

The effects of molecular hydrogen H2 administration on spinal cord ischemia have also been reported.(,) Huang et al.()investigated the effects of molecular hydrogen H2 gas inhalation in a rabbit spinal cord ischemia–reperfusion model. They reviewed the effects of molecular hydrogen H2 inhalation with different concentrations (1, 2, and 4%) and reported that molecular hydrogen H2 gas inhalation at concentrations of 2% and 4% inhibited neuronal death. However, they did not observe significant differences between the two groups in terms of effects with 2% and 4% being equally effective.() It has been reported that the inhalation of 2% molecular hydrogen H2 gas inhibits apoptosis following spinal cord injury caused by ischemia–reperfusion. In addition, molecular hydrogen H2 gas inhalation regulates caspase-3 activity, the production of inflammatory cytokines, oxidative stress, and the decrease in endogenous antioxidant substances. Zhou et al.() also reported that molecular hydrogen H2-rich saline administration (i.p.) has beneficial effects on spinal cord ischemia–reperfusion injury in rabbits.

Other acute neurological conditions

In recent years, research has shown that there is a high incidence of comorbid central nervous system symptoms in sepsis cases.() Using a mice cecal ligation and puncture (CLP) model, Liu et al.() reported that molecular hydrogen H2 gas inhalation improves septic encephalopathy. They reported that 2%molecular hydrogen H2 gas inhalation inhibited post-CLP apoptosis, brain edema, BBB permeability, cytokine production, and oxidative stress in the CA1 hippocampus region as well as improves cognitive function. Nakano et al.() reported that maternal administration of  molecular hydrogen H2 has a suppressive effect on fetal brain injury caused by intrauterine inflammation with maternal intraperitoneal injection of lipopolysaccharide (LPS).

The treatment of carbon monoxide (CO) poisoning encephalopathy, which is a common gas poisoning, is yet to be established.(,) Sun et al.() and Shen et al.() investigated the effects of molecular hydrogen H2-rich saline. They reported that in a CO poisoning model, the administration of molecular hydrogen H2-rich saline decreased glial activation, cytokine production, oxidative stress, and caspase 3 and 9 production as well as inhibited nerve cell death.

It is known that oxidative stress causes nerve cell impairments.() The consumption of molecular hydrogen H2-rich water inhibits oxidative stress and thereby inhibits the onset of stress-induced brain damage.()

Hypoxic brain injury caused by asphyxiation, hypoxic ischemic encephalopathy, neonatal asphyxia, and other similar hypoxia-mediated event is a common clinical condition in medical emergencies. Molecular hydrogen H2 treatment has been found to inhibit cell death in an in vitro hypoxia/reoxygenation model using immortalized mouse hippocampal (HT-22) cells. Molecular hydrogen  H2 treatment increased phosphorylated Akt (p-Akt) and B-cell leukemia/lymphoma-2 (BCL-2), while it decreased Bax and cleaved caspase-3.() In recent years, it has been found that the microRNA-200 (miR-200) family regulates oxidative stress.() The inhibition of miR-200 suppresses H/R-induced cell death, reducing ROS production and MMP. Molecular hydrogen  H2 treatment suppressed H/R-induced expression of miR-200. In Japan, a double blind randomized controlled trial for post cardiac arrest syndrome has started from 2017 (Table 1).

 

abbreviations

AD Alzheimer’s disease
APP amyloid precursor protein
ATP adenosine triphosphate
BBB blood brain barrier
CA1 Cornet d’Armon 1
CLP cecal ligation and puncture
CO carbon monoxide
ICH intracerebral hemorrhage
LRP lipoprotein receptor-related protein
MCAO middle cerebral artery occlusion
miR-200 microRNA-200
MMP matrix metalloproteinase
PD Parkinson’s disease
ROS reactive oxygen species
SAH subarachnoid hemorrhage
TBI traumatic brain injury
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5525017/

References

1. Huang WJ, Zhang X, Chen WW. Role of oxidative stress in Alzheimer’s disease. Biomed Rep. 2016;4:519–522. [PMC free article] [PubMed]
2. Dohi K, Ohtaki H, Nakamachi T, et al. Gp91phox (NOX2) in classically activated microglia exacerbates traumatic brain injury. J Neuroinflammation. 2010;7:41. [PMC free article] [PubMed]
3. Lewen A, Matz P, Chan PH. Free radical pathways in CNS injury. J Neurotrauma. 2000;17:871–890.[PubMed]
4. Gaetani P, Pasqualin A, Rodriguez y Baena R, Borasio E, Marzatico F. Oxidative stress in the human brain after subarachnoid hemorrhage. J Neurosurg. 1998;89:748–754. [PubMed]
5. Erickson MA, Dohi K, Banks WA. Neuroinflammation: a common pathway in CNS diseases as mediated at the blood-brain barrier. Neuroimmunomodulation. 2012;19:121–130. [PMC free article][PubMed]
6. Dohi K, Miyamoto K, Fukuda K, et al. Status of systemic oxidative stress during therapeutic hypothermia in patients with post-cardiac arrest syndrome. Oxid Med Cell Longev. 2013;2013:562429.[PMC free article] [PubMed]
7. Yoritaka A, Hattori N, Uchida K, Tanaka M, Stadtman ER, Mizuno Y. Immunohistochemical detection of 4-hydroxynonenal protein adducts in Parkinson disease. Proc Natl Acad Sci U S A. 1996;93:2696–2701.[PMC free article] [PubMed]
8. Dohi K, Satoh K, Mihara Y, et al. Alkoxyl radical-scavenging activity of edaravone in patients with traumatic brain injury. J Neurotrauma. 2006;23:1591–1599. [PubMed]
9. Dohi K, Satoh K, Nakamachi T, et al. Does edaravone (MCI-186) act as an antioxidant and a neuroprotector in experimental traumatic brain injury? Antioxid Redox Signal. 2007;9:281–287. [PubMed]
10. Kaneko T, Kasaoka S, Nakahara T, et al. Effectiveness of lower target temperature therapeutic hypothermia in post-cardiac arrest syndrome patients with a resuscitation interval of ≤30 min. J Intensive Care. 2015;3:28. [PMC free article] [PubMed]
11. Silveira RC, Procianoy RS. Hypothermia therapy for newborns with hypoxic ischemic encephalopathy. J Pediatr (Rio J) 2015;91 (6 Suppl 1):S78–S83. [PubMed]
12. Ohsawa I, Ishikawa M, Takahashi K, et al. Hydrogen acts as a therapeutic antioxidant by selectively reducing cytotoxic oxygen radicals. Nat Med. 2007;13:688–694. [PubMed]
13. Ohta S. Molecular hydrogen as a preventive and therapeutic medical gas: initiation, development and potential of hydrogen medicine. Pharmacol Ther. 2014;144:1–11. [PubMed]
14. Terasaki Y, Ohsawa I, Terasaki M, et al. Hydrogen therapy attenuates irradiation-induced lung damage by reducing oxidative stress. Am J Physiol Lung Cell Mol Physiol. 2011;301:L415–L426. [PubMed]
15. Yang Y, Li B, Liu C, et al. Hydrogen-rich saline protects immunocytes from radiation-induced apoptosis. Med Sci Monit. 2012;18:BR144–BR148. [PMC free article] [PubMed]
16. Zeng K, Huang H, Jiang XQ, Chen XJ, Huang W. Protective effects of hydrogen on renal ischemia/reperfusion injury in rats. Sichuan Da Xue Xue Bao Yi Xue Ban. 2014;45:39–42. (in Chinese)[PubMed]
17. Ichihara M, Sobue S, Ito M, Ito M, Hirayama M, Ohno K. Beneficial biological effects and the underlying mechanisms of molecular hydrogen – comprehensive review of 321 original articles. Med Gas Res. 2015;5:12. [PMC free article] [PubMed]
18. Dohi K, Kraemer BC, Erickson MA, et al. Molecular hydrogen in drinking water protects against neurodegenerative changes induced by traumatic brain injury. PLoS One. 2014;9:e108034.[PMC free article] [PubMed]
19. Chen CH, Manaenko A, Zhan Y, et al. Hydrogen gas reduced acute hyperglycemia-enhanced hemorrhagic transformation in a focal ischemia rat model. Neuroscience. 2010;169:402–414.[PMC free article] [PubMed]
20. Yang Y, Estrada EY, Thompson JF, Liu W, Rosenberg GA. Matrix metalloproteinase-mediated disruption of tight junction proteins in cerebral vessels is reversed by synthetic matrix metalloproteinase inhibitor in focal ischemia in rat. J Cereb Blood Flow Metab. 2007;27:697–709. [PubMed]
21. Ji Q, Hui K, Zhang L, Sun X, Li W, Duan M. The effect of hydrogen-rich saline on the brain of rats with transient ischemia. J Surg Res. 2011;168:e95–e101. [PubMed]
22. Domoki F, Oláh O, Zimmermann A, et al. Hydrogen is neuroprotective and preserves cerebrovascular reactivity in asphyxiated newborn pigs. Pediatr Res. 2010;68:387–392. [PubMed]
23. Nagatani K, Nawashiro H, Takeuchi S, et al. Safety of intravenous administration of hydrogen-enriched fluid in patients with acute cerebral ischemia: initial clinical studies. Med Gas Res. 2013;3:13.[PMC free article] [PubMed]
24. Song G, Li M, Sang H, et al. Hydrogen-rich water decreases serum LDL-cholesterol levels and improves HDL function in patients with potential metabolic syndrome. J Lipid Res. 2013;54:1884–1893.[PMC free article] [PubMed]
25. Kajiyama S, Hasegawa G, Asano M, et al. Supplementation of hydrogen-rich water improves lipid and glucose metabolism in patients with type 2 diabetes or impaired glucose tolerance. Nutr Res. 2008;28:137–143. [PubMed]
26. Nakao A, Toyoda Y, Sharma P, Evans M, Guthrie N. Effectiveness of hydrogen rich water on antioxidant status of subjects with potential metabolic syndrome—an open label pilot study. J Clin Biochem Nutr. 2010;46:140–149. [PMC free article] [PubMed]
27. Hashimoto M, Katakura M, Nabika T, et al. Effects of hydrogen-rich water on abnormalities in a SHR.Cg-Leprcp/NDmcr rat – a metabolic syndrome rat model. Med Gas Res. 2011;1:26. [PMC free article][PubMed]
28. Manaenko A, Lekic T, Ma Q, Zhang JH, Tang J. Hydrogen inhalation ameliorated mast cell-mediated brain injury after intracerebral hemorrhage in mice. Crit Care Med. 2013;41:1266–1275. [PMC free article][PubMed]
29. Zhuang Z, Zhou ML, You WC, et al. Hydrogen-rich saline alleviates early brain injury via reducing oxidative stress and brain edema following experimental subarachnoid hemorrhage in rabbits. BMC Neurosci. 2012;13:47. [PMC free article] [PubMed]
30. Zhuang Z, Sun XJ, Zhang X, et al. Nuclear factor-κB/Bcl-XL pathway is involved in the protective effect of hydrogen-rich saline on the brain following experimental subarachnoid hemorrhage in rabbits. J Neurosci Res. 2013;91:1599–1608. [PubMed]
31. Hong Y, Shao A, Wang J, et al. Neuroprotective effect of hydrogen-rich saline against neurologic damage and apoptosis in early brain injury following subarachnoid hemorrhage: possible role of the Akt/GSK3β signaling pathway. PLoS One. 2014;9:e96212. [PMC free article] [PubMed]
32. Takeuchi S, Mori K, Arimoto H, et al. Effects of intravenous infusion of hydrogen-rich fluid combined with intra-cisternal infusion of magnesium sulfate in severe aneurysmal subarachnoid hemorrhage: study protocol for a randomized controlled trial. BMC Neurol. 2014;14:176. [PMC free article] [PubMed]
33. Ji X, Liu W, Xie K, et al. Beneficial effects of hydrogen gas in a rat model of traumatic brain injury via reducing oxidative stress. Brain Res. 2010;1354:196–205. [PubMed]
34. Eckermann JM, Chen W, Jadhav V, et al. Hydrogen is neuroprotective against surgically induced brain injury. Med Gas Res. 2011;1:7. [PMC free article] [PubMed]
35. Chen C, Chen Q, Mao Y, et al. Hydrogen-rich saline protects against spinal cord injury in rats. Neurochem Res. 2010;35:1111–1118. [PubMed]
36. Huang Y, Xie K, Li J, et al. Beneficial effects of hydrogen gas against spinal cord ischemia-reperfusion injury in rabbits. Brain Res. 2011;1378:125–136. [PubMed]
37. Zhou L, Wang X, Xue W, et al. Beneficial effects of hydrogen-rich saline against spinal cord ischemia-reperfusion injury in rabbits. Brain Res. 2013;1517:150–160. [PubMed]
38. Gofton TE, Young GB. Sepsis-associated encephalopathy. Nat Rev Neurol. 2012;8:557–566. [PubMed]
39. Liu L, Xie K, Chen H, et al. Inhalation of hydrogen gas attenuates brain injury in mice with cecal ligation and puncture via inhibiting neuroinflammation, oxidative stress and neuronal apoptosis. Brain Res. 2014;1589:78–92. [PubMed]
40. Nakano T, Kotani T, Mano Y, et al. Maternal molecular hydrogen administration on lipopolysaccharide-induced mouse fetal brain injury. J Clin Biochem Nutr. 2015;57:178–182. [PMC free article] [PubMed]
41. Shen MH, Cai JM, Sun Q, et al. Neuroprotective effect of hydrogen-rich saline in acute carbon monoxide poisoning. CNS Neurosci Ther. 2013;19:361–363. [PubMed]
42. Sun Q, Cai J, Zhou J, et al. Molecular Hydrogen-rich saline reduces delayed neurologic sequelae in experimental carbon monoxide toxicity. Crit Care Med. 2011;39:765–769. [PubMed]
43. Nagata K, Nakashima-Kamimura N, Mikami T, Ohsawa I, Ohta S. Consumption of molecular hydrogen prevents the stress-induced impairments in hippocampus-dependent learning tasks during chronic physical restraint in mice.  Neuropsychopharmacology. 2009;34:501–508. [PubMed]
44. Wei R, Zhang R, Xie Y, Shen L, Chen F. MOLECULAR hydrogen suppresses hypoxia/reoxygenation-induced cell death in hippocampal neurons through reducing oxidative stress. Cell Physiol Biochem. 2015;36:585–598.[PubMed]
45. Schapira AH. Mitochondria in the aetiology and pathogenesis of Parkinson’s disease. Lancet Neurol. 2008;7:97–109. [PubMed]
46. Ito M, Hirayama M, Yamai K, et al. Drinking molecular hydrogen water and intermittent hydrogen gas exposure, but not lactulose or continuous hydrogen gas exposure, prevent 6-hydorxydopamine-induced Parkinson’s disease in rats. Med Gas Res. 2012;2:15. [PMC free article] [PubMed]
47. Fujita K, Seike T, Yutsudo N, et al. Hydrogen in drinking water reduces dopaminergic neuronal loss in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine mouse model of Parkinson’s disease. PLoS One. 2009;4:e7247. [PMC free article] [PubMed]
48. Fu Y, Ito M, Fujita Y, et al. Molecular hydrogen is protective against 6-hydroxydopamine-induced nigrostriatal degeneration in a rat model of Parkinson’s disease. Neurosci Lett. 2009;453:81–85. [PubMed]
49. Yoritaka A, Takanashi M, Hirayama M, Nakahara T, Ohta S, Hattori N. Pilot study of molecular hydrogen H2 therapy in Parkinson’s disease: a randomized double-blind placebo-controlled trial. Mov Disord. 2013;28:836–839.[PubMed]
50. Yoritaka A, Abe T, Ohtsuka C, et al. A randomized double-blind multi-center trial of molecular hydrogen water for Parkinson’s disease: protocol and baseline characteristics. BMC Neurol. 2016;16:66. [PMC free article][PubMed]
51. Wang C, Li J, Liu Q, et al. Molecular hydrogen-rich saline reduces oxidative stress and inflammation by inhibit of JNK and NF-κB activation in a rat model of amyloid-beta-induced Alzheimer’s disease. Neurosci Lett. 2011;491:127–132. [PubMed]
52. Jucker M, Walker LC. Pathogenic protein seeding in Alzheimer disease and other neurodegenerative disorders. Ann Neurol. 2011;70:532–540. [PMC free article] [PubMed]
53. Li J, Wang C, Zhang JH, Cai JM, Cao YP, Sun XJ. Molecular hydrogen-rich saline improves memory function in a rat model of amyloid-beta-induced Alzheimer’s disease by reduction of oxidative stress. Brain Res. 2010;1328:152–161. [PubMed]
54. Gu Y, Huang CS, Inoue T, et al. Drinking  molecular hydrogen water ameliorated cognitive impairment in senescence-accelerated mice. J Clin Biochem Nutr. 2010;46:269–276. [PMC free article] [PubMed]
55. Liu C, Kurokawa R, Fujino M, Hirano S, Sato B, Li XK. Estimation of the molecular hydrogen concentration in rat tissue using an airtight tube following the administration of molecular hydrogen via various routes. Sci Rep. 2014;4:5485. [PMC free article] [PubMed]

Molecular Hydrogen water effects on Mild Cognitive Impairment

Abstract

Background:

Oxidative stress is one of the causative factors in the pathogenesis of neuro-degenerative diseases including mild cognitive impairment (MCI) and dementia. We previously reported that molecular hydrogen (H2) acts as a therapeutic and preventive antioxidant.

Objective:

We assess the effects of drinking H2 hydrogen-water (water infused with hydrogen gas H2) on oxidative stress model mice and human subjects with MCI.

Methods:

Transgenic mice expressing a dominant-negative form of aldehyde dehydrogenase 2 were used as a dementia model. The mice with enhanced oxidative stress were allowed to drink hydrogen H2-water.

For a ran-domized double-blind placebo-controlled clinical study, 73 subjects with mild cognitive impairment MCI drank ~300 mL of hydrogen H2-water (H2-group) or placebo water (control group) per day, and the Alzheimer’s Disease Assessment Scale-cognitive subscale (ADAS-cog) scores were determined after 1 year.

Results:

In mice, drinking hydrogen H2-water decreased oxidative stress markers and suppressed the decline of memory impairment and neurodegeneration. Moreover, the mean lifespan in the hydrogen H2-water group was longer than that of the control group.’

In MCI subjects, although there was no significant difference between the hydrogen water H2- and control groups in ADAS-cog score after 1 year, carriers of the apolipoprotein E4 (APOE4) geno-type in the H2-group were improved significantly on total ADAS-cog score and word recall task score (one of the sub-scores in the ADAS-cog score).

Conclusion:

H2-water may have a potential for suppressing dementia in an oxidative stress model and in the APOE4 carriers with MCI.

1. INTRODUCTION

Oxidative stress is one of the causative factors in the pathogenesis of major neurodegenerative diseases including Alzheimer’s disease (AD), mild cognitive impairment (MCI), and Parkinson disease (PD) []. Moreover, the genotype of apolipoprotein E4 (APOE4) is a genetic risk for AD, and the increased oxidative stress in the APOE4 carriers is considered as one of the modifiers for the risk [].

To explore effective dietary antioxidants to mitigate age-dependent neurodegeneration, it may be useful to construct model mice in which AD phenotypes would progress in an age-dependent manner in response to oxidative stress. We constructed transgenic DAL101 mice expressing a polymorphism of the mitochondrial aldehyde dehydrogenase 2 gene (ALDH2*2) []. ALDH2*2 is responsible for a deficiency in ALDH2 activity and is specific to North-East Asians []. We reported previously that ALDH2 deficiency is a risk factor for late-onset AD in the Japanese population, [] which was reproduced by Chinese and Korean studies in their respective populations []. DAL101 mice exhibited a decreased ability to detoxify 4-hydroxy-2-nonenal (4-HNE) in cortical neurons, and consequently an age-dependent neurodegeneration, cognitive decline, and a shortened lifespan [].

We proposed that molecular hydrogen (H2) has potential as a novel antioxidant, [] and numerous studies have strongly suggested its potential for preventive and therapeutic applications []. In addition to extensive animal experiments, more than 25 clinical studies examining the efficacy of molecular hydrogen H2 have been reported, [] including double-blind clinical studies. Based on these studies, the field of hydrogen medicine is growing rapidly.

There are several methods to administer hydrogen H2, including inhaling hydrogen gas (H2-gas), drinking hydrogen H2-dissolved water (H2-water), and injecting hydrogen H2-dissolved saline (hydrogen-rich saline) []. Drinking hydrogen H2-water prevented the chronic stress-induced impairments in learning and memory by reducing oxidative stress in mice [] and protects neural cells by stimulating the hormonal expression of ghrelin []. Additionally, injection of hydrogen-rich saline improved memory function in a rat model of amyloid-β-induced dementia by reducing oxidative stress []. Moreover, hydrogen inhalation during normoxic resuscitation improved neurological outcome in a rat model of cardiac arrest independently of targeted temperature management [].

In this study, we examined whether drinking hydrogen H2-water could suppress aging-dependent memory impairment induced by oxidative stress in DAL101 mice. Next, in a randomized double-blind placebo-controlled study, we investigated whether H2-water could delay the progression of MCI as assessed by the scores on the Alzheimer’s Disease Assessment Scale-cognition sub-scale (ADAS-cog) [] from baseline at 1-year. We found a significant improvement in cognition at 1 year in carriers with the APOE4 genotype in the H2-group using sub- and total ADAS-cog scores.

2. MATERIALS AND METHODS

2.1. Ethical Approval and Consent to Participate

This animal study was approved by the Animal Care and Use Committee of Nippon Medical School. The methods were carried out in “accordance” with the relevant guidelines and regulations.

The clinical study protocol was approved by the ethics committees of University of Tsukuba, and registered in the university hospital medical information network (UMIN) as UMIN000002218 on July 17, 2009 at https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr.cgi?function=history&action =list&type= summary&recptno= R000002-725&language=J.

Participants were enrolled from July 2009. All patients provided written informed consent prior to research investigations, which were conducted according to the Declaration of Helsinki and subsequent revisions.

2.2. Transgenic DAL101 Mice

Transgenic mice (DAL101) that express a transgene containing a mouse version of ALDH2*2 were constructed as described previously []. Since the number of mice used for each experiment was not consistent because of a breeding difficulty, the number of the mice used was specified. All mice were kept in a 12-hr light/dark cycle with ad libitum access to food and water. Examiners performed experiments in a blinded fashion. Since no significant decline was observed in cognitive impairment at the age of 18 months in wild-type mice with the same genetic background (C57BL/6), [] the effects of hydrogen H2-water were not assessed in this study.

2.3. Hydrogen Water

For animal experiments, saturated hydrogen H2-water was prepared as described previously []. In brief, hydrogen  H2 was dissolved in water under high pressure (0.4 MPa) to a supersaturated level, and the saturated H2-water was stored under atmospheric pressure in an aluminum bag with no headspace. As a control, H2-water was completely degassed by gentle stirring for one day. Mice were given water freely using closed glass vessels equipped with an outlet line containing two ball bearings, which kept the water from being degassed. The vessel was freshly refilled with H2-water 6 days per week at 2:00 pm. The hydrogen H2-concentration was still more than 0.3 mM on the next day.

For this clinical study, commercially available hydrogen H2-water was a gift from Blue Mercury, Inc. (Tokyo, Japan). The hydrogen H2-water (500 mL) was packed in an aluminum pouch with no headspace to maintain H2 concentration, and sterilized at 80°C for 30 min. The concentration of hydrogen H2 was measured using a hydrogen sensor (Unisense, Aarhus N, Denmark), and used if the value was more than 0.6 mM. Placebo water packed in an identical package (500 mL) was also provided by Blue Mercury Inc. This company played no role in collection of data, management, analysis, or interpretation of the data. One package with 500 mL of placebo or hydrogen H2-water per day was provided after showing previous empty packages, by which self-reported compliance rates in the intervention group were calculated as the volume of hydrogen  H2-water at 1-year.

2.4. Measurement of Oxidative Stress

As an oxidative stress marker, 8-OHdG [] was measured using urine samples, which were collected between 9:00 and 10:00 am as described previously [], by using a competitive enzyme-linked immunoassay (New 8-OHdG check; Japan Institute for the Control of Aging, Shizuoka, Japan). The values were normalized by urinary creatinine concentration, which was assayed using a standard kit (Wako, Kyoto, Japan). As an additional oxidative stress marker in the brain, accumulated MDA was determined using a Bioxytech MDA-586 Assay Kit (Percipio Biosciences, CA, USA). Malondialdehyde(MDA)levels were normalized against protein concentrations.

2.5. Measurement of Memory Impairment: Object Recognition Task

Learning and memory abilities were examined using objection recognition task (ORT) []. A mouse was habituated in a cage for 4 h, and then two different-shaped objects were presented to the mouse for 10 min as training. The number of times of exploring and/or sniffing each object was counted for the first 5 min (Training test). The frequencies (%) in training test were considered as the backgrounds. To test memory retention after 1 day, one of the original objects was replaced with a novel one of a different shape and then times of exploration and/or sniffing was counted for the first 5 min (Retention test). When mice would lose learning and memory abilities, the frequencies of exploration and/or sniffing of each object should be equal (about 50%) in the training session, indicating that mice showed a similar interest in each object because of lack of memory for the objects. Learning and memory abilities were evaluated as the subtraction of the frequencies (%) in the retention test from each background (Training test).

2.6. Measurement of Memory Impairment: Passive Avoidance Task (PA)

The apparatus consisted of two compartments, one light and the other dark, separated by a vertical sliding door []. On day 1, we initially placed a mouse in the light compartment for 20 s. After the door was opened, the mouse could enter the dark compartment (mice instinctively prefer being in the dark). On day 2, the mouse was again placed in the light section to allow the mouse to move into the dark section. After the mouse entered the dark compartment, the door was closed. After 20 s, the mouse was given a 0.3 mA electric shock for 2 s. The mouse was allowed to recover for 10 s, and was then returned to the home cage. On day 3, 24h after the shock, the mouse was again placed in the light section with the door opened to allow the mouse to move into the dark section. We examined the latency time for stepping through the door. Learning and memory abilities were assessed as the subtraction of the latency times after the electric shock from each background (before).

2.7. Immunostaining of the Hippocampal CA1 Region

To examine neuronal loss and glial activation, the hippocampus region was stained with a pyramidal neuron-specific anti-NeuN antibody (clone A60; Merck Millipore, Darmstadt, Germany), an astrocyte-specific anti-glial fibrillary acidic protein (anti-GFAP) antibody (Thermo Scientific, MA, USA) or a microglia-specific anti-IbaI antibody (Wako). Mice were transcardially perfused to be fixed with 4% paraformaldehyde in phosphate-buffered saline (PBS) under anesthesia, and their brains were cryoprotected with 30% sucrose, and then frozen brain was sectioned at 8 μm thickness. After incubation with each primary antibody, sections were treated with secondary antibodies (Vector Laboratories, CA, USA) and their immunereactivity was visualized by the avidin-biotin complex method (Vector Laboratories).

2.8. Subjects of the Clinical Study

This study was a randomized, double-blind, placebo-controlled trial undertaken as a part of Tone project, an ongoing epidemiological study conducted in Tone Town, Ibaraki, Japan as described in detail previously []. This town is located approximately 40 km northeast of central Tokyo and consists of 22 districts. The baseline survey of the Tone project included 1,032 participants in July 2009, and subjects of the present study were recruited from these participants.

Eligibility criteria are age 67 years or older, being able to give written informed consent for participation in the present study, with a diagnosis of MCI, being able to observe the following requirement: good compliance with water consumption; participation in the scheduled examinations for assessment; keeping a log-diary recording consumption of the water, with a modified Hachinski Ischemic score of 4 or less and a 15-item Geriatric Depression Scale score of 6 or less. In brief, 3 months before this clinical study, all participants underwent a group assessment which used a set of 5 tests that measured the following cognitive domains: attention; memory; visuospatial function; language; and reasoning as described previously []. Objective impairment in at least 1 cognitive domain based on the average of the scores on the neuropsychological measures within that domain and 1 SD cut-off using normative corrections for age, years of education, and sex.

Exclusion criteria were having “The Diagnostic and Statistical Manual of Mental Disorders (DSM)-IV TR” criteria for dementing illnesses, a serious or unstable illnesses, a history within the past 5 years of serious infectious disease affecting the brain and/or malignant diseases, a history of alcohol or drug abuse or dependence (on DSM-IV TR) within the past 5 years, and receiving any types of anti-Alzheimer drugs and recent (within 4 weeks) initiation of medications that affect the central nervous system. When the score of Mini Mental State Examination (MMSE) [] was less than 24, the subjects were excluded.

In this study, subjects were randomly assigned to either to an intervention group, who received H2-water every-day for 1 year, or a control group, who received placebo water. The allocation sequence was determined by computer-generated random numbers that were concealed from the investigators and subjects. Drs. Nakajima and Ikejima generated the random allocation sequence, enrolled participants, and assigned participants to interventions. Any participants and care providers were blindly masked.

In the original protocol, we planed to administer H2-water for 2 years and assess the secondary outcomes; however, we had to stop the project in 2011 by the Tsunami-disaster and could not obtained the 2-year data and secondary outcomes.

The APOE4 genotype was determined as described [].

2.9. Statistical Considerations

All statistical analyses were performed by an academic biostatistician using SAS software version 9.2 (SAS Institute Inc, Cary, NC, USA). Results were considered significant at p < 0.05.

For the comparison of two groups in learning and memory abilities, and lifespans, unpaired two-tailed Student’s t-test was used for the comparison of H2-group with control group. For the other animal experiments, one-way analysis of variance (ANOVA) with Tukey-Kramer or Dunnett post hoc analysis was applied unless otherwise mentioned.

For the clinical trial, we planned to recruit a total of 120 patients, which would provide 90% power to detect an effect size of 0.6 using a two-sided test with a 5% significance level, but the actual sample size for the primary analysis was 73, leading to 70% power in the same setting. End-points were scores in the Japanese version of ADAS-cog at 1-year, and the changes were evaluated by Mann-Whitney’s U test (non-parametric analysis) as well as Student’s t-test (parametric analysis).

3. RESULTS

3.1. Hydrogen-water Reduced Oxidative Stress in DAL Mice

Male DAL101 mice were given H2– or control water to drink ad libitum from the age of 1 month, and continued until the age of 18 months. The H2-water DAL101 group showed a significant decrease in the level of an oxidative stress marker, urinary 8-hydroxy-2’-deoxyguanosine (8-OHdG)[] at the age of 14months (Suppl. Fig. S1A). Moreover, DAL101 mice increased oxidative stress in the brain as measured by the level of MDA as an alternative oxidative stress marker, and H2-water showed a significant recovery of this increased level of MDA in DAL101 mice (Suppl. Fig. S1B).

3.2. Hydrogen Water Suppressed a Decline in Learning and Memory Impairment

We examined learning and memory abilities using ORT []. As described in MATERIALS AND METHODS, learning and memory abilities were evaluated as the subtraction of the frequency (%) in Retention test from each background (Training test). Mice were provided with control or H2-water from the age of 1 month. At the age of 14 months, the H2-group significantly memorized the original objects and showed the preference for the novel object more than the control group (Fig. 1A1A 14-month-old).

An external file that holds a picture, illustration, etc. Object name is CAR-15-482_F1.jpg

Hydrogen water prevented cognitive decline. H2-water was provided from the age of 1 month (A, C), and from the age of 8 months (B). The mice were subjected to the first objection recognition task (ORT) at the age of 14 months (A, B, 14-month-old) and the second ORT at the age of 18 months (A, B, 18-month-old).

The recognition indexes were obtained as the frequency (%) of exploring and/or sniffing the object that would be replaced or the novel one that had been replaced. ΔRecognition index (%) indicates the frequencies in Retention test of ORT after the subtraction of those in Training test (background). WT, wild-type; (DAL, H2-),

DAL101 mice drinking degassed control water; (DAL, H2+), DAL101 mice drinking hydrogen water. Data are shown as the mean ± SEM. n = 9, *p < 0.05, **p < 0.01 by Student’s t-test. (C) The mice were subjected to a passive avoidance task. Step-through latencies before and after the electric shock are obtained and ΔStep-through latency (s) indicates the subtraction of Step-through latencies after from before the electric shock. WT, wild-type (n = 10); DAL, H2-, DAL101 mice receiving degassed control water (n = 8); and DAL, H2+, DAL101 mice receiving H2-water (n = 8). Data are shown as the mean ± SEM. *p < 0.05.

At the age of 18 months, the mice were subjected to the second ORT, which can be done by using different objects at the age of 18 months []. The aged DAL101 mice drinking H2-water still significantly memorized the original objects and preferred the novel one more than the control group (Fig. 1A1A 18-month-old).

Next, to test the drinking effects of H2-water from the later stage, we started giving H2-water to male DAL101 mice at the age of 8 months instead of 1 month, and subjected to ORT at the age of 14 months (Fig. 1B1B 14-month-old) and the second ORT at the age of 18 months (Fig. 1B1B 18-month-old). Even when the mice began to drink at the age of 8 months, H2-water significantly suppressed the decline in the learning and memory abilities at the age of 18 months as well as at the age of 14 months (Fig. 1B1B).

Moreover, we subjected the mice to PA [] at the age 18 months as an alternative method. One day after a 0.3 mA electric shock for 2 s was given, wild-type C57BL/6 mice memorized the shock as evaluated by the subtraction of the latency time (s) to re-enter the dark compartment from each background (Fig. 1C1C). The H2-water group significantly suppressed the decline in learning and memory more than the control group (Fig. 1C1C).

Thus, drinking hydrogen H2-water suppressed the learning and memory impairment in the oxidative stress mice.

3.3. Hydrogen-water Suppressed Neurodegeneration

To examine whether hydrogen H2-water could prevent neurodegeneration in aged DAL101 mice, we stained the hippocampus with a neuron-specific anti-NeuN antibody (Fig. 2A2A). Neurodegeneration was evaluated by glial activations using an anti-GFAP antibody and a microglia-specific anti-Iba-I antibody. Immune-positive cells per field of view (FOV) were counted in the CA1 region (Fig. 2B2B).

An external file that holds a picture, illustration, etc. Object name is CAR-15-482_F2.jpg

Hydrogen water suppressed neurodegeneration. (A) The hippocampal CA1 region was stained with antibodies against NeuN (a neuronal marker), GFAP (an astrocytic marker) or Iba-1 (a microglial marker) (Scale bars: 50 µm). Right panels show magnified images of the squares in the left panels (Scale bars: 10 µm). (B) Cells positive for anti-NeuN, anti-GFAP and anti-Iba-I antibodies per field of view (FOV) were counted in the CA1 region (n = 5). Data are shown as the mean ± SD. *p < 0.05, **p < 0.01 (wild-type vs DAL), #p < 0.05 (H2-water vs. control water in DAL).

The number of neurons was decreased in the control DAL101 group as the comparison with wild type group, and the H2-DAL101 group showed a trend in recovery of the decrease (Fig. 2A2A). As has been described previously, [] the control DAL101 mice exhibited an increase in glial activation, and the H2-water group suppressed the enhanced glial activation in the CA1 region (Fig. 22, GFAP and Iba-I).

3.4. Hydrogen-water Extended the Average Lifespan of Mice

DAL101 mice showed a shorter lifespan, which has also been described previously []. To examine whether consumption of hydrogen H2-water attenuated the shortened lifespan, female DAL101 mice started drinking control or H2-water at the age of 1 month. Although hydrogen H2-water did not extend the maximum lifespan (Fig. 3A3A), hydrogen H2-water significantly extended the mean of lifespan of DAL101 mice (Fig. 3B3B).

An external file that holds a picture, illustration, etc. Object name is CAR-15-482_F3.jpg

Extension of the average lifespan by continuous drinking H2-water. (A) Kaplan-Meier curve representing the survival of female C57BL/6 mice (wild-type), female DAL101 mice drinking control water (control water) and H2-water (H2-water). (B) Each dot indicates the lifespan of each mouse. The bars indicate the average lifespan of each group. *p < 0.05 (p = 0.036) by Student’s t-test.

3.5. A Randomized, Placebo Controlled Clinical Study

Fig. (44) shows the profile on the recruitment, randomization, and follow-up of this study. A total of 81 subjects of the 1,032 participants were randomized; however, 3 in the control group and 5 in the intervention group were diagnosed as ineligible after randomization and not included in this analysis. Baseline characteristics and lifestyle factors were balanced between the study groups (Table 11). Random assignment was stratified by age of ~74 years and MMSE score of ~28 points. The average compliance rate of drinking water was estimated as 64% in both groups at 1-year, meaning the subjects drank 320 mL/day on the average. The mean total ADAS-cog scores in the H2– and control groups were 8.04 and 7.89, respectively, with no significance.

An external file that holds a picture, illustration, etc. Object name is CAR-15-482_F4.jpg

Profile of the recruitment, randomization, and follow-up of this study. This study was a randomized, double-blind, placebo-controlled trial undertaken as a part of Tone project, an ongoing epidemiological study conducted in Tone Town, Ibaraki, Japan [].

Table 1

Background characteristics of 73 subjects with mild cognitive impairment.

Control (n=38) Intervention (n=35)
Mean SD or % Mean SD or %
Woman * 20 (52.6%) 19 (54.3%)
Age (years) 74.45 5.44 73.97 5.11
Body mass index (kg/m2) 23.55 2.59 23.19 4.08
Systolic blood pressure (mmHg) 131.26 12.35 135.14 13.31
Diastolic blood pressure (mmHg) 77.92 7.13 78.89 9.53
Education (years) 11.26 2.71 11.57 2.83
Current alcohol drinker * 19 (50.0%) 14 (40.0%)
Current smoker * 4 (10.5%) 5 (14.3%)
Current exercise habit * 27 (71.1%) 22 (62.9%)
APOE4 carrier * 6 (15.7%) 7 (20.0%)
Family history * 2 (5.3%) 2 (5.7%)
Comorbidity *
Hypertension 15 (39.5%) 14 (40.0%)
Diabetes mellitus 4 (10.5%) 5 (14.3%)
Dyslipidemia 4 (10.5%) 4 (11.4%)
Stroke 2 (5.3%) 1 (2.9%)
Depression 1 (2.6%) 2 (5.7%)
MMSE 28.08 1.66 27.83 1.74
ADAS-cog 7.89 3.19 8.04 3.47

* indicates frequency (%).

After 1 year, no observable harms or unintended effects in each group were found, and there was a trend to improve total ADA-cog score both in the H2– and control-groups (Suppl. Table S1), probably because of interventions such as moderate exercise by the Tone project. Moreover, the subjects in the H2-group had more trends for the improvement than those in the control-groups although there was no significance (Suppl. Table S1). However, when we pay attention to score-changes in carriers of the APOE4 genotype, the total ADAS-cogs and word recall task scores (one of the sub-scores) significantly improved as assessed by the distribution of the score change in each subject (Fig. 55). In the APOE4 carriers, the hydrogen  water H2-group significantly improved, whereas the control group slightly worsened. Moreover, Fig. (66) shows the score change of each subject as an alternative presentation. Although the subjects in the control group did not improved, six and five out of 7 subjects improved on the total ADAS score and word recall task scores, respectively, in the hydrogen water H2-group of the APOE4 carriers.

An external file that holds a picture, illustration, etc. Object name is CAR-15-482_F5.jpg

Distribution of changes of sub- and total-ADAS-cog score. Distribution of change of word recall task score (A), a sub-score of ADAS-cog, and (B) total ADAS-cogs score in APOE4 non-carriers (left) and APOE4 carriers (right). Each dot indicates the change of individual subjects. The difference between the H2- and control groups was significant in APOE4 carriers by a non-parametric analysis as well as a parametric analysis. (Ap = 0.036 (by Student’s t-test) and p =0.047 (by Mann-Whitney’s U test) and (Bp = 0.037 (by Student’s t-test) and p = 0.044 (by Mann-Whitney’s U test) for (A) and (B), respectively. Middle bars in lozenges indicate median values.

An external file that holds a picture, illustration, etc. Object name is CAR-15-482_F6.jpg

Changes in a sub-sore and total ADAS-cog score of each subject in the APOE4 carriers. Each line indicates the 1-year change in the word recall task score (A) and total ADAS-cog score (B) of a subject in the APOE4 carriers. * indicates p < 0.05 as shown in the legend of Fig. 5.

DISCUSSION

Age-dependent neurodegenerative disorders are involved in oxidative stress. In this study, we showed that drinking hydrogen H2-water suppressed the biochemical, behavioral, and pathological decline in oxidative stress mice. The score of ADAS-cog [] is the most widely used general cognitive measure in clinical trials of AD []. The ADAS-cog score assesses multiple cognitive domains including memory, language, praxis, and orientation. Overall, the ADAS-cog has proven successful for its intended purpose. The present clinical study shows that drinking hydrogen H2-water significantly improved the ADAS-cog score of APOE4 genotype-carriers.

We have previously showed that DAL101 mice show age-dependent neurodegeneration and cognitive decline and the shorten lifespan []. DAL101 mice exhibit dementia phenotypes in an age-dependent manner in response to an increasing amount of oxidative stress []. Oxidative stress enhances lipid peroxidation, leading to the formation of highly reactive α, β-unsaturated aldehydes, such as MDA and 4-HNE []. The accumulation of 4-HNE-adducted proteins in pyramidal neurons has been observed in the brains of patients with AD and PD []. The decline of ALDH2*2 ability failed to detoxify cytotoxic aldehydes, and consequently increases in oxidative stress [].

Moreover, double-transgenic mice were constructed by crossing DAL101 mice with Tg2576 mice, which express a mutant form of human amyloid precursor protein (APP). They showed accelerated amyloid deposition, tau phosphorylation, and gliosis, as well as impaired learning and memory abilities. The lifespan of APP/DAL mice was significantly shorter than that of APP and DAL101 mice []. Thus, these model animals may be helpful to explore antioxidants that could be able to prevent age-dependent dementia. Indeed, a diet containing Chlorella showed mitigated effects on cognitive decline in DAL101 [].

One of the most potent risk factors for AD is carrier status of the APOE4 genotype, and the roles of APOE4 on the progression of AD have been extensively examined from various aspects []. APOE4 also increase the number of atherogenic lipoproteins, and accelerate atherogenesis []. The increased oxidative stress in APOE4 carriers is considered as one of the modifiers for the risk []. A combination of antioxidants improved cognitive function of aged subjects after 3 years, especially in APOE4 carriers []. This previous clinical result agrees with the present study. hydrogen H2 acts as an efficient antioxidant inside cells owing to its ability to rapidly diffuse across membranes []. Moreover, as a secondary anti-oxidative function, H2 seems to activate NF-E2-related factor 2 (Nrf2), [] which reduces oxidative stress by expression a variety of antioxidant enzymes []. We reported that drinking hydrogen H2-water prevented arteriosclerosis using APOE knockout mice, a model of the spontaneous development of atherosclerosis accompanying a decrease in oxidative stress []. Thus, it is possible that drinking H2-water improves vascular damage by decreasing oxidative stress as a direct or indirect antioxidant, leading to the improvement of a demintia model and MCI subjects. In this study, we focused on the genotype of APOE-isoforms; however, the polymorphism of the APOE gene in the promoter region influences the expression of the APOE gene []. Thus, it will be important to examine the effect of hydrogen H2-water under this polymorphism.

For mitigating AD, significant attention has been given to regular, moderate exercise to help reduce the risk of dementia and prevent MCI from developing in aging patients [ – ]. Moderate exercise enhances energy metabolism and suppresses the expression of pro-inflammatory cytokines, [] and protects vascular systems [].molecular hydrogen H2 exhibits multiple functions by a decrease in the levels of pro-inflammatory cytokines and an increase in energy metabolism in addition to anti-oxidative roles. To exert multiple functions, molecular hydrogen H2 regulates various signal transduction pathways and the expression of many genes []. For examples,molecular hydrogen H2 protects neural cells and stimulates energy metabolism by stimulating the hormonal expression of ghrelin [] and fibroblast growth factor 21, [] respectively. In contrast, molecular hydrogen H2 relieves inflammation by decreasing pro-inflammatory cytokines []. Thus, the combination of these functions of molecular hydrogen H2 on anti-inflammation and energy metabolism-stimulation might prevent the decline in brain function, [] both of which are improved by regular and moderate exercise. Thus, it is possible that the multiple functions of molecular hydrogen H2, including energy metabolism-stimulation and anti-inflammation, may contribute to the improvement of the dementia model and the MCI subjects.

As an alternative aspect, molecular hydrogen H2 suppresses the nuclear factor of activated T cell (NFAT) transcription pathway to regulate various gene expression patterns []. NFAT signaling is altered in AD and plays an important role in driving amyloid β-mediated neurodegeneration []. Moreover, the NFAT transcriptional cascade contributes to amyloid β synaptotoxicity []. Additionally, an active involvement of the NFAT-mediated signaling pathway in α-syn-mediated degeneration of neurons in PD []. Indeed, patients with PD improved by drinking molecular hydrogen H2-water as revealed by a double-blind, placebo-controlled clinical study, [] and a larger scale of a clinical trial is under investigation []. Thus, the beneficial effects of molecular hydrogen H2 on the neurodegenerative diseases may be explained by the suppression of NFAT transcriptional regulation.

CONCLUSION

The present study suggests a possibility for slowing the progress of dementia by drinking molecular hydrogen H2-water by means of animal experiments and a clinical intervention study for APOE4 carriers; however, a longer and larger scale of trials will be necessary to clarify the effect of H2-water on MCI.

PMCID: PMC5872374
PMID: 29110615
Effects of Molecular Hydrogen Assessed by an Animal Model and a Randomized Clinical Study on Mild Cognitive Impairment
This is an open access article licensed under the terms of the Creative Commons Attribution-Non-Commercial 4.0 International Public License (CC BY-NC 4.0) (https://creativecommons.org/licenses/by-nc/4.0/legalcode), which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.

Associated Data

Supplementary Materials

ACKNOWLEDGEMENTS

We thank Blue Mercury, Inc. (Tokyo, Japan) for providing H2-water and placebo water, Ms. Hiroe Murakoshi for technical assistance and Ms. Suga Kato for secretarial work. Financial support for this study was provided by Grants-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (23300257, 24651055, and 26282198 to S.O.; 23500971 and 25350907 to K.N.). Financial support for this study was provided by Grants-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (23300257, 24651055, and 26282198 to S.O.; 23500971 and 25350907 to K.N.).

LIST OF ABBREVIATIONS

APOE4 Apolipoprotein E4
MCI Mild cognitive Impairment
ALDH2 Aldehyde Dehydrogenase 2
ADAS-cog Alzheimer’s Disease Assessment Scale-cognitive subscale
AD Alzheimer’s Disease
PD Parkinson’s Disease
DAL101 Dominant Negative Type 101 of the ALDH2 Mutant Polymorphism (ALDH2*2)
4-HNE 4-Hydroxy-2-nonenal
8-OHdG 8-Hydroxy-2’-deoxyguanosine
MDA Malondialdehyde
ORT Object Recognition Task
PA Passive Avoidance Task
GFAP Glial Fibrillary Acidic Protein
PBS Phosphate-buffered Saline
ANOVA One-way Analysis of Variance
CI Confidence Interval
MMSE Mini Mental State Examination
FOV Field of View
APP Amyloid Precursor Protein
Nrf2 NF-E2-related Factor 2
NFAT Nuclear Factor of Activated T Cell

 

SUPPLEMENTARY MATERIAL

Supplementary material is available on the publisher’s web site along with the published article.

ETHICS APPROVAL AND CONSENT TO PARTICIPATE

The animal study was approved by the Animal Care and Use Committee of Nippon Medical School.

The human clinical study protocol was approved by the ethics committees of University of Tsukuba.

HUMAN AND ANIMAL RIGHTS

All animal research procedures followed were in accordance with the standards set forth in the eighth edition of Guide for the Care and Use of Laboratory Animals published by the National Academy of Sciences, The National Academies Press, Washington, D.C.).

All human material was obtained in accordance with the standards set forth in the Declaration of Helsinkiprinciples of 1975, as revised in 2008 (http://www.wma.net/en/10ethics/10helsinki/<http://www.wma.net/en/10ethics/10helsinki/>).

Consent for Publication

All the patients provided written informed consent priority to research investigations.

CONFLICT OF INTEREST

We declare that there is no actual and potential conflict of interest on this study. Although SO was a scientific advisor of Blue Mercury, Inc. (Tokyo, Japan) from 2,005 to 2,008, there was no involvement during this study.

REFERENCES

1. Lin M.T., Beal M.F. Mitochondrial dysfunction and oxidative stress in neurodegenerative diseases. Nature. 2006;443:787–795. [PubMed[]
2. Mecocci P., Polidori M.C. Antioxidant clinical trials in mild cognitive impairment and Alzheimer’s disease. Biochim. Biophys. Acta. 2012;1822:631–638. [PubMed[]
3. Jofre-Monseny L., Minihane A.M., Rimbach G. Impact of apoE genotype on oxidative stress, inflammation and disease risk. Mol. Nutr. Food Res. 2008;52:131–145. [PubMed[]
4. Ohsawa I., Nishimaki K., Murakami Y., Suzuki Y., Ishikawa M., Ohta S. Age-dependent neurodegeneration accompanying memory loss in transgenic mice defective in mitochondrial aldehyde dehydrogenase 2 activity. J. Neurosci. 2008;28:6239–6249. [PMC free article] [PubMed[]
5. Chen C.H., Ferreira J.C., Gross E.R., Mochly-Rosen D. Targeting aldehyde dehydrogenase 2: new therapeutic opportunities. Physiol. Rev. 2014;94:1–34. [PMC free article] [PubMed[]
6. Kamino K., Nagasaka K., Imagawa M., Yamamoto H., Yoneda H., Ueki A., et al. Deficiency in mitochondrial aldehyde dehydrogenase increases the risk for late-onset Alzheimer’s disease in the Japanese population. Biochem. Biophys. Res. Commun. 2000;273:192–196. [PubMed[]
7. Jo S.A., Kim E.K., Park M.H., Han C., Park H.Y., Jang Y., et al. A Glu487Lys polymorphism in the gene for mitochondrial aldehyde dehydrogenase 2 is associated with myocardial infarction in elderly Korean men. Clin. Chim. Acta. 2007;382:43–47. [PubMed[]
8. Wang B., Wang J., Zhou S., Tan S., He X., Yang Z., et al. The association of mitochondrial aldehyde dehydrogenase gene (ALDH2) polymorphism with susceptibility to late-onset Alzheimer’s disease in Chinese. J. Neurol. Sci. 2008;268:172–175. [PubMed[]
9. Ohsawa I., Ishikawa M., Takahashi K., Watanabe M., Nishimaki K., Yamagata K., et al. Hydrogen acts as a therapeutic antioxidant by selectively reducing cytotoxic oxygen radicals. Nat. Med. 2007;13:688–694. [PubMed[]
10. Ohta S. Molecular hydrogen as a preventive and therapeutic medical gas: initiation, development and potential of hydrogen medicine. Pharmacol. Ther. 2014;144:1–11. [PubMed[]
11. Ichihara M., Sobue S., Ito M., Ito M., Hirayama M., Ohno K. Beneficial biological effects and the underlying mechanisms of molecular hydrogen – comprehensive review of 321 original articles. Med. Gas Res. 2015;5:12. [PMC free article] [PubMed[]
12. Iketani M., Ohsawa I. Molecular Hydrogen as a Neuroprotective Agent. Curr. Neuropharmacol. 2017;15:324–331. [PMC free article] [PubMed[]
13. Ohta S. Molecular hydrogen as a novel antioxidant: overview of the advantages of hydrogen for medical applications. Methods Enzymol. 2015;555:289–317. [PubMed[]
14. Nagata K, Nakashima-Kamimura N, Mikami T, Ohsawa I, Ohta S. Consumption of molecular hydrogen prevents the stress-induced impairments in hippocampus-dependent learning tasks during chronic physical restraint in mice. 2009. [PubMed]
15. Matsumoto A., Yamafuji M., Tachibana T., Nakabeppu Y., Noda M., Nakaya H. Oral ‘hydrogen water’ induces neuroprotective ghrelin secretion in mice. Sci. Rep. 2013;3:3273. [PMC free article] [PubMed[]
16. Li J., Wang C., Zhang J.H., Cai J.M., Cao Y.P., Sun X.J. Hydrogen-rich saline improves memory function in a rat model of amyloid-beta-induced Alzheimer’s disease by reduction of oxidative stress. Brain Res. 2010;1328:152–161. [PubMed[]
17. Hayashida K., Sano M., Kamimura N., Yokota T., Suzuki M., Ohta S., et al. Hydrogen inhalation during normoxic resuscitation improves neurological outcome in a rat model of cardiac arrest, independent of targeted temperature management. Circulation. 2014;130:2173–2180. [PubMed[]
18. Rosen W.G., Mohs R.C., Davis K.L. A new rating scale for Alzheimer’s disease. Am. J. Psychiatry. 1984;141:1356–1364. [PubMed[]
19. Connor D.J., Sabbagh M.N. Administration and scoring variance on the ADAS-Cog. J. Alzheimers Dis. 2008;15:461–464. [PMC free article] [PubMed[]
20. de Zwart L.L., Meerman J.H., Commandeur J.N., Vermeulen N.P. Biomarkers of free radical damage applications in experimental animals and in humans. Free Radic. Biol. Med. 1999;26:202–226. [PubMed[]
21. Kamimura N., Nishimaki K., Ohsawa I., Ohta S. Molecular hydrogen improves obesity and diabetes by inducing hepatic FGF21 and stimulating energy metabolism in db/db mice. Obesity (Silver Spring) 2011;19:1396–1403. [PubMed[]
22. O’Riordan K.J., Huang I.C., Pizzi M., Spano P., Boroni F., Egli R., et al. Regulation of nuclear factor kappaB in the hippocampus by group I metabotropic glutamate receptors. J. Neurosci. 2006;26:4870–4879.[PMC free article] [PubMed[]
23. Bun S., Ikejima C., Kida J., Yoshimura A., Lebowitz A.J., Kakuma T., et al. A combination of supplements may reduce the risk of Alzheimer’s disease in elderly Japanese with normal cognition. J. Alzheimers Dis. 2015;45:15–25. [PubMed[]
24. Miyamoto M., Kodama C., Kinoshita T., Yamashita F., Hidaka S., Mizukami K., et al. Dementia and mild cognitive impairment among non-responders to a community survey. J. Clin. Neurosci. 2009;16:270–276. [PubMed[]
25. Sasaki M., Kodama C., Hidaka S., Yamashita F., Kinoshita T., Nemoto K., et al. Prevalence of four subtypes of mild cognitive impairment and APOE in a Japanese community. Int. J. Geriatr. Psychiatry. 2009;24:1119–1126. [PubMed[]
26. Arevalo-Rodriguez I., Smailagic N., Roque I.F.M., Ciapponi A., Sanchez-Perez E., Giannakou A., et al. Mini-Mental State Examination (MMSE) for the detection of Alzheimer’s disease and other dementias in people with mild cognitive impairment (MCI). Cochrane Database Syst. Rev. 2015;3:CD010783.[PMC free article] [PubMed[]
27. Ihl R., Ferris S., Robert P., Winblad B., Gauthier S., Tennigkeit F. Detecting treatment effects with combinations of the ADAS-cog items in patients with mild and moderate Alzheimer’s disease. Int. J. Geriatr. Psychiatry. 2012;27:15–21. [PubMed[]
28. Karin A., Hannesdottir K., Jaeger J., Annas P., Segerdahl M., Karlsson P., et al. Psychometric evaluation of ADAS-Cog and NTB for measuring drug response. Acta Neurol. Scand. 2014;129:114–122.[PubMed[]
29. Schneider C., Tallman K.A., Porter N.A., Brash A.R. Two distinct pathways of formation of 4-hydroxynonenal. Mechanisms of nonenzymatic transformation of the 9- and 13-hydroperoxides of linoleic acid to 4-hydroxyalkenals. J. Biol. Chem. 2001;276:20831–20838. [PubMed[]
30. Csala M., Kardon T., Legeza B., Lizak B., Mandl J., Margittai E., et al. On the role of 4-hydroxynonenal in health and disease. Biochim. Biophys. Acta. 2015;1852:826–838. [PubMed[]
31. Endo J., Sano M., Katayama T., Hishiki T., Shinmura K., Morizane S., et al. Metabolic remodeling induced by mitochondrial aldehyde stress stimulates tolerance to oxidative stress in the heart. Circ. Res. 2009;105:1118–1127. [PubMed[]
32. Kanamaru T., Kamimura N., Yokota T., Iuchi K., Nishimaki K., Takami S., et al. Oxidative stress accelerates amyloid deposition and memory impairment in a double-transgenic mouse model of Alzheimer’s disease. Neurosci. Lett. 2015;587:126–131. [PubMed[]
33. Nakashima Y., Ohsawa I., Konishi F., Hasegawa T., Kumamoto S., Suzuki Y., et al. Preventive effects of Chlorella on cognitive decline in age-dependent dementia model mice. Neurosci. Lett. 2009;464:193–198. [PubMed[]
34. De Marco M., Vallelunga A., Meneghello F., Varma S., Frangi A.F., Venneri A. ApoE epsilon4 allele related alterations in hippocampal connectivity in early Alzheimer’s disease support memory performance. Curr. Alzheimer Res. 2017;14:766–777. [PubMed[]
35. Shackleton B., Crawford F., Bachmeier C. Apolipoprotein E-mediated modulation of ADAM10 in Alzheimer’s disease. Curr. Alzheimer Res. 2017;14:578–585. [PMC free article] [PubMed[]
36. Hanson A.J., Craft S., Banks W.A. The APOE genotype: modification of therapeutic responses in Alzheimer’s disease. Curr. Pharm. Des. 2015;21:114–120. [PubMed[]
37. Johnson D.A., Johnson J.A. Nrf2-a therapeutic target for the treatment of neurodegenerative diseases. Free Radic. Biol. Med. 2015;88:253–267. [PMC free article] [PubMed[]
38. Ohsawa I., Nishimaki K., Yamagata K., Ishikawa M., Ohta S. Consumption of hydrogen water prevents atherosclerosis in apolipoprotein E knockout mice. Biochem. Biophys. Res. Commun. 2008;377:1195–1198. [PubMed[]
39. Maloney B., Ge Y.W., Petersen R.C., Hardy J., Rogers J.T., Perez-Tur J., et al. Functional characterization of three single-nucleotide polymorphisms present in the human APOE promoter sequence: Differential effects in neuronal cells and on DNA-protein interactions. Am. J. Med. Genet. B. Neuropsychiatr. Genet. 2010;153B:185–201. [PMC free article] [PubMed[]
40. Uemura K., Doi T., Shimada H., Makizako H., Yoshida D., Tsutsumimoto K., et al. Effects of exercise intervention on vascular risk factors in older adults with mild cognitive impairment: a randomized controlled trial. Dement. Geriatr. Cogn. Disord. Extra. 2012;2:445–455. [PMC free article] [PubMed[]
41. Gates N., Fiatarone Singh M.A., Sachdev P.S., Valenzuela M. The effect of exercise training on cognitive function in older adults with mild cognitive impairment: a meta-analysis of randomized controlled trials. Am. J. Geriatr. Psychiatry. 2013;21:1086–1097. [PubMed[]
42. Suzuki T., Shimada H., Makizako H., Doi T., Yoshida D., Ito K., et al. A randomized controlled trial of multicomponent exercise in older adults with mild cognitive impairment. PLoS One. 2013;8:e61483.[PMC free article] [PubMed[]
43. Smart N.A., Steele M. The effect of physical training on systemic proinflammatory cytokine expression in heart failure patients: a systematic review. Congest. Heart Fail. 2011;17:110–114. [PubMed[]
44. Cooper C., Li R., Lyketsos C., Livingston G. Treatment for mild cognitive impairment: systematic review. Br. J. Psychiatry. 2013;203:255–264. [PMC free article] [PubMed[]
45. Lavie C.J., Arena R., Swift D.L., Johannsen N.M., Sui X., Lee D.C., et al. Exercise and the cardiovascular system: clinical science and cardiovascular outcomes. Circ. Res. 2015;117:207–219.[PMC free article] [PubMed[]
46. Buchholz B.M., Kaczorowski D.J., Sugimoto R., Yang R., Wang Y., Billiar T.R., et al. Hydrogen inhalation ameliorates oxidative stress in transplantation induced intestinal graft injury. Am. J. Transplant. 2008;8:2015–2024. [PubMed[]
47. Iuchi K., Imoto A., Kamimura N., Nishimaki K., Ichimiya H., Yokota T., et al. Molecular hydrogen regulates gene expression by modifying the free radical chain reaction-dependent generation of oxidized phospholipid mediators. Sci. Rep. 2016;6:18971. [PMC free article] [PubMed[]
48. Abdul H.M., Sama M.A., Furman J.L., Mathis D.M., Beckett T.L., Weidner A.M., et al. Cognitive decline in Alzheimer’s disease is associated with selective changes in calcineurin/NFAT signaling. J. Neurosci. 2009;29:12957–12969. [PMC free article] [PubMed[]
49. Hudry E., Wu H.Y., Arbel-Ornath M., Hashimoto T., Matsouaka R., Fan Z., et al. Inhibition of the NFAT pathway alleviates amyloid beta neurotoxicity in a mouse model of Alzheimer’s disease. J. Neurosci. 2012;32:3176–3192. [PMC free article] [PubMed[]
50. Luo J., Sun L., Lin X., Liu G., Yu J., Parisiadou L., et al. A calcineurin- and NFAT-dependent pathway is involved in alpha-synuclein-induced degeneration of midbrain dopaminergic neurons. Hum. Mol. Genet. 2014;23:6567–6574. [PMC free article] [PubMed[]
51. Yoritaka A., Takanashi M., Hirayama M., Nakahara T., Ohta S., Hattori N. Pilot study of H(2) therapy in Parkinson’s disease: a randomized double-blind placebo-controlled trial. Mov. Disord. 2013;28:836–839. [PubMed[]
52. Yoritaka A., Abe T., Ohtsuka C., Maeda T., Hirayama M., Watanabe H., et al. A randomized double-blind multi-center trial of hydrogen water for Parkinson’s disease: protocol and baseline characteristics. BMC Neurol. 2016;16:66. [PMC free article] [PubMed[]

molecular hydrogen water benefits for recovering from ACUTE BRAIN STEM INFARCT – clinical trial

Background

In acute stage of cerebral infarction, MRI indices (rDWI & rADC) deteriorate during the first 3-7 days after the ictus and then gradually normalize in approximately 10 days (pseudonormalization time), although the tissue is already infarcted. Since effective treatments improve these indices significantly and in less than the natural pseudonormalization time, a combined analysis of these changes provides an opportunity for objective evaluation on the effectiveness of various treatments for cerebral infarction. Hydroxyl radicals are highly destructive to the tissue and aggravate cerebral infarction. We treated brainstem infarction patients in acute stage with hydroxyl radical scavengers (Edaravone and hydrogen) by intravenous administration and evaluated the effects of the treatment by a serial observation and analysis of these MRI indices. The effects of the treatment were evaluated and compared in two groups, an Edaravone alone group and a combined group with Edaravone and hydrogen, in order to assess beneficial effects of addition of hydrogen.

Methods

The patients were divided in Edaravone only group (E group. 26 patients) and combined treatment group with Edaravone and hydrogen enriched saline (EH group. 8 patients). The extent of the initial hump of rDWI, the initial dip of rADC and pseudo-normalization time were determined in each patient serially and averages of these data were compared in these two groups and also with the natural course in the literatures.

Results

The initial hump of rDWI reached 2.0 in the E group which was better than 2.5 of the natural course but was not as good as 1.5 of the EH group. The initial dip of rADC was 0.6 in the E group which was close to the natural course but worse than 0.8 of the EH group. Pseudonormalization time of rDWI and rADC was 9 days only in EH group but longer in other groups. Addition of hydrogen caused no side effects.

Conclusions

Administration of hydroxyl radical scavengers in acute stage of brainstem infarction improved MRI indices against the natural course. The effects were more obvious and significant in the EH group. These findings may imply the need for more frequent daily administration of hydroxyl scavenger, or possible additional hydrogen effects on scavenger mechanisms.

Background

Clinical care of cerebral infarction patients begins with visual evaluation of MRI (magnetic resonance image). It is well known now that the diffusion based MRI sequences can detect the abnormality within minutes after the onset of severe ischemia in the brain tissue. However, the differences in the MRI scan machinery, display software and filing methods may make the visual interpretation of the MRI images sometimes inconsistent. The diffusion data are more useful when presented as a comparison to those in the identical area of the other side of the brain, because in this way, all the hardware related inconsistency can be removed. The comparison utilizes a ratio of the MRI data, particularly the data capable of determining the degree of water molecule diffusion in the tissue such as DWI (Diffusion Weighted Image) and ADC (Apparent Diffusion Coefficient). The ratio is calculated by dividing the data in the pathological side by those in the normal side and designated as rDWI (relative DWI) and rADC (relative ADC).

The cells in severely ischemic brain tissue swell due to accumulation of water and electrolytes in the cells, immediately after the Na pump fails. The swelling reduces the extracellular space where the free motion of water molecules was a major source of the tissue diffusion. Thus, MRI indices (rADC and rDWI) deteriorate within minutes after the Na pump failure and continue to get worse for the first 3 to 5 days in the infarcted brain tissue [], unless recanalization or restoration of blood flow occurs []. The deterioration of the indices is characterized by the initial rDWI increase (initial hump) up to 2.5 or higher and the initial rADC decrease (initial dip) down to 0.6 or below [], reaching to a lowest value on Day3 []. Then, both indices gradually return to close to a normal level or 1.0, despite of the fact that the tissue is already infarcted (pseudonormalization) in 10 to 11 days (pseudo normalization time) after the ischemic ictus in the white matter []. After the pseudonormalization, rADC continues to increase (late hike) for many months [,]. However, recanalization treatment alters this natural course dramatically and the hump and the dip of diffusion related MRI indices may not appear at all and the pseudonormalization time shortens significantly down to 24 hrs or less after the treatment [,], only when the recanalization successfully restores the blood flow in the area. Although recanalization treatment such as with tPA (tissue plasminogen activator) is the most potent treatment of all for acute cerebral infarction, the treatment needs to be started within 3 hrs after the onset of the symptoms and has to satisfy rigid criteria. Therefore, except for few lucky tPA treated patients, the majority of the acute cerebral infarct patients are currently treated with diverse medications, including scavengers of reactive oxygen species (ROS). The ROS aggravate the ischemic tissue by a self-propagating chain reaction of depriving another electron from near-by molecules. In Japan, Edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one) [] is the only medication approved since 2001 for the use in acute stage of cerebral infarction patients as a scavenger of hydroxyl radicals and a neuroprotectant [].

However, in our preliminary study, the treatment of acute cerebral infarction with Edaravone improved the initial hump and the initial dip of the MRI indices only slightly and it shortened the pseudo normalization time but rather mildly. Edaravone is known to have a rather short t1/2 beta, or elimination half life of the drug level, particularly in elderly patients who occupy a majority of cerebral infarction population. In addition, Cmax, or maximum drug concentration in the blood, of the Edaravone, with currently approved intravenous administration of 30 mg remains at about 1/10 level of a standard 1-10 micromole concentration used in many in vitro experiments. In addition, because of possible side effects, Edaravone may not be given to the patients who have compromised liver or kidney function and also not more than twice a day according to the governmental approval. On the other hand, molecular hydrogen, which is well known to have potent scavenger actions against hydroxyl radicals and related harmful oxidation [] had no risk of complications in our preliminary study even on the patients who had already established kidney or liver disease. Our current study was designed to supplement possible low and short blood level of Edaravone with hydrogen for the treatment of acute cerebral infarction. The effects of the supplementing with hydrogen were evaluated by comparing the results of the treatment in a group treated with Edaravone only (E group) and in a combined Edaravone and hydrogen group (EH group) and also against the natural course published in the literatures []. Since subtle neurological changes after cerebral infarction during the acute stage are sometimes difficult to substantiate, a totally objective method using MRI indices, rADC and rDWI, was adopted for the evaluation. These indices were calculated at the infarction sites of the patients serially and averaged and compared daily in the two groups. In addition, regular neurological evaluation of the patients was done mainly with NIHSS (NIH stroke score).

Methods

Patients

Consecutive 34 patients who were diagnosed as having cerebral infarction of BAD type (branch atheromatous disease) in the brainstem were enrolled in the study. All of these patients lived in the local area of our hospital and were brought in within 4 to 24 hours after the onset of the symptoms. The first 26 patients were treated with Edaravone alone (E group) and the following 8 patients received hydrogen-rich intravenous fluid in addition to Edaravone (EH group). For the EH group of 8 patients, intravenous Edaravone (30 mg Edaravone Kit) was given at 6 AM and 6 PM as a regular schedule and hydrogen-rich intravenous solutions were added at 10 AM and 4 PM. These treatments lasted for 7 days. Neurological status was recorded essentially with NIHSS and compared at the time of admission and discharge from the hospital. The neurological evaluation was based upon the NIHSS method and was equally performed in the two groups. Since the dramatic and substantial improvements in clinical conditions and MRI indices after recanalization may overwhelm any effects of other medications, only those patients who were diagnosed as stroke due to branch atheromatous disease (BAD), which is a non-recanalization type cerebral infarction, in the brainstem were recruited. BAD involves perforating arteries particularly at lateral striate artery (LSA) region or at parapontine artery (PPA) region and is known as a type of progressive stroke [] also.

The informed consent in a form approved by the Nishijima Hospital Ethics Committee was obtained from all the patients before the treatment or from their legal guardians when the patients could not sign the consent, by the time of initiation of the treatment.

Production of hydrogen-rich intravenous fluid

Regular intravenous fluid bags were immersed, without opening the bag and without adding any alteration on the bag, in a hydrogen water tank which is capable of producing hydrogen-rich water up to 1.6 ppm concentration (Miz.Co, Fujisawa, Japan, Patent No.4486157, Patent Gazette of Japan 2010). The hydrogen concentration increased in the bag by diffusion through the totally intact wall of the plastic bag to more than 250 micromole/L and to saturation, depending upon the duration of the immersion and temperature. A saline bag of 250 ml size (Terumo Co. Tokyo, Japan) and a maltose solution bag of 200 ml size (Airomu Co. Atsugi, Japan) were chosen according to the highest diffusibility of the bag wall we could find.

MRI analysis

MRI signal intensities in DWI and ADC of each infarction site were observed first and then, serial changes of these images were compared in the E group and the EH group. The DWI and ADC signal intensities were also compared with those in the exactly same area of the other side of the brain and the ratio was calculated as rDWI (relative DWI) and rADC (relative ADC). Averages of these indices were compared in the two groups and also with the previous publications by using the data in the literature [] for a statistical significance. A special attention was paid for the determination of abnormal area. Firstly, all of the MRI images of the patient were reviewed and the largest area of the abnormality was chosen to be the site and size of the lesion for the calculation and the pixel size of the area were recorded. Then, the area was copied on a transparent film together with surrounding recognizable structures as a template, which was used for calculation of the remainder of MRIs. This is to prepare, in case of size changes of the abnormality or even disappearance of the abnormality, to calculate the indices exactly in the same area and in a same manner. If an ADC map was not distinct enough by the naked eye, then the DWI template was used to define the area of abnormality. The MRI scan was taken on the day of admission (Day1) and follow-up MRIs were scheduled to be taken every other day but this could not be accomplished in every patient when other tests such as patient’s vascular evaluation or cardiopulmonary function test were thought to be more urgent.

The study was approved by Nishijima Hospital Ethics Committee and the production of hydrogen rich IV fluid as “Hospital Preparation” and its clinical use in Nishijima Hospital, were conducted upon the advice from Nishijima Hospital Pharmacists Council and Japanese Welfare-Labour Administration (Tokai-Hokuriku District Bureau) and Sizuoka Prefectural Administration (Pharmaceutical Affair, Regulatory Audit Section).

Results

MRI images (DWI and ADC) of infarction areas and comparison of the images in the E group (treated with Edaravone only, Figure Figure11 upper) and the EH group (treated with a combination of Edaravone and hydrogen, Figure Figure11 lower)

An external file that holds a picture, illustration, etc. Object name is 2045-9912-1-12-1.jpg

Serial MRI changes in the upper brain stem lesion slices (1st & 3rd row) and lower brain stem lesion slices (2nd and 4th row) of DWI (1st & 2nd row) and ADC (3rd & 4th row) imagesupper. Serial MRI of a representative patient in E group on Day 1, 3, 6 (left to right). The lesion involved two adjacent slices at the upper (1st row) and lower (2nd row) brain stem. The DWI signal intensity (whiteness) of the upper slice increased on Day3 (presence of the initial hump), but remained almost unchanged on Day 1,3& 6 in the lower slice (2nd row) by the naked eye. The reduced ADC signal intensity (blackness) of the same lesion was seen even on Day6, particularly in the lower lesion slice (4th row). lower. Serial MRI of a representative patient in EH group on Day1, 2, 7, 9 (left to right). The lesions also involved two adjacent slices. The DWI signal intensity of the upper slice (1st row) was seen on Day1 but was invisible on the Day2 &7 (absence of the initial hump). The initial hump was seen only in the anterior part of the lower lesion slice (2nd row) but not in the posterior-lateral extension of the lesion towards the cerebellum which had disappeared on Day2 & 7(absence of the initial hump). The ADC signal was clearly darker in the lower brainstem lesion (4th row) on Day 2 but disappearing on Day7 and became grey colour on Day9 (shortened pseudonormalization time and late hike, 4th row, right end).

The results were firstly evaluated by MRI images (DWI and ADC) without indices (Figure (Figure1).1). The DWI images generally showed increased signal intensity (appeared with more whiteness) at the infarction sites in both groups. The ADC images, on the other hand, showed decreased signal intensity (appeared with more blackness) at the lesion sites, which were rather difficult to see as compared to the lesions in DWI images. These signal intensities of the lesions in the E group and the EH group differed obviously in many cases but in some cases, the differences were rather subtle when compared by single images and by the naked eye. However, when these single images were arranged serially, the differences between the two groups became more apparent and the initial hump, the initial dip and the pseudonormalization time could be assessed even without the indices, after getting used to the visual evaluation. In the E group, the DWI signal intensities increased from Day3 to Day7 in most cases (Figure (Figure11 upper, 1st row) and the change was confirmed to be the initial hump by the rDWI. However, in the EH group, the increase was significantly less and in some cases, no increase was seen at all (absence of the initial hump, Figure Figure11 lower, 1st row). In addition, in the E group, the increase lasted longer than 9 days, which was regarded as the lack of shortening of the pseudonormalization time (Figure (Figure11 upper, 2nd row) and this was also confirmed by indices. In the EH group, however, the increase returned to a normal level by Day 9 in many cases (the shortened pseudonormalization time, Figure Figure11 lower, 1st and 2nd row).

The ADC images when observed in a serial manner also showed substantial differences between the E group and the EH group. The degree of reduction of the ADC signal intensities at the lesion sites was less in EH group (Figure (Figure11 lower, 3rd and 4th row) and then, increased to the normal level within Day9, which qualified for the shortening of the pseudonormalization time. On the contrary, in the E group, the ADC image at the lesion site was darker and lasted longer without returning to a normal level within 9 days (lack of shortening of the pseudonormalization time, Figure Figure11 upper, 3rd and 4th row). The dark ADC intensity at the lesion site became greyish in colour after 9 days in the EH group and the whiteness gradually increased further (late hike) afterwards. In many lesions where the differences were not obvious by the naked eye, the evaluation by the indices still demonstrated significant differences. For an example, in the upper brain stem lesion of the E group (Figure (Figure11 upper, 1st row), the initial hump was not too obvious by the naked eye but the indices (rDWI) were above the normal level of 1.20 on Day3 and Day5 (1.54 and 1.30, respectively), indicating the presence of the initial hump. Since ADC images are more difficult to evaluate by the naked eye, the lack of the pseudonormalization of the lesions such as in the Figure Figure11 upper, 3rd and 4th row could only be evaluated by the indices (rADC), which, at these lesions, had changed from 0.48 to 0.31 to 065 (3rd row) and 0.79 to 0.39 to 0.82 (4th row) on Day1, Day3 and Day6, respectively. All of these indices were below the normal level of 0.9 and remained depressed longer than Day10 and therefore the changes were regarded as showing the lack of the pseudonormalization (or failure of shortening of the pseudonormalization time). On the other hand, the presence of shortened pseudonormalization time in the EH group was shown by the both indices as in Figure Figure11 lower lesions. The lesions showed the initial hump of rDWI (2nd row, 2.03) and the initial dip of rADC (4th row, 0.54) on Day2 but these data improved to 1.14 (rDWI, as compared to the normal value of less than 1.2) and to 2.50 (rADC, as compared to the normal value of more than 0.9), by the Day9 (therefore, the shortened pseudonormalization time and late hike).

Serial rDWI averages in the E group (treated with Edaravone only) and in the EH group (treated with a combination of Edaravone and hydrogen (Figure (Figure22 upper)

An external file that holds a picture, illustration, etc. Object name is 2045-9912-1-12-2.jpg

Serial changes in rDWI (upper) and rADC (lower)upper: Daily averages of rDWI in the E group patients showed a mild initial hump (Day4 to Day8, up to 2.2) but remained less than a natural course (rDWI of 2.5, Huang et al []). In the EH group, the initial hump was not seen (p < 0.05 on the Day 5, 8 and 9). No shortening of the pseudonormalization time was seen in E group (the rDWI average remained above 1.2 by Day9). In the EH group, the rDWI averages on Day 8 reached the normal level of 1.2 (shortened pseudonormalization time). Lower: Daily averages of rADCs in the E group patients showed a mild initial dip (Day4 to 7). In the EH group, the initial dip was rather short lived on Day 5 but no data available on Day6 & 7. No pseudonormalization of the rADC was noted within 9 days in the E group. In the EH group, however, the shortening was seen on Day 9. Then, the rADC of EH group increased (late hike). The differences of the rADC in the two groups reached a statistical significance on the Day5, 8 and 9.

Daily averages of rDWI in the E group patients showed a definite initial hump (above 1.2) between Day4 and Day8. However, the highest rDWI averages of the E group remained at 2.1 levels and did not deteriorate as high as 2.5, as in the natural course [] and the difference was statistically significant on Day4 (Figure (Figure22 upper). On the other hand, the initial hump was not seen in the EH group and the difference was significant (p < 0.05) on the Day5, 8 and 9 (absence of the initial hump). The rDWI averages of the E group did not fall below a normal level of 1.2 by Day10 and thus failed to shorten the pseudonormalization time. However, in the EH group, the rDWI averages on Day8 and Day9 reached 1.2 or less and thus qualified for the shortening of the pseudonormalization time. These findings indicate that the treatment in the E group did not abolish the initial hump and did not shorten the pseudonormalization. However, both conditions were accomplished in the EH group and in this sense, although the differences may appear rather minuscule, the results of the treatment in EH group was superior to those of the E group, when evaluated by the rDWI. The degree of the initial hump of the E group was significantly less and better than that of the natural course, however.

Serial rADC averages in the E group (treated with Edaravone only) and in the EH group (treated with a combination of Edaravone and hydrogen) (Figure (Figure22 lower)

Daily averages of rADCs in the E group patients showed the initial dip on the Day4 and Day5. In the EH group, however, the initial dip appeared to be delayed and rather short lived on the Day5 and possibly on the Day6 or Day7 but no data available during this period. These patients were usually scheduled for MRA (MRI angiogram) of the cervical carotid artery on the Day3 and other cardiopulmonary studies on Day6 or Day7 and the lack of the MRI data on these hospital days made it difficult to assert the duration of the short lived initial dip. Definite pseudonormalization of the rADC was not noted within 10 days in the E group while in the EH group, the shortening of the pseudonormalization time was seen on Day9. The rADC of the EH group increased gradually afterwards (late hike). The difference of the daily averages between the E group and the EH group reached a statistical significance on the Day5, 8 and 9. The results of the treatment in EH group were, therefore, superior to those of E group when evaluated by the rADC also.

Neurological outcomes in the E group (treated with Edaravone only) and in the EH group (treated with a combination of Edaravone and hydrogen)

The neurological conditions of the patients recorded on the Day1 and at the time of discharge from the hospital were compared. There were 4, 2 and 20 patients, who were regarded as improved, worse and unchanged, respectively, in the E group. However, all of the patients in the EH group were regarded as unchanged, except one patient who had a very high blood sugar from uncontrolled diabetes and got worse. The neurological evaluation was based upon NIHSS and if the score did not show any change, then, the result of the MMT was added. The difference of the neurological changes in the two groups was statistically not significant.

Discussion

MRI analysis

Since MRI scan is an essential part of the diagnosis of the cerebral infarction patients, the effects of the infarction treatment have frequently been evaluated by the MRI scan also. Previous publications utilized the area of DWI abnormality as an equivalent to the size of infarction. However, it is now well known that areas of the DWI abnormality are consisted of heterogeneous tissues and all of the area of DWI abnormalities may not progress to infarction. The increase in the size and density of the DWI abnormality may not reflect worsening and/or expansion of the infarction because the DWI data include T2 sequence of the MRI. Therefore, the increase may simply reflect the increase in water content of the area from vasogenic edema or from proliferated primitive and leaky neovasculature and the phenomena are inclusively called “T2 shine through” []. Therefore, if the effects of the treatment were analyzed only by the increase or decrease of the size and density of the DWI abnormality, the analysis may falsely conclude the treatment to be ineffective or effective, respectively. The ADC is not influenced by the T2 change and more valuable than DWI. However, since the ischemic tissue abnormality reduces the ADC data and this makes the area of the ADC abnormality very difficult to discern from the surrounding tissue. Therefore, the analysis of the effects of the treatment based upon the size of the DWI/ADC abnormality was thought to be inappropriate and we adopted the current technique. The technique is to calculate the average number of DWI/ADC raw data within the identical area of the brain within the recorded pixel size in all the MRI images obtained during the hospitalization by using a specific template made for each patient. This appeared to have accomplished the calculation in exactly same area of the same size in a consistent manner. This technique has been utilized in pharmacological evaluation of medications in the ischemic brain in the past but mainly in the animal experiments, probably due to difficulty in obtaining frequent MRI scans in clinical settings.

Our study included only brainstem infarction cases because of ease of defining the perimeter of the lesion for the calculation. The brainstem infarctions are usually round or oval in shape and small and very discrete from the surrounding tissue. In addition, the tissue is mainly consisted of white matter and devoid of CSF space. The MRI indices are influenced by the heterogeneity of the tissue [] and particularly by the presence of CSF space in the tissue as in the cerebral cortical lesions.

Neurological evaluation of brainstem infarction patients with NIHSS

All of the patients in the EH group were regarded as neurologically unchanged except one patient after the combined treatment with Edaravone and hydrogen, based upon the NIHSS. However, all of these patients in the EH group except one were satisfied with significant improvement of their preadmission symptoms by the time of discharge from the hospital. NIHSS is the most reliable and most accepted neurological scoring system for stroke patients which is calculated and recorded after performing well described and rather simple neurological examinations. However, these examinations are heavily weighted for the evaluation of anterior circulation stroke. Major symptoms of our brainstem stroke patients were due to posterior circulation abnormality and included dizzy sensation, vertigo without nystagmus, vague and subjective paresthesia of one side of the body with normal touch sensation, difficulty in walking from some swaying and staggering sensation but with normal knee to heel tests, normal diadochokinesis and normal muscle strength, in addition to some sensation of swallowing difficulty with normal gag reflex etc. None of these symptoms are calculable by NIHSS and therefore, the patient’s satisfaction in the EH group was not reflected as improvement in the NIHSS.

Effects of hydroxyl radical scavengers, Edaravone and hydrogen on cerebral infarction

The beneficial effects of Edaravone in the treatment of cerebral infarction have been well established []. Edaravone is known for its unique property with both water and lipid solubility and has potent scavenger action against hydroxyl and peroxynitrite radicals and ROS []. It acts also in reducing the brain edema of the ischemic brain tissue by protecting endothelial cells from ROS and by keeping integrity of the blood brain barrier and also by reducing the inflammatory responses in the ischemic area of the brain []. Initially, Edaravone was thought to be a simple quencher of the radicals but later many neuroprotective properties were found [,], and effectiveness in many organs and many disease conditions are added [,]. Currently, it is recognized as a most effective scavenger of radicals and also neuroprotective agents in Japanese neurosurgical community but additional clinical studies were discussed in the U.S.A [].

Hydrogen is also known as a potent scavenger of the hydroxyl and peroxynitrite radicals and does not affect NO production which is advantageous to the ischemic brain tissue. The investigational and clinical interests have been promulgated recently by epochal articles [] and a review []. Direct actions of hydrogen on extracellular and intracellular hydroxyl radical provide protection of mitochondria and nuclear DNA but hydrogen does not harm other cellular elements which relate to signal transduction. When hydrogen was given during reperfusion in an animal ischemic brain model, it protected ischemia-reperfusion injury of the brain, although only when hydrogen was given during the reperfusion but not during the ischemic period. However, these effects were actually better than those of Edaravone and FK506 combination []. Since FK506 alone is known to decrease the ischemic brain size, it is remarkable that hydrogen superseded the effects of the combination. In addition, hydrogen demonstrated extended effectiveness in many other organs and in various situations such as in diabetes[], intestinal grafts[], tumor growth inhibition [], allograft nephropathy[], cardiac ischemia/reperfusion[], sepsis [], liver injury [], haemodialysis[], spinal cord injury[], an animal model of Parkinson’s disease[] and Alzheimer’s disease[], in addition to health promotion []. Therefore, there is nothing to indicate that hydrogen is inferior to Edaravone for the treatment of cerebral infarction and it is quite possible that a single use of hydrogen is as effective as Edaravone treatment and probably much safer. However, it would be an unethical conduct until larger controlled clinical studies accumulate more evidences, because of limitations of our study. However, if the advantages in the EH group of current study were substantiated in the future studies, the advantages may be due to the increased frequency of administration of the radical scavengers as was in EH group (4 times per day vs. 2 times per day), and/or direct hydrogen effects on the inflammatory cells, chemokines and growth and antiapoptoic factors and/or a direct neutralizing action on the residual radical substances of intermediate Edaravone metabolites in ischemic and hypoxic brain tissue. Edaravone putatively provides electrons and becomes a radical by itself until it reacts with oxygen and then changes, through Edaravone peroxyl radical, to a non-radical material, 2-oxo-3-(phenylhydrazono)-butanoic acid (OPB) [] which may accumulate in the brain eventually. Hydrogen may have interacted with those intermediate radical products favourably and provided better MRI changes in our study. At the beginning of this study, our concerns included the government approved and recommended Edaravone dose (60 mg/day for 2 weeks = 840 mg) and subsequent blood level dynamics. It is interesting that a currently on going Phase 2 study in Europe increased the Edaravone doses from 840 mg to 1000 mg and 2000 mg []. The results of the study may solve some of our concerns.

The limitations of our study include a non-controlled way of patient selection, inclusion of rather small number of the patients particularly in the combined group, use of current NIHSS for neurological evaluation for the brainstem infarction, lack of long term follow-up etc. We are organizing a new study to improve these limitations currently.

Conclusions

Administration of hydroxyl radical scavengers in acute stage of brainstem infarction improved MRI indices (rDWI, rADC) against the natural course. The favourable effects were more obvious and significant in the EH group (a combined group of Edaravone and hydrogen) as compared to the E group (Edaravone alone group). These findings may imply the need for more frequent daily administration of hydroxyl radical scavenger, or possible presence of additional hydrogen effects on scavenger mechanisms

 

Logo of mgr

Link to Publisher's site
. 2011; 1: 12.
Published online 2011 Jun 7. doi: 10.1186/2045-9912-1-12
PMCID: PMC3231971
PMID: 22146068
Improved brain MRI indices in the acute brain stem infarct sites treated with hydroxyl radical scavengers, Edaravone and hydrogen, as compared to Edaravone alone. A non-controlled study
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Competing interests

The authors declare that they have no competing interests and were not compensated at all by any pharmaceutical and biotechnology company or any other companies to contribute this article to the peer-reviewed scientific literature.

Authors’ contributions

The authors equally contributed to the production of this article and have read and approved the final manuscript.

Acknowledgements

The authors would like to thank Miz Company for technical assistance for setting up the hydrogen water tank and initial measurement of hydrogen concentration in the intravenous fluid bag.

References

  • Yang Q, Brian M, Tress BM, Barber PA, Desmond PM, Darby DG, Gerraty RP, Li T, Davis SM. Study of apparent diffusion coefficient and anisotropy in patients with Acute Stroke. Stroke. 1999;30:2382–2390. doi: 10.1161/01.STR.30.11.2382. [PubMed] [CrossRef[]
  • Schwamm LH, Koroshetz WJ, Sorensen GA, Wang B, Copen WA, Rordorf G, Buonanno FS, Schaefer PW, Gonzalez GR. Serial Diffusion-and Hemodynamic-Weighted Magnetic Resonance Imaging. Stroke. 1998;29:2268–2276. doi: 10.1161/01.STR.29.11.2268. [PubMed] [CrossRef[]
  • Huang IJ, Chen CY, Chung HW, Chang DC, Lee CC, Chin SC, Liou M. Time Course of Cerebral Infarction in the Middle Cerebral Arterial Territory: Deep Watershed versus Territorial Subtypes on Diffusion-weighted MR Images. Radiology. 2001;221:35–42. doi: 10.1148/radiol.2211001412.[PubMed] [CrossRef[]
  • Fiebach JB, Schellinger JO, Sartor HW. Serial analysis of the apparent diffusion coefficient time course in human stroke. Neuroradiology. 2002;44:294–298. doi: 10.1007/s00234-001-0720-8.[PubMed] [CrossRef[]
  • Liu S, Karonen JO, Liu Y, Vanninen Ft, Partanen K, Cinbnen MK, Vainio P, Aronen HJ. Serial Measurements of the Apparent Diffusion Coefficient in Human Stroke on Five Time Points over Three Months. Proc Intl Sot Mag Reson Med. 2000;8:1203. []
  • Huang L, Wong XH, Li G. The application of DWI and ADC map in cerebral infarction. Proc Intl Soc Mag Reson Med. 2001;9:1446. []
  • Marks MP, Tong DC, Beaulieu C, Albers GW, deCrespigny A, Moseley MR. Evaluation of early reperfusion and i.v. tPA therapy using diffusion-and perfusion-weighted MRI. Neurology. 1999;52:1792–1798. [PubMed[]
  • Schaefer POW, Hassankhani A, Putman C, Sorensen GA, Schwamm L, Koroshez W, Gonzalez GR. Characterization and evolution of diffusion MNRE imaging abnormalities in Stroke patients undergoing intra-arterial thrombolysis. ANJR. 2004;25:951–957. [PubMed[]
  • Tanaka M. Pharmacological and clinical profile of the free radical scavenger edaravone as a neuroprotective agent. Folia Pharmacol Jpn. 2002;119:301–308. doi: 10.1254/fpj.119.301. [PubMed] [CrossRef[]
  • Kageyama M, Toriyama S, Tsubosita A, Muraki S, Yamada T, Ishibashi A. A post-marketing drug use survey of a neuroprotecive drug Radicut injection 30 mg(non-proprietary name: edaravone) for acute ischemic stroke. J New Rem Clin. 2009;58:1212–1226. []
  • Ohsawa I, Ishikawa M, Takahashi K, Watanabe M, Nishimaki K, Yamagata K, Katsura K, Katayama Y, Asoh S, Ohta S. Hydrogen acts as a therapeutic antioxidant by selectively reducing cytotoxic oxygen radicals. Nat Med. 2007;13:688–694. doi: 10.1038/nm1577. [PubMed] [CrossRef[]
  • Takagi M. Concept of branch atheromatous disease. Neurol Med. 2008;69:542–549.[]
  • Burdett JH, Elster AD, Ricci PE. Acute Cerebral Infarction: Quantification of Spin-Density and T2 Shine-through Phenomena on Diffusion-weighted MR Images. Radiology. 1999;212:333–339.[PubMed[]
  • Edaravone Acute Infarction Study Group. Effect of a novel free radical scavenger, edaravone (MCI-186), on acute brain infarction. Randomized, placebo-controlled, double-blind study at multicenters. Cerebrovasc Dis. 2003;15:222–229. [PubMed[]
  • Yamamoto Y, Kuwahara T, Watanabe K, Watanabe K. Antioxidant activity of 3-methyl-1-phenyl-2-pyrazolin-5-one. Redox Report. 1996;2:333–338. [PubMed[]
  • Zhang N, Komine-Kobayashi M, Tanaka R, Liu M, Mizuno Y, Urabe T. Edaravone reduces early accumulation of oxidative products and sequential inflammatory responses after transient focal ischemia in mice brain. Stroke. 2005;36:2220–2225. doi: 10.1161/01.STR.0000182241.07096.06.[PubMed] [CrossRef[]
  • Kawai H, Nakai H, Suga M, Yuki S, Watanabe T, Saito KI. Effects of a novel free radical scavenger, MCl-186, on ischemic brain damage in the rat distal middle cerebral artery occlusion model. J Pharmacol Exp Ther. 1997;281:921–927. [PubMed[]
  • Yoshida H, Metoki N, Ishikawa A, Imaizumi T, Matsumiya T, Tanji K, Ota K, Ohyama C, Satoh K. Edaravone improves the expression of nerve growth factor in human astrocytes subjected to hypoxia/reoxygenation. Neurosci Res. 2010;66:284–289. doi: 10.1016/j.neures.2009.11.011.[PubMed] [CrossRef[]
  • Zhang W, Sato K, Hayashi T, Omori N, Nagano I, Kato S, Horiuchi S, Abe K. Extension of ischemic therapeutic time window by a free radical scavenger, Edaravone, reperfused with tPA in rat brain. Neurol Res. 2004;26:342–348. doi: 10.1179/016164104225014058. [PubMed] [CrossRef[]
  • Watanabe T, Tahara M, Todo S. The Novel Antioxidant Edaravone: From Bench to Bedside. Cardiovascular Therapeutics. 2008;26:101–114. doi: 10.1111/j.1527-3466.2008.00041.x. [PubMed] [CrossRef[]
  • Lapchak PA. A critical assessment of edaravone acute ischemic stroke efficacy trials: is edaravone an effective neuroprotective therapy? Expert Opinion on Pharmacotherapy. 2010;11:1753–1763. doi: 10.1517/14656566.2010.493558. [PMC free article] [PubMed] [CrossRef[]
  • Nakao A, Sugimoto R, Billiar TR, McCurry KR. Therapeutic antioxidant medical gas. J Clin Biochem Nutr. 2009;44:1–13. doi: 10.3164/jcbn.08-193R. [PMC free article] [PubMed] [CrossRef[]
  • Kajiyama S, Hasegawa G, Asano M, Hosoda H, Fukui M, Nsksmura N, Kitawaki J, Imai S, Nakano K, Ohta M, Adachi T, Obayashi H, Yoshikawa T. Supplementation of hydrogen-rich water improves lipid andd glucose metabolism in patients with type 2 diabetes or impaired glucose tolerance. Nur Res. 2008;28:137–143. [PubMed[]
  • Buchholz BM, Kaczorowski DJ, Sugimoto R, Yang R, Wang Y, Billiar TR, McCurry KR, Bauer AJ, Nakao A. Hydrogen inhalation ameliorates oxidative stress in transplantation induced intestinal graft injury. Am I transplant. 2008;8:2015–2024. [PubMed[]
  • Saitoh Y, Okayasu H, Xiao L, Harata Y, Miwa N. Neutral pH hydrogen-enriched electrolyzed water achieves tumor-preferential clonal growth inhibition over normal cells and tumor invasion inhibition concurrently with intracellular oxidant repression. Oncol Res. 2008;17:247–255. doi: 10.3727/096504008786991620. [PubMed] [CrossRef[]
  • Cardinal JS, Zhan J, Wang Y, Sugimoto R, Tsung A, McCurry KR, Billar R, Nakao A. Oral administration of hydrogen water prevents chronic allograft nephropathy in rat renal transplantation. Kidney Int. 2010;77:101–109. doi: 10.1038/ki.2009.421. [PubMed] [CrossRef[]
  • Nakao A, Kaczorowski DJ, Wang Y, Cardinal JS, Buchholz BM, Sugimoto R, Tobita K, Lee S, Toyoda Y, Billar TR, McCurry KR. Amelioration of rat cardiac cold ischemia/reperfusion injury with inhaled hydrogen or carbon monoxide, or both. J Heart Lung Transplant. 2010;29:544–553. doi: 10.1016/j.healun.2009.10.011. [PubMed] [CrossRef[]
  • Xie K, Yu Y, Pei Y, Hou L, Chen S, Xiong L, Wang G. Protective effects of hydrogen gas on murine polymicrobial sepsis via reducing oxidative stress and HMGB1 release. Shock. 2010;34:90–97.[PubMed[]
  • Liu Q, Shen WF, Sun HY, Fan DF, Nakao A, Cai JM, Yan G, Zhou WP, Shen RX, Yang JM, Sun XJ. Hydrogen-rich saline protects against liver injury in rats with obstructive jaundice. Liver Int. 2010;30:958–968. doi: 10.1111/j.1478-3231.2010.02254.x. [PubMed] [CrossRef[]
  • Nakayama M, Nakao H, Hamada H, Itami N, Nakazawa R, Ito S. A novel bioactive hemodialysis system using dissolved dihydrogen(H2) produced by water electrolysis: a clinical trial. Nephrol Dial Transplant. 2010;25:3026–3033. doi: 10.1093/ndt/gfq196. [PubMed] [CrossRef[]
  • Chen CW, Chen QB, Mao YF, Xu SM, Xia CY, Shi XY, Zang ZH, Yuan HB, Sun XJ. Hydrogen-rich saline protects against spinal cord injury in rats. Neurochem Res. 2010;35:1111–1118. doi: 10.1007/s11064-010-0162-y. [PubMed] [CrossRef[]
  • Fujita K, Seike T, Yutsudo N, Ohno M, Yamada H, Yamaguchi H, Sakumi K, Yamakawa Y, Kido M, Takaki A, Katafuchi T, Tanaka Y, Nakabeppu y, Noda M. Hydrogen in drinking water reduces dopaminergic neuronal loss in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine mouse model of Parkinson disease. PloS One. 2009;30:1–10. e7247. [PMC free article] [PubMed[]
  • Li J, Wang C, Zhang JH, Cai JM, Cao YP, Sun XJ. Hydrogen-rich saline improves memory function in a rat model of amyloid-beta-induced Alzheimer’s disease by reduction of oxidative stress. Brain Res. 2010;1328:152–161. [PubMed[]
  • Nakao A, Toyoda Y, Sharma P, Evans M, Guthrie N. Effectiveness of Hydrogen Rich Water on Antioxidant Status of Subjects with Potential Metabolic Syndrome–An Open Label Pilot Study. J Clin Biochem Nutr. 2010;46:140–149. doi: 10.3164/jcbn.09-100. [PMC free article] [PubMed] [CrossRef[]
  • Higashi Y, Jitsuiki D, Chayama K, Yoshizumi M. Edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one), a novel free radical scavenger, for treatment of cardiovascular disease. Recent Patents on Cardiovascular Drug Discovery. 2006;1:85–93. doi: 10.2174/157489006775244191. [PubMed] [CrossRef[]

Articles from Medical Gas Research are provided here courtesy of Wolters Kluwer — Medknow Publications

Drinking hydrogen water enhances ENDURANCE and relieves psychometric FATIGUE: a randomized, double-blind, placebo-controlled study 

Drinking hydrogen water enhances endurance and relieves psychometric fatigue: a randomized, double-blind, placebo-controlled study

Abstract

Acute physical exercise increases reactive oxygen species in skeletal muscle, leading to tissue damage and fatigue. Molecular hydrogen (H2) acts as a therapeutic antioxidant directly or indirectly by inducing antioxidative enzymes.

Here, we examined the effects of drinking hydrogen H2 water (H2-infused water) on psychometric fatigue and endurance capacity in a randomized, double-blind, placebo-controlled fashion.

In Experiment 1, all participants(humans) drank only placebo water in the first cycle ergometer exercise session, and for comparison they drank either hydrogen H2 water or placebo water 30 min before exercise in the second examination.In these healthy non-trained participants (n = 99), psychometric fatigue judged by visual analogue scales was significantly decreased in the hydrogen H2 water group after mild exercise. When each group was divided into 2 subgroups, the subgroup with higher visual analogue scale values was more sensitive to the effect of hydrogen water H2.

In Experiment 2, trained participants (n = 60) were subjected to moderate exercise by cycle ergometer in a similar way as in Experiment 1, but exercise was performed 10 min after drinking hydrogen H2 water. Endurance/fatigue were significantly improved/relieved in the hydrogen water H2 group as judged by maximal oxygen consumption and Borg’s scale, respectively.

Taken together, drinking hydrogen H2 water just before exercise exhibited anti-fatigue and improved endurance effects.

PMID:31251888
DOI:10.1139/cjpp-2019-0059
 2019 Jun 28:1-6. doi: 10.1139/cjpp-2019-0059. [Epub ahead of print]
Drinking hydrogen water enhances endurance and relieves psychometric fatigue: a randomized, double-blind, placebo-controlled study 1.

Author information

1 Department of Health and Sports Science, Nippon Medical School, Musashino, Tokyo 180-0023, Japan.
2 Fitness Club, Asahi Big S Mukogaoka, Kawasaki-city, Kanagawa pref. 214-0014, Japan.
3 Hydrogen Health Medical Laboratory, Co., Ltd., Arakawa-ku, Tokyo 116-0001, Japan.
4 Slovak Academy of Sciences, Centre of Experimental Medicine, Institute for Heart Research, Bratislava 84005, Slovak Republic.
5 Molecular Hydrogen Institute, Enoch, UT 84721, USA.
6Department of Neurology Medicine, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo 113-8421, Japan.

molecular hydrogen water PERIODONTITIS

Oxidative stress is involved in the pathogenesis of periodontitis. A reduction of oxidative stress by drinking molecular hydrogen-rich water (HW) might be beneficial to periodontal health.

In this pilot study, we compared the effects of non-surgical periodontal treatment with or without drinking molecular hydrogen-rich water HW on periodontitis.

13 patients (3 women, 10 men) with periodontitis were divided into two groups: The control group (n = 6) or the molecular hydrogen-rich water HW group (n = 7). In the molecular hydrogen-rich water HW group, participants consumed molecular hydrogen-rich water HW 4-5 times/day for eight weeks. At two to four weeks, all participants received non-surgical periodontal treatment. Oral examinations were performed at baseline, two, four and eight weeks, and serum was obtained at these time points to evaluate oxidative stress. At baseline, there were no significant differences in periodontal status between the control and molecular hydrogen-rich water HW groups. The molecular hydrogen-rich water HW group showed greater improvements in probing pocket depth and clinical attachment level than the control group at two, four and eight weeks (p < 0.05). The molecular hydrogen-rich water HW group also exhibited an increased serum level of total antioxidant capacity at four weeks, compared to baseline (p < 0.05). Drinking molecular hydrogen-rich water HW enhanced the effects of non-surgical periodontal treatment, thus improving periodontitis.

PMID:26783840
PMCID:PMC4665424
DOI:10.3390/antiox4030513

 

 2015 Jul 9;4(3):513-22. doi: 10.3390/antiox4030513.
Drinking Hydrogen-Rich Water Has Additive Effects on Non-Surgical Periodontal Treatment of Improving Periodontitis: A Pilot Study.

Author information

1
Departments of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan. tetsuji@md.okayama-u.ac.jp.
2
Departments of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan. de18053@s.okayama-u.ac.jp.
3
Departments of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan. dekuni7@md.okayama-u.ac.jp.
4
Departments of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan. de18019@s.okayama-u.ac.jp.
5
Departments of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan. de18017@s.okayama-u.ac.jp.
6
Center for Innovative Clinical Medicine, Okayama University Hospital, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan. t-maru@md.okayama-u.ac.jp.
7
Departments of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan. tomofu@md.okayama-u.ac.jp.
8
Departments of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan. mmorita@md.okayama-u.ac.jp.