Chronic hydrogen-rich saline treatment attenuates vascular dysfunction in spontaneous hypertensive rats

Can molecular hydrogen supplementation enhance physical performance in healthy adults? A systematic review and meta-analysis

Background

Physical exertion during exercise often leads to increased oxidative stress and inflammatory responses, significantly affecting physical performance. Current strategies to mitigate these effects are limited by their effectiveness and potential side effects. Molecular hydrogen (H₂) has gained attention for its antioxidant and anti-inflammatory properties. Studies have suggested that H2 supplementation contributes to antioxidant potential and anti-fatigue during exercise, but the variance in the observations and study protocols is presented across those studies.

Objective

This systematic review and meta-analysis aimed to comprehensively characterize the effects of H₂ supplementation on physical performance (i.e., endurance, muscular strength, and explosive power), providing knowledge that can inform strategies using H2 for enhancing physical performance.

Methods

We conducted a literature search of six databases (PubMed, Web of Science, Medline, Sport-Discus, Embase, and PsycINFO) according to the PRISMA guidelines. The data were extracted from the included studies and converted into the standardized mean difference (SMD). After that, we performed random-effects meta-analyses and used the I 2 statistic to evaluate heterogeneity. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) was used to assess the quality of the evidence obtained from this meta-analysis.

Results

In total, 27 publications consisting of 597 participants were included. The search finally included aerobic endurance, anaerobic endurance, muscular strength, lower limb explosive power, rating of perceived exertion (RPE), blood lactate (BLA), and average heart rate (HRavg) in the effect size (ES) synthesis. The ES of H2 on aerobic endurance, including V̇O2max (SMD = 0.09, p = 0.394; I 2 = 0%) and aerobic endurance exercise (SMD = 0.04, p = 0.687; I 2 = 0%), were not significant and trivial; the ES of H2 on 30 s maximal anaerobic endurance (SMD = 0.19, p = 0.239; I 2 = 0%) was not significant and trivial; the ES of H2 on muscular strength (SMD = 0.19, p = 0.265; I 2 = 0%) was not significant and trivial; but the ES of H2 on lower limb explosive power (SMD = 0.30, p = 0.018; I 2 = 0%) was significant and small. In addition, H2 reduces RPE (SMD = -0.37, p = 0.009; I 2 = 58.0%) and BLA (SMD = -0.37, p = 0.001; I 2 = 22.0%) during exercise, but not HRavg (SMD = -0.27, p = 0.094; I 2 = 0%).

Conclusion

These findings suggest that H2 supplementation is favorable in healthy adults to improve lower limb explosive power, alleviate fatigue, and boost BLA clearance, but may not be effectively improving aerobic and anaerobic endurance and muscular strength. Future studies with more rigorous designs are thus needed to examine and confirm the effects of H2 on these important functionalities in humans.

Systematic review registration

http://www.crd.york.ac.uk/PROSPERO.

Serum Metabolomics and Proteomics to Study the Antihypertensive Effect of Protein Extracts from Tenebrio molitor

Hypertension is the leading risk factor for premature death worldwide and significantly contributes to the development of all major cardiovascular disease events. The management of high blood pressure includes lifestyle changes and treatment with antihypertensive drugs. Recently, it was demonstrated that a diet supplemented with Tenebrio molitor (TM) extracts is useful in the management of numerous pathologies, including hypertension. This study is aimed at unveiling the underlying mechanism and the molecular targets of intervention of TM dietary supplementation in hypertension treatment by means of proteomics and metabolomics techniques based on liquid chromatography coupled with high-resolution mass spectrometry. We demonstrate that serum proteome and metabolome of spontaneously hypertensive rats are severely altered with respect to their normotensive counterparts. Additionally, our results reveal that a diet enriched with TM extracts restores the expression of 15 metabolites and 17 proteins mainly involved in biological pathways associated with blood pressure maintenance, such as the renin–angiotensin and kallikrein–kinin systems, serin protease inhibitors, reactive oxygen scavenging, and lipid peroxidation. This study provides novel insights into the molecular pathways that may underlie the beneficial effects of TM, thus corroborating that TM could be proposed as a helpful functional food supplement in the treatment of hypertension.

Role of Molecular Hydrogen in Ageing and Ageing-Related Diseases

Ageing is a physiological process of progressive decline in the organism function over time. It affects every organ in the body and is a significant risk for chronic diseases. Molecular hydrogen has therapeutic and preventive effects on various organs. It has antioxidative properties as it directly neutralizes hydroxyl radicals and reduces peroxynitrite level. It also activates Nrf2 and HO-1, which regulate many antioxidant enzymes and proteasomes. Through its antioxidative effect, hydrogen maintains genomic stability, mitigates cellular senescence, and takes part in histone modification, telomere maintenance, and proteostasis. In addition, hydrogen may prevent inflammation and regulate the nutrient-sensing mTOR system, autophagy, apoptosis, and mitochondria, which are all factors related to ageing. Hydrogen can also be used for prevention and treatment of various ageing-related diseases, such as neurodegenerative disorders, cardiovascular disease, pulmonary disease, diabetes, and cancer. This paper reviews the basic research and recent application of hydrogen in order to support hydrogen use in medicine for ageing prevention and ageing-related disease therapy.

A Preliminary Study on the Effect of Hydrogen Gas on Alleviating Early CCl4-Induced Chronic Liver Injury in Rats

As a small-molecule reductant substance, hydrogen gas has an obvious antioxidant function. It can selectively neutralize hydroxyl radicals (^•OH) and peroxynitrite (ONOO^•) in cells, reducing oxidative stress damage. The purpose of this study was to investigate the effect of hydrogen gas (3%) on early chronic liver injury (CLI) induced by CCl₄ and to preliminarily explore the protective mechanism of hydrogen gas on hepatocytes by observing the expression of uncoupling protein 2 (UCP2) in liver tissue. Here, 32 rats were divided into four groups: the control group, CCl₄ group, H₂ (hydrogen gas) group, and CCl₄ + H₂ group. The effect of hydrogen gas on early CLI was observed by serological tests, ELISA, hematoxylin and eosin staining, and oil red O staining. Immunohistochemical staining and Western blotting were used to observe the expression of UCP2 in liver tissues. We found that CCl₄ can induce significant steatosis in hepatocytes. When the hydrogen gas was inhaled, hepatocyte steatosis was reduced, and the UCP2 expression level in liver tissue was increased. These results suggest that hydrogen gas might upregulate UCP2 expression levels, reduce the generation of intracellular oxygen free radicals, affect lipid metabolism in liver cells, and play a protective role in liver cells.

Recent Advances in Molecular Hydrogen Research Reducing Exercise-Induced Oxidative Stress and Inflammation

Physical exercise-induced oxidative stress and inflammation may be beneficial when exercise is a regular activity, but it is rather harmful when exercise is exhaustive and performed by unaccustomed organisms. Molecular hydrogen (H₂) has recently appeared as a potent antioxidant and anti-inflammatory molecule in numerous pathological conditions. However, its role is relatively unknown under physiological conditions such as physical exercise. Therefore, this review summarizes the current knowledge of the H₂, reducing oxidative stress and inflammation in physical exercise, reporting data from both animal and human studies.

Hydrogen Gas as an Exotic Performance-Enhancing Agent: Challenges and Opportunities

BACKGROUND

Hydrogen gas (H₂) has entered the world of experimental therapeutics approximately four and a half decades ago. Over the years, this simple molecule appears to drive more scientific attention, perhaps due to a dualism of H₂ affirmative features demonstrated in numerous in vitro, animal and human studies on one side, and still puzzling mechanism(s) of its biological activity on the other. Up to this point, H₂ was scrutinized for more than 170 different disease models and pathologies, and many research groups across the world have lately started to dynamically investigate its conceivable performance-enhancing potential.

METHODS

We outlined here the studies indexed in leading research databases (PubMed, Web of Science, SCOPUS, JSTORE) that explored the effects of hydrogen on exercise performance, and also addressed important restraints, open questions, and windows of opportunities for forthcoming research and possible H₂ enactment in exercise physiology. About two dozen trials have been identified in this domain, with most of the trials published during the past 5 years, while drinking hydrogen-rich water recognized as the most convenient method to deliver H₂ in both animal and human studies.

RESULTS

Either administered as an inhalational gas, enteral hydrogen-rich water, or intravenous hydrogen-rich saline, H₂ seems to favorably affect various exercise performance outcomes and biomarkers of exercise-associated fatigue, inflammation, and oxidative stress. Not all studies have shown corroborative effects, and it appears that the gold-standard protocol for applying H₂ in the field of exercise science does not exist at the moment, with studies markedly differ in the dose of H₂ administered, the duration of treatment, and the source of hydrogen.

CONCLUSION

H₂ is a newfangled and rather effective performance-enhancing agent, yet its promising ergogenic potency has to be further validated and characterized in more well-controlled, appropriately sampled and longterm mechanistic trials. Also, appropriate regulation of hydrogen utilization in sport as an exotic medical gas may require distinctive legislative actions of relevant regulatory agencies in the future.

Oxidative Stress and Pathways of Molecular Hydrogen Effects in Medicine

There are many situations of excessive production of reactive oxygen species (ROS) such as radiation, ischemia/reperfusion (I/R), and inflammation. ROS contribute to and arises from numerous cellular pathologies, diseases, and aging. ROS can cause direct deleterious effects by damaging proteins, lipids, and nucleic acids as well as exert detrimental effects on several cell signaling pathways. However, ROS are important in many cellular functions. The injurious effect of excessive ROS can hypothetically be mitigated by exogenous antioxidants, but clinically this intervention is often not favorable. In contrast, molecular hydrogen provides a variety of advantages for mitigating oxidative stress due to its unique physical and chemical properties. H₂ may be superior to conventional antioxidants, since it can selectively reduce ●OH radicals while preserving important ROS that are otherwise used for normal cellular signaling. Additionally, H₂ exerts many biological effects, including antioxidation, anti-inflammation, anti-apoptosis, and anti-shock. H₂ accomplishes these effects by indirectly regulating signal transduction and gene expression, each of which involves multiple signaling pathways and crosstalk. The Keap1-Nrf2-ARE signaling pathway, which can be activated by H₂, plays a critical role in regulating cellular redox balance, metabolism, and inducing adaptive responses against cellular stress. H₂ also influences the crosstalk among the regulatory mechanisms of autophagy and apoptosis, which involve MAPKs, p53, Nrf2, NF-κB, p38 MAPK, mTOR, etc. The pleiotropic effects of molecular hydrogen on various proteins, molecules and signaling pathways can at least partly explain its almost universal pluripotent therapeutic potential.

Hydrogen Gas: A Novel Type of Antioxidant in Modulating Sexual Organs Homeostasis

Sex is a science of cutting edge but bathed in mystery. Coitus or sexual intercourse, which is at the core of sexual activities, requires healthy and functioning vessels to supply the pelvic region, thus contributing to clitoris erection and vaginal lubrication in female and penile erection in male. It is well known that nitric oxide (NO) is the main gas mediator of penile and clitoris erection. In addition, the lightest and diffusible gas molecule hydrogen (H2) has been shown to improve erectile dysfunction (ED), testis injuries, sperm motility in male, preserve ovarian function, protect against uterine inflammation, preeclampsia, and breast cancer in female. Mechanistically, H2 has strong abilities to attenuate excessive oxidative stress by selectively reducing cytotoxic oxygen radicals, modulate immunity and inflammation, and inhibit injuries-induced cell death. Therefore, H2 is a novel bioactive gas molecule involved in modulating sexual organs homeostasis.

Hydrogen: A Novel Option in Human Disease Treatment

H₂ has shown anti-inflammatory and antioxidant ability in many clinical trials, and its application is recommended in the latest Chinese novel coronavirus pneumonia (NCP) treatment guidelines. Clinical experiments have revealed the surprising finding that H₂ gas may protect the lungs and extrapulmonary organs from pathological stimuli in NCP patients. The potential mechanisms underlying the action of H₂ gas are not clear. H₂ gas may regulate the anti-inflammatory and antioxidant activity, mitochondrial energy metabolism, endoplasmic reticulum stress, the immune system, and cell death (apoptosis, autophagy, pyroptosis, ferroptosis, and circadian clock, among others) and has therapeutic potential for many systemic diseases. This paper reviews the basic research and the latest clinical applications of H₂ gas in multiorgan system diseases to establish strategies for the clinical treatment for various diseases.

Molecular hydrogen: A potential radioprotective agent

In recent years, many studies have shown that hydrogen has therapeutic and preventive effects on various diseases. Its selective antioxidant properties were well noticed. Most of the ionizing radiation-induced damage is caused by hydroxyl radicals (OH) from radiolysis of H₂O. Since hydrogen can mitigate such damage through multiple mechanisms, it presents noteworthy potential as a novel radio-protective agent. This review analyses possible mechanisms for hydrogen's radioprotective properties and effective delivery methods. We also look into details of vitro and vivo studies for hydrogen's radioprotective effects, and clinical practices. We conclude that hydrogen has good potential in radio-protection, with evidence that warrants greater research efforts in this field.

Molecular hydrogen: current knowledge on mechanism in alleviating free radical damage and diseases

Ever since molecular hydrogen was first reported as a hydroxyl radical scavenger in 2007, the beneficial effect of hydrogen was documented in more than 170 disease models and human diseases including ischemia/reperfusion injury, metabolic syndrome, inflammation, and cancer. All these pathological damages are concomitant with overproduction of reactive oxygen species (ROS) where molecular hydrogen has been widely demonstrated as a selective antioxidant. Although it is difficult to construe the molecular mechanism of hydrogen's biomedical effect, an increasing number of studies have been helping us draw the picture clearer with days passing by. In this review, we summarized the current knowledge on systemic and cellular modulation by hydrogen treatment. We discussed the antioxidative, anti-inflammatory, and anti-apoptosis effects of hydrogen, as well as its protection on mitochondria and the endoplasmic reticulum, regulation of intracellular signaling pathways, and balancing of the immune cell subtypes. We hope that this review will provide organized information that prompts further investigation for in-depth studies of hydrogen effect.

A new insight into the molecular hydrogen effect on coenzyme Q and mitochondrial function of rats

Mitochondria are the major source of cellular energy metabolism. In the cardiac cells, mitochondria produce by way of the oxidative phosphorylation more than 90% of the energy supply in the form of ATP, which is utilized in many ATP-dependent processes, like cycling of the contractile proteins or maintaining ion gradients. Reactive oxygen species (ROS) are by-products of cellular metabolism and their levels are controlled by intracellular antioxidant systems. Imbalance between ROS and the antioxidant defense leads to oxidative stress and oxidative changes to cellular biomolecules. Molecular hydrogen (H₂) has been proved as beneficial in the prevention and therapy of various diseases including cardiovascular disorders. It selectively scavenges hydroxyl radical and peroxynitrite, reduces oxidative stress, and has anti-inflammatory and anti-apoptotic effects. The effect of H₂ on the myocardial mitochondrial function and coenzyme Q levels is not well known. In this paper, we demonstrated that consumption of H₂-rich water (HRW) resulted in stimulated rat cardiac mitochondrial electron respiratory chain function and increased levels of ATP production by Complex I and Complex II substrates. Similarly, coenzyme Q₉ levels in the rat plasma, myocardial tissue, and mitochondria were increased and malondialdehyde level in plasma was reduced after HRW administration. Based on obtained data, we hypothesize a new metabolic pathway of the H₂ effect in mitochondria on the Q-cycle and in mitochondrial respiratory chain function. The Q-cycle contains three coenzyme Q forms: coenzyme Q in oxidized form (ubiquinone), radical form (semiquinone), or reduced form (ubiquinol). H₂ may be a donor of both electron and proton in the Q-cycle and thus we can suppose stimulation of coenzyme Q production. When ubiquinone is reduced to ubiquinol, lipid peroxidation is reduced. Increased CoQ₉ concentration can stimulate electron transport from Complex I and Complex II to Complex III and increase ATP production via mitochondrial oxidative phosphorylation. Our results indicate that H₂ may function to prevent/treat disease states with disrupted myocardial mitochondrial function.

Myalgic encephalomyelitis/chronic fatigue syndrome: From pathophysiological insights to novel therapeutic opportunities

Myalgic encephalomyelitis (ME) or chronic fatigue syndrome (CFS) is a common and disabling condition with a paucity of effective and evidence-based therapies, reflecting a major unmet need. Cognitive behavioural therapy and graded exercise are of modest benefit for only some ME/CFS patients, and many sufferers report aggravation of symptoms of fatigue with exercise. The presence of a multiplicity of pathophysiological abnormalities in at least the subgroup of people with ME/CFS diagnosed with the current international consensus "Fukuda" criteria, points to numerous potential therapeutic targets. Such abnormalities include extensive data showing that at least a subgroup has a pro-inflammatory state, increased oxidative and nitrosative stress, disruption of gut mucosal barriers and mitochondrial dysfunction together with dysregulated bioenergetics. In this paper, these pathways are summarised, and data regarding promising therapeutic options that target these pathways are highlighted; they include coenzyme Q₁₀, melatonin, curcumin, molecular hydrogen and N-acetylcysteine. These data are promising yet preliminary, suggesting hopeful avenues to address this major unmet burden of illness.

Vasculoprotective effects of Centella asiatica, Justicia gendarussa and Imperata cylindrica decoction via the NOXs-ROS-NF-κB pathway in spontaneously hypertensive rats

Background and aim

Centella asiatica, Justicia gendarussa and Imperata cylindrica decoction (CJID) is efficacious for hypertension. NADPH (nicotinamide adenine dinucleotide phosphate) oxidase (NOX)-induced reactive oxygen species (ROS) generation modulates nuclear factor kappa B (NF-κB) activation and thus mediates hypertension-induced vascular remodeling. This research aims to investigate the anti-remodeling effect of CJID through the mechanism of NOXs-ROS-NF-κB pathway in spontaneously hypertensive rats (SHRs).

Experimental procedure

CJID was orally administered once a day for five weeks in SHRs and normotensive-WKY (Wistar Kyoto) rats. All rats were sacrificed at the end of study and different assays were performed to determine whether CJID ameliorates vascular remodeling in SHRs, such as histological examination; lactate dehydrogenase (LDH), nitric oxide (NO), malondialdehyde (MDA) and superoxide dismutase (SOD) assays; superoxide and hydrogen peroxide (H₂O₂) generation assays, immunohistochemistry and immunofluorescence assays. . Changes in levels of inducible nitric oxide synthase (iNOS), NF-κB-p65, NF-κB inhibitor alpha/IκBα (inhibitory kappa B- alpha), phosphorylation of IκBα (p-IκBα) and NOX1, NOX2, NOX4 in the thoracic aorta were determined.

Results

Vascular remodeling indicators, media thickness, collagen and elastic accumulation in the thoracic aorta, of SHRs-treated CJID were attenuated. Redox homeostasis, aortic superoxide and hydrogen peroxide generation were decreased in SHRs-treated group. Aortic iNOS, p-IκBα, NF-κB-p65 and NOX1, NOX2, NOX4 expressions were suppressed.

Conclusions

CJI treatment diminishes oxidative stress response in the thoracic aorta of SHRs via regulation of NOXs-ROS-NF-κB signaling pathway. These findings indicate that CJI possess protective effect against hypertension-induced vascular remodeling in SHRs.

Recent Advances in Studies of Molecular Hydrogen against Sepsis

Sepsis is a syndrome comprised of a series of life-threatening organ dysfunctions caused by a maladjusted body response to infection with no effective treatment. Molecular hydrogen is a new type of antioxidant with strong free radical scavenging ability, which has been demonstrated to be effective for treating various diseases, such as infection, trauma, poisoning, organ ischemia-reperfusion, metabolic diseases, and tumors. Molecular hydrogen exerts multiple biological effects involving anti-inflammation, anti-oxidation, anti-apoptosis, anti-shock, and autophagy regulation, which may attenuate the organ and barrier damage caused by sepsis. However, the underlying molecular mechanisms remain elusive, but are likely related to the signaling pathways involved. This review focuses on the research progress and potential mechanisms of molecular hydrogen against sepsis to provide a theoretical basis for clinical treatment.

Hydrogen attenuated oxidized low-density lipoprotein-induced inflammation through the stimulation of autophagy via sirtuin 1

Chronic inflammation is a central pathogenic mechanism underlying the induction and progression of atherosclerosis (AS). Hydrogen has been demonstrated to serve a protective role in diverse models of disease. However, the potential effects and mechanism of hydrogen with respect to ox-LDL-induced inflammation have not yet been completely elucidated. In the present study, various concentrations (0, 50 and 100 mg/l) of oxidized low-density lipoprotein (ox-LDL) were used to treat RAW264.7 cells. A Cell Counting kit-8 assay was used to determine cell viability and western blot analysis was performed to determine the expression of proteins that are involved in autophagy. The expression of inflammatory cytokines in ox-LDL-treated macrophages was detected using ELISA. Small interfering (si)RNA against sirtuin 1 (SIRT1) was employed to investigate the mechanism underlying hydrogen-activated autophagy. The results indicated that ox-LDL stimulation promoted inflammatory cytokine expression and impaired autophagic flux in RAW264.7 cells. Furthermore, hydrogen inhibited ox-LDL-induced inflammatory cytokine expression by upregulating autophagic flux. SIRT1 mediated the upregulation of autophagic flux via hydrogen in ox-LDL-treated macrophages. To conclude, the present study provided novel insights into the role of defective autophagy in the pathogenesis of AS and identified autophagy to be a promising therapeutic target for the treatment of AS. Notably, hydrogen may represent a potential agent for the treatment of AS.

Post-reperfusion hydrogen gas treatment ameliorates ischemia reperfusion injury in rat livers from donors after cardiac death: a preliminary study

BACKGROUND AND PURPOSE

We reported previously that hydrogen gas (H₂) reduced hepatic ischemia and reperfusion injury (IRI) after prolonged cold storage (CS) of livers retrieved from heart-beating donors. The present study was designed to assess whether H₂ reduced hepatic IRI during donation of a cardiac death (DCD) graft with subsequent CS.

METHODS

Rat livers were harvested after 30-min cardiac arrest and stored for 4 h in University of Wisconsin solution. The graft was reperfused with oxygenated buffer, with or without H₂ (H₂ or NT groups, respectively), at 37° for 90 min on isolated perfused rat liver apparatus.

RESULTS

In the NT group, liver enzyme leakage, apoptosis, necrosis, energy depletion, redox status, impaired microcirculation, and bile production were indicative of severe IRI, whereas in the H₂ group these impairments were significantly suppressed. The phosphorylation of cytoplasmic MKK4 and JNK were enhanced in the NT group and suppressed in the H₂ group. NFkB-p65 and c-Fos in the nucleus were unexpectedly unchanged by IRI regardless of H₂ treatment, indicating the absence of inflammation in this model.

CONCLUSION

H₂ was observed to ameliorate IRI in the DCD liver by maintaining microcirculation, mitochondrial functions, and redox status, as well as suppressing the cytoplasmic MKK4-JNK-mediated cellular death pathway.

Does H2 Alter Mitochondrial Bioenergetics via GHS-R1α Activation?

More than 400 original articles have been published from 2007 onwards evaluating therapeutic potential of molecular hydrogen (H₂), the youngest member of medical gases family with selective anti-oxidative properties. However, recent studies suggest that H₂ may tackle other mitochondrial processes besides oxidative stress, including metabolic pathways that drive cellular energy.

Molecular hydrogen ameliorates several characteristics of preeclampsia in the Reduced Uterine Perfusion Pressure (RUPP) rat model

Oxidative stress plays an important role in the pathogenesis of preeclampsia. Recently, molecular hydrogen (H₂) has been shown to have therapeutic potential in various oxidative stress-related diseases. The aim of this study is to investigate the effect of H₂ on preeclampsia. We used the reduced utero-placental perfusion pressure (RUPP) rat model, which has been widely used as a model of preeclampsia. H₂ water (HW) was administered orally ad libitum in RUPP rats from gestational day (GD) 12-19, starting 2 days before RUPP procedure. On GD19, mean arterial pressure (MAP) was measured, and samples were collected. Maternal administration of HW significantly decreased MAP, and increased fetal and placental weight in RUPP rats. The increased levels of soluble fms-like tyrosine kinase-1 (sFlt-1) and diacron reactive oxygen metabolites as a biomarker of reactive oxygen species in maternal blood were decreased by HW administration. However, vascular endothelial growth factor level in maternal blood was increased by HW administration. Proteinuria, and histological findings in kidney were improved by HW administration. In addition, the effects of H₂ on placental villi were examined by using a trophoblast cell line (BeWo) and villous explants from the placental tissue of women with or without preeclampsia. H₂ significantly attenuated hydrogen peroxide-induced sFlt-1 expression, but could not reduce the expression induced by hypoxia in BeWo cells. H₂ significantly attenuated sFlt-1 expression in villous explants from women with preeclampsia, but not affected them from normotensive pregnancy. The prophylactic administration of H₂ attenuated placental ischemia-induced hypertension, angiogenic imbalance, and oxidative stress. These results support the theory that H₂ has a potential benefit in the prevention of preeclampsia.

Beneficial effects of grape seed proanthocyanidin extract on arterial remodeling in spontaneously hypertensive rats via protecting against oxidative stress

Arterial remodeling is a pathogenic occurrence during hypertension and, in turn, is closely associated with the development and complications of hypertension. Grape seed proanthocyanidin extract (GSPE) has been reported to exhibit a protective effect on cardiovascular disease, however its effect on arterial remodeling remains to be fully elucidated. In the present study, the effects of GSPE on arterial remodeling were analyzed by treating spontaneously hypertensive rats (SHRs) with GSPE (250 mg/kg·day). Arterial remodeling was quantified through morphological methods; thoracic aortas were stained with hematoxylin-eosin or sirius red‑victoria blue. The arterial ultrastructure was imaged using transmission electron microscopy. The content of nitric oxide (NO) and endothelin‑1 (ET‑1) were examined to determine endothelial function. Oxidative stress was assessed by malondialdehyde (MDA) levels and the activities of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT). Administration of GSPE markedly alleviated hypertension‑induced arterial remodeling, which was not associated with blood pressure control. ET‑1 production was reduced, while NO production was increased in the GSPE group, which exhibited improved endothelial function. In addition, treatment with GSPE significantly ameliorated oxidative stress by improving SOD and CAT activities and reducing MDA formation. In conclusion, GSPE may attenuate hypertension‑induced arterial remodeling by repressing oxidative stress and is recommended as a potential anti‑arterial remodeling agent for patients with hypertensive vascular diseases.

Hydrogen-rich saline attenuates steroid-associated femoral head necrosis through inhibition of oxidative stress in a rabbit model

A growing body of evidence suggests that hydrogen is a novel, selective antioxidant that exerts a protective effect against organ damage. The present study investigated the effect of hydrogen-rich saline on corticosteroid-induced necrosis of the femoral head in an animal model established using prednisolone. A total of 30 healthy, male, adult New Zealand white rabbits were randomly divided into two groups: Hydrogen-rich saline (treated with hydrogen-rich saline via intraperitoneal injection) and placebo (treated with normal saline). At the set time-points, the structure of the femoral head was examined using a microscope; the concentrations of glutathione (GSH), lipid peroxide (LPO), vascular endothelial growth factor (VEGF) and thrombomodulin (TM) in the plasma were measured and the microvessel density was quantified. The results showed that hydrogen-rich saline significantly decreased the levels of VEGF, TM and LPO and increased the GSH level in steroid-associated necrosis of the femoral head in the rabbit model. A significant increase in the microvessel density was observed in the hydrogen-rich saline group. Histopathological staining confirmed the results of the biochemical analysis. The present study demonstrates that hydrogen treatment may alleviate steroid-associated osteonecrosis by inhibiting oxidative stress. Hydrogen-rich saline may provide an alternative treatment for steroid-associated necrosis of the femoral head.

Beneficial biological effects and the underlying mechanisms of molecular hydrogen - comprehensive review of 321 original articles

Therapeutic effects of molecular hydrogen for a wide range of disease models and human diseases have been investigated since 2007. A total of 321 original articles have been published from 2007 to June 2015. Most studies have been conducted in Japan, China, and the USA. About three-quarters of the articles show the effects in mice and rats. The number of clinical trials is increasing every year. In most diseases, the effect of hydrogen has been reported with hydrogen water or hydrogen gas, which was followed by confirmation of the effect with hydrogen-rich saline. Hydrogen water is mostly given ad libitum. Hydrogen gas of less than 4 % is given by inhalation. The effects have been reported in essentially all organs covering 31 disease categories that can be subdivided into 166 disease models, human diseases, treatment-associated pathologies, and pathophysiological conditions of plants with a predominance of oxidative stress-mediated diseases and inflammatory diseases. Specific extinctions of hydroxyl radical and peroxynitrite were initially presented, but the radical-scavenging effect of hydrogen cannot be held solely accountable for its drastic effects. We and others have shown that the effects can be mediated by modulating activities and expressions of various molecules such as Lyn, ERK, p38, JNK, ASK1, Akt, GTP-Rac1, iNOS, Nox1, NF-κB p65, IκBα, STAT3, NFATc1, c-Fos, and ghrelin. Master regulator(s) that drive these modifications, however, remain to be elucidated and are currently being extensively investigated.

Treatment with hydrogen molecule attenuates cardiac dysfunction in streptozotocin-induced diabetic mice

INTRODUCTION

Diabetic cardiomyopathy, a disorder of the heart muscle in diabetic patients, is one of the major causes of heart failure. The aim of present study was to investigate the therapeutic effect of hydrogen molecule on streptozotocin-induced diabetic cardiomyopathy in mice.

METHODS

Diabetes was induced in adult male mice by consecutive peritoneal injection of streptozotocin (50 mg/kg/day) for 5 days. Then, they were treated with hydrogen water (1.3±0.2 mg/l) for 8 weeks (four groups, n=83-88 in each group).

RESULTS

Although treatment of diabetic mice with hydrogen water did not significantly affect blood glucose level, it significantly attenuated cardiac hypertrophy and reduced expression of atrial natriuretic factor and β-myosin heavy chain; it alleviated cardiac fibrosis and reduced expression of collagen I and III, transforming growth factor beta, alpha-smooth muscle actin, and osteopontin; it reduced cardiac caspase-3 activity and ratio of bax/bcl-2. Importantly, hydrogen water treatment improved cardiac function in streptozotocin-diabetic mice. Furthermore, it was found that hydrogen water treatment abated oxidative stress, suppressed inflammation, and attenuated endoplasmic reticulum stress in the hearts of streptozotocin-diabetic mice. In addition, hydrogen water treatment suppressed activation of Jun NH2-terminal kinase and p38 mitogen activated protein kinase signaling and nuclear factor κB signaling in the hearts of streptozotocin-diabetic mice.

CONCLUSION

Treatment with hydrogen molecule attenuated cardiac dysfunction in streptozotocin-induced diabetic mice, which was independent of glycemic control.

SUMMARY

Treatment with hydrogen molecule attenuated cardiac dysfunction in streptozotocin-induced type 1 diabetic mice. Molecular hydrogen could thus be envisaged as a nutritional countermeasure for diabetic cardiomyopathy.

Effects of peroxynitrite on relaxation through the NO/sGC/cGMP pathway in isolated rat iliac arteries

BACKGROUND/AIMS

The present study investigated the mechanism by which peroxynitrite impairs vascular function through the nitric oxide (NO)/soluble guanylate cyclase (sGC)/cGMP pathway.

METHODS

Mechanical responses of rat external iliac arteries without endothelium were studied under exposure to peroxynitrite. cGMP concentrations were determined by enzyme immunoassay.

RESULTS

Relaxation induced by BAY 41-2272 (sGC stimulator) was impaired under exposure to peroxynitrite, whereas that by BAY 60-2770 (sGC activator) was enhanced. These responses were correlated with tissue levels of cGMP. Effects of peroxynitrite on the relaxant responses to BAY compounds were also observed in the presence of superoxide dismutase (SOD) or tempol, both of which scavenge a certain kind of reactive molecules other than peroxynitrite. As is the case with the relaxant response to BAY 41-2272, acidified NaNO2- and nitroglycerin-induced relaxations were markedly attenuated by exposing the arteries to peroxynitrite, which was not abolished by preincubation with SOD or tempol. On the other hand, peroxynitrite exposure had no effect on the 8-Br-cGMP-induced vasorelxation.

CONCLUSION

These findings suggest that peroxynitrite interferes with the NO/sGC/cGMP pathway by altering the redox state of sGC. It is likely that peroxynitrite can shift the sGC redox equilibrium to the NO-insensitive state in the vasculature.

Contribution of renin-angiotensin system to exercise-induced attenuation of aortic remodeling and improvement of endothelial function in spontaneously hypertensive rats

INTRODUCTION

It is well known that exercise alleviates aortic remodeling and preserves endothelial function in spontaneously hypertensive rats (SHRs). However, the underlying molecular mechanism remains unclear. This study aimed to investigate the role of renin-angiotensin system (RAS) components in exercise-induced attenuation of aortic remodeling and improvement of endothelial function in an animal model of human essential hypertension.

METHODS

The 10-week-old male SHR and age-matched normotensive Wistar-Kyoto rats were given moderate-intensity exercise for 12weeks (four groups, n=80-86 in each group).

RESULTS

In this work, exercise training reduced blood pressure and effectively attenuated aortic remodeling, marked by a reduction in aortic weight/length, wall thickness, and aortic levels of elastin and hydroxyproline, and improved endothelium-mediated vascular relaxations of aortas in response to acetylcholine. Exercise training in SHR reduced angiotensin II (AngII) levels and enhanced Ang-(1-7) levels in aortas. Exercise training in SHR suppressed aortic angiotensin-converting enzyme (ACE) and AngII type 1 receptor (AT1R) messenger RNA (mRNA) levels and protein expression and up-regulated ACE2, AngII type 2 receptor, and Mas mRNA levels and protein expression. In addition, exercise training in SHR increased levels of microRNA-27a (targeting ACE) and microRNA-155 (targeting AT1R) and decreased levels of microRNA-143 (targeting ACE2) in the aortas.

CONCLUSION

Chronic aerobic exercise training improved RAS balance in the aortas, which may in part explain the protective effect of exercise on aortic function and structure.

SUMMARY

Chronic aerobic exercise training improved RAS balance in the aortas, which may explain the protective effect of exercise on aortic function and structure, at least in part.

Consumption of hydrogen-rich water alleviates renal injury in spontaneous hypertensive rats

In hypertensive animals and patients, oxidative stress represents the primary risk factor for progression of renal disease. Recently, it has been demonstrated that hydrogen, as a novel antioxidant, can selectively reduce hydroxyl radicals and peroxynitrite anion to exert therapeutic antioxidant activity. Herein, we investigated the protective effect of hydrogen-rich water (HW) against renal injury in spontaneously hypertensive rats (SHR). The 8-week-old male SHR and age-matched Wistar-Kyoto rats were randomized into HW-treated (1.3 ± 0.2 mg/l for 3 months, drinking) and vehicle-treated group. Although treatment with HW had no significant effect on blood pressure, it significantly ameliorated renal injury in SHR. Treatment with HW lowered reactive oxygen species formation, upregulated the activities of superoxide dismutase, glutathione peroxidase, glutathione-S-epoxide transferase, and catalase, and suppressed NADPH oxidase activity. Treatment with HW in SHR depressed pro-inflammatory cytokines expression including TNF-α, IL-6, IL-1β, and macrophage chemoattractant protein 1, which might be mediated by suppressing nuclear factor-κB activation. In addition, treatment with HW had protective effect on mitochondrial function including adenosine triphosphate formation and membrane integrity in SHR. In conclusion, consumption of HW is a promising strategy to alleviate renal injury as a supplement for anti-hypertensive therapy.

(-)-Epicatechin reduces blood pressure and improves vasorelaxation in spontaneously hypertensive rats by NO-mediated mechanism

Studies in humans have found consumption of certain flavanoid-containing foods to be associated with improvement in endothelial function and with reduction of blood pressure (BP). (-)-Epicatechin is a compound representative of the flavanols (a subfamily of flavonoids), abundant in cocoa seeds, which is preserved during the industrialization process to chocolate. The antihypertensive effect of dietary (-)-epicatechin was investigated on spontaneously hypertensive rats (SHRs). Consumption of (-)-epicatechin-supplemented diet (3 g (-)-epicatechin/kg diet) decreased BP in SHR by 27 and 23 mm Hg on days 2 and 6, respectively. On day 6, a 173% increase of nitric oxide synthase (NOS) activity was observed in the aorta of EPI-SHR as compared to nonsupplemented SHR (P < 0.05). Responses to acetylcholine (ACh) were then examined in femoral arteries in the absence and the presence of L-NAME, a nonselective NOS inhibitor, to assess the ACh-mediated relaxation ascribed to NO-dependent and -independent mechanisms. Acetylcholine-induced endothelium-dependent relaxation in the femoral artery was significantly higher in EPI-SHR than in SHR, with a predominance of the NO-dependent component of this relaxation. The endothelium-independent relaxation, assayed by using the NO donor sodium nitroprusside, resulted in nonsignificant difference in the three experimental groups, demonstrating an unaffected function of vascular smooth muscle cells. These results give further support to the concept that (-)-epicatechin can modulate BP in hypertension by increasing NO levels in the vasculature.

Administration of telmisartan reduced systolic blood pressure and oxidative stress probably through the activation of PI3K/Akt/eNOS pathway and NO release in spontaneously hypertensive rats

We investigated the effects of telmisartan, the blocker of angiotensin II receptor 1, on the regulation of systolic blood pressure (SBP) and oxidative stress through endothelial nitric oxide (NO) release in spontaneously hypertensive rats (SHRs). SHRs randomly received placebo, oral feeding of telmisartan (5 mg/kg or 10 mg/kg) every day and Wistar-Kyoto rats (WKYs) served as normotensive control. The SBP of rat was measured before and weekly thereafter. After a total of 8-week treatment, rats were killed for experimental measurements. Parameters that subject to measurements in isolated aorta endothelial cells include: NO concentration, protein expression levels of angiotensin II receptor 1, nitrotyrosine, 8-isoprostane, SOD, PI3K, Akt, AMPK and eNOS. In addition, L-NMMA, a general inhibitor of nitric oxide synthase, was also applied to test the inhibition of NO concentration. We found that SBPs were significantly lower in telmisartan therapy group than in placebo treated hypertensive rats and WKYs (p<0.05). The NO concentration was significantly higher in telmisartan-treated group with increased activity of the PI3K/Akt pathway and activated eNOS signaling. Blockade of Akt activity reversed such effects. Activation of AMPK also contributed to the phosphorylation of eNOS. L-NMMA treatment reduced less NO concentration in SHR rats than the telmisartan co-treated groups. Oxidative stress in SHRs was also attenuated by telmisartan administration, shown by reduced formation of nitrotyrosine, 8-isoprostane, and recovered SOD protein level. Telmisartan enhanced NO release by activating the PI3K/Akt system, AMPK phosphorylation and eNOS expression, which attenuated the blood pressure and oxidative stress in SHRs.

Contribution of hydrogen sulfide and nitric oxide to exercise-induced attenuation of aortic remodeling and improvement of endothelial function in spontaneously hypertensive rats

It is well known that exercise training attenuates aortic remodeling and improves endothelial function in spontaneously hypertensive rats (SHR). However, the underlying molecular mechanism remains unclear. Hydrogen sulfide (H(2)S) and nitric oxide (NO), as two established physiologic messenger molecules, have important roles in the development of aortic remodeling and endothelial dysfunction in hypertensive animals and patients. In this work, it was found that exercise training had no significant effect on blood pressure, but effectively attenuated baroreflex dysfunction in SHR. Exercise training in SHR attenuated aortic remodeling and improved endothelium-mediated vascular relaxations of aortas in response to acetylcholine. Interestingly, exercise training in SHR restored plasma H(2)S levels and aortic H(2)S formation and enhanced levels of mRNA for cystathionine γ-lyase in aortas. Furthermore, exercise training in SHR resulted in augmentation of nitrite and nitrate (NOx) contents and reduction of asymmetric dimethylarginine contents of aortas, upregulation of dimethylarginine dimethylaminohydrolase 2, and phosphorylation of nitric oxide synthase 3, but had no significant effect on protein levels of NOS3. In addition, exercise training could effectively reduce malondialdehyde production and suppressed formation of O(2) (-), and OONO(-) in aortas of SHR through enhancing activities of superoxide dismutase and catalase, and suppressing NADPH oxidase activity. In conclusion, exercise training ameliorates aortic hypertrophy and endothelial dysfunction, possibly via restoring bioavailabilities of hydrogen sulfide and nitric oxide in SHR.