Hydrogen-rich saline ameliorates the severity of l-arginine-induced acute pancreatitis in rats

The role of ischaemia-modified albumin in the prognosis of acute pancreatitis and its correlation with the NF-B-mediated inflammatory response

OBJECTIVE

To investigate the correlation between the serum levels of ischaemia-modified albumin (IMA) and disease severity in rats with acute pancreatitis (AP).

METHODS

A rat AP model was established and blood samples from each group were analysed at different time points. After the experiment, the pancreatic tissues of the rats were collected for pathological examination and the measurement of protein levels of NF-κB and NF-κB p65. Serum levels of amylase (α-AMY), tumour necrosis factor-α (TNF-α), interleukin (IL)-6 and IL-8 were also compared between groups of rats.

RESULTS

The serum IMA concentration in the severe acute pancreatitis (SAP) group was greater than that in the mild acute pancreatitis (MAP) group. The levels of the NF-κB and NF-κB p65 proteins were increased in the MAP and SAP groups in a time-dependent manner. α-AMY, TNF-α and IL-6 were increased at all time points in the MAP and SAP groups. The increases were greatest at 24 h in the SAP group. In terms of pathological changes in the pancreas, renal and lung tissues, the damage in the SAP group was more obvious than that in the MAP group.

CONCLUSIONS

Serum IMA level was associated with inflammatory markers and NF-κB p65 in rats with AP.

Evaluation of the effect of enriched hydrogen saline solution on distant organ (lung) damage in skeletal muscle ischemia reperfusion in rats

INTRODUCTION

Ischemia-reperfusion (IR) injury is a major concern that frequently occurs during vascular surgeries. Hydrogen-rich saline (HRS) solution exhibits antioxidant and anti-inflammatory properties. This study aimed to examine the effects of HRS applied before ischemia in the lungs of rats using a lower extremity IR model.

MATERIAL AND METHODS

After approval was obtained from the ethics committee, 18 male Wistar albino rats weighing 250-280 g were randomly divided into three groups: control (C), IR and IR-HRS. In the IR and IR-HRS groups, an atraumatic microvascular clamp was used to clamp the infrarenal abdominal aorta, and skeletal muscle ischemia was induced. After 120 min, the clamp was removed, and reperfusion was achieved for 120 min. In the IR-HRS group, HRS was administered intraperitoneally 30 min before the procedure. Lung tissue samples were examined under a light microscope and stained with hematoxylin-eosin (H&E). Malondialdehyde (MDA) levels, total sulfhydryl (SH) levels, and histopathological parameters were evaluated in the tissue samples.

RESULTS

MDA and total SH levels were significantly higher in the IR group than in the control group (p < 0.0001 and p = 0.001, respectively). MDA and total SH levels were significantly lower in the IR-HRS group than in the IR group (p < 0.0001 and p = 0.013, respectively). A histopathological examination revealed that neutrophil infiltration/aggregation, alveolar wall thickness, and total lung injury score were significantly higher in the IR group than in the control group (p < 0.0001, p = 0.001, and p < 0.0001, respectively). Similarly, alveolar wall thickness and total lung injury scores were significantly higher in the IR-HRS group than in the control group (p = 0.009 and p = 0.004, respectively). A statistically significant decrease was observed in neutrophil infiltration/aggregation and total lung injury scores in the IR-HRS group compared to those in the IR group (p = 0.023 and p = 0.022, respectively).

CONCLUSION

HRS at a dose of 20 mg/kg, administered intraperitoneally 30 min before ischemia in rats, reduced lipid peroxidation and oxidative stress, while also reducing IR damage in lung histopathology. We believe that HRS administered to rats prior to IR exerts a lung-protective effect.

Recent Advances in Metal-Hydride-Based Disease Treatment

In comparison to traditional antioxidant treatment methods, the use of hydrogen to eliminate reactive oxygen species from the body has the advantages of high biological safety, strong selectivity, and high clearance rate. As an energy storage material, metal hydrides have been extensively studied and used in transporting hydrogen as clean energy, which can achieve a high hydrogen load and controlled hydrogen release. Considering the antioxidant properties of hydrogen and the delivery ability of metal hydrides, metal-hydride-based disease treatment strategies have attracted widespread attention. Up to now, metal hydrides have been reported for the treatment of tumors and a range of inflammation-related diseases. However, limited by the insufficient investment, the use of metal hydrides in disease treatment still has many shortcomings, such as low targeting efficiency, limited therapeutic activity, and complex material preparation process. Particularly, metal hydrides have been found to have a series of optical, acoustic, and catalytic properties when scaled up to the nanoscale, and these properties are also widely used to promote disease treatment effects. From this new perspective, we comprehensively summarize the very recent research progress on metal-hydride-based disease treatment in this review. Ultimately, the challenges and prospects of such a burgeoning cancer theranostics modality are outlooked to provide inspiration for the further development and clinical translation of metal hydrides.

Redox-Mechanisms of Molecular Hydrogen Promote Healthful Longevity

Age-related diseases represent the largest threat to public health. Aging is a degenerative, systemic, multifactorial and progressive process, coupled with progressive loss of function and eventually leading to high mortality rates. Excessive levels of both pro- and anti-oxidant species qualify as oxidative stress (OS) and result in damage to molecules and cells. OS plays a crucial role in the development of age-related diseases. In fact, damage due to oxidation depends strongly on the inherited or acquired defects of the redox-mediated enzymes. Molecular hydrogen (H2) has recently been reported to function as an anti-oxidant and anti-inflammatory agent for the treatment of several oxidative stress and aging-related diseases, including Alzheimer's, Parkinson's, cancer and osteoporosis. Additionally, H2 promotes healthy aging, increases the number of good germs in the intestine that produce more intestinal hydrogen and reduces oxidative stress through its anti-oxidant and anti-inflammatory activities. This review focuses on the therapeutic role of H2 in the treatment of neurological diseases. This review manuscript would be useful in knowing the role of H2 in the redox mechanisms for promoting healthful longevity.

Hydrogen-Rich Water Mitigates LPS-Induced Chronic Intestinal Inflammatory Response in Rats via Nrf-2 and NF-κB Signaling Pathways

Long-term exposure to low-dose lipopolysaccharide can impair intestinal barriers, causing intestinal inflammation and leading to systemic inflammation. Hydrogen-rich water possesses antioxidant and anti-inflammatory functions and exerts inhibitory effects on various inflammatory diseases. In this study, we investigated whether oral hydrogen-rich water could prevent lipopolysaccharide-induced chronic intestinal inflammation. An experimental model was established by feeding hydrogen-rich water, followed by the injection of lipopolysaccharide (200 μg/kg) in the tail vein of rats after seven months. ELISA, Western blot, immunohistochemistry, and other methods were used to detect related cytokines, proteins related to the NF-κB and Nrf-2 signaling pathways, and tight-junction proteins to study the anti-inflammatory and antioxidant effects of hydrogen-rich water. The obtained results show that hydrogen-rich water significantly increased the levels of superoxide dismutase and structural proteins; activated the Nrf-2 signaling pathway; downregulated the expression of inflammatory factors cyclooxygenase-2, myeloperoxidase, and ROS; and decreased the activation of the NF-κB signaling pathway. These results suggest that hydrogen-rich water could protect against chronic intestinal inflammation in rats caused by lipopolysaccharide-induced activation of the NF-κB signaling pathway by regulating the Nrf-2 signaling pathway.

Pyroptosis in acute pancreatitis and its therapeutic regulation

Pyroptosis defines a new type of GSDMs-mediated programmed cell death, distinguishes from the classical concepts of apoptosis and necrosis-mediated cell death and is prescribed by cell swelling and membrane denaturation, leading to the extensive secretion of cellular components and low-grade inflammatory response. However, NLRP3 inflammasome activation can trigger its downstream inflammatory cytokines, leading to the activation of pyroptosis-regulated cell death. Current studies reveal that activation of caspase-4/5/11-driven non-canonical inflammasome signaling pathways facilitates the pathogenesis and progression of acute pancreatitis (AP). In addition, a large number of studies have reported that NLRP3 inflammasome-dependent pyroptosis is a crucial player in driving the course of the pathogenesis of AP. Excessive uncontrolled GSDMD-mediated pyroptosis has been implicated in AP. Therefore, the pyroptosis-related molecule GSDMD may be an independent prognostic biomarker for AP. The present review paper summarizes the molecular mechanisms of pyroptotic signaling pathways and their pathophysiological impacts on the progress of AP. Moreover, we briefly present some experimental compounds targeting pyroptosis-regulated cell death for exploring novel therapeutic directions for the treatment and management of AP. Our review investigations strongly suggest that targeting pyroptosis could be an ideal therapeutic approach in AP.

A new therapy against ulcerative colitis via the intestine and brain using the Si-based agent

Ulcerative colitis (UC) is a non-specific inflammatory bowel disease that causes ulcers and erosions in the colonic mucosa and becomes chronic with cycles of amelioration and exacerbation. Because its exact etiology remains largely unclear, and the primary therapy is limited to symptomatic treatment, the development of new therapeutic agent for UC is highly desired. Because one of the disease pathogenesis is involvement of oxidative stress, it is likely that an appropriate antioxidant will be an effective therapeutic agent for UC. Our silicon (Si)-based agent, when ingested, allowed for stable and persistent generation of massive amounts of hydrogen in the gastrointestinal tract. We demonstrated the Si-based agent alleviated the mental symptom as well as the gastrointestinal symptoms, inflammation, and oxidation associated with dextran sodium sulfate-induced UC model through Hydrogen and antioxidant sulfur compounds. As the Si-based agent was effective in treating UC in the brain and large intestine of mice, it was considered to be capable of suppressing exacerbations and sustaining remission of UC.

Local Treatment of Hydrogen-Rich Saline Promotes Wound Healing In Vivo by Inhibiting Oxidative Stress via Nrf-2/HO-1 Pathway

Wound healing is a complex dynamic process involving a large number of biological events. Excessive oxidative stress is a key factor delaying wound healing. Hydrogen is an antioxidant, anti-inflammatory, and antiapoptotic medical gas with safety, effectiveness, and penetrability. However, the effects of local treatment of hydrogen on wound healing and its potential mechanisms remain unclear. In this study, Kunming (KM) mice were used to set up a wound model. All the mice were randomly divided into the control, the local treatment with saline group, the local treatment with the hydrogen-rich saline group, and the intraperitoneal injection of the hydrogen-rich saline group. To evaluate the impact of hydrogen-rich saline on wound healing, we assessed the wound healing rate, wound closure time, histomorphology, oxidative stress indicators, inflammatory cytokines, the apoptosis index, and the expression of the nuclear factor-erythroid-related factor 2(Nrf-2). Furthermore, the immortalized nontumorigenic human epidermal (HaCaT) cells were chosen to investigate the therapeutic effects of hydrogen-rich medium on oxidative stress and its underlying mechanisms. The results showed that local treatment of hydrogen-rich saline shortened wound closure time and reduced the level of proinflammatory cytokines and lipid peroxidation. Meanwhile, it decreased the cell apoptosis index and increased the Nrf-2 expression. Besides, hydrogen-rich medium relieved the oxidative stress via the activation of the Nrf-2/heme oxygenase-1 (HO-1) pathway. In conclusion, local treatment of hydrogen-rich saline exhibits the healing-promoting function through antioxidant, anti-inflammatory, and antiapoptotic effects. Hydrogen relieves the oxidative stress in the wound microenvironment via Nrf-2/HO-1 signaling pathway. This study may offer a new strategy to promote wound healing and a new perspective to illustrate the mechanism of wound healing.

Evaluation of the hydrogen-rich water alleviation potential on mercury toxicity in earthworms using ATR-FTIR and LC-ESI-MS/MS spectroscopy

The toxic effects of mercury in earthworms and the potential alleviation effect of hydrogen-rich water (HRW) using ATR-FTIR and LC-MS analysis methods were investigated. Different concentrations of mercury chloride (H1: 5 µg/mL, H2: 10 µg/mL, H3: 20 µg/mL, H4: 40 µg/mL, and C1: control) and mercury chloride prepared in hydrogen-rich water (H5: 5 µg/mL, H6: 10 µg/mL, H7: 20 µg/mL, H8: 40 µg/mL, and C2: control) were injected into earthworms. The changes and reductions in some bands representing proteins, lipids, and polysaccharides (3280 cm^-1, 2922 cm^-1, 2855 cm^-1, 1170 cm^-1, and 1047 cm^-1) showed that protective effects could occur in groups prepared with hydrogen-rich water. In the FTIR results, it was found that these bands in the H3 group were more affected and decreased by the influence of mercury on earthworms than the H7 group prepared with hydrogen. LC-MS analysis showed that the changes in some ions of the highest dose groups (H4 and H8) were different, and mercury caused oxidative DNA damage in earthworms. When the high-level application groups of mercury, i.e., H4 and H8 were compared with the controls, the ion exchange ([M + H] + ; m/z 283.1) representing the 8-Oxo-dG level in earthworms was higher in the H4 group than the H8 group. This reveals that HRW exhibited the potential ability to alleviate the toxic effects of mercury; however, a longer period of HRW treatment may be necessary to distinguish an obvious effect. The ATR-FTIR spectroscopy provided a rapid and precise method for monitoring the changes in biological tissues caused by a toxic compound at the molecular level.

Hydrogen-rich water partially alleviate inflammation, oxidative stress and intestinal flora dysbiosis in DSS-induced chronic ulcerative colitis mice

PURPOSE

Oxidative damage and intestinal flora dysbiosis play important roles in the progression of chronic ulcerative colitis (UC). This study explored the effect and mechanism of molecular hydrogen in chronic UC.

MATERIALS AND METHODS

Male C57BL/6 mice (19.6 ​± ​0.4 ​g, 7 weeks) were randomly divided into 3 groups: normal control (NC) group, UC (Dextran Sulfate Sodium, DSS) group, and hydrogen-rich water (HRW, 0.8 ​ppm)-treated UC (DSS ​+ ​HRW) group. Mice in the DSS treatment group were treated with DSS for the following 3 cycles to establish chronic UC model: the first 2 cycles consisted of 2.5% DSS for 5 days, followed by drinking water for 16 days, and a third cycle consisted of 2% DSS for 4 days, followed by drinking water for 10 days. The mice in the DSS ​+ ​HRW group were administered HRW daily throughout the experiment.

RESULTS

The mice in the DSS groups developed typical clinical signs of colitis. HRW treatment partially ameliorated colitis symptoms, improved histopathological changes, significantly increased glutathione (GSH) concentration and decreased TNF-α level. Notably, HRW treatment significantly inhibited the growth of Enterococcus faecalis, Clostridium perfringens and Bacteroides fragilis (P ​< ​0.05 vs. DSS group), with the relative abundance that was close to the levels in the NC group. Microarray analysis revealed that 252 genes were significantly modified after HRW treatment compared with those in the DSS treatment alone group, and 17 genes were related to inflammation, including 9 interferon-stimulated genes (ISGs).

CONCLUSIONS

Hydrogen-rich water partially alleviates inflammation, oxidative stress and intestinal flora dysbiosis in DSS-induced chronic UC mice.

Quantification of dissolved H2 and continuous monitoring of hydrogen-rich water for haemodialysis applications: An experimental study

The prevalence of oxidative and inflammatory stress in end-stage renal disease (ESRD) patients has often been associated with chronic haemodialysis therapies. Over the past decades, several reports have shown the potential of hydrogen molecule as an antioxidant in the treatment of various medical conditions in animal models, as well as in pilot studies with human patients. Recently, a hydrogen-enriched dialysate solution has been introduced, holding promise in reducing the oxidative and/or inflammatory complications arising during haemodialysis. To this end, a standardised measuring method to determine the levels of hydrogen in dialysate and subsequently in blood is required. This study explores the possibility of quantifying hydrogen concentration using a novel contactless sensor that detects dissolved hydrogen in liquids. An experimental circuit is assembled to validate the sensitivity and accuracy of the hydrogen monitoring system (Pureron Japan Co., Ltd) through in vitro investigations with physiological solutions. Measurements of dissolved molecular hydrogen concentration are corroborated by an established oxygen sensor providing continuous partial pressure readings. The relationship between the applied H₂ content in the gaseous mixture and the H₂ concentration value at equilibrium is linear. At the same time, the hydrogen monitoring system has a rather long response time, and its readings seem to slightly diverge from sensor to sensor as well as at different temperatures. For this reason, a sensor recalibration might be necessary, which could become part of the product's ongoing development. Nevertheless, the aforementioned minor deficiencies can be mostly considered negligible in applications such as haemodialysis.

Hydrogen inhalation in rehabilitation program of the medical staff recovered from COVID-19

Active hydrogen inhalation (H(H2O)m) has powerful antioxidant and antiapoptotic effects. In recent years, it has been used in a number of experimental and clinical studies.

Aim. To study the safety and effectiveness of inhalation of the “active form of hydrogen” (AFV;(H(H2O)m)) in the rehabilitation program of coronavirus disease 2019 (COVID-19) survivors during the recovery period.

Material and methods. This randomized controlled parallel prospective study included 60 COVID-19 survivors with post-COVID-19 syndrome (ICD-10: U09.9) during the recovery period, with clinical manifestations of chronic fatigue syndrome (CFS), who received standard therapy in accordance with the management protocol of patients with CFS (ICD-10: G93.3): physiotherapy and medication therapy with drugs containing magnesium, B vitamins and L-carnitine. The patients were divided into 2 groups. The experimental group (n=30) included patients who received hydrogen inhalation for 90 minutes every day during 10 days (SUISONIA hydrogen inhalation device, Japan). The control group (n=30) consisted of patients who received standard therapy. In both groups, patients were comparable in sex and mean age: in the experimental group — 53 (22; 70) years, in the control group — 51 (25; 70) years. Biological markers of systemic inflammation, oxygen transport, lactate metabolism, intrapulmonary shunting, 6-minute walk test, and vascular endothelial function were determined in all patients on the 1st and 10th days of follow-up.

Results. In the experimental group, a decrease in following parameters was revealed: stiffness index (SI), from 8,8±1,8 to 6,8±1,5 (p<0,0001); ALT, from 24,0±12,7 to 20,22±10,61 U/L (p<0,001); venous blood lactate, from 2,5±0,8 to 1,5±1,0 mmol/L (p<0,001); capillary blood lactate, from 2,9±0,8 to 2,0±0,8 mmol/L (p<0,0001); estimated pulmonary shunt fraction (Qs/Qt, Berggren equation, 1942) from 8,98±5,7 to 5,34±3,2 (p<0,01); white blood cells, from 6,64±1,57 to 5,92±1,32 109/L. In addition, we revealed an increase in the refractive index (RI) from 46,67±13,26% to 63,32±13,44% (p<0,0001), minimum blood oxygen saturation (SpO2) from 92,25±2,9 to 94,25±1, 56% (p<0,05), direct bilirubin from 2,99±1,41 to 3,39±1,34 pmol/L (p<0,01), partial oxygen tension (PvO2) from 26,9±5,0 to 34,8±5,6 mm Hg (p<0,0001), venous oxygen saturation (SvO2) from 51,8±020,6 to 61,1±018,1% (p<0,05), partial capillary oxygen tension (PcO2) from 48,7±15,4 to 63,8±21,2 mm Hg (p<0,01), capillary oxygen saturation (ScO2) from 82,2±4,2 to 86,2±4,8% (p<0,01), distance in 6 minute walk test from 429±45,0 to 569±60 m.

Conclusion. Inhalation therapy with H(H2O)m in the rehabilitation program of COVID-19 survivors during the recovery period is a safe and highly effective method. Manifestations of silent hypoxemia and endothelial dysfunction decreased, while exercise tolerance increased. As for laboratory tests, a decrease in the white blood cell count, estimated pulmonary shunt fraction and lactate content parameters was revealed.

Randomized, crossover clinical efficacy trial in humans and mice on tear secretion promotion and lacrimal gland protection by molecular hydrogen

The incidence of dry eye disease is increasing worldwide because of the aging population and increasing use of information technology. Dry eye disease manifests as tear-layer instability and inflammation caused by osmotic hypersensitization in tear fluids; however, to our knowledge, no agent that treats both pathologies simultaneously is available. Molecular hydrogen (H₂) is known to be effective against various diseases; therefore, we aimed to elucidate the effects of H₂ on tear dynamics and the treatment of dry eye disease. We revealed that administering a persistent H₂-generating supplement increased the human exhaled H₂ concentration (p < 0.01) and improved tear stability (p < 0.01) and dry eye symptoms (p < 0.05) significantly. Furthermore, H₂ significantly increased tear secretion in healthy mice (p < 0.05) and significantly suppressed tear reduction in a murine dry eye model (p = 0.007). H₂ significantly and safely improved tear stability and dry eye symptoms in a small exploratory group of 10 human subjects, a subset of whom reported dry eye symptoms prior to treatment. Furthermore, it increased tear secretion rapidly in normal mice. Therefore, H₂ may be a safe and effective new treatment for dry eye disease and thus larger trials are warranted.

Advances in the Protective Mechanism of NO, H2S, and H2 in Myocardial Ischemic Injury

Myocardial ischemic injury is among the top 10 leading causes of death from cardiovascular diseases worldwide. Myocardial ischemia is caused mainly by coronary artery occlusion or obstruction. It usually occurs when the heart is insufficiently perfused, oxygen supply to the myocardium is reduced, and energy metabolism in the myocardium is abnormal. Pathologically, myocardial ischemic injury generates a large number of inflammatory cells, thus inducing a state of oxidative stress. This sharp reduction in the number of normal cells as a result of apoptosis leads to organ and tissue damage, which can be life-threatening. Therefore, effective methods for the treatment of myocardial ischemic injury and clarification of the underlying mechanisms are urgently required. Gaseous signaling molecules, such as NO, H₂S, H₂, and combined gas donors, have gradually become a focus of research. Gaseous signaling molecules have shown anti-apoptotic, anti-oxidative and anti-inflammatory effects as potential therapeutic agents for myocardial ischemic injury in a large number of studies. In this review, we summarize and discuss the mechanism underlying the protective effect of gaseous signaling molecules on myocardial ischemic injury.

Recent advances in studies of molecular hydrogen in the treatment of pancreatitis

Pancreatitis is an inflammatory disease of the pancreas characterized by acinar cell injury and is associated with the abnormal release of trypsin, which results in high mortality due to systemic inflammatory response syndrome (SIRS) and multiple organ dysfunction syndrome (MODS). The inflammatory response, impaired autophagic flux, endoplasmic reticulum stress (ERS) and their interactions are involved in the development of pancreatitis. Molecular hydrogen (H₂) is a novel antioxidant that possesses the features of selective scavenging of oxygen free radicals and nontoxic metabolites and has been shown to be efficacious for treating infection, injury, tumors, ischemia-reperfusion organ injury, metabolic disease and several other diseases. Recent studies have found that H₂ is also useful in the treatment of pancreatitis, which may be related to the mechanism of antioxidative stress, anti-inflammation, anti-apoptosis, regulation of immunity and regulation of molecular pathways. This review focuses on the pathogenesis of pancreatitis and the research progress and potential mechanisms of H₂ against pancreatitis to provide theoretical bases for future research and clinical application of H₂ therapy for pancreatitis.

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.

Hydrogen gas protects against ovariectomy-induced osteoporosis by inhibiting NF-κB activation

OBJECTIVES

Osteoporosis is a prevalent condition among postmenopausal women, and lacks satisfactory therapeutic options. Hydrogen (H2) has been shown to be effective in alleviating many diseases. This study aimed to investigate the effects of H2 on inhibiting osteoclastogenesis and bone loss in ovariectomized mice.

METHODS

Osteoclast differentiation from Raw264.7 cells was induced with receptor activator NF-κB ligand (RANKL) with or without 60% H2. The number and resorption activity of osteocalsts were assessed by tartrate-resistant acid phosphatase staining and pit formation assay, respectively. The expression of osteoclast markers and NF-κB phosphorylation were detected by western blot. NF-κB nuclear translocation was assessed by immunofluorescence. NF-κB transcriptional activity was analyzed by luciferase assay. Bone loss in mice was induced by ovariectomy (OVX). OVX mice were given either regular air or 60% H2. Bone structure was analyzed by micro-computed tomography and hematoxylin and eosin staining. Cytokine levels were measured by enzyme-linked immunosorbent assay. The data were analyzed with one-way or two-way ANOVA followed by Bonferroni post hoc tests.

RESULTS

H2 did not have any measurable effect on the proliferation of Raw264.7 cells. The number of osteoclasts and size of resorption pits of RANKL+H2-treated cells were 3 to 4 times less than RANKL treated cells. The expression of osteoclast marker genes of RANKL+H2-treated cells was 30% to 60% lower than RANKL-treated cells (P < 0.05). H2 markedly inhibited RANKL-induced activation, nuclear translocation, and transcriptional activity of NF-κB (P < 0.05, RANKL+H2 vs RANKL). The amount and density of trabecular bone and bone mineral density of ovariectomized mice were significantly less than sham-operated mice (P < 0.05 OVX vs sham). The amount of trabecular bone and bone mineral density of OVX mice that inhaled H2 were more than 40% higher, whereas the levels of serum proinflammatory cytokine interleukin 1β, IL-6, and tumor necrosis factor-α were more than 50% lower than those of OVX mice (P < 0.05).

CONCLUSIONS

These results demonstrated that H2 could be an effective therapeutic agent of postmenopausal osteoporosis.

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.

Morphological and molecular response of small intestine to lactulose and hydrogen-rich water in female piglets fed Fusarium mycotoxins contaminated diet

Background

Following the intake of Fusarium mycotoxin-contaminated feed, small intestines may be exposed to high levels of toxic substances that can potentially damage intestinal functions in livestock. It is well known that Fusarium mycotoxins will lead a breakdown of the normally impeccable epithelial barrier, resulting in the development of a “leaky” gut. H₂ administration with different methods has been proved definitely potentials to prevent serious intestinal diseases. The goal of this study is to investigate the roles of lactulose (LAC) and hydrogen-rich water (HRW) in preventing intestinal dysfunction in piglets fed Fusarium mycotoxin-contaminated feed.

Methods

A total of 24 female piglets were evenly assigned to 4 groups: negative control (NC) group, mycotoxin-contaminated (MC) feed group, MC feed with LAC treatment (MC + LAC), and MC feed with HRW treatment (MC + HRW), respectively. Piglets in the NC group were fed uncontaminated control diet, while remaining piglets were fed Fusarium mycotoxin-contaminated diet. For the NC and MC groups, 10 mL/kg body weight (BW) of hydrogen-free water (HFW) was orally administrated to piglets twice daily; while in the MC + LAC and MC + HRW groups, piglets were treated with the same dose of LAC solution (500 mg/kg BW) and HRW twice daily, respectively. On d 25, serum was collected and used for biochemical analysis. Intestinal tissues were sampled for morphological examination as well as relative genes and protein expression analysis.

Results

Our data showed that Fusarium mycotoxins induced higher serum diamine oxidase (DAO) activities (P < 0.05), D-lactic acid levels (P < 0.01), and endotoxin status (P < 0.01), lower villus height (P < 0.01) and ratio of villus height to crypt depth (P < 0.05) in small intestine, greater apoptosis index and higher mRNA expression related to tight junctions (P < 0.05). In addition, the distribution and down-regulation of claudin-3 (CLDN3) protein in the small intestinal was also observed. As expected, oral administrations of HRW and LAC were found to remarkably provide beneficial effects against Fusarium mycotoxin-induced apoptosis and intestinal leaking. Moreover, either HRW or LAC treatments were also revealed to prevent abnormal intestinal morphological changes, disintegrate tight junctions, and restore the expression and distribution of CLDN3 protein in the small intestinal mucosal layer in female piglets that were fed Fusarium mycotoxins contaminated diet.

Conclusions

Our data suggest that orally administrations of HRW and LAC result in less Fusarium mycotoxin-induced apoptosis and leak in the small intestine. Either HRW or LAC treatments could prevent the abnormal changes of intestinal morphology and molecular response of tight junctions as well as restore the distribution and expression of CLDN3 protein of small intestinal mucosa layer in female piglets that were fed Fusarium mycotoxins contaminated diet.

Electronic supplementary material

The online version of this article (10.1186/s40104-019-0320-2) contains supplementary material, which is available to authorized users.

Protective Effects of Different Kinds of Filtered Water on Hypertensive Mouse by Suppressing Oxidative Stress and Inflammation

Oxidative stress and inflammation play an important role in hypertensive animals and patients. Hydrogen plays a role of antioxidation and anti-inflammation. Calcium and magnesium play an important role in reducing hypertension and antioxidant. Filtered water contains abundant hydrogen and a large number of other essential elements of the human body. We investigated the protective effects of filtered water on hypertensive mice. To establish hypertension model, ICR mice were administered with N′-nitro-L-arginine methyl ester (L-NAME) hydrochloride 64 mg/kg per day for 1 month. The hypertensive mice were, respectively, administered with pure water, tap water, and filtered water for 2 months. Lipid peroxidation, antioxidant enzymatic activity, endothelin-1 (ET-1), angiotensin II (Ang II), and proinflammatory cytokines (TNF-α, IL-6, and IL-1β) were assessed. Expressions of phosphorylated NF-κB P65 in the kidney were analyzed by western blot. qRT-PCR analysis was adopted to determine the expression levels of the proinflammatory cytokines and NF-κB P65. The results demonstrated that filtered water can reduce the blood pressure. Filtered water treatment restored the activity of antioxidant enzymes, downregulated ET-1, and Ang II in the serum of mice. Filtered water treatment suppressed proinflammatory cytokines and decreased the mRNA expression of TNF-α, IL-6, IL-1β, and NF-κB P65. Consumption of filtered water inhibited the expression of NF-κB P65. This suggests that filtered water can reduce the blood pressure. The protection mechanisms include downregulating oxidative stress and inhibiting inflammation, which is partly due to the inhibition of the NF-κB signaling pathway.

Therapeutic efficacy of hydrogen‑rich saline alone and in combination with PI3K inhibitor in non‑small cell lung cancer

The aim of the present study was to investigate the effects of combination therapy of LY294002, a specific inhibitor of phosphatidylinositol 3-kinase (PI3K), with hydrogen-rich saline on the proliferation and apoptosis of the non-small cell lung cancer (NSCLC) A549 cell line and the mechanisms underpinning this. Excessive production of reactive oxygen species (ROS) may induce DNA mutations, DNA damage, genomic instability and cell proliferation, and ROS are involved in several types of cancer, particularly lung cancer. In a previous study, hydrogen was recognized as an antioxidant in preventive and therapeutic applications. The PI3K/protein kinase B (Akt) pathway is an important signaling pathway that may activate downstream of a series of extracellular signals and impact on cellular processes including cell proliferation, apoptosis and survival. To date, the PI3K/Akt signaling pathway has been indicated as a feasible target for novel antineoplastic drugs. Different strategies combining the two treatment modalities have been used in cancer therapy in order to achieve an improved therapeutic response and longer control of tumor modalities control. The present study investigated the effect of hydrogen-rich saline alone and in combination with the PI3K inhibitor, LY294002, on the proliferation, oxidative stress and apoptosis of NSCLC A549 cells. This combination therapy may be more effective than separate drug treatment; it decreased the malondialdehyde level and increased the superoxide dismutase activity. The combination therapy also enhanced the efficacy of anti-proliferation and apoptosis. Similarly, the results of the present study demonstrated that administration of the two agents in combination may inhibit phospho-Akt activity, and reduce expression of heme oxygenase-1 and nuclear factor-κB p65. The results further suggested that the combination therapy may reduce cell proliferation and promote cell apoptosis by downregulating Akt phosphorylation and inhibiting the PI3K pathway in NSCLC cell lines. Therefore, the present study provided evidence that combined therapy may be a novel therapeutic option for patients with NSCLC.

Protective effect of hydrogen-rich saline on pressure overload-induced cardiac hypertrophyin rats: possible role of JAK-STAT signaling

Background

Molecular hydrogen has been shown to have antioxidant effect and have been used to prevent oxidative stress-related diseases. The goal of this study was to explore if hydrogen-rich saline (HRS) plays a cardioprotective effect on abdominal aortic constriction (AAC) induced cardiac hypertrophy in rats. 60adult Sprague–Dawley rats received surgically the AAC for 6-week. After the surgery, the rats were randomly divided into 4 groups (15 for each):1: sham-operated (sham); 2: AAC-model; 3: AAC + Low HRS (LHRS); and 4: AAC + High HRS (HHRS). The rats in sham and AAC-model groups were treated with normal saline intraperitoneally, while rats in LHRS and HHRS groups were intraperitoneally treated with 3 or 6 mL/kg HRS daily, respectively, for 6-week.

Results

The ratios of HW/BW and LVW/BW were shown in an order of Model > LHRS > HHRS > SHAM groups. The cardiac hypertrophy was also manifested with increased expressions of atrial natriuretic peptide (ANP), brain natriuretic peptides (BNP) and fibrosis of cardiac tissues in AAC-model group, which could likewise be restrained in LHRS and HHRS groups. Moreover, the JAK-STAT (Janus Kinase-Signal transducers and activators of transcription) signaling molecule expressions were decreased with HRS treatment.

Conclusions

Our results showed a protective effect of HRS on pressure overload-induced cardiac hypertrophy in rats, which may be associated to a decreasing in JAK-STAT signaling pathway.

Hydrogen protects against liver injury during CO2 pneumoperitoneum in rats

The aim of the current study was to identify the protective effect of hydrogen gas against liver injury during CO₂ pneumoperitoneum. Rats were randomly divided into three groups: control group (C group), pneumoperitoneum group (P15 group) and hydrogen group (H₂ group). Rats in the C group were subjected to anesthesia for 90 min. Rats in the P15 group received an abdominal insufflation of CO₂ for 90 min at an intra-abdominal pressure of 15 mmHg. Rats in the H₂ group received a hypodermic injection of hydrogen gas (0.2 mL/kg) and after 10 min they received an abdominal insufflation of CO₂ for 90 min at an intra-abdominal pressure of 15 mmHg. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured to evaluate liver function. Malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione (GSH) content were measured to evaluate oxidative stress. Nuclear factor E2-related factor 2 (Nrf2) and Nrf2 downstream target genes, apoptosis-related genes and inflammatory cytokine mRNA and protein expression were detected. Liver injury was detected under the microscope. Our results revealed that liver function, antioxidants content, inflammation and liver injury were improved after hydrogen preconditioning in H₂ group compared with P15 group. Overall, our results revealed that subcutaneous hydrogen injection could exert a protective effect against liver injury during CO₂ pneumoperitoneum through reducing oxidative stress, cell apoptosis and inflammatory cytokines release.

Molecular hydrogen: a preventive and therapeutic medical gas for various diseases

Since the 2007 discovery that molecular hydrogen (H2) has selective antioxidant properties, multiple studies have shown that H2 has beneficial effects in diverse animal models and human disease. This review discusses H2 biological effects and potential mechanisms of action in various diseases, including metabolic syndrome, organ injury, and cancer; describes effective H2 delivery approaches; and summarizes recent progress toward H2 applications in human medicine. We also discuss remaining questions in H2 therapy, and conclude with an appeal for a greater role for H2 in the prevention and treatment of human ailments that are currently major global health burdens. This review makes a case for supporting hydrogen medicine in human disease prevention and therapy.

Possible clinical effects of molecular hydrogen (H2) delivery during hemodialysis in chronic dialysis patients: Interim analysis in a 12 month observation

Background and aim

It is supposed that enhanced oxidative stress and inflammation are involved with the poor clinical outcomes in patients on chronic dialysis treatment. Recent studies have shown that molecular hydrogen (H₂) is biologically active as an anti-inflammatory agent. Thus, we developed a novel hemodialysis (E-HD) system which delivers H₂ (30 to 80 ppb)-enriched dialysis solution, to conduct a prospective observational study (UMIN000004857) in order to compare the long-term outcomes between E-HD and conventional-HD (C-HD) in Japan. The present interim analysis aimed to look at potential clinical effects of E-HD during the first 12 months observation.

Subjects and method

262 patients (140, E-HD; 122, C-HD) were subjected for analysis for comprehensive clinical profiles. They were all participating in the above mentioned study, and they had been under the respective HD treatment for 12 consecutive months without hospitalization. Collected data, such as, physical and laboratory examinations, medications, and self-assessment questionnaires on subjective symptoms (i.e., fatigue and pruritus) were compared between the two groups.

Results

In a 12-month period, no clinical relevant differences were found in dialysis-related parameters between the two groups. However, there were differences in the defined daily dose of anti-hypertensive agents, and subjective symptoms, such as severe fatigue, and pruritus, which were all less in the E-HD group. Multivariate analysis revealed E-HD was an independent significant factor for the reduced use of anti-hypertensive agents as well as the absence of severe fatigue and pruritus at 12 months after adjusting for confounding factors.

Conclusion

The data indicates E-HD could have substantial clinical benefits beyond conventional HD therapy, and support the rationale to conduct clinical trials of H₂ application to HD treatment.

Saturated hydrogen saline ameliorates lipopolysaccharide-induced acute lung injury by reducing excessive autophagy

The pathogenesis of acute lung injury (ALI) induced by lipopolysaccharide (LPS) involves excessive pulmonary inflammation and oxidative stress. In turn, autophagy is associated with inflammatory diseases and organ dysfunction, and studies have demonstrated that LPS treatment may trigger autophagy. Thus, excessive autophagy may stimulate the strong inflammatory response observed in the development of LPS-induced ALI. Saturated hydrogen saline may alleviate LPS-induced ALI by inhibiting autophagy, however its underlying mechanisms of action remain unknown. It has been suggested that saturated hydrogen saline may downregulate expression of nuclear factor (NF)-κB, leading to a decrease in Beclin-1 transcription and inhibition of autophagy. Inhibition of autophagy also occurs via the phosphorylation of Unc-51-like autophagy activating kinase 1 and autophagy-related protein-13 by mechanistic target of rapamycin, which in turn may be upregulated by saturated hydrogen saline. In addition, signaling pathways involving heme oxygenase-1 and p38 mitogen-activated protein kinase are associated with the alleviative effects of saturated hydrogen saline on LPS-induced autophagy. The present review focuses on potential molecular mechanisms regarding the effects of saturated hydrogen saline in the reduction of autophagy during LPS-induced ALI.

Anti-inflammatory signaling: the point of convergence for medical gases in neuroprotection against ischemic stroke

Recent studies suggest that a variety of medical gases confer neuroprotective effects against cerebral ischemia, extending function beyond their regular clinical applications. The mechanisms underlying ischemic neuroprotection afforded by medical gases have been intensively studied over the past two decades. A number of signaling pathways have been proposed, among which anti-inflammatory signaling has been proven to be critical. Pursuit of the role for anti-inflammatory signaling may shed new light on the translational application of medical gas-afforded neuroprotection.

Transcriptome Analysis of mRNA and miRNA in Somatic Embryos of Larix leptolepis Subjected to Hydrogen Treatment

Hydrogen is a therapeutic antioxidant that has been used extensively in clinical trials. It also acts as a bioactive molecule that can alleviate abiotic stress in plants. However, the biological effects of hydrogen in somatic embryos and the underlying molecular basis remain largely unknown. In this study, the morphological and physiological influence of exogenous H₂ treatment during somatic embryogenesis was characterized in Larix leptolepis Gordon. The results showed that exposure to hydrogen increased the proportions of active pro-embryogenic cells and normal somatic embryos. We sequenced mRNA and microRNA (miRNA) libraries to identify global transcriptome changes at different time points during H₂ treatment of larch pro-embryogenic masses (PEMs). A total of 45,393 mRNAs and 315 miRNAs were obtained. Among them, 4253 genes and 96 miRNAs were differentially expressed in the hydrogen-treated libraries compared with the control. Further, a large number of the differentially expressed mRNAs and miRNAs were related to reactive oxygen species (ROS) homeostasis and cell cycle regulation. We also identified 4399 potential target genes for 285 of the miRNAs. The differential expression data and the mRNA-miRNA interaction network described here provide new insights into the molecular mechanisms that determine the performance of PEMs exposed to H₂ during somatic embryogenesis.

Hydrogen-Rich Saline Attenuates Acute Hepatic Injury in Acute Necrotizing Pancreatitis by Inhibiting Inflammation and Apoptosis, Involving JNK and p38 Mitogen-Activated Protein Kinase-dependent Reactive Oxygen Species

OBJECTIVES

The objective of this study was to study the role of hydrogen-rich saline (HRS) on acute hepatic injury (AHI) in acute necrotizing pancreatitis (ANP).

METHODS

Rats were used for this study and an ANP model was induced by injecting 5% sodium taurocholate into the biliary-pancreatic duct. Experiments were performed in 3 groups: sham, ANP, and ANP + HRS (HRS). Animals were killed at 3, 12, and 24 hours after operation, and then blood and tissue samples were harvested. Various physiological, histological, and cellular and molecular parameters were analyzed.

RESULTS

Analyses of serum, lipase, alanine transaminase, and aspartate aminotransferase indicated that ANP-induced AHI model was established successfully and HRS attenuated hepatic dysfunction. Hepatic superoxide dismutase and malondialdehyde levels showed HRS against oxidative stress. Cellular and molecular analyses including p-p38, p-JNK, p-ERK, and caspase-3, caspase-9, NF-κB, and TNF-α in hepatic tissues revealed that HRS attenuated ANP-induced AHI by inhibiting apoptosis and phosphorylation of JNK and p38, as well as NF-κB activation.

CONCLUSIONS

Hydrogen-rich saline plays a protective role in ANP-induced AHI through inhibiting inflammation and apoptosis, involving JNK and p38 MAPK-dependent reactive oxygen species.

Neuroprotective Effect of Hydrogen-Rich Saline in Global Cerebral Ischemia/Reperfusion Rats: Up-Regulated Tregs and Down-Regulated miR-21, miR-210 and NF-κB Expression

Recently, it has been suggested that molecular hydrogen (H2) can selectively reduce the levels of hydroxyl radicals (.OH), and ameliorate oxidative and inflammatory injuries to organs in global cerebral ischemia reperfusion models. Global cerebral ischemia/reperfusion (I/R) can induce a sudden activation of inflammatory cytokines and later influence the systemic immunoreactivity which may contribute to a worse outcome. Regulatory T cells (Tregs) are involved in several pathological aspects of cerebral I/R. In addition, miRNA took part in the processes of cellular response to hypoxia. Since the expression of a specific set of miRNA called "hypoxamirs" is upregulated by hypoxia. Therefore, the aim of this study was to analyze the effect of HRS on I/R inducing cerebral damage, Tregs, and specific miRNA. Our results showed that rats undergone global cerebral I/R and treated with HRS have milder injury than I/R animals without HRS treatment. miR-210 expression in the hippocampus of the I/R group at 6, 24 and 96 h after reperfusion was significantly increased at each time point, while its expression in the group treated with HRS was significantly decreased. In addition, Tregs number in group I/R was decreased at each time points, while its number in the group treated with HRS was increased at 24 and 96 h after reperfusion. We focus on the relationship among Tregs, TGF-β1, TNF-α and NF-κB at 24 h, and we found that there is a high correlation among them. Therefore, our results indicated that the brain resuscitation mechanism in the HRS-treated rats may be related with the effect of upregulating the number of Treg cells.

Neuroprotective potential of molecular hydrogen against perinatal brain injury via suppression of activated microglia

Exposure to inflammation in utero is related to perinatal brain injury, which is itself associated with high rates of long-term morbidity and mortality in children. Novel therapeutic interventions during the perinatal period are required to prevent inflammation, but its pathogenesis is incompletely understood. Activated microglia are known to play a central role in brain injury by producing a variety of pro-inflammatory cytokines and releasing oxidative products. The study is aimed to investigate the preventative potential of molecular hydrogen (H2), which is an antioxidant and anti-inflammatory agent without mutagenicity. Pregnant ICR mice were injected with lipopolysaccharide (LPS) intraperitoneally on embryonic day 17 to create a model of perinatal brain injury caused by prenatal inflammation. In this model, the effect of maternal administration of hydrogen water (HW) on pups was also evaluated. The levels of pro-inflammatory cytokines, oxidative damage and activation of microglia were determined in the fetal brains. H2 reduced the LPS-induced expression of pro-inflammatory cytokines, oxidative damage and microglial activation in the fetal brains. Next, we investigated how H2 contributes to neuroprotection, focusing on microglia, using primary cultured microglia and neurons. H2 prevented LPS- or cytokine-induced generation of reactive oxidative species by microglia and reduced LPS-induced microglial neurotoxicity. Finally, we identified several molecules influenced by H2, involved in the process of activating microglia. These results suggested that H2 holds promise for the prevention of inflammation related to perinatal brain injury.

MAPKs and Hsc70 are critical to the protective effect of molecular hydrogen during the early phase of acute pancreatitis

Molecular hydrogen (H2 ) has been proven to be an effective agent that can cure multiple organ diseases by reducing oxidative stress. Although the protective effect of hydrogen on acute pancreatitis (AP) has been confirmed, its molecular mechanism is still unclear. In this article, we aimed to investigate the changes in pancreatic cell protein expression associated with the protective effect of H2 against AP and attempted to uncover the molecular mechanism underlying this process. A proteomic analysis identified 73 differentially expressed proteins and generated the protein-protein interaction networks of these proteins. The results triggered our interest in mitogen-activated protein kinase (MAPK) and heat shock cognate 71 kDa protein (Hsc70). The subsequent in vitro experiments showed that H2 treatment inhibited the phosphorylation of extracellular signal-regulated kinase (ERK), c-jun N-terminal kinase (JNK), and p38 MAPK, and activated NF-κB and the expression of tumor necrosis factor α and interleukin-1β, while simultaneously preventing the translocation of phospho-ERK, phospho-JNK, and phospho-p38 from the cytoplasm to the nucleus. Furthermore, Hsc70 expression was upregulated by H2 administration. The animal experimental results were consistent with those of the in vitro experiments. In conclusion, H2 treatment can ameliorate the inflammatory response and reduce the expression of inflammatory mediators during the early phase of AP by inhibiting the MAPK pathways and increasing Hsc70 expression.

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.

Hydrogen-rich saline may be an effective and specific novel treatment for osteoradionecrosis of the jaw

Hydrogen, a therapeutic medical gas, can exert antioxidant activity via selectively reducing cytotoxic reactive oxygen species such as hydroxyl radicals. Hydrogen-rich saline is an alternative form of molecular hydrogen that has been widely used in many studies, including metabolic syndrome, cerebral, hepatic, myocardial ischemia/reperfusion, and liver injuries with obstructive jaundice, with beneficial results. Osteoradionecrosis of the jaw is a serious complication following radiotherapy for head and neck cancers. It has long been known that most radiation-induced symptoms are caused by free radicals generated by radiolysis of H₂O, and the hydroxyl radical is the most reactive of these. Reducing the hydroxyl radical can distinctly improve the protection of cells from radiation damage. We hypothesized that hydrogen-rich saline might be an effective and specific method of managing and preventing osteoradionecrosis of the jaw.

Hydrogen resuscitation, a new cytoprotective approach

1. Hydrogen is a colourless, odourless, tasteless and flammable gas. Hydrogen is considered a physiologically inert gas and is often used in deep sea diving medicine. In mammals, endogenous hydrogen is produced as a result of the fermentation of non-digestible carbohydrates by intestinal bacteria and it is absorbed into the systemic circulation. 2. Recent evidence indicates that hydrogen is a potent anti-oxidative, anti-apoptotic and anti-inflammatory agent and so may have potential medical application. The present review evaluates the concept of 'hydrogen resuscitation', based on knowledge that hydrogen treatment effectively protects cells, tissues and organs against oxidative injury and helps them recover from dysfunction. 3. Hydrogen therapy can be delivered by inhalation, the administration of hydrogen-enriched fluid or by approaches that affect endogenous hydrogen production. 4. Studies have shown that hydrogen resuscitation has cytoprotective effects in different cell types and disease models, including ischaemia-reperfusion injury, inflammation, toxicity, trauma and metabolic disease. The underlying mechanism may be the selective elimination of hydroxyl radicals, although other mechanisms may also be involved (e.g. hydrogen functioning as a gaseous signalling molecule). 5. Hydrogen resuscitation may have several potential advantages over current pharmacological therapies for oxidative injuries. However, more work is needed to identify the precise mechanism underlying the actions of hydrogen and to validate its therapeutic potential in the clinical setting.

Hydrogen water alleviates lung injury induced by one-lung ventilation

BACKGROUND

With the development of thoracic surgeries, one-lung ventilation (OLV) has been routinely used to facilitate surgical exposure. However, OLV can cause lung injury during the surgical process and becomes an important factor affecting the outcomes. To date, effective treatments for the prevention of lung injury caused by OLV are lacking. Hydrogen has been demonstrated to have effective protection against tissue injuries caused by oxidative stress, inflammation, and apoptosis. This study investigated the efficacy of hydrogen water consumption on the prevention of lung injury induced by OLV in rats.

MATERIALS AND METHODS

Male Sprague-Dawley rats (n = 32, 240-260 g) were divided randomly into the following four groups: sham group, sham + H2 group, OLV group, OLV + H2 group. The rats drank hydrogen water or degassed hydrogen water for 4 wk before the operation and received OLV for 60 min and two-lung ventilation for 60 min. Lung tissues were assayed for wet-to-dry ratio, oxidative stress variables, proinflammatory cytokines, and hematoxylin-eosin staining.

RESULTS

Hydrogen water consumption reduced wet-to-dry weight ratio, malondialdehyde and myeloperoxidase activity and decreased the concentration of TNF-α, IL-1β, and IL-6 in the lung tissues compared with sham group and sham + H2 group. Hydrogen water consumption further attenuated NF-κB activation and caused histopathologic alterations.

CONCLUSIONS

Our data demonstrated that hydrogen water consumption ameliorated OLV-induced lung injury, and it may exert its protective role by its anti-inflammation, antioxidation and reducing NF-κB activity in the lung tissues.

Hydrogen-rich saline attenuates acute renal injury in sodium taurocholate-induced severe acute pancreatitis by inhibiting ROS and NF-κB pathway

Hydrogen (H₂), a new antioxidant, was reported to reduce ^•OH and ONOO⁻ selectively and inhibit certain proinflammatory mediators to product, without disturbing metabolic redox reactions or ROS involved in cell signaling. We herein aim to explore its protective effects on acute renal injury in sodium taurocholate-induced acute pancreatitis and its possible mechanisms. Rats were injected with hydrogen-rich saline (HRS group) or normal saline (SO and SAP group) through tail intravenously (6 mL/kg) and compensated subcutaneously (20 mL/kg) after successful modeling. Results showed that hydrogen-rich saline attenuated the following: (1) serum Cr and BUN, (2) pancreatic and renal pathological injuries, (3) renal MDA, (4) renal MPO, (5) serum IL-1β, IL-6, and renal TNF-α, HMGB1, and (6) tyrosine nitration, IκB degradation, and NF-κB activation in renal tissues. In addition, it increased the level of IL-10 and SOD activity in renal tissues. These results proved that hydrogen-rich saline attenuates acute renal injury in sodium taurocholate-induced acute pancreatitis, presumably because of its detoxification activity against excessive ROS, and inhibits the activation of NF-κB by affecting IκB nitration and degradation. Our findings highlight the potential value of hydrogen-rich saline as a new therapeutic method on acute renal injury in severe acute pancreatitis clinically.

Hydrogen-rich saline protects against ischemia/reperfusion injury in grafts after pancreas transplantations by reducing oxidative stress in rats

Purpose. This study aimed to investigate the therapeutic potential of hydrogen-rich saline on pancreatic ischemia/reperfusion (I/R) injury in rats. Methods. Eighty heterotopic pancreas transplantations (HPT) were performed in syngenic rats. The receptors were randomized blindly into the following three groups: the HPT group and two groups that underwent transplantation and administration of hydrogen-rich saline (HS, >0.6 mM, 6 mL/kg) or normal saline (NS, 6 mL/kg) via the tail vein at the beginning of reperfusion (HPT + HS group, HPT + NS group). Samples from the pancreas and blood were taken at 12 hours after reperfusion. The protective effects of hydrogen-rich saline against I/R injury were evaluated by determining the changes in histopathology and measuring serological parameters, oxidative stress-associated molecules, and proinflammatory cytokines. Results. Administration of hydrogen-rich saline produced notable protection against pancreatic I/R injury in rats. Histopathological improvements and recovery of impaired pancreatic function were observed. In addition, TNF-α, IL-1β, and IL-6 were reduced markedly in the HPT + HS group. Additionally, there were noticeable inhibitory effects on the pancreatic malondialdehyde level and considerable recruitment of SOD and GPx, which are antioxidants. Conclusion. Hydrogen-rich saline treatment significantly attenuated the severity of pancreatic I/R injury in rats, possibly by reducing oxidative stress and inflammation.

Hydrogen-rich saline ameliorates lung injury associated with cecal ligation and puncture-induced sepsis in rats

AIMS

Although hydrogen has been proved to be a novel therapeutic medical gas in several lung injury animal models, to our knowledge, it has not been tested yet in acute lung injury (ALI) induced by cecal ligation and puncture (CLP). This study was to investigate the hypothesis that hydrogen could ameliorate CLP-induced lung injury in rats.

METHODS AND RESULTS

Our experiments exhibited that gas exchange dysfunction and lung tissue inflammation were observed in animals exposed to CLP. Hydrogen-rich saline treatment significantly attenuated lung injury as indicated by significantly improved gas exchange and histological changes in the lung and significantly reduced lung water content (LWC) and neutrophil infiltration 8h after CLP. Lipid peroxidation and DNA oxidation in the lung tissue were significantly reduced along with a decreased nitrotyrosine content and maintained superoxide dismutase activity in the presence of hydrogen, demonstrating antioxidant role of hydrogen in CLP-induced ALI. Importantly, hydrogen-rich saline treatment significantly inhibited the activation of p-p38 and NF-κB while suppressing the production of several proinflammatory mediators.

CONCLUSIONS

This observation indicated that hydrogen-rich saline peritoneal injection improves histological and functional assessment in rat model of CLP-induced ALI. The therapeutic effects of hydrogen-rich saline may be related to antioxidant and anti-inflammatory actions.

Anti-fatigue activities of polysaccharides extracted from Hericium erinaceus

Hericium erinaceus (HEP) is a notable medicinal fungus grown in China and other oriental countries. Polysaccharides from HEP have recently attracted considerable attention due to their numerous physiological activities. The objective of this study was to evaluate the anti-fatigue activity of HEP in a mouse model. After one week of acclimation, mice were randomly divided into four groups: a control group, a low-dose HEP-treated group, a moderate-dose HEP-treated group, and a high-dose HEP-treated group. The treated groups received HEP (50, 100 and 200 mg/kg, ig), while the control group received saline solution. Following treatment for 28 days, the mice performed a forced swimming test until they were exhausted, then the exhaustive swimming time was recorded along with certain biochemical parameters related to fatigue, including blood lactic acid (BLA), serum urea nitrogen (SUN), tissue glycogen, superoxide dismutase (SOD), glutathione peroxidase (GPx) and malondialdehyde (MDA). These results suggested that HEP has significant anti-fatigue activity by decreasing BLA, SUN and MDA content, as well as increasing tissue glycogen content and antioxidant enzyme activity. Based on these results, this study provided theoretical support for the application of HEP in the field of sports nutrition.

Cardioprotective Effect of Hydrogen-rich Saline on Isoproterenol-induced Myocardial Infarction in Rats

BACKGROUND

Infusion with hydrogen gas-saturated saline has recently been reported to exert antioxidant and anti-inflammatory activity that may protect against organ damage induced by oxidative stress. Therefore because oxidative stress plays a significant role in the pathophysiology of myocardial infarction (MI), the aim of our study was to investigate whether hydrogen-rich saline has cardioprotective effects against isoproterenol-induced MI in rats.

METHODS

An acute MI model was induced in male Wistar rats by subcutaneous injection of isoproterenol. Different doses of hydrogen-rich saline (5, 7.5, and 10 mL/kg body weight i.p.) or Vitamin C (250 mg/kg body weight i.g.) were administered to the rats. Oxidative stress indices including levels of myocardial marker enzymes, inflammatory cytokines, membrane-bound myocardial enzymes and histopathological changes were measured.

RESULTS

Compared with those in isoproterenol-MI group, hydrogen-rich saline decreased malondialdehyde and 8-hydroxy-desoxyguanosine concentrations, enhanced superoxide dismutase and Na(+)-K(+)-ATPase activity, lowered Ca(2+)-ATPase activity and decreased interleukin-6 and tumour necrosis factor-α levels in the serum and/or cardiac tissue of rats. Hydrogen-rich saline pretreatment also diminished infarct size, improved left heart function, and ameliorated pathological changes of the left heart.

CONCLUSION

From these results, hydrogen-rich saline exerts cardiovascular protective effects against isoproterenol-induced MI at least in part via interactions which evoke antioxidant and anti-inflammatory activities.

Review and prospect of the biomedical effects of hydrogen

Hydrogen, the simplest gas in nature, was recently reported as a therapeutic antioxidant through selectively reducing cytotoxic oxygen radicals. Though hundreds of studies on curative effects of hydrogen were published and justified, the mechanism remains unclear. We proposed several promising directions in this area by relatively in-depth analysis. Firstly, the physiological function of hydrogen was regarded neutralizing free radicals at a low dose; however, physiological effects of an excessive dose of hydrogen were necessary for the comprehensive understanding. Secondly, the therapeutic effects and mechanisms were explained by anti-oxidative, anti-inflammatory and apoptosis ways, while the limitation was obvious and needed update. Thirdly, further studies might be focused on the possible networks including effecters and receptors of hydrogen, and the evolutionary perspective was a good point of view. In conclusion, this review might be a reference and guidance for relative scholars.

A review of experimental studies of hydrogen as a new therapeutic agent in emergency and critical care medicine

Hydrogen is the most abundant chemical element in the Universe, but is seldom regarded as a therapeutic agent. Recent evidence has shown that hydrogen is a potent antioxidative, antiapoptotic and anti-inflammatory agent and so may have potential medical applications in cells, tissues and organs. There are several methods to administer hydrogen, such as inhalation of hydrogen gas, aerosol inhalation of a hydrogen-rich solution, drinking hydrogen dissolved in water, injecting hydrogen-rich saline (HRS) and taking a hydrogen bath. Drinking hydrogen solution (saline/pure water/other solutions saturated with hydrogen) may be more practical in daily life and more suitable for daily consumption. This review summarizes the findings of recent studies on the use of hydrogen in emergency and critical care medicine using different disease models.

Inhaled hydrogen gas therapy for prevention of noise-induced hearing loss through reducing reactive oxygen species

Reactive oxygen species (ROS) that form in the inner ear play an important role in noise-induced hearing loss (NIHL). Recent studies have revealed that molecular hydrogen (H2) has great potential for reducing ROS. In this study, we examined the potential of hydrogen gas to protect against NIHL. We tested this hypothesis in guinea pigs with 0.5%, 1.0% and 1.5% H2 inhalation in air for 5h a day after noise exposure, for five consecutive days. All animals underwent measurements for auditory brainstem response after the noise exposure; the results revealed that there was a better improvement in the threshold shift for the 1.0% and 1.5% H2-treated groups than the non-treated group. Furthermore, outer hair cell (OHC) loss was examined 7 days after noise exposure. A significantly higher survival rate of OHCs was observed in the 1.0% and 1.5% H2-treated group as compared to that of the non-treated group in the basal turn. Immunohistochemical analyses for 8-hydroxy-2'-deoxyguanosine (8-OHdG) were performed to examine the amount of oxidative DNA damage. While strong immunoreactivities against 8-OHdG were observed of the non-treated group, the H2-treated group showed decreased immunoreactivity for 8-OHdG. These findings strongly suggest that inhaled hydrogen gas protects against NIHL.

Hydrogen-rich saline inhibits NLRP3 inflammasome activation and attenuates experimental acute pancreatitis in mice

Increasing evidence has demonstrated that reactive oxygen species (ROS) induces oxidative stress and plays a crucial role in the pathogenesis of acute pancreatitis (AP). Hydrogen-rich saline (HRS), a well-known ROS scavenger, has been shown to possess therapeutic benefit on AP in many animal experiments. Recent findings have indicated that the NOD-like receptor family, pyrin domain-containing 3 (NLRP3) inflammasome, an intracellular multiprotein complex required for the maturation of interleukin- (IL-) 1β, may probably be a potential target of HRS in the treatment of AP. Therefore, in this study, we evaluated the activation of NLRP3 inflammasome and meanwhile assessed the degree of oxidative stress and inflammatory cascades, as well as the histological alterations in mice suffering from cerulein-induced AP after the treatment of HRS. The results showed that the activation of NLRP3 inflammasome in AP mice was substantially inhibited following the administration of HRS, which was paralleled with the decreased NF-κB activity and cytokines production, attenuated oxidative stress and the amelioration of pancreatic tissue damage. In conclusion, our study has, for the first time, revealed that inhibition of the activation of NLRP3 inflammasome probably contributed to the therapeutic potential of HRS in AP.

Estimation of the hydrogen concentration in rat tissue using an airtight tube following the administration of hydrogen via various routes

Hydrogen exerts beneficial effects in disease animal models of ischemia-reperfusion injury as well as inflammatory and neurological disease. Additionally, molecular hydrogen is useful for various novel medical and therapeutic applications in the clinical setting. In the present study, the hydrogen concentration in rat blood and tissue was estimated. Wistar rats were orally administered hydrogen super-rich water (HSRW), intraperitoneal and intravenous administration of hydrogen super-rich saline (HSRS), and inhalation of hydrogen gas. A new method for determining the hydrogen concentration was then applied using high-quality sensor gas chromatography, after which the specimen was prepared via tissue homogenization in airtight tubes. This method allowed for the sensitive and stable determination of the hydrogen concentration. The hydrogen concentration reached a peak at 5 minutes after oral and intraperitoneal administration, compared to 1 minute after intravenous administration. Following inhalation of hydrogen gas, the hydrogen concentration was found to be significantly increased at 30 minutes and maintained the same level thereafter. These results demonstrate that accurately determining the hydrogen concentration in rat blood and organ tissue is very useful and important for the application of various novel medical and therapeutic therapies using molecular hydrogen.

Hydrogen-rich saline promotes survival of retinal ganglion cells in a rat model of optic nerve crush

OBJECTIVE

To investigate the effect of molecular hydrogen (H2) in a rat model subjected to optic nerve crush (ONC).

METHODS

We tested the hypothesis that after optic nerve crush (ONC), retinal ganglion cell (RGC) could be protected by H₂. Rats in different groups received saline or hydrogen-rich saline every day for 14 days after ONC. Retinas from animals in each group underwent measurements of hematoxylin and eosin (H&E) staining, cholera toxin beta (CTB) tracing, gamma synuclein staining, and terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL) staining 2 weeks post operation. Flash visual evoked potentials (FVEP) and pupillary light reflex (PLR) were then tested to evaluate the function of optic nerve. The malondialdehyde (MDA) level in retina was evaluated.

RESULTS

H&E, gamma synuclein staining and CTB tracing showed that the survival rate of RGCs in hydrogen saline-treated group was significantly higher than that in saline-treated group. Apoptosis of RGCs assessed by TUNEL staining were less observed in hydrogen saline-treated group. The MDA level in retina of H₂ group was much lower than that in placebo group. Furthermore, animals treated with hydrogen saline showed better function of optic nerve in assessments of FVEP and PLR.

CONCLUSION

These results demonstrated that H₂ protects RGCs and helps preserve the visual function after ONC and had a neuroprotective effect in a rat model subjected to ONC.