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.

Neuroprotective effects of Si-based hydrogen-producing agent on 6-hydroxydopamine-induced neurotoxicity in juvenile mouse model.

Neurotoxins have been extensively investigated, particularly in the field of neuroscience. They induce toxic damage, oxidative stress, and inflammation on neurons, triggering neuronal dysfunction and neurodegenerative diseases. Here we demonstrate the neuroprotective effect of a silicon (Si)-based hydrogen-producing agent (Si-based agent) in a juvenile neurotoxic mouse model induced by 6-hydroxydopamine (6-OHDA). The Si-based agent produces hydrogen in bowels and functions as an antioxidant and anti-inflammatory agent. However, the effects of the Si-based agent on neural degeneration in areas other than the lesion and behavioral alterations caused by it are largely unknown. Moreover, the neuroprotective effects of Si-based agent in the context of lactation and use during infancy have not been explored in prior studies. In this study, we show the neuroprotective effect of the Si-based agent on 6-OHDA during lactation period and infancy using the mouse model. The Si-based agent safeguards against the degradation and neuronal cell death of dopaminergic neurons and loss of dopaminergic fibers in the striatum (STR) and ventral tegmental area (VTA) caused by 6-OHDA. Furthermore, the Si-based agent exhibits a neuroprotective effect on the length of axon initial segment (AIS) in the layer 2/3 (L2/3) neurons of the medial prefrontal cortex (mPFC). As a result, the Si-based agent mitigates hyperactive behavior in a juvenile neurotoxic mouse model induced by 6-OHDA. These results suggest that the Si-based agent serves as an effective neuroprotectant and antioxidant against neurotoxic effects in the brain, offering the possibility of the Si-based agent as a neuroprotectant for nervous system diseases.

[Rehabilitation program of post-COVID-19 syndrome with the use of nitric oxide and molecular hydrogen].

Рost-COVID-19 syndrome (PS) is one of the medical and social problem. According to WHO, 10-20% of COVID-19 patients suffer from PS. The use of medical gases - inhaled nitric oxide (iNO) and molecular hydrogen (iH2) - may influence on the mechanisms of development PC. AIM: To evaluate the safety and efficacy of the combined inhalation of NO and H2 (iNO/iH2) in patients with respiratory manifestations of PS. MATERIALS AND METHODS: 34 patients with PS (11 men/23 women, 60.0±11.7 years) were included in the prospective open-label controlled study in parallel groups: the main group (n=17) received iNO/iH2 for 90 minutes once a day for 10 days (concentration of NO 60 ppm, H2<4% in the gas mixture), the control group (n=17) didn't receive inhalations. The period from the confirmation of COVID-19 to the start of the study was 641.8±230.5 days. The groups did not differ in the baseline parameters. The clinical symptoms (from the self-observation diary and mMRC questionnaires, "dyspnea language"), FAS, HADS, SF-36 scores, 6-minute walk test, the blood serum parameters of oxidative stress, the dynamics of the microcirculation in the eye bulbar conjunctiva were evaluated. The individual dose of iNO has chosen during a 15-minute test (the positive dynamics of the microcirculation have indicated that the dose was selected correctly). RESULTS: The decrease the symptoms severity, such as dyspnea, cough, fatigue and palpitations (p<0.005), the increase in SF-36 questionnaire scores (p=0.006) and a reducing of FAS score (p=0.001), as well as the anxiety component of HADS (p=0.02) were revealed at the end of treatment in the main group compared to the control group. We observed an improvement in distance walked (p=0.01) and the values SpO2 (p=0.04) in 6-minute walk test, the increase in the volumetric blood flow velocity in venules (p<0.001), and the date in oxidative damage (p<0.001) and antioxidant activity (p=0.03) parameters in the blood serum. CONCLUSION: The results of the study demonstrate clinical efficacy iNO/iH2 on clinical indicators, parameters of oxidative stress and microcirculation in patients with PS.

In Vivo Proof of Biological Safety and Physiological Effects of Orally Ingested Water Containing H2-Filled Ultrafine Bubbles (UFBs).

Owing to their unique physicochemical properties and diverse biological effects, ultrafine bubbles (UFBs) have recently been expected to be utilized for industrial and biological purposes. Thus, this study investigated the biological safety of UFBs in water for living beings in drinking the water with a view to future use in health sciences. In this study, we used H2-filled UFBs (NanoGAS®) that can hold hydrogen in the aqueous phase for a long time. Mice were randomly assigned to one of three groups: those receiving NanoGAS® water, reverse osmosis water, or natural mineral water, and they ingested it ad libitum for one month or three months. As a result, subchronic drinking of NanoGAS® water does not affect either the common blood biochemical parameters or the health of the organs and mucosal membranes. Our results, for the first time, scientifically demonstrated the biological safety of H2-filled UFBs water for subchronic oral consumption.

Microbial hydrogen economy alleviates colitis by reprogramming colonocyte metabolism and reinforcing intestinal barrier.

With the rapid development and high therapeutic efficiency and biosafety of gas-involving theranostics, hydrogen medicine has been particularly outstanding because hydrogen gas (H2), a microbial-derived gas, has potent anti-oxidative, anti-apoptotic, and anti-inflammatory activities in many disease models. Studies have suggested that H2-enriched saline/water alleviates colitis in murine models; however, the underlying mechanism remains poorly understood. Despite evidence demonstrating the importance of the microbial hydrogen economy, which reflects the balance between H2-producing (hydrogenogenic) and H2-utilizing (hydrogenotrophic) microbes in maintaining colonic mucosal ecosystems, minimal efforts have been exerted to manipulate relevant H2-microbe interactions for colonic health. Consistent with previous studies, we found that administration of hydrogen-rich saline (HS) ameliorated dextran sulfate sodium-induced acute colitis in a mouse model. Furthermore, we demonstrated that HS administration can increase the abundance of intestinal-specific short-chain fatty acid (SCFA)-producing bacteria and SCFA production, thereby activating the intracellular butyrate sensor peroxisome proliferator-activated receptor γ signaling and decreasing the epithelial expression of Nos2, consequently promoting the recovery of the colonic anaerobic environment. Our results also indicated that HS administration ameliorated disrupted intestinal barrier functions by modulating specific mucosa-associated mucolytic bacteria, leading to substantial inhibition of opportunistic pathogenic Escherichia coli expansion as well as a significant increase in the expression of interepithelial tight junction proteins and a decrease in intestinal barrier permeability in mice with colitis. Exogenous H2 reprograms colonocyte metabolism by regulating the H2-gut microbiota-SCFAs axis and strengthens the intestinal barrier by modulating specific mucosa-associated mucolytic bacteria, wherein improved microbial hydrogen economy alleviates colitis.

Molecular hydrogen alleviates lung injury after traumatic brain injury: Pyroptosis and apoptosis.

BACKGROUND: Traumatic brain injury (TBI)-induced acute lung injury (ALI) is a critical condition, and inflammation and apoptosis play essential roles. Molecular hydrogen (H2) exerts anti-inflammatory and anti-apoptotic effects. Our previous work has shown that 42% H2 can improve TBI. In the current study, we tested the hypothesis that inhalation of hydrogen (42% H2, 21% O2, balanced nitrogen) for 1 h per day can improve TBI-induced ALI. METHODS: Sprague-Dawley male rats were randomly divided into 3 groups. Except for the sham group (group S), rats were subjected to a fluid percussion injury (FPI) and the H2 treatment group were given inhaled hydrogen for 1 h per day. We evaluated the lung function, pyroptosis and apoptosis at 24 h, 48 h and 72 h. RESULTS: Compared with group S, the rats in the TBI group (group T) showed obvious pulmonary edema after a TBI. Inhalation of high-concentration hydrogen significantly improved the rats. During this process, rats had some tendency to heal on their own, and H2 also accelerated the self-healing process. Lung injury scores, oxygenation index and pulmonary edema were consistent. Compared with group S, the pyroptosis-related proteins Caspase-1, apoptosis-associated speck-like protein containing CARD (ASC) and Gasdermin-D (GSDM-D) in the lung tissues of the rats in group T were significantly increased after a TBI. In the H2 treatment group (group H), these proteins were significantly decreased. The levels of IL-1ß and IL-18 were significantly increased after TBI while in group H were significantly decreased. At the same time, cleaved caspase-3 and BCL-2/Bax were also changed after H2 treatment. These demonstrates the powerful ameliorating effect of H2 on pyroptosis, apoptosis and systemic inflammation. However, rats also had tendency to heal on their own, and H2 also accelerated the self-healing process at the same time. CONCLUSIONS: H2 improves TBI-ALI, and the mechanism may be due to the decrease of both pyroptosis and apoptosis and the alleviation of inflammation. These findings provide a reference and evidence for the use of H2 in TBI-ALI patients in the intensive care unit (ICU).

The Anti-Inflammatory Effect of Hydrogen Gas Inhalation and Its Influence on Laser-Induced Choroidal Neovascularization in a Mouse Model of Neovascular Age-Related Macular Degeneration.

BACKGROUND: Age-related macular degeneration (AMD) is a leading cause of blindness in the elderly. Choroidal neovascularization (CNV) is the major pathologic feature of neovascular AMD. Oxidative damages and the ensuing chronic inflammation are representative of trigger events. Hydrogen gas (H2) has been demonstrated as an antioxidant and plays a role in the regulation of oxidative stress and inflammation. This experiment aimed to investigate the influence of H2 inhalation on a mouse model of CNV. METHODS: Laser was used to induce CNV formation. C57BL/6J mice were divided into five groups: the control group; the laser-only group; and the 2 h, 5 h, and 2.5 h/2.5 h groups that received laser and H2 inhalation (21% oxygen, 42% hydrogen, and 37% nitrogen mixture) for 2 h, 5 h, and 2.5 h twice every day, respectively. RESULTS: The severity of CNV leakage on fluorescence angiography showed a significant decrease in the H2 inhalation groups. The mRNA expression of hypoxia-inducible factor 1 alpha and its immediate downstream target vascular endothelial growth factor (VEGF) showed significant elevation after laser, and this elevation was suppressed in the H2 inhalation groups in an inhalation period length-related manner. The mRNA expression of cytokines, including tumor necrosis factor alpha and interlukin-6, also represented similar results. CONCLUSION: H2 inhalation could alleviate CNV leakage in a laser-induced mouse CNV model, and the potential mechanism might be related to the suppression of the inflammatory process and VEGF-driven CNV formation.

An H2-infused, nitric oxide-producing functional beverage as a neuroprotective agent for TBIs and concussions.

Traumatic brain injuries (TBIs) are a leading cause of death and disability. Sports-related TBIs are estimated to be more than several million per year. The pathophysiology of TBIs involves high levels of inflammation, oxidative stress, dysregulation of ion homeostasis, mitochondrial dysfunction, and apoptosis. There is also a reduction in cerebral blood flow, leading to hypoxia and reduced removal of metabolic waste, which further exacerbates the injury. There is currently no recognized effective medical treatment or intervention for TBIs, which may in part be due to the difficulty of drug delivery through the blood-brain barrier. Molecular hydrogen has recently emerged as a neuroprotective medical gas against cerebral infarction and neurodegenerative diseases including TBIs. Its small molecular size and nonpolar nature allow it to easily diffuse through the blood-brain barrier, cell membranes and subcellular compartments. Hydrogen has been shown to exert selective anti-inflammatory, antioxidant, and anti-apoptotic effects by regulating various transcription factors and protein phosphorylation cascades. Nitric oxide is another well-recognized medical gas that plays divergent roles in protecting from and in the recovery of TBIs, as well as in contributing to their pathophysiology and injury. Excessive activation of inducible nitric oxide synthase leads to excess inflammation and oxidative/nitrosative damage as well as a paradoxical nitric oxide depletion in the locations it is needed. Hydrogen regulates nitric oxide production and metabolism, which enhances its benefits while reducing its harms. A novel H2-infused, nitric oxide producing beverage, Hydro Shot, may have important neuroprotective benefits for TBIs. We report preliminary indications that Hydro Shot may be a meaningful adjuvant treatment for TBIs.

Hydrogen Attenuates Myocardial Injury in Rats by Regulating Oxidative Stress and NLRP3 Inflammasome Mediated Pyroptosis.

Purpose: Hydrogen (H2) is an antioxidant with anti-inflammatory and apoptosis functions.This study aimed to estimate the effects of H2 on acute myocardial infarction (AMI) in rats and its association with the inhibition of oxidative stress and cardiomyocyte pyroptosis. Methods: Sixty-four rats were randomly divided into three groups (Sham, AMI, and H2). The left anterior descending coronary artery (LAD) of rats in the AMI and H2 groups was ligated, while rats in the Sham group were threaded without ligation. In addition, 2% H2 was administered by inhalation for 24 h after ligation in the H2 group. Transthoracic echocardiography was performed after H2 inhalation, followed by collection of the serum and cardiac tissue of all rats. Results: H2 inhalation ameliorated the cardiac dysfunction, infarct size and inflammatory cell infiltration caused by AMI. Meanwhile, H2 inhalation reduced the concentration of serum Troponin I (TnI), brain natriuretic peptide (BNP), reactive oxygen species (ROS), cardiac malondialdehyde (MDA), and 8-OHdG. In addition, H2 inhalation inhibited cardiac inflammation and pyroptosis relative proteins expression. Conclusion: H2 effectively promoted heart functions in AMI rats by regulating oxidative stress and pyroptosis.

Mechanism of hydrogen on cervical cancer suppression revealed by high­throughput RNA sequencing.

Cervical cancer is considered one of the diseases with the highest mortality among women and with limited treatment options. Hydrogen (H2) inhalation has been reported to have a variety of tumor­suppressive effects, but the exact mechanism remains unclear. In the present study, HeLa cervical cancer cells and HaCaT keratinocytes treated with H2, and a HeLa xenograft mouse model subjected to H2 inhalation were established. TUNEL, Cell Counting Kit­8 and Ki67 staining assays were used to detect cell apoptosis and proliferation. Oxidative stress was determined according to the levels of reactive oxygen species, malondialdehyde and superoxide dismutase. Tumor growth was recorded every 3 days, and the excised tumors were stained with hematoxylin and eosin. High­throughput RNA sequencing and subsequent Gene Ontology (GO) enrichment analysis were performed in HeLa­treated and un­treated HeLa cells. The expression of hypoxia­inducible factor (HIF)­1α and NF­κB p65 was verified by western blotting, immunohistochemistry and reverse transcription­quantitative PCR. The results revealed an increased apoptosis rate, and reduced cell proliferation and oxidative stress in H2­treated HeLa cells but not in HaCaT cells. Similarly, decreased tumor growth and cell proliferation, and enhanced cell apoptosis were observed in H2­treated HeLa tumors. RNA sequencing and GO analysis suggest that downregulated HIF1A (HIF­1α mRNA) and RelA (NF­κB p65) levels, and reduced NF­κB signaling were associated with the antitumor effect of H2. Finally, decreased HIF­1α and NF­κB p65 expression both at the transcriptional and translational levels were observed in H2­treated HeLa cells and in HeLa­derived tumors. In conclusion, the present study reveals a novel mechanism of H2 against cervical cancer, which may serve as a potential therapeutic target in clinical practice.

Hydrogen/oxygen therapy for the treatment of an acute exacerbation of chronic obstructive pulmonary disease: results of a multicenter, randomized, double-blind, parallel-group controlled trial.

BACKGROUND: To investigate whether the administration of hydrogen/oxygen mixture was superior to oxygen in improving symptoms in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). METHODS: This prospective, randomized, double-blind, controlled clinical trial in 10 centres enrolled patient with AECOPD and a Breathlessness, Cough, and Sputum Scale (BCSS) score of at least 6 points. Eligible patients were randomly assigned (in a 1:1 ratio) to receive either hydrogen/oxygen mixture or oxygen therapy. Primary endpoint was the change from baseline in BCSS score at day 7. Adverse events (AEs) were recorded to evaluate safety. RESULTS: Change of BCSS score in Hydrogen/oxygen group was larger than that in Oxygen group (- 5.3 vs. - 2.4 point; difference: - 2.75 [95% CI - 3.27 to - 2.22], meeting criteria for superiority). Similar results were observed in other time points from day 2 through day 6. There was a significant reduction of Cough Assessment Test score in Hydrogen/oxygen group compared to control (- 11.00 vs. - 6.00, p < 0.001). Changes in pulmonary function, arterial blood gas and noninvasive oxygen saturation did not differ significantly between groups as well as other endpoints. AEs were reported in 34 (63.0%) patients in Hydrogen/oxygen group and 42 (77.8%) in Oxygen group. No death and equipment defects were reported during study period. CONCLUSIONS: The trial demonstrated that hydrogen/oxygen therapy is superior to oxygen therapy in patient with AECOPD with acceptable safety and tolerability profile. TRIAL REGISTRATION: Name of the registry: U.S National Library of Medicine Clinical Trials; Trial registration number: NCT04000451; Date of registration: June 27, 2019-Retrospectively registered; URL of trial registry record: https://www.clinicaltrials.gov/ct2/show/study/NCT04000451?term=04000451&draw=2&rank=1 .

Pre-inhalation of hydrogen-rich gases protect against caerulein-induced mouse acute pancreatitis while enhance the pancreatic Hsp60 protein expression.

BACKGROUND: Acute pancreatitis (AP) lacks targeted prevention and treatment measures. Some key points in the pathogenesis of AP remain unclear, such as early activation of pancreatic enzymes. Several recent reports have shown the protective effect of hydrogen on several AP animal models, and the mechanism is related to antioxidant activity. Heat shock protein 60 (Hsp60) is known to accompany pancreatic enzymes synthesis and secretion pathway of in pancreatic acinar cells, while role of hsp60 in AP remains a topic. Aim of this study was to investigate effect of hydrogen pretreatment on AP and the mechanisms, focusing on pancreatic oxidative stress and Hsp60 expression. METHODS: 80 mice were randomly assigned into four groups: HAP group, AP group, HNS group, and NS group and each group were set 3 observation time point as 1 h, 3 h and 5 h (n = 6-8). Mouse AP model was induced by intraperitoneal injection of 50 µg/kg caerulein per hour for 6 injections both in AP and HAP groups, and mice in NS group and HNS group given normal saline (NS) injections at the same way as control respectively. Mice in HAP group and HNS group were treated with hydrogen-rich gases inhalation for 3 days before the first injection of caerulein or saline, while mice in AP group and NS group in normal air condition. Histopathology of pancreatic tissue, plasma amylase and lipase, plasma IL-1 and IL-6, pancreatic glutathione (GSH) and malondialdehyde (MDA), and Hsp60 mRNA and protein expression were investigated. Comparisons were made by one-way analysis of variance. RESULTS: The pancreatic pathological changes, plasma amylase and lipase activity, and the increase of plasma IL-1 and IL-6 levels in AP mice were significantly improved by the hydrogen-rich gases pretreatment, Meanwhile, the pancreatic GSH content increased and the pancreatic MDA content decreased. And, the hydrogen-rich gases pretreatment improved the Hsp60 protein expression in pancreatic tissues of AP mice at 1 h and 5 h. CONCLUSIONS: Pre-inhalation of hydrogen-rich gases have a good protective effect on AP mice, and the possible mechanisms of reduced oxidative stress and the early increased pancreatic Hsp60 protein deserve attention.

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.

Hydrogen enriched saline alleviates morphine tolerance via inhibiting neuroinflammation, GLT-1, GS nitration and NMDA receptor trafficking and functioning in the spinal cord of rats.

The development and maintenance of morphine tolerance showed association with neuroinflammation and dysfunction of central glutamatergic system (such as nitration of glutamate transporter). Recent evidence indicated that hydrogen could reduce the levels of neuroinflammation and oxidative stress, but its role in morphine tolerance has not been studied. The rats were intrathecally administered with morphine (10 µg/10 µL each time, twice/day for 5 days). Hydrogen enriched saline (HS) or saline was given intraperitoneally at 1, 3 and 10 mL/kg for 10 min before each dose of morphine administration. The tail-flick latency, mechanical threshold and thermal latency were assessed one day (baseline) before and daily for up to 5 days during morphine injection. The pro-inflammatory cytokine expressions [tumor necrosis factor-alpha (TNF-α), interleukin-1ß (IL-1ß), IL-6)] (by western blotting), astrocyte activation (by immunofluorescence and western blotting), and nitration of glutamate transporter-1 (GLT-1) and glutamine synthetase (GS) (by immunoprecipitation), membrane and total expression of N-methyl-d-aspartic acid (NMDA) receptor NR1 and NR2B subunits were carried out in the spinal dorsal horns. Chronic morphine administration induced antinociceptive tolerance, and together led to increased TNF-α, IL-1ß and IL-6 expression, astrocyte activation, GLT-1 and GS nitration, increased membrane and total NR1, NR2B expression. Injection of HS attenuated morphine tolerance in a dose-dependent manner, decreased proinflammatory cytokine expression, inhibited astrocyte activation, decreased GLT-1 and GS nitration, and inhibited membrane trafficking of NMDA receptor. Our result showed that hydrogen pretreatment prevented morphine tolerance by reducing neuroinflammation, GLT-1, GS nitration, NMDA receptor trafficking in the spinal dorsal horn. Pretreatment with hydrogen might be considered as a novel therapeutic strategy for the prevention of morphine tolerance.

Peritoneal lavage with hydrogen-rich saline can be an effective and practical procedure for acute peritonitis.

PURPOSE: Acute peritonitis has remained a fatal disease despite of recent advances in care and treatment, including antibiotic and anticoagulant treatments. The cause of death is mostly sepsis-induced multiple organ failure. Oxidative stress can play an important role in this situation, but antioxidant therapy to capture any excessive reactive oxygen species has not yet been fully established. METHODS: Two experiments were performed. In the first experiment, we confirmed the effects of peritoneal lavage with hydrogen-rich saline (HRS) after a cecal ligation and puncture (CLP) operation in rats. In the second experiment, the changes in the hemodynamic state following this procedure were observed in a porcine model of abdominal sepsis to evaluate its safety and utility. RESULTS: Peritoneal lavage with HRS significantly improved the survival after CLP in rats, and it ameliorated the levels of sepsis-induced organ failure. Moreover, it showed anti-inflammatory and anti-apoptosis as well as antioxidant effects. The second experiment demonstrated the potential safety and feasibility of this procedure in a large animal model. CONCLUSION: This procedure can improve survival after sepsis through mitigating the sepsis-induced organ failure by inhibiting oxidative stress, apoptosis, and inflammatory pathways. Peritoneal lavage with HRS may therefore be an effective, safe, and practical therapy for patients with acute peritonitis.

High-flow hydrogen inhalation might suppresses the immune function of middle-aged participants: a self-controlled study.

Hydrogen inhalation therapy has been proven to be safe and effective in disease treatment in multiple clinical reports, but the gas flow rates used in different studies vary greatly. Since there is no upper limit for the safe concentration of hydrogen, this study tested the effects of high-flow (not high concentration) hydrogen inhalation on immune function. From October 2019 to January 2020, 20 adult participants (31-60 years old) were enrolled in a self-controlled study to check the immune function in peripheral blood lymphocyte subsets before and after a 2-week hydrogen inhalation protocol. The participants inhaled hydrogen for 2 or 4 hours each day. After 2 weeks of hydrogen inhalation, statistically significant changes were observed in follicular helper T cells, helper and cytotoxic T cells, natural killer and natural killer T cells, and gamma delta T cells, generally suggesting a decrease in their proportions. These results show that high-flow hydrogen inhalation has an inhibitory effect on the immune function of healthy participants. The study protocol received ethical approval from the Ethics Committee of Fuda Cancer Hospital, Jinan University on December 7, 2018 (approval No. Fuda20181207).

Hydrogen gas inhalation alleviates myocardial ischemia-reperfusion injury by the inhibition of oxidative stress and NLRP3-mediated pyroptosis in rats.

AIMS: Reperfusion therapy is the most common and effective treatment against ischemic heart disease (IHD), but the process inflicts massive ischemia/reperfusion (I/R) injury for which no treatment exists. Notably, reperfusion after ischemia causes ischemia/reperfusion injury (IR injury) and the "no-reflow" phenomenon seriously affecting the therapeutic effects in clinical practice. The principle purpose of this study is to validate the effect of hydrogen gas on IHD and further explore the mechanism of hydrogen gas in alleviating myocardial I/R injury and no-reflow phenomenon. MATERIALS AND METHODS: The rat model of myocardial ischemia-reperfusion was well established. Myocardial infarct size was evaluated by TTC & Evans blue staining. The no-reflow area and the cardiac function were assessed by thioflavin-S staining and echocardiography respectively. Microstructure and mitochondria of myocardial tissue were assessed by transmission electron microscope. Western blot and immunohistochemistry were used to evaluate the expression of NLRP3 mediated pyroptosis related proteins. The 8-OHdG, MDA and serum total ROS were used to evaluate the degree of oxidative stress. KEY FINDINGS: The myocardial infarct size, no-reflow area, cardiac function, microstructure and mitochondrial morphology of I/R model rats were significantly improved after hydrogen inhalation. In addition, the expression of 8-OHdG, MDA, ROS and NLRP3 mediated pyroptosis related proteins were significantly decreased. SIGNIFICANCE: We found that oxidative stress and NLRP3 mediated pyroptosis are the important mechanisms for hydrogen to alleviate myocardial I/R injury, and we also confirmed that hydrogen can significantly improve no reflow phenomenon caused by ischemia-reperfusion.

Hydrogen Gas Therapy Attenuates Inflammatory Pathway Signaling in Septic Mice.

BACKGROUND: Molecular hydrogen (H2) has been used in clinical cases. However, there are few studies of H2 therapy to treat sepsis, and anti-inflammatory mechanisms of H2 are mostly unknown. We aimed to confirm effects of H2 therapy on sepsis and reveal its therapeutic mechanism via RNA sequencing in multiple organs in septic mice. METHODS: Nine-week-old C57BL/6 male mice underwent cecal ligation and puncture (CLP) or sham procedure. Subsequently, the CLP model received immediate ± continuous inhalation of 7% H2. Mice were observed for a week to assess survival rates. Serum inflammatory cytokines were evaluated at 24 h after CLP procedure. Liver, intestine, and lungs in CLP mice receiving 24-h ± H2 therapy were assessed by RNA sequencing. Data were analyzed with Ingenuity Pathways Analysis (QIAGEN Inc). RESULTS: Seven-day survival rate in septic mice was significantly improved in the H2 inhalation group compared with that in the control group (75% versus 40%, P < 0.05). H2 treatment attenuated serum interleukin-6 and tumor necrosis factor-α levels at 24 h after CLP, and blood glucose levels were maintained in the H2-treated group. In RNA sequencing, canonical pathway analysis revealed inactivity of various inflammatory signaling pathways, for example, acute phase response signaling and STAT3 pathways, in the liver and intestine in the CLP model after 24-h H2 inhalation. We detected significantly decreased expressions of upstream regulator genes such as the CD14 antigen gene in the liver and various cytokine receptor genes in the intestine and lungs in the H2-treated group. CONCLUSIONS: These findings may contribute to clarifying the mechanism of action of H2 therapy in sepsis.

Application of Molecular Hydrogen as an Antioxidant in Responses to Ventilatory and Ergogenic Adjustments during Incremental Exercise in Humans.

We investigated effects of molecular hydrogen (H2) supplementation on acid-base status, pulmonary gas exchange responses, and local muscle oxygenation during incremental exercise. Eighteen healthy, trained subjects in a randomized, double-blind, crossover design received H2-rich calcium powder (HCP) (1500 mg/day, containing 2.544 µg/day of H2) or H2-depleted placebo (1500 mg/day) for three consecutive days. They performed cycling incremental exercise starting at 20-watt work rate, increasing by 20 watts/2 min until exhaustion. Breath-by-breath pulmonary ventilation (V˙E) and CO2 output (V˙CO2) were measured and muscle deoxygenation (deoxy[Hb + Mb]) was determined via time-resolved near-infrared spectroscopy in the vastus lateralis (VL) and rectus femoris (RF). Blood gases' pH, lactate, and bicarbonate (HCO3-) concentrations were measured at rest and 120-, 200-, and 240-watt work rates. At rest, the HCP group had significantly lower V˙E, V˙CO2, and higher HCO3-, partial pressures of CO2 (PCO2) versus placebo. During exercise, a significant pH decrease and greater HCO3- continued until 240-watt workload in HCP. The V˙E was significantly lower in HCP versus placebo, but HCP did not affect the gas exchange status of V˙CO2 or oxygen uptake (V˙O2). HCP increased absolute values of deoxy[Hb + Mb] at the RF but not VL. Thus, HCP-induced hypoventilation would lead to lower pH and secondarily impaired balance between O2 delivery and utilization in the local RF during exercise, suggesting that HCP supplementation, which increases the at-rest antioxidant potential, affects the lower ventilation and pH status during incremental exercise. HPC induced a significantly lower O2 delivery/utilization ratio in the RF but not the VL, which may be because these regions possess inherently different vascular/metabolic control properties, perhaps related to fiber-type composition.