Protective Effects of Hydrogen on Myocardial Mitochondrial Functions in Septic Mice

Effects of perioperative hydrogen inhalation on brain edema and prognosis in patients with glioma: a single-center, randomized controlled study

Introduction

Brain edema is a life-threatening complication that occurs after glioma surgery. There are no noninvasive and specific treatment methods for brain edema. Hydrogen is an anti-inflammatory and antioxidant gas that has demonstrated therapeutic and preventative effects on several diseases, particularly in the nervous system. This study aimed to determine the therapeutic effects of hydrogen administration on brain edema following glioma surgery and elucidate its mechanism.

Methods

A single-center, randomized controlled clinical trial of hydrogen inhalation was conducted (China Clinical Trial Registry [ChiCTR-2300074362]). Participants in hydrogen (H) group that inhaled hydrogen experienced quicker alleviation of postoperative brain edema compared with participants in control (C) group that inhaled oxygen.

Results

The volume of brain edema before discharge was significantly lower in the H group (p < 0.05). Additionally, the regression rate of brain edema was higher in the H group than in the C group, which was statistically significant (p < 0.05). Furthermore, 3 days after surgery, the H group had longer total sleep duration, improved sleep efficiency, shorter sleep latency, and lower numerical rating scale (NRS) scores (p < 0.05).

Discussion

In conclusion, hydrogen/oxygen inhalation effectively reduced postoperative brain edema in glioma patients. Further research is necessary to understand the underlying mechanisms of hydrogen's therapeutic effects. Hydrogen is expected to become a new target for future adjuvant therapy for brain edema.

Molecular hydrogen attenuates sepsis-induced cardiomyopathy in mice by promoting autophagy

BACKGROUND

Approximately 40 to 60% of patients with sepsis develop sepsis-induced cardiomyopathy (SIC), which is associated with a substantial increase in mortality. We have found that molecular hydrogen (H2) inhalation improved the survival rate and cardiac injury in septic mice. However, the mechanism remains unclear. This study aimed to explore the regulatory mechanism by which hydrogen modulates autophagy and its role in hydrogen protection of SIC.

METHODS

Cecal ligation and puncture (CLP) was used to induce sepsis in adult C57BL/6J male mice. The mice were randomly divided into 4 groups: Sham, Sham + 2% hydrogen inhalation (H2), CLP, and CLP + H2 group. The 7-day survival rate was recorded. Myocardial pathological scores were calculated. Myocardial troponin I (cTnI) levels in serum were detected, and the levels of autophagy- and mitophagy-related proteins in myocardial tissue were measured. Another four groups of mice were also studied: CLP, CLP + Bafilomycin A1 (BafA1), CLP + H2, and CLP + H2 + BafA1 group. Mice in the BafA1 group received an intraperitoneal injection of the autophagy inhibitor BafA1 1 mg/kg 1 h after operation. The detection indicators remained the same as before.

RESULTS

The survival rate of septic mice treated with H2 was significantly improved, myocardial tissue inflammation was improved, serum cTnI level was decreased, autophagy flux was increased, and mitophagy protein content was decreased (P < 0.05). Compared to the CLP + H2 group, the CLP + H2 + BafA1 group showed a decrease in autophagy level and 7-day survival rate, an increase in myocardial tissue injury and cTnI level, which reversed the protective effect of hydrogen (P < 0.05).

CONCLUSION

Hydrogen exerts protective effect against SIC, which may be achieved through the promotion of autophagy and mitophagy.

Hydrogen: A Rising Star in Gas Medicine as a Mitochondria-Targeting Nutrient via Activating Keap1-Nrf2 Antioxidant System

The gas molecules O2, NO, H2S, CO, and CH4, have been increasingly used for medical purposes. Other than these gas molecules, H2 is the smallest diatomic molecule in nature and has become a rising star in gas medicine in the past few decades. As a non-toxic and easily accessible gas, H2 has shown preventive and therapeutic effects on various diseases of the respiratory, cardiovascular, central nervous system, and other systems, but the mechanisms are still unclear and even controversial, especially the mechanism of H2 as a selective radical scavenger. Mitochondria are the main organelles regulating energy metabolism in living organisms as well as the main organelle of reactive oxygen species' generation and targeting. We propose that the protective role of H2 may be mainly dependent on its unique ability to penetrate every aspect of cells to regulate mitochondrial homeostasis by activating the Keap1-Nrf2 phase II antioxidant system rather than its direct free radical scavenging activity. In this review, we summarize the protective effects and focus on the mechanism of H2 as a mitochondria-targeting nutrient by activating the Keap1-Nrf2 system in different disease models. In addition, we wish to provide a more rational theoretical support for the medical applications of hydrogen.

Inflation using hydrogen improves donor lung quality by regulating mitochondrial function during cold ischemia phase

BACKGROUND

Mitochondrial dysfunction results in poor organ quality, negatively affecting the outcomes of lung transplantation. Whether hydrogen benefits mitochondrial function in cold-preserved donors remain unclear. The present study assessed the effect of hydrogen on mitochondrial dysfunction in donor lung injury during cold ischemia phase (CIP) and explored the underlying regulatory mechanism.

METHODS

Left donor lungs were inflated using 40% oxygen + 60% nitrogen (O group), or 3% hydrogen + 40% oxygen + 57% nitrogen (H group). Donor lungs were deflated in the control group and were harvested immediately after perfusion in the sham group (n = 10). Inflammation, oxidative stress, apoptosis, histological changes, mitochondrial energy metabolism, and mitochondrial structure and function were assessed. The expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) were also analyzed.

RESULTS

Compared with the sham group, inflammatory response, oxidative stress, histopathological changes, and mitochondrial damage were severe in the other three groups. However, these injury indexes were remarkably decreased in O and H groups, with increased Nrf2 and HO-1 levels, elevated mitochondrial biosynthesis, inhibition of anaerobic glycolysis and restored mitochondrial structure and function compared with the control group. Moreover, inflation using hydrogen contributed to stronger protection against mitochondrial dysfunction and higher levels of Nrf2 and HO-1 when comparing with O group.

CONCLUSIONS

Lung inflation using hydrogen during CIP may improve donor lung quality by mitigating mitochondrial structural anomalies, enhancing mitochondrial function, and alleviating oxidative stress, inflammation, and apoptosis, which may be achieved through activation of the Nrf2/HO-1 pathway.

Hydrogen therapy as a potential therapeutic intervention in heart disease: from the past evidence to future application

Cardiovascular disease is the leading cause of mortality worldwide. Excessive oxidative stress and inflammation play an important role in the development and progression of cardiovascular disease. Molecular hydrogen, a small colorless and odorless molecule, is considered harmless in daily life when its concentration is below 4% at room temperature. Owing to the small size of the hydrogen molecule, it can easily penetrate the cell membrane and can be metabolized without residue. Molecular hydrogen can be administered through inhalation, the drinking of hydrogen-rich water, injection with hydrogen-rich-saline, and bathing of an organ in a preservative solution. The utilization of molecular hydrogen has shown many benefits and can be effective for a wide range of purposes, from prevention to the treatment of diseases. It has been demonstrated that molecular hydrogen exerts antioxidant, anti-inflammatory, and antiapoptotic effects, leading to cardioprotective benefits. Nevertheless, the exact intracellular mechanisms of its action are still unclear. In this review, evidence of the potential benefits of hydrogen molecules obtained from in vitro, in vivo, and clinical investigations are comprehensively summarized and discussed with a focus on the cardiovascular aspects. The potential mechanisms involved in the protective effects of molecular hydrogen are also presented. These findings suggest that molecular hydrogen could be used as a novel treatment in various cardiovascular pathologies, including ischemic-reperfusion injury, cardiac injury from radiation, atherosclerosis, chemotherapy-induced cardiotoxicity, and cardiac hypertrophy.

Molecular hydrogen is a potential protective agent in the management of acute lung injury

Acute lung injury (ALI) and acute respiratory distress syndrome, which is a more severe form of ALI, are life-threatening clinical syndromes observed in critically ill patients. Treatment methods to alleviate the pathogenesis of ALI have improved to a great extent at present. Although the efficacy of these therapies is limited, their relevance has increased remarkably with the ongoing pandemic caused by the novel coronavirus disease 2019 (COVID-19), which causes severe respiratory distress syndrome. Several studies have demonstrated the preventive and therapeutic effects of molecular hydrogen in the various diseases. The biological effects of molecular hydrogen mainly involve anti-inflammation, antioxidation, and autophagy and cell death modulation. This review focuses on the potential therapeutic effects of molecular hydrogen on ALI and its underlying mechanisms and aims to provide a theoretical basis for the clinical treatment of ALI and COVID-19.

Hydrogen, a Novel Therapeutic Molecule, Regulates Oxidative Stress, Inflammation, and Apoptosis

Molecular hydrogen (H₂) is a colorless and odorless gas. Studies have shown that H₂ inhalation has the therapeutic effects in many animal studies and clinical trials, and its application is recommended in the novel coronavirus pneumonia treatment guidelines in China recently. H₂ has a relatively small molecular mass, which helps it quickly spread and penetrate cell membranes to exert a wide range of biological effects. It may play a role in the treatment and prevention of a variety of acute and chronic inflammatory diseases, such as acute pancreatitis, sepsis, respiratory disease, ischemia reperfusion injury diseases, autoimmunity diseases, etc.. H₂ is primarily administered via inhalation, drinking H₂-rich water, or injection of H₂ saline. It may participate in the anti-inflammatory and antioxidant activity (mitochondrial energy metabolism), immune system regulation, and cell death (apoptosis, autophagy, and pyroptosis) through annihilating excess reactive oxygen species production and modulating nuclear transcription factor. However, the underlying mechanism of H₂ has not yet been fully revealed. Owing to its safety and potential efficacy, H₂ has a promising potential for clinical use against many diseases. This review will demonstrate the role of H₂ in antioxidative, anti-inflammatory, and antiapoptotic effects and its underlying mechanism, particularly in coronavirus disease-2019 (COVID-19), providing strategies for the medical application of H₂ for various diseases.

Perspective of Molecular Hydrogen in the Treatment of Sepsis

Sepsis is the main cause of death in critically ill patients with no effective treatment. Sepsis is lifethreatening organ dysfunction due to a dysregulated host response to infection. As a novel medical gas, molecular hydrogen (H₂) has a therapeutic effect on many diseases, such as sepsis. H₂ treatment exerts multiple biological effects, which can effectively improve multiple organ injuries caused by sepsis. However, the underlying molecular mechanisms of hydrogen involved in the treatment of sepsis remain elusive, which are likely related to anti-inflammation, anti-oxidation, anti-apoptosis, regulation of autophagy and multiple signaling pathways. This review can help better understand the progress of hydrogen in the treatment of sepsis, and provide a theoretical basis for the clinical application of hydrogen therapy in sepsis in the future.