Attenuation of cigarette smoke-induced airway mucus production by hydrogen-rich saline in rats

Hydrogen therapy: recent advances and emerging materials

Hydrogen therapy, leveraging its selective attenuation of hydroxyl radicals (˙OH) and ONOO-, has emerged as a pivotal pathophysiological modulator with antioxidant, anti-inflammatory, and antiapoptotic attributes. Hydrogen therapy has been extensively studied both preclinically and clinically, especially in diseases with an inflammatory nature. Despite the substantial progress, challenges persist in achieving high hydrogen concentrations in target lesions, especially in cancer treatment. A notable breakthrough lies in water/acid reactive materials, offering enhanced hydrogen generation and sustained release potential. However, limitations include hydrogen termination upon material depletion and reduced bioavailability at targeted lesions. To overcome these challenges, catalytic materials like photocatalytic and sonocatalytic materials have surfaced as promising solutions. With enhanced permeability and retention effects, these materials exhibit targeted delivery and sustained stimuli-reactive hydrogen release. The future of hydrogen therapy hinges on continuous exploration and modification of catalytic materials. Researchers are urged to prioritize improved catalytic efficiency, enhanced lesion targeting effects, and heightened biosafety and biocompatibility in future development.

Caveolin-1-derived peptide attenuates cigarette smoke-induced airway and alveolar epithelial injury

Chronic obstructive pulmonary disease (COPD) is a debilitating lung disease with no effective treatment that can reduce mortality or slow the disease progression. COPD is the third leading cause of global death and is characterized by airflow limitations due to chronic bronchitis and alveolar damage/emphysema. Chronic cigarette smoke (CS) exposure damages airway and alveolar epithelium and remains a major risk factor for the pathogenesis of COPD. We found that the expression of caveolin-1, a tumor suppressor protein; p53; and plasminogen activator inhibitor-1 (PAI-1), one of the downstream targets of p53, was markedly increased in airway epithelial cells (AECs) as well as in type II alveolar epithelial (AT2) cells from the lungs of patients with COPD or wild-type mice with CS-induced lung injury (CS-LI). Moreover, p53- and PAI-1-deficient mice resisted CS-LI. Furthermore, treatment of AECs, AT2 cells, or lung tissue slices from patients with COPD or mice with CS-LI with a seven amino acid caveolin-1 scaffolding domain peptide (CSP7) reduced mucus hypersecretion in AECs and improved AT2 cell viability. Notably, induction of PAI-1 expression via increased caveolin-1 and p53 contributed to mucous cell metaplasia and mucus hypersecretion in AECs, and reduced AT2 viability, due to increased senescence and apoptosis, which was abrogated by CSP7. In addition, treatment of wild-type mice having CS-LI with CSP7 by intraperitoneal injection or nebulization via airways attenuated mucus hypersecretion, alveolar injury, and significantly improved lung function. This study validates the potential therapeutic role of CSP7 for treating CS-LI and COPD. NEW & NOTEWORTHY Chronic cigarette smoke (CS) exposure remains a major risk factor for the pathogenesis of COPD, a debilitating disease with no effective treatment. Increased caveolin-1 mediated induction of p53 and downstream plasminogen activator inhibitor-1 (PAI-1) expression contributes to CS-induced airway mucus hypersecretion and alveolar wall damage. This is reversed by caveolin-1 scaffolding domain peptide (CSP7) in preclinical models, suggesting the therapeutic potential of CSP7 for treating CS-induced lung injury (CS-LI) and COPD.

Molecular Hydrogen Reduces the Degree of Endothelial Alteration under Conditions of Chronic Heart Failure

We studied the effect of molecular hydrogen H2 on the content of circulating endothelial cells and the macrohistological structure of the heart in rats with simulated chronic heart failure. Inhalation with 2% H2 was carried out repeatedly (40 min per day for 5 consecutive days) or once (40 min). Molecular hydrogen inhalations in both regimens caused a decrease in the number of circulating endothelial cells; the most pronounced effect was observed after repeated inhalations on day 14 after chronic heart failure modeling. The decrease in the count of circulating endothelial cells under the action of H2 was accompanied by recovery of the myocardial structure and a decrease in its weight. Molecular hydrogen in chronic heart failure limited the damage to endothelial cells and improved the structure of rat myocardium, which allows us to consider H2 inhalations as the means reducing the progression of chronic heart failure.

Hydrogen Therapy and Its Future Prospects for Ameliorating COVID-19: Clinical Applications, Efficacy, and Modality

Molecular hydrogen is renowned as an odorless and colorless gas. The recommendations developed by China suggest that the inhalation of hydrogen molecules is currently advised in COVID-19 pneumonia treatment. The therapeutic effects of molecular hydrogens have been confirmed after numerous clinical trials and animal-model-based experiments, which have expounded that the low molecular weight of hydrogen enables it to easily diffuse and permeate through the cell membranes to produce a variety of biological impacts. A wide range of both chronic and acute inflammatory diseases, which may include sepsis, pancreatitis, respiratory disorders, autoimmune diseases, ischemia-reperfusion damages, etc. may be treated and prevented by using it. H₂ can primarily be inoculated through inhalation, by drinking water (which already contains H₂), or by administrating the injection of saline H₂ in the body. It may play a pivotal role as an antioxidant, in regulating the immune system, in anti-inflammatory activities (mitochondrial energy metabolism), and cell death (apoptosis, pyroptosis, and autophagy) by reducing the formation of excessive reactive O₂ species and modifying the transcription factors in the nuclei of the cells. However, the fundamental process of molecular hydrogen is still not entirely understood. Molecular hydrogen H₂ has a promising future in therapeutics based on its safety and possible usefulness. The current review emphasizes the antioxidative, anti-apoptotic, and anti-inflammatory effects of hydrogen molecules along with the underlying principle and fundamental mechanism involved, with a prime focus on the coronavirus disease of 2019 (COVID-19). This review will also provide strategies and recommendations for the therapeutic and medicinal applications of the hydrogen molecule.

The effects of hydrogen treatment in a cigarette smoke solution-induced chronic obstructive pulmonary disease-like changes in an animal model

Background

Molecular hydrogen, with its antioxidant and anti-inflammatory properties, may be suitable for the prevention and treatment of chronic obstructive pulmonary disease (COPD). This study aims to investigate the therapeutic efficacy of hydrogen-oxygen (H₂/O₂) treatment in cigarette smoke solution (CSS)-induced COPD-like injury in a female BALB/c mouse model.

Methods

Thirty mice were randomly assigned to three groups: Control (n=8), COPD (n=10), and COPD + H₂/O₂ (n=12). CSS was administered by intraperitoneal (IP) injection twice weekly for 6 weeks during the COPD induction phase. Simultaneously, the COPD + H₂/O₂ group started received 75 minutes of inhalation therapy (42% H₂) delivered by the Oxy-Hydrogen Generator twice daily for 9 weeks. Mice body weights and survival were measured throughout the study period. Neutrophil elastase (NE) activity and lung histopathological changes were also evaluated.

Results

The results showed a higher survival rate in the COPD + H₂/O₂ group compared to the COPD group (100% vs. 80%) during the induction phase. Slight decreases in body weight gains were observed in the COPD and COPD + H₂/O₂ groups during the first 15 days of the induction phase, but there was no significant difference in mean body weights among the three groups throughout the study period. NE activity was numerically lower in the COPD + H₂/O₂ group compared to the COPD group. The histopathological evaluation showed significant improvements in the H₂/O₂-treated mice with respect to mean linear intercept (MLI) and lesion (inflammation and emphysema) scores. Improvements in goblet cell hypertrophy and hyperplasia of airway epithelium were not significant.

Conclusions

A 9-week H_2/O₂ inhalation therapy delivered by the Oxy-Hydrogen Generator to CSS-induced COPD-like injury in mice showed improvement in survival rate, alveolar structural changes, and histopathological lesion scores of the lung.

Molecular hydrogen is a promising therapeutic agent for pulmonary disease

Molecular hydrogen exerts biological effects on nearly all organs. It has anti-oxidative, anti-inflammatory, and anti-aging effects and contributes to the regulation of autophagy and cell death. As the primary organ for gas exchange, the lungs are constantly exposed to various harmful environmental irritants. Short- or long-term exposure to these harmful substances often results in lung injury, causing respiratory and lung diseases. Acute and chronic respiratory diseases have high rates of morbidity and mortality and have become a major public health concern worldwide. For example, coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a global pandemic. An increasing number of studies have revealed that hydrogen may protect the lungs from diverse diseases, including acute lung injury, chronic obstructive pulmonary disease, asthma, lung cancer, pulmonary arterial hypertension, and pulmonary fibrosis. In this review, we highlight the multiple functions of hydrogen and the mechanisms underlying its protective effects in various lung diseases, with a focus on its roles in disease pathogenesis and clinical significance.

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.

Role of Hydrogen in Atherosclerotic Disease: From Bench to Bedside

Atherosclerotic cardiovascular and cerebrovascular diseases are among the leading causes of morbidity and mortality worldwide. Given our recent understanding of its role as a small-molecule antioxidant and anti- inflammatory agent, hydrogen may play an important role in preventing and treating atherosclerotic cardiovascular and cerebrovascular disease. In the past decade, more than 50 publications in the English language literature considered the role of hydrogen as an anti-atherosclerotic agent. In this review, we summarized the pathophysiological characteristics and risk factors associated with atherosclerosis (AS) and the laboratory research data that focuses on hydrogen to prevent and treat this condition, including the responses observed in both animal models and human studies. We will also consider the molecular mechanisms underlying the efficacy of hydrogen molecules with respect to atherosclerotic disease. Future studies might include clinical trials with larger sample populations as well as experiments designed to explore the molecular mechanisms associated with hydrogen treatment in greater depth.

Hydrogen: A Potential New Adjuvant Therapy for COVID-19 Patients

Hydrogen has been shown to have antioxidant, anti-inflammatory, hormone-regulating, and apoptosis-resistance properties, among others. Based on a review of the research, the use of hydrogen might reduce the destructive cytokine storm and lung injury caused by SARS-CoV-2 during COVID-19 (Corona Virus Disease 2019) in the early stage, stimulating ropy sputum drainage, and ultimately reducing the incidence of severe disease. Molecular hydrogen treatment has the potential to become a new adjuvant therapy for COVID-19, but its efficacy and safety require large clinical trials and further confirmation.

Protective Role of Hydrogen Gas on Oxidative Damage and Apoptosis in Intestinal Porcine Epithelial Cells (IPEC-J2) Induced by Deoxynivalenol: A Preliminary Study

To explore the protective role of hydrogen gas (H2) on oxidative damage and apoptosis in intestinal porcine epithelial cells (IPEC-J2) induced by deoxynivalenol (DON), cells were assigned to four treatment groups, including control, 5 μM DON, H2-saturated medium, and 5 μM DON + H2-saturated medium treatments. After 12 h of different treatments, the cell viability, biomarkers of cell redox states, and gene expression of antioxidant enzymes and apoptosis were observed and detected. Furthermore, caspase-3 and Bax protein expressions were measured by Western blot analysis. Our results demonstrated that the 5 μM DON significantly caused cytotoxicity to IPEC-J2 cells by reducing cell viability and increasing lactate dehydrogenase release in culture supernatants. Moreover, DON treatments significantly increased levels of 8-hydroxy-2'-deoxyguanosine, 3-nitrotyrosine, and malonaldehyde; however, they decreased total superoxide dismutase and catalase activities and downregulated messenger RNA (mRNA) expression related to antioxidant enzymes in cells. The 5 μM DON treatment also downregulated Bcl-2 expression and upregulated caspase-3 and Bax expression. However, the H2-saturated medium significantly improved cell growth status and reversed the change of redox states and expression of genes and proteins related to apoptosis induced by DON in IPEC-J2 cells. In conclusion, H2 could protect IPEC-J2 cells from DON-induced oxidative damage and apoptosis in vitro.

Nix/BNIP3L-dependent mitophagy accounts for airway epithelial cell injury induced by cigarette smoke

Cigarette smoke-induced airway epithelial cell mitophagy is an important mechanism in the pathogenesis of chronic obstructive pulmonary disease (COPD). Mitochondrial protein Nix (also known as BNIP3L) is a selective autophagy receptor and participates in several human diseases. However, little is known about the role of Nix in airway epithelial cell injury during the development of COPD. The aim of the present study is to investigate the effects of Nix on mitophagy and mitochondrial function in airway epithelial cells exposed to cigarette smoke extract (CSE). Our present study has found that CSE could increase Nix protein expression and induce mitophagy in airway epithelial cells. And Nix siRNA significantly inhibited mitophagy and attenuated mitochondrial dysfunction and cell injury when airway epithelial cells were stimulated with 7.5% CSE. In contrast, Nix overexpression enhanced mitophagy and aggravated mitochondrial dysfunction and cell injury when airway epithelial cells were incubated with 7.5% CSE. These data suggest that Nix-dependent mitophagy promotes airway epithelial cell and mitochondria injury induced by cigarette smoke, and may be involved in the pathogenesis of COPD and other cigarette smoke-associated diseases.

Houttuynia cordata polysaccharide alleviated intestinal injury and modulated intestinal microbiota in H1N1 virus infected mice

Houttuynia cordata polysaccharide (HCP) is extracted from Houttuynia cordata, a key traditional Chinese medicine. The study was to investigate the effects of HCP on intestinal barrier and microbiota in H1N1 virus infected mice. Mice were infected with H1N1 virus and orally administrated HCP at a dosage of 40 mg(kg⁻¹(d⁻¹. H1N1 infection caused pulmonary and intestinal injury and gut microbiota imbalance. HCP significantly suppressed the expression of hypoxia inducible factor-1α and decreased mucosubstances in goblet cells, but restored the level of zonula occludens-1 in intestine. HCP also reversed the composition change of intestinal microbiota caused by H1N1 infection, with significantly reduced relative abundances of Vibrio and Bacillus, the pathogenic bacterial genera. Furthermore, HCP rebalanced the gut microbiota and restored the intestinal homeostasis to some degree. The inhibition of inflammation was associated with the reduced level of Toll-like receptors and interleukin-1β in intestine, as well as the increased production of interleukin-10. Oral administration of HCP alleviated lung injury and intestinal dysfunction caused by H1N1 infection. HCP may gain systemic treatment by local acting on intestine and microbiota. This study proved the high-value application of HCP.

Effects of alkaline-electrolyzed and hydrogen-rich water, in a high-fat-diet nonalcoholic fatty liver disease mouse model

AIM

To identify the effect of hydrogen-rich water (HRW) and electrolyzed-alkaline water (EAW) on high-fat-induced non-alcoholic fatty acid disease in mice.

METHODS

Mice were divided into four groups: (1) Regular diet (RD)/regular water (RW); (2) high-fat diet (HFD)/RW; (3) RD/EAW; and (4) HFD/EAW. Weight and body composition were measured. After twelve weeks, animals were sacrificed, and livers were processed for histology and reverse-transcriptase polymerase chain reaction. A similar experiment was performed using HRW to determine the influence and importance of molecular hydrogen (H₂) in EAW. Finally, we compared the response of hepatocytes isolated from mice drinking HRW or RW to palmitate overload.

RESULTS

EAW had several properties important to the study: (1) pH = 11; (2) oxidation-reduction potential of -495 mV; and (3) H₂ = 0.2 mg/L. However, in contrast to other studies, there were no differences between the groups drinking EAW or RW in either the RD or HFD groups. We hypothesized that the null result was due to low H₂ concentrations. Therefore, we evaluated the effects of RW and low and high HRW concentrations (L-HRW = 0.3 mg H₂/L and H-HRW = 0.8 mg H₂/L, respectively) in mice fed an HFD. Compared to RW and L-HRW, H-HRW resulted in a lower increase in fat mass (46% vs 61%), an increase in lean body mass (42% vs 28%), and a decrease in hepatic lipid accumulation (P < 0.01). Lastly, exposure of hepatocytes isolated from mice drinking H-HRW to palmitate overload demonstrated a protective effect from H₂ by reducing hepatocyte lipid accumulation in comparison to mice drinking regular water.

CONCLUSION

H₂ is the therapeutic agent in electrolyzed-alkaline water and attenuates HFD-induced nonalcoholic fatty liver disease in mice.

Effects of nitrous acid exposure on baseline pulmonary resistance and Muc5ac in rats

We examined the baseline pulmonary resistance (RLung), baseline dynamic lung compliance (Cdyn), cytokine inductions, and histological alterations in rats exposed to nitrous acid (HONO) with secondary products of nitrogen dioxide (NO₂) and nitric oxide (NO) to assess its biological effects. We exposed three groups of nine male F344 rats to different doses of HONO for six weeks (24 h/day). The cumulative values of HONO concentration were measured twice. The average concentrations of nitrogen oxide for each group were 5.8 parts per million (ppm) HONO with secondary products of 0.7 ppm NO₂ and 2.3 ppm NO, 4.1 ppm HONO with 0.1 ppm NO₂ and 0.6 ppm NO, and a clean air control. We measured baseline RLung and baseline Cdyn using tracheal cannulation. A tracheal tube was inserted into the trachea by tracheostomy, and lung function measurements (baseline RLung and baseline Cdyn) were conducted in mechanically ventilated rats. We measured mRNA levels of Cxcl-1, TNF-α, and Muc5ac in the right lung using quantitative RT-PCR, and observed histological alterations and the alveolar mean linear intercept (Lm) on the left lung. Our results demonstrated that HONO exposure significantly increased baseline RLung, Lm and Muc5ac expression, but did not affect baseline Cdyn or expression of Cxcl-1 and TNF-α. Further, we identified bronchial smooth muscle hypertrophy, pulmonary emphysema-like alterations in the alveolar duct centriacinar regions, and increased goblet cells in HONO-exposed rats. The present results suggest that HONO (with secondary products) adversely affects respiratory function, but that these pathologies may be unrelated to inflammation.

Hydrogen gas inhalation protects against cigarette smoke-induced COPD development in mice

Background

Chronic obstructive pulmonary disease (COPD) is a chronic lung disease with limited treatment options. Hydrogen (H₂) has been shown to be anti-oxidative and anti-inflammatory. This study aimed to evaluate the beneficial effects of H₂ inhalation on COPD development in mice.

Methods

A COPD mouse model was established in male C57BL mice by cigarette smoke (CS) exposure. The H₂ intervention was administered by atomisation inhalation. Lung functions were assessed by using Buxco lung function measurement system. The inflammatory cells were counted and the levels of IL-6 and KC in BALF were assayed with ELISA. The lung tissue was subjected to H&E or PAS or Masson's trichrome stain. Furthermore, 16HBE cells were used to evaluate the effects of H₂ on signaling change caused by hydrogen peroxide (H₂O₂). H₂O₂ was used to treat 16HBE cells with or without H₂ pretreatment. The IL-6 and IL-8 levels in cell culture medium were measured. The levels of phosphorylated ERK1/2 and nucleic NF-κB in lungs and 16HBE cells were determined.

Results

H₂ ameliorated CS-induced lung function decline, emphysema, inflammatory cell infiltration, small-airway remodelling, goblet-cell hyperplasia in tracheal epithelium and activated ERK1/2 and NF-κB in mouse lung. In 16HBE airway cells, H₂O₂ increased IL-6 and IL-8 secretion in conjunction with ERK1/2 and NF-κB activation. These changes were reduced by H₂ treatment.

Conclusions

These findings demonstrated that H₂ inhalation could inhibit CS-induced COPD development in mice, which is associated with reduced ERK1/2 and NF-κB-dependent inflammatory responses.

Inhalation of hydrogen gas attenuates airway inflammation and oxidative stress in allergic asthmatic mice

Background

Asthma is a worldwide common chronic airway disease that cannot be cured and results in the huge burden in public health. Oxidative stress was considered an important mechanism in the pathogenesis of asthma. Hydrogen gas been demonstrated to function as a novel antioxidant and exert therapeutic antioxidant activity in a number of diseases and the function of this nontoxic gas in asthma was unclear. The purpose of the study aims to examine the effect of inhalation hydrogen gas on the pathophysiology of a mouse model of asthma.

Methods

A murine model of ovalbumin (OVA)-induced allergic airway inflammation was used in this study. Briefly, Mice were sensitized to ovalbumin and received inhalation of 67% high concentration of hydrogen gas for 60 min once a day for 7 consecutive days after OVA or PBS challenge respectively. Lung function was assessed in the apparatus with 4 channels of biological signal system. Morphology and goblet cell hyperplasia were stained by H/E and Periodic acid-Schiff staining. Cytologic classification in the bronchial alveolar lavage fluid (BALF) was analyzed by Wright Giemsa staining. Serum, BALF and lung tissue were collected for biochemical assay. One-way analysis of variance (ANOVA) was used to determine statistical significance between groups. Multiple comparisons were made by Bonferroni’s Multiple Comparison Test by using GraphPad Prism 5 software.

Results

Inhalation of hydrogen gas abrogated ovalbumin-induced the increase in lung resistance. Concomitantly, the asthmatic mice showed severe inflammatory infiltration and goblet cell hyperplasia which were reversed by hydrogen gas inhalation. Hydrogen gas inhalation reduced significantly the number of total cells, eosinophils and lymphocytes in BALF. Increased level of IL-4, IL-13, TNF-α and CXCL15 in the BALF and IL-4 in the serum were decreased significantly after inhalation. Hydrogen gas inhalation markedly upregulated the activity of decreased superoxide dismutase and significantly attenuated the increased level of malondialdehyde and myeloperoxidase.

Conclusions

Hydrogen gas inhalation improves lung function and protects established airway inflammation in the allergic asthmatic mice model which may be associated with the inhibition of oxidative stress process. This study provides a potential alternative therapeutic opportunity for the clinical management of asthma.

The transfer of hydrogen from inert gas to therapeutic gas

Hydrogen is the most abundant chemical element in the universe, and has been used as an inert gas for a long time. More recent studies have shown that molecular hydrogen as a kind of antioxidant, anti-inflammatory, anti-apoptosis, gene expression and signal modulation molecule, can be used for the treatment of many diseases. This review mainly focuses on the research progresses of hydrogen in various medical fields and the possible action mechanisms.

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.

Hydrogen-rich pure water prevents cigarette smoke-induced pulmonary emphysema in SMP30 knockout mice

Chronic obstructive pulmonary disease (COPD) is predominantly a cigarette smoke (CS)-triggered disease with features of chronic systemic inflammation. Oxidants derived from CS can induce DNA damage and stress-induced premature cellular senescence in the respiratory system, which play significant roles in COPD. Therefore, antioxidants should provide benefits for the treatment of COPD; however, their therapeutic potential remains limited owing to the complexity of this disease. Recently, molecular hydrogen (H₂) has been reported as a preventive and therapeutic antioxidant. Molecular H₂ can selectively reduce hydroxyl radical accumulation with no known side effects, showing potential applications in managing oxidative stress, inflammation, apoptosis, and lipid metabolism. However, there have been no reports on the efficacy of molecular H₂ in COPD patients. In the present study, we used a mouse model of COPD to investigate whether CS-induced histological damage in the lungs could be attenuated by administration of molecular H₂. We administered H₂-rich pure water to senescence marker protein 30 knockout (SMP30-KO) mice exposed to CS for 8 weeks. Administration of H₂-rich water attenuated the CS-induced lung damage in the SMP30-KO mice and reduced the mean linear intercept and destructive index of the lungs. Moreover, H₂-rich water significantly restored the static lung compliance in the CS-exposed mice compared with that in the CS-exposed H₂-untreated mice. Moreover, treatment with H₂-rich water decreased the levels of oxidative DNA damage markers such as phosphorylated histone H2AX and 8-hydroxy-2'-deoxyguanosine, and senescence markers such as cyclin-dependent kinase inhibitor 2A, cyclin-dependent kinase inhibitor 1, and β-galactosidase in the CS-exposed mice. These results demonstrated that H₂-rich pure water attenuated CS-induced emphysema in SMP30-KO mice by reducing CS-induced oxidative DNA damage and premature cell senescence in the lungs. Our study suggests that administration of molecular H₂ may be a novel preventive and therapeutic strategy for COPD.

Hydrogen-rich saline inhibits tobacco smoke-induced chronic obstructive pulmonary disease by alleviating airway inflammation and mucus hypersecretion in rats

Chronic obstructive pulmonary disease induced by tobacco smoke has been regarded as a great health problem worldwide. The purpose of this study is to evaluate the protective effect of hydrogen-rich saline, a novel antioxidant, on chronic obstructive pulmonary disease and explore the underlying mechanism. Sprague-Dawley rats were made chronic obstructive pulmonary disease models via tobacco smoke exposure for 12 weeks and the rats were treated with 10 ml/kg hydrogen-rich saline intraperitoneally during the last 4 weeks. Lung function testing indicated hydrogen-rich saline decreased lung airway resistance and increased lung compliance and the ratio of forced expiratory volume in 0.1 s/forced vital capacity in chronic obstructive pulmonary disease rats. Histological analysis revealed that hydrogen-rich saline alleviated morphological impairments of lung in tobacco smoke-induced chronic obstructive pulmonary disease rats. ELISA assay showed hydrogen-rich saline lowered the levels of pro-inflammatory cytokines (IL-8 and IL-6) and anti-inflammatory cytokine IL-10 in bronchoalveolar lavage fluid and serum of chronic obstructive pulmonary disease rats. The content of malondialdehyde in lung tissue and serum was also determined and the data indicated hydrogen-rich saline suppressed oxidative stress reaction. The protein expressions of mucin MUC5C and aquaporin 5 involved in mucus hypersecretion were analyzed by Western blot and ELISA and the data revealed that hydrogen-rich saline down-regulated MUC5AC level in bronchoalveolar lavage fluid and lung tissue and up-regulated aquaporin 5 level in lung tissue of chronic obstructive pulmonary disease rats. In conclusion, these results suggest that administration of hydrogen-rich saline exhibits significant protective effect on chronic obstructive pulmonary disease through alleviating inflammation, reducing oxidative stress and lessening mucus hypersecretion in tobacco smoke-induced chronic obstructive pulmonary disease rats. Impact statement This study was designed to evaluate protective effect of hydrogen-rich saline, a novel antioxidant, on tobacco smoke (TS)-induced chronic obstructive pulmonary disease (COPD) in rats and explore the underlying mechanism. Our results suggest that administration of hydrogen-rich saline improves lung function and alleviates morphological impairments of lung through alleviating inflammation, reducing oxidative stress and lessening mucus hypersecretion in TS-induced COPD rats.

Hydrogen-rich water ameliorates bronchopulmonary dysplasia (BPD) in newborn rats

Bronchopulmonary dysplasia (BPD) is characterized by developmental arrest of the alveolar tissue. Oxidative stress is causally associated with development of BPD. The effects of hydrogen have been reported in a wide range of disease models and human diseases especially caused by oxidative stress. We made a rat model of BPD by injecting lipopolysaccharide (LPS) into the amniotic fluid at E16.5. The mother started drinking hydrogen-rich water from E9.5 and also while feeding milk. Hydrogen normalized LPS-induced abnormal enlargement of alveoli at P7 and P14. LPS increased staining for nitrotyrosine and 8-OHdG of the lungs, and hydrogen attenuated the staining. At P1, LPS treatment decreased expressions of genes for FGFR4, VEGFR2, and HO-1 in the lungs, and hydrogen increased expressions of these genes. In contrast, LPS treatment and hydrogen treatment had no essential effect on the expression of SOD1. Inflammatory marker proteins of TNFα and IL-6 were increased by LPS treatment, and hydrogen suppressed them. Treatment of A549 human lung adenocarcinoma epithelial cells with 10% hydrogen gas for 24 hr decreased production of reactive oxygen species in both LPS-treated and untreated cells. Lack of any known adverse effects of hydrogen makes hydrogen a promising therapeutic modality for BPD. Pediatr Pulmonol. 2016; 51:928-935. © 2016 Wiley Periodicals, Inc.

Cigarette smoke induces mucin hypersecretion and inflammatory response through the p66shc adaptor protein-mediated mechanism in human bronchial epithelial cells

The p66Shc adaptor protein is a newly recognized mediator of mitochondrial dysfunction and might play a role in cigarette smoke (CS)-induced airway epithelial cell injury. CS can induce an excessive amount of reactive oxygen species (ROS) generation, which can cause mitochondrial depolarization and injury through the oxidative stress-mediated Serine36 phosphorylation of p66Shc. The excessive production of ROS can trigger an inflammatory response and mucin hypersecretion by enhancing the transcriptional activity of pro-inflammatory cytokines and mucin genes. Therefore, we speculate that p66Shc plays an essential role in airway epithelial cell injury and the process of mucin generation in CS-induced chronic inflammatory airway diseases. Our present study focuses on the role of p66Shc in ROS generation, and on the resulting mitochondrial dysfunction, inflammatory response and mucus hypersecretion in CS-stimulated human bronchial epithelial cells (16HBE). We found that CS disturbed the mitochondrial function by increasing the level of phosphorylated p66Shc in these cells and that the effects were significantly reduced by silencing p66Shc. Conversely, the ectopic overexpression of wild-type p66Shc enhanced these effects. We also found that high levels of ROS inhibited FOXO3a transcriptional activity, which led to NF-κB activation. Subsequently, activated NF-κB promoted pro-inflammatory cytokine production and mucin hypersecretion. Thus, manipulating p66Shc might offer a new therapeutic modality with which to treat chronic inflammatory airway diseases.

Callicarpa japonica Thunb. attenuates cigarette smoke-induced neutrophil inflammation and mucus secretion

ETHNOPHARMACOLOGICAL RELEVANCE

Callicarpa japonica Thunb. (CJT) is traditionally used as an herbal remedy for the treatment of inflammatory diseases in Korea, China, and Japan. In this study, we evaluated the effects of C. japonica Thunb. (CJT) on the development of COPD using a Cigarette smoke (CS)-induced murine model and cigarette smoke condensate (CSC)-stimulated H292 cells, human pulmonary mucoepidermoid cell line.

MATERIAL AND METHODS

C. japonica Thunb. was isolated from the leaves and stem of C. japonica. The methanol extract profile was obtained by UPLC Q-TOF-MS analysis. In in vivo experiment, the mice received 1h of cigarette smoke for 10 days. C. japonica Thunb. was administered to mice by oral gavage 1h before cigarette smoke exposure for 10 days. In in vitro experiment, we evaluated the effect of C. japonica Thunb. on the expression of MUC5AC and proinflammatory cytokines in H292 cells stimulated with CSC.

RESULTS

CJT treatment effectively suppressed the infiltration of neutrophils, and decreased the production of ROS and the activity of neutrophil elastase in the bronchoalveolar lavage fluid (BALF) induced by CS. CJT also significantly attenuated production of proinflammatory cytokines such as IL-6 and TNF-α in the BALF, and reduced the infiltration of inflammatory cells and the production of mucus in lung tissue induced by CS. In in vitro experiments, CJT decreased the expression of MUC5AC and proinflammatory cytokines in CSC-stimulated H292 cells. Furthermore, CJT attenuated the phosphorylation of ERK induced by CSC in H292 cells. Taken together, CJT effectively reduced the neutrophil airway inflammation and mucus secretion induced by CS in murine model, and inhibited the expression of MUC5AC in CSC-stimulated H292 human lung cell line. These findings suggest that CJT has a therapeutic potential for the treatment of COPD.

Molecular Regulation of Toll-like Receptors in Asthma and COPD

Asthma and chronic obstructive pulmonary disease (COPD) have both been historically associated with significant morbidity and financial burden. These diseases can be induced by several exogenous factors, such as pathogen-associated molecular patterns (PAMPs) (e.g., allergens and microbes). Endogenous factors, including reactive oxygen species, and damage-associated molecular patterns (DAMPs) recognized by toll-like receptors (TLRs), can also result in airway inflammation. Asthma is characterized by the dominant presence of eosinophils, mast cells, and clusters of differentiation (CD)4⁺ T cells in the airways, while COPD typically results in the excessive formation of neutrophils, macrophages, and CD8⁺ T cells in the airways. In both asthma and COPD, in the respiratory tract, TLRs are the primary proteins of interest associated with the innate and adaptive immune responses; hence, multiple treatment options targeting TLRs are being explored in an effort to reduce the severity of the symptoms of these disorders. TLR-mediated pathways for both COPD and asthma have their similarities and differences with regards to cell types and the pro-inflammatory cytotoxins present in the airway. Because of the complex TLR cascade, a variety of treatments have been used to minimize airway hypersensitivity and promote bronchodilation. Although unsuccessful at completely alleviating COPD and severe asthmatic symptoms, new studies are focused on possible targets within the TLR cascade to ameliorate airway inflammation.

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.

Methane-rich saline attenuates ischemia/reperfusion injury of abdominal skin flaps in rats via regulating apoptosis level

Background

In plastic surgery, skin damage induced by ischemia/reperfusion (I/R) is a multifactorial process that often occurs. Methane gas has been reported to be a new therapeutic gas for attenuating I/R injury. In this study, we assessed the effects of methane-rich saline (MRS) in regulating apoptosis on skin flap I/R injury.

Methods

Male Sprague–Dawley rats, 6–8 weeks old, were divided randomly into three groups: one sham surgery group (SH) and two surgery groups. After undergoing 6 h of I/R management of an abdominal skin flap, surgery groups were treated with physiological saline (I/R-P) or methane-rich saline (I/R-M). On the 3rd postoperative day, a laser Doppler flowmeter was used to measure flap blood supply, and hematoxylin and eosin (H&E) staining was used to observe morphological changes. TdT-mediated dUTP-X nick end labeling (TUNEL) staining was also used to observe early apoptosis and is presented as the percentage of TUNEL-positive cells. Moreover, pASK-1, pJNK, Bcl-2 and Bax were detected by immunohistochemical technology. Caspase-3 activity was also measured to evaluate the effects of MRS.

Results

Compared to the I/R-P group, the flaps in the I/R-M group presented a larger survival area and better blood perfusion with less inflammatory infiltration and cell apoptosis, a higher expression of Bcl-2, a lower expression of pASK-1, pJNK and Bax, and a lower caspase-3 activity.

Conclusion

According to the results, MRS attenuated I/R injury by regulating apoptosis and has the potential to be applied as a new therapy for improving skin flap survival.

Protective Effects of Hydrogen-Rich Saline on Rats with Smoke Inhalation Injury

OBJECTIVE

To explore the protective effects of hydrogen-rich saline on rats with smoke inhalation injury.

METHODS

36 healthy male Sprague-Dawley rats were randomly divided into 3 groups (n = 12 per group): sham group (S), inhalation injury plus normal saline treatment group (I+NS), and inhalation injury plus hydrogen-rich saline treatment group (I+HS). 30 min after injury, normal saline and hydrogen-rich saline were injected intraperitoneally (5 mL/kg) in I+NS group and I+HS group, respectively. All rats were euthanized and blood and organ specimens were collected for determination 24 h after inhalation injury.

RESULTS

Tumor necrosis factor-alpha (TNF-α) levels, malondialdehyde (MDA) concentrations, nuclear factor kappa B (NF-κB) p65 expression, and apoptosis index (AI) in I+HS group were significantly decreased (P < 0.05), while superoxide dismutase (SOD) activities were increased compared with those in I+NS group; and a marked improvement in alveolar structure was also found after hydrogen-rich saline treatment.

CONCLUSIONS

Hydrogen-rich saline treatment exerts protective effects in acute lung injury induced by inhalation injury, at least in part through the activation of anti-inflammatory and antioxidant pathways and inhibition of apoptosis.

Hydrogen-water enhances 5-fluorouracil-induced inhibition of colon cancer

Oxidative stress is involved in cancer development. Hydrogen (H₂) is a potent antioxidant and exhibits anti-inflammatory and potentially anticancer-like activities. This study aimed to investigate the role of H₂ incombination with 5-fluorouracil (5-FU) in cancer treatment both in vitro and in vivo using the colon 26 cell line. The survival rate was determined using the Kaplan–Meier survival test, and cell viability was assessed using cell viability imaging kit and the MTT assay, and activation of the cell apoptosis pathway (Phosphorylated adenosine monophosphate activated protein kinase (p-AMPK), Apoptosis-inducing factor (AIF) and Caspase 3) were characterized by western blots. Hydrogen water administration improved the survival of mice with colon 26-induced cancer. Furthermore, hydrogen water enhanced cell apoptosis in cancer cells, resulting in a marked increase in the expression of p-AMPK, AIF and Caspase 3 in colon 26 cells. Hydrogen water also increased the inhibitory effect of 5-FU on colon 26 cells with spect to cell survival rate and anticancer functions. Additionally, high-content hydrogen water exhibited stronger antioxidative and anticancer activity than did the natural hydrogen water. In conclusion, high-content hydrogen water can inhibit colon cancer, particularly in combination with 5-fluorouracil.

Hydrogen-rich saline attenuates skin ischemia/reperfusion induced apoptosis via regulating Bax/Bcl-2 ratio and ASK-1/JNK pathway

INTRODUCTION

Many pathways have been reported involving the effect of hydrogen-rich saline on protecting skin flap partial necrosis induced by the inflammation of ischemia/reperfusion injury. This study focused on the influence of hydrogen-rich saline treatment on apoptosis pathway of ASK-1/JNK and Bcl-2/Bax radio in I/R injury of skin flaps.

METHODS

Adult male Sprague-Dawley rats were divided into three groups. Group 1 was sham surgery group, Group 2 and 3 were ischemia/reperfusion surgery treated with physiological saline and hydrogen-rich saline respectively. Blood perfusion of flap was measured by Laser doppler flowmeters. Hematoxylin and eosin staining was used to observe morphological changes. Early apoptosis in skin flap was observed through TUNEL staining and presented as the percentage of TUNEL-positive cells of total cells. pASK-1, pJNK, Bcl-2 and Bax were examined by immunodetection. In addition Bcl-2, Bax and caspase-3 were detected by qPCR. Caspase-3 activity was also measured.

RESULTS

Compared to the Group 2, tissues from the group 3 were observed with a high expression of Bcl-2 and a low expression of pASK-1, pJNK, and Bax, a larger survival area and a high level of blood perfusion. Hydrogen-rich saline ameliorated inflammatory infiltration and decreased cell apoptosis.

CONCLUSION

The results indicate that hydrogen-rich saline could ameliorate ischemia/reperfusion injury and improve flap survival rate by inhibiting the apoptosis factor and, at the same time, promoting the expression of anti-apoptosis factor.

Muc5ac mucin expression during rat skin development

Some mucin genes have been detected during human embryonic and fetal organ development; however, little is known about mucin expression in epidermal development, neither in humans nor in other species. The present research was developed to explore Muc5ac skin expression during pre- and post-natal rat development. Immunohistochemistry (IHC), Western blotting (WB) and RT-PCR were employed. By IHC, Muc5ac protein was found early in embryonic epidermis from day 13 of gestation until seven days after birth when the surface epidermis became negative and the reaction was restricted to secreting sebum cells. In coincidence with IHC findings, WB analysis showed a band at approximately 200KDa at the same periods of development. Results were also confirmed by RT-PCR.

Muc5ac expression in rat embryonic epidermis suggests that Muc5ac may play a protective role in embryonic skin previous to birth which may be replaced by pile covering. To our knowledge, this is the first report that confirmed Muc5ac expression during skin development.

Molecular hydrogen as a novel antioxidant: overview of the advantages of hydrogen for medical applications

Molecular hydrogen (H2) was believed to be inert and nonfunctional in mammalian cells. We overturned this concept by demonstrating that H2 reacts with highly reactive oxidants such as hydroxyl radical ((•)OH) and peroxynitrite (ONOO(-)) inside cells. H2 has several advantages exhibiting marked effects for medical applications: it is mild enough neither to disturb metabolic redox reactions nor to affect signaling by reactive oxygen species. Therefore, it should have no or little adverse effects. H2 can be monitored with an H2-specific electrode or by gas chromatography. H2 rapidly diffuses into tissues and cells to exhibit efficient effects. Thus, we proposed the potential of H2 for preventive and therapeutic applications. There are several methods to ingest or consume H2: inhaling H2 gas, drinking H2-dissolved water (H2-water), injecting H2-dissolved saline (H2-saline), taking an H2 bath, or dropping H2-saline onto the eyes. Recent publications revealed that, in addition to the direct neutralization of highly reactive oxidants, H2 indirectly reduces oxidative stress by regulating the expression of various genes. Moreover, by regulating gene expression, H2 functions as an anti-inflammatory, antiallergic, and antiapoptotic molecule, and stimulates energy metabolism. In addition to growing evidence obtained by model animal experiments, extensive clinical examinations were performed or are under way. Since most drugs specifically act on their specific targets, H2 seems to differ from conventional pharmaceutical drugs. Owing to its great efficacy and lack of adverse effects, H2 has potential for clinical applications for many diseases.

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.

Molecular hydrogen as a preventive and therapeutic medical gas: initiation, development and potential of hydrogen medicine

Molecular hydrogen (H2) has been accepted to be an inert and nonfunctional molecule in our body. We have turned this concept by demonstrating that H2 reacts with strong oxidants such as hydroxyl radical in cells, and proposed its potential for preventive and therapeutic applications. H2 has a number of advantages exhibiting extensive effects: H2 rapidly diffuses into tissues and cells, and it is mild enough neither to disturb metabolic redox reactions nor to affect signaling reactive oxygen species; therefore, there should be no or little adverse effects of H2. There are several methods to ingest or consume H2; inhaling H2 gas, drinking H2-dissolved water (H2-water), injecting H2-dissolved saline (H2-saline), taking an H2 bath, or dropping H2-saline into the eyes. The numerous publications on its biological and medical benefits revealed that H2 reduces oxidative stress not only by direct reactions with strong oxidants, but also indirectly by regulating various gene expressions. Moreover, by regulating the gene expressions, H2 functions as an anti-inflammatory and anti-apoptotic, and stimulates energy metabolism. In addition to growing evidence obtained by model animal experiments, extensive clinical examinations were performed or are under investigation. Since most drugs specifically act to their targets, H2 seems to differ from conventional pharmaceutical drugs. Owing to its great efficacy and lack of adverse effects, H2 has promising potential for clinical use against many diseases.