Hydrogen–oxygen therapy can alleviate radiotherapy-induced hearing loss in patients with nasopharyngeal cancer

Three patients with nasopharyngeal carcinoma developed binaural secretory otitis media 12, 2, and 0.5 years after radiotherapy, respectively. The secretions subsided after conventional drug and drainage treatments, but hearing continued to deteriorate until severe loss was documented in both ears. After examination of the eardrum and tympanum, patients were enrolled in a clinical trial in the first half of 2019 (ClinicalTrials.gov: NCT03818347). After 0.5, 1 and 2 months of continuous hydrogen–oxygen therapy, our first three patients reported different levels of improvement in binaural hearing. This is the first report to show that, after treatment for nasopharyngeal carcinoma, hearing loss can be alleviated using hydrogen–oxygen therapy.

Sirt3 mediates the protective effect of hydrogen in inhibiting ROS-induced retinal senescence

Hydrogen possesses antioxidative effects and cures numerous types of ophthalmopathy, but the mechanism of hydrogen on ROS-induced retinal senescence remains elusive. In this study, retinal morphology revealed that hydrogen reduced the number and size of vitreous black deposits in Bruch’s membrane in NaIO3 mice. Hydrogen also reduced ROS levels in the retina as assessed by DHE staining. Moreover, this result was consistent with the downregulation of expression of the oxidative stress hallmark OGG1. These findings suggested that hydrogen can reduce retinal oxidative stress induced by NaIO3, and this result was further verified using the antioxidant ALCAR. Mechanistic analysis revealed that hydrogen significantly inhibited the downregulation of Sirt3 expression, and this notion was confirmed using AICAR, which restores Sirt3 expression and activity. Moreover, hydrogen reduced the expression of p53, p21 and p16 and the number of blue-green precipitations in the retinas of NaIO3 mice as assessed by SA-β-gal staining. We also found that hydrogen decreased the expression of the DNA damage-related protein ATM, cyclinD1 and NF-κB but increased the expression of the DNA repair-related protein HMGB1, suggesting that hydrogen inhibits senescence in retinas of NaIO3 mice. Additionally, OCT examination revealed that hydrogen suppressed retinal high reflex formation significantly and prevented the retina from thinning. This result was supported by ERG assays that demonstrated that hydrogen prevented the reduction in a- and b-wave amplitude induced by NaIO3 in mice. Thus, our data suggest that hydrogen may inhibit retinal senescence by suppressing the downregulation of Sirt3 expression through reduced oxidative stress reactions.

Hydrogen Indirectly Suppresses Increases in Hydrogen Peroxide in Cytoplasmic Hydroxyl Radical-Induced Cells and Suppresses Cellular Senescence

Bacteria inhabiting the human gut metabolize microbiota-accessible carbohydrates (MAC) contained in plant fibers and subsequently release metabolic products. Gut bacteria produce hydrogen (H2), which scavenges the hydroxyl radical (•OH). Because H2 diffuses within the cell, it is hypothesized that H2 scavenges cytoplasmic •OH (cyto •OH) and suppresses cellular senescence. However, the mechanisms of cyto •OH-induced cellular senescence and the physiological role of gut bacteria-secreted H2 have not been elucidated. Based on the pyocyanin-stimulated cyto •OH-induced cellular senescence model, the mechanism by which cyto •OH causes cellular senescence was investigated by adding a supersaturated concentration of H2 into the cell culture medium. Cyto •OH-generated lipid peroxide caused glutathione (GSH) and heme shortage, increased hydrogen peroxide (H2O2), and induced cellular senescence via the phosphorylation of ataxia telangiectasia mutated kinase serine 1981 (p-ATMser1981)/p53 serine 15 (p-p53ser15)/p21 and phosphorylation of heme-regulated inhibitor (p-HRI)/phospho-eukaryotic translation initiation factor 2 subunit alpha serine 51 (p-eIF2α)/activating transcription factor 4 (ATF4)/p16 pathways. Further, H2 suppressed increased H2O2 by suppressing cyto •OH-mediated lipid peroxide formation and cellular senescence induction via two pathways. H2 produced by gut bacteria diffuses throughout the body to scavenge cyto •OH in cells. Therefore, it is highly likely that gut bacteria-produced H2 is involved in intracellular maintenance of the redox state, thereby suppressing cellular senescence and individual aging. Hence, H2 produced by intestinal bacteria may be involved in the suppression of aging

Protective effects of hydrogen inhalation during the warm ischemia phase against lung ischemia-reperfusion injury in rat donors after cardiac death

Background: Successful amelioration of long-term warm ischemia lung injury in donors after cardiac death (DCDs) can remarkably improve outcomes. Hydrogen gas provides potent anti-inflammatory and antioxidant effects against ischemia-reperfusion injury (IRI). This study observed the effects of hydrogen inhalation on lung grafts during the warm ischemia phase in cardiac death donors. Methods: After cardiac death, rat donor lungs (n = 8) underwent mechanical ventilation with 40% oxygen plus 60% nitrogen (control group) or 3% hydrogen and 40% oxygen plus 57% nitrogen (hydrogen group) for 2 h during the warm ischemia phase in situ. Then, lung transplantation was performed after 2 h of cold storage and 3 h of recipient reperfusion prior to lung graft assessment. Rats that underwent left thoracotomy without transplantation served as the sham group (n = 8). The results of static compliance and arterial blood gas analysis were assessed in the recipients. The wet-to-dry weight ratio (W/D), inflammation, oxidative stress, cell apoptosis and histologic changes were evaluated after 3 h of reperfusion. Nuclear factor kappa B (NF-κB) protein expression in the graft was analyzed by Western blotting. Results: Compared with the sham group, lung function, W/D, inflammatory reaction, oxidative stress and histological changes were decreased in both transplant groups (control and hydrogen groups). However, compared with the control group, exposure to 3% hydrogen significantly improved lung graft static compliance and oxygenation and remarkably decreased the wet-to-dry weight ratio, inflammatory reactions, and lipid peroxidation. Furthermore, hydrogen improved the lung graft histological changes, decreased the lung injury score and apoptotic index and reduced NF-κB nuclear accumulation in the lung grafts. Conclusion: Lung inhalation with 3% hydrogen during the warm ischemia phase attenuated lung graft IRI via NF-κB-dependent anti-inflammatory and antioxidative effects in rat donors after cardiac death.

Porphyrin-Palladium Hydride MOF Nanoparticles for Tumor-Targeted Photoacoustic Imaging-Guided Hydrogenothermal Therapy of Cancer

Hydrogen molecule as important energy gas recently was discovered to have high value in the treatment of many diseases, while the current constraint is low efficacy of stable hydrogen storage and delivery. By virtue of strong hydrogen-binding and catalytic hydrogenation capacity of Pd, here we develop a nanoscale porphyrin-palladium metal-organic framework (Pd-MOF) with highly dispersive Pd atoms as hydrogen carrier to efficiently load highly reductive hydrogen for tumor-targeted photoacoustic imaging (PAI)-guided hydrogenothermal therapy of cancer. The hydrogenated Pd-MOF (PdH-MOF) exhibits high hydrogen loading capacity, sustained hydrogen release profile, high tumor targeting ability, high photothermal effect and excellent PAI performance. Utilizing these unique advantages of PdH-MOF nanoparticles, high efficacy of hydrogenothermal therapy has been achieved by tumor-targeted delivery and PAI-guided therapy and sustained release of high payload of highly reductive hydrogen. This work proposes a new strategy for hydrogen storage, activation, delivery and combined therapy by using MOF as a versatile platform.

Polymer Dots Compartmentalized in Liposomes as Photocatalyst for In Situ Hydrogen Therapy

Semiconducting polymer dots (Pdots) have recently attracted considerable attention because of their photocatalytic activity as well as tunable optical band gap. In this contribution, we describe the therapeutic application of Pdots through in situ photocatalytic hydrogen generation. A liposome was employed as a nanoreactor to confine the Pdot photocatalyst, reactants, intermediates, and by‐products. Upon photon absorption by the Pdots, the catalytic cycle is initiated and repeated within the aqueous interior, while the H2 product diffuses across the lipid bilayer to counteract reactive oxygen species (ROS) overexpressed in diseased tissues. Ensemble and single‐particle Förster resonance energy transfer microscopy confirmed the proposed nanoreactor model. We demonstrate that a liposomal nanoreactor containing Pdots and a sacrificial electron donor is a potential photocatalytic nanoreactor for in situ hydrogen therapy.

Hydrogen gas distribution in organs after inhalation: Real-time monitoring of tissue hydrogen concentration in rat

Hydrogen has therapeutic and preventive effects against various diseases. Although animal and clinical studies have reported promising results, hydrogen distribution in organs after administration remains unclear. Herein, the sequential changes in hydrogen concentration in tissues over time were monitored using a highly sensitive glass microsensor and continuous inhalation of 3% hydrogen gas. The hydrogen concentration was measured in the brain, liver, kidney, mesentery fat and thigh muscle of rats. The maximum concentration, time to saturation, and other measurements representing the dynamics of distribution were obtained from the concentration curves, and the results obtained for different organs were compared. The time to saturation was significantly longer (20.2 vs 6.3–9.4 min. P = 0.004 in all cases) and increased more gradually in muscle than in the other organs. The maximum concentration was the highest in liver and the lowest in the kidney (29.0 ± 2.6 vs 18.0 ± 2.2 μmol/L; P = 0.03 in all cases). The concentration varied significantly depending on the organ (P = 0.03). These results provide the fundamentals for elucidating the mechanisms underlying the in vivo favourable effects of hydrogen gas in mammalian systems.

In vitro biocompatibility study approaches to evaluate the safety profile of electrolyzed water for skin and eye

Electrolyzed water (EW) is a widely used disinfectant agent with high oxidation–reduction potential (ORP). Although EW has been used in many areas, such as food hygiene, agriculture, and animal husbandry, the studies presented in the literature are not enough to clarify the toxic effects of EW. The aim of this study is, therefore, to produce EWs at different pH, ORP, and chlorine concentrations and to assess their safety in terms of toxicology. At the beginning of the study, the antimicrobial activity of the EW types with respect to bacteria and fungus was investigated. EWs below pH 7 were all effective in inactivating Enterococcus hirae, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans completely. In vitro studies of cell cultures revealed that different concentrations of EWs were not cytotoxic for the L929 cells under 10- to 80-fold dilutions. In addition, it has been determined that produced EWs did not have irritation potential, according to the in vitro EpiDerm ™ , reconstituted skin irritation test in the frames of biocompatibility tests. For the mucous membrane irritation test, the hen’s egg test-chorioallantoic membrane experiment was performed, and EWs were found to have no eye irritation. In conclusion, it has been shown that produced EWs with antimicrobial efficacy were found to be safe for skin and eye according to in vitro biocompatibility study studies. Thus, the establishment of a technological infrastructure for the EW production and the use of produced EW as an effective disinfectant in the food, medical, and agricultural areas should be encouraged.

Molecular hydrogen accelerates the reversal of acute obstructive cholangitis‑induced liver dysfunction by restoring gap and tight junctions

Gap junctions (GJs) and tight junctions (TJs) are essential to maintain the function of hepatocytes. Changes in biliary tract pressure and the effect of lipopolysaccharide (LPS) may lead to acute obstructive cholangitis (AOC) and cause liver injury via GJ and TJ dysfunction. Hydrogen has been confirmed to have a protective role in various organs during pathological conditions and inflammation. The present study investigated the function of junction proteins and the potential application of H2 in AOC‑induced liver injury. An AOC rat model was established by LPS injection through a bile duct catheter, while the distal bile duct was closed. The catheter sealing caps were removed and bile was allowed to flow out from the catheters at 12 h after LPS infusion. The potential application of H2 was studied in the AOC rat model with biliary drainage. It was observed that AOC induced the disruption of junction proteins of both GJs and TJs. H2 administration reversed AOC‑induced disruption of GJs and TJs after biliary drainage. The mechanism of this phenomenon suggests that H2 may have effectively attenuated AOC‑induced inflammatory and oxidative damage, and decreased matrix metalloproteinase activity. H2 may accelerate the reversal of AOC‑induced liver dysfunction, and this phenomenon may depend on reversing the inhibition of GJs and TJs.

L-Arabinose Elicits Gut-Derived Hydrogen Production and Ameliorates Metabolic Syndrome in C57BL/6J Mice on High-Fat-Diet

Obesity and metabolic syndrome (MS) associated with excess calorie intake has become a great public health concern worldwide. L-arabinose, a naturally occurring plant pentose, has a promising future as a novel food ingredient with benefits in MS; yet the mechanisms remain to be further elucidated. Gut microbiota is recently recognized to play key roles in MS. Molecular hydrogen, an emerging medical gas with reported benefits in MS, can be produced and utilized by gut microbes. Here we show oral L-arabinose elicited immediate and robust release of hydrogen in mice in a dose-and-time-dependent manner while alleviating high-fat-diet (HFD) induced MS including increased body weight especially fat weight, impaired insulin sensitivity, liver steatosis, dyslipidemia and elevated inflammatory cytokines. Moreover, L-arabinose modulated gene-expressions involved in lipid metabolism and mitochondrial function in key metabolic tissues. Antibiotics treatment abolished L-arabinose-elicited hydrogen production independent of diet type, confirming gut microbes as the source of hydrogen. q-PCR of fecal 16S rDNA revealed modulation of relative abundances of hydrogen-producing and hydrogen-consuming gut microbes as well as probiotics by HFD and L-arabinose. Our data uncovered modulating gut microbiota and hydrogen yield, expression of genes governing lipid metabolism and mitochondrial function in metabolic tissues is underlying L-arabinose’s benefits in MS.