Anti-inflammatory and antitumor action of hydrogen via reactive oxygen species

A comprehensive review of molecular hydrogen as a novel nutrition therapy in relieving oxidative stress and diseases: Mechanisms and perspectives

Oxidative stress is responsible for the pathogenesis of many diseases, and antioxidants are commonly included in their treatment protocols. Over the past two decades, numerous biomedical reports have revealed the therapeutic benefits of molecular hydrogen (H2) in relieving oxidation-related diseases. H2 has been found to have selective antioxidant properties against the most dangerous oxidants (hydroxyl radicals and peroxynitrite). H2 demonstrates numerous biologically therapeutic properties, including anti-inflammatory, antioxidant, anti-cancer, anti-stress, anti-apoptotic, anti-allergic effects, signaling molecule functions, regulation of redox balance, modulation of antioxidant enzyme gene expression, improvement of blood vessel function, down-regulation of pro-inflammatory cytokines, stimulation of energy metabolism, and protection of the nervous system. Experimental and clinical studies have shown the potential use of hydrogen nutrition therapy for ameliorating various diseases, including cardiovascular, respiratory, and metabolic disorders, as well as obesity, gastrointestinal disorders, and brain and nervous system disorders. The administration methods of hydrogen include inhalation, hydrogen-rich water, hydrogen-rich saline, hydrogen-rich eye drops, and hydrogen-rich bathing. Hydrogen nutritional therapy can be applied to different diseases, and it offers a natural alternative to chemical and radiation therapies. This review covers the different administration methods and the latest experimental and clinical research on the potential applications of H2 in nutritional therapy for different diseases.

Efficient Co-Delivery of Metformin and Ammonia Borane via a Hollow Mesoporous Polydopamine Nanogenerator for Enhanced Chemo-Photothermal Therapy against Melanoma

Melanoma, a highly aggressive skin cancer, poses significant challenges due to its rapid metastases and high mortality rates. While metformin (Met), a first-line medication for type 2 diabetes, has shown promise in inhibiting tumor growth and metastases, its clinical efficacy in cancer therapy is limited by low bioavailability, short half-life, and gastrointestinal adverse reactions associated with oral administration. In this study, we developed a hollow mesoporous polydopamine nanocomposite (HMPDA-PEG@Met@AB) coloaded with Met and ammonia borane (AB), designed to enable a combined gas-assisted, photothermal, and chemotherapeutic approach for melanoma treatment. This system releases Met and H2 in response to the acidic tumor microenvironment both in vitro and in vivo. The released H2 facilitates nanocomposites escape from lysosomes and inhibits heat shock protein expression in B16-F10 cells. Concurrently, Met and H2 disrupt the mitochondrial respiratory chain, reduce mitochondrial membrane potential, and inhibit ATP synthesis, ultimately activating AMPK signaling and suppressing mTOR activity. The system also elevates reactive oxygen species (ROS) levels, leading to tumor cell apoptosis. Under 808 nm near-infrared irradiation, the photothermal effect of HMPDA enhances Met release, further inhibiting tumor growth. In vivo experiments demonstrated efficient Met delivery, achieving therapeutic levels that activated AMPK in tumors without inducing hypoglycemia. These findings suggest that this drug delivery system holds significant clinical potential for melanoma treatment.

New possibilities of the prevention and treatment of cardiovascular pathologies. the potential of molecular hydrogen in the reduction of oxidative stress and its consequences

Disproportion between reactive oxygen species (ROS) production and the body's antioxidant system can cause oxidative stress, which is considered a common denominator in various pathological conditions, including cardiovascular diseases, aging, and cognitive disorders. The generation of free radicals, which occurs through partial reduction of oxygen, can quickly overwhelm the endogenous antioxidant system capacity of the cell. This causes lipid, protein, DNA and RNA damage, inflammation, and overall cell degeneration, which can be mitigated by various antioxidants. However, their use in human medicine did not bring the expected effect. Molecular hydrogen (H2), due to its unique physical and chemical properties, provides a number of benefits for alleviating oxidative stress. H2 is superior to conventional antioxidants as it can selectively reduce (.)OH radicals while preserving important ROS that are otherwise used for normal cell signaling. Key words Oxidative stress, Cardiovascular diseases, Molecular hydrogen, ROS, Inflammation.

Role of Pyroptosis in Endometrial Cancer and Its Therapeutic Regulation

Pyroptosis is an inflammatory cell death induced by inflammasomes that release several pro-inflammatory mediators such as interleukin-18 (IL-18) and interleukin-1β (IL-1β). Pyroptosis, a type of programmed cell death, has recently received increased interest both as a therapeutic and immunological mechanism. Numerous studies have provided substantial evidence supporting the involvement of inflammasomes and pyroptosis in a variety of pathological conditions including cancers, nerve damage, inflammatory diseases and metabolic conditions. Researchers have demonstrated that dysregulation of pyroptosis and inflammasomes contribute to the progression of endometriosis and gynecological malignancies. Current research also indicates that inflammasome and pyroptosis-dependent signaling pathways may further induce the progression of endometrial cancer (EC). More specifically, dysregulation of NLR family pyrin domain 3 (NLRP3) and caspase-1-dependent pyroptosis play a contributory role in the pathogenesis and development of EC. Therefore, pyroptosis-regulated protein gasdermin D (GSDMD) may be an independent prognostic biomarker for the detection of EC. This review presents the molecular mechanisms of pyroptosis-dependent signaling pathways and their contributory role and function in advancing EC. Moreover, this review offers new insights into potential future applications and innovative approaches in utilizing pyroptosis to develop effective anti-cancer therapies.

Novel Strategies for Tumor Treatment: Harnessing ROS-Inducing Active Ingredients from Traditional Chinese Medicine Through Multifunctional Nanoformulations

Reactive oxygen species (ROS) encompass a diverse group of chemically reactive molecules or ions distinguished by their substantial oxidative potential. Empirical studies have shown that the targeted administration of high toxic concentrations of ROS can effectively induce tumor cell death in various types. Numerous bioactive ingredients derived from traditional Chinese medicine (TCM), recognized for their ROS-inducing properties, have demonstrated significant anti-tumor activity. Nonetheless, their clinical application has been hindered by challenges such as low solubility, limited bioavailability, and poor selectivity. Multifunctional nanoformulations possess the potential to overcome these challenges and enhance the anticancer efficacy of ROS-inducing active compounds. Through extensive searches of various academic databases and a thorough review and screening of relevant literature, this study aims to systematically summarize and generalize multiple active ingredients in TCM that induce ROS generation, along with their multifunctional nanoformulations, from various perspectives. The objective is to provide new insights and references for fundamental cancer research and clinical treatments. Furthermore, we acknowledge that although numerous active ingredients and their nanoformulations in TCM have demonstrated ROS-inducing and anti-tumor potentials, potentially offering novel strategies for tumor therapy, the underlying mechanisms require further comprehensive investigation.

Dramatically Enhancing Multiphoton Harvesting Metal-Organic Frameworks for NIR-II Photocatalysis through Functional Regulation of Octupolar Molecules

The development of effective multiphoton absorption (MPA) materials for near-infrared (NIR) light-driven photocatalysis holds great significance. In this study, we incorporated two multibranched cyclometallated iridium(III) modules with varying degrees of conjugation onto MPA-inert metal-organic frameworks (MOFs) to active MPA performance. Subsequently, the MOFs were further modified with Co(II) and hyaluronic acid (HA) to fabricate MINCH and MISCH, respectively. By introducing octupolar molecules and expanding the conjugation, MISCH exhibited a larger MPA cross section for efficient NIR light absorption and improved carrier transfer, leading to outstanding NIR light-driven multiphoton photocatalytic hydrogen production. Moreover, the HA modification enabled MISCH to achieve specific multiphoton photocatalytic hydrogen therapy for cancer cells. This study provides valuable insights into constructing highly active MPA materials for NIR light-driven photocatalysis, presenting a potential platform for hydrogen therapy in tumor treatment.

H2 generated by fermentation in the human gut microbiome influences metabolism and competitive fitness of gut butyrate producers

BACKGROUND

Hydrogen gas (H2) is a common product of carbohydrate fermentation in the human gut microbiome and its accumulation can modulate fermentation. Concentrations of colonic H2 vary between individuals, raising the possibility that H2 concentration may be an important factor differentiating individual microbiomes and their metabolites. Butyrate-producing bacteria (butyrogens) in the human gut usually produce some combination of butyrate, lactate, formate, acetate, and H2 in branched fermentation pathways to manage reducing power generated during the oxidation of glucose to acetate and carbon dioxide. We predicted that a high concentration of intestinal H2 would favor the production of butyrate, lactate, and formate by the butyrogens at the expense of acetate, H2, and CO2. Regulation of butyrate production in the human gut is of particular interest due to its role as a mediator of colonic health through anti-inflammatory and anti-carcinogenic properties.

RESULTS

For butyrogens that contained a hydrogenase, growth under a high H2 atmosphere or in the presence of the hydrogenase inhibitor CO stimulated production of organic fermentation products that accommodate reducing power generated during glycolysis, specifically butyrate, lactate, and formate. Also as expected, production of fermentation products in cultures of Faecalibacterium prausnitzii strain A2-165, which does not contain a hydrogenase, was unaffected by H2 or CO. In a synthetic gut microbial community, addition of the H2-consuming human gut methanogen Methanobrevibacter smithii decreased butyrate production alongside H2 concentration. Consistent with this observation, M. smithii metabolic activity in a large human cohort was associated with decreased fecal butyrate, but only during consumption of a resistant starch dietary supplement, suggesting the effect may be most prominent when H2 production in the gut is especially high. Addition of M. smithii to the synthetic communities also facilitated the growth of E. rectale, resulting in decreased relative competitive fitness of F. prausnitzii.

CONCLUSIONS

H2 is a regulator of fermentation in the human gut microbiome. In particular, high H2 concentration stimulates production of the anti-inflammatory metabolite butyrate. By consuming H2, gut methanogenesis can decrease butyrate production. These shifts in butyrate production may also impact the competitive fitness of butyrate producers in the gut microbiome. Video Abstract.

Antioxidation activity of molecular hydrogen via protoheme catalysis in vivo: an insight from ab initio calculations

Recently, molecular hydrogen has been found to exhibit antioxidation activity through many clinical experiments, but the mechanism has not been fully understandable at atomic level. In this work, we perform systematic ab initio calculations of protoheme-hydrogen complexes to clarify the antioxidation mechanism of molecular hydrogen. We make molecular modeling of iron-protoporphyrin coordinated by imidazole, FeP(Im), and its hydrogen as well as dihydrogen complexes, together with reactive oxygen/nitrogen species (RONS). We carry out structural optimization and Mulliken charge analysis, revealing the two kinds of bonding characteristics between FeP(Im) and H[Formula: see text]: dihydrogen bonding in the end-on asymmetric configuration and Kubas bonding in the side-on symmetric configuration of H[Formula: see text] molecule. The activation barriers for adsorption and dissociation of H[Formula: see text] on and further desorption of H atom from FeP(Im) are found to be below 2.78 eV at most, which is remarkably lower than the H-H bond breaking energy of 4.64 eV in free H[Formula: see text] molecule. We find that the hydrogen bond dissociation energies of FeP(Im)-H[Formula: see text] and -H complexes are lower than those of RONS-H complexes, indicating the decisive role of protoheme as an effective catalyst in RONS antioxidation by molecular hydrogen in vivo.

Impact of nutraceuticals and dietary supplements on mitochondria modifications in healthy aging: a systematic review of randomized controlled trials

BACKGROUND

To date, the mitochondrial function has been related to several pathways involved in the cellular aging process. Dietary supplements might have reciprocal and multilevel interactions with mitochondria network; however, no systematic review assessed the role of different nutraceuticals in mitochondria modification of healthy older adults.

AIM

To assess the effects of different dietary supplements on mitochondria modifications in older adults.

METHODS

On February 22, 2022, PubMed, Scopus, Web of Science, and Cochrane were systematically searched from inception for randomized controlled trials (RCTs). According to PICO model, we considered healthy older adults as participants, nutraceutical treatment as intervention, any treatment as comparator, mitochondrial modifications as outcome. Jadad scale was used for the quality assessment.

RESULTS

Altogether, 8489 records were identified and screened until 6 studies were included. A total of 201 healthy older adults were included in the systematic review (mean age ranged from 67.0 ± 1.0 years to 76.0 ± 5.6 years). The dietary supplements assessed were sodium nitrite, N-3 polyunsaturated fatty acids, hydrogen-rich water, nicotinamide riboside, urolithin A, and whey protein powder. Positive effects were reported in terms of mitochondrial oxidative and antioxidant capacity, volume, bioenergetic capacity, and mitochondrial transcriptome based on the nutritional supplements. The quality assessment underlined that all the studies included were of good quality.

DISCUSSION

Although dietary supplements might provide positive effects on mitochondria modifications, few studies are currently available in this field.

CONCLUSION

Further studies are needed to better elucidate the reciprocal and multilevel interactions between nutraceuticals, mitochondria, and environmental stressors in healthy older adults.

Hydrogen-Rich Water Alleviates the Nickel-Induced Toxic Responses (Inflammatory Responses, Oxidative Stress, DNA Damage) and Ameliorates Cocoon Production in Earthworm

In recent years, studies investigating the protective effect of hydrogen-rich water (HRW) against different diseases and the toxicity of some substances have attracted increasing attention. Here, we assessed the effects of hydrogen-rich water on different nickel-induced toxic responses (reactive oxygen species (ROS), tumor necrosis factor-alpha (TNF-α), and 8-hydroxy-2'-deoxyguanosine (8-OHdG) of stress responses, histopathological changes) and cocoon production in earthworm model. Earthworms were randomly divided into two main groups: water (W) group including control (CW: ultrapure water), 10 (10W), 200 (200W), and 500 (500W), and hydrogen-rich ultrapure water (HRW) group including control (CHRW: hydrogen-rich ultrapure water), 10 (10HRW), 200 (200HRW), and 500 (500HRW) mg of nickel chloride kg-1 soil for 14 days. We found that cocoon production was less affected by the nickel exposure of earthworms in the 500HRW group compared to the 500W group. The ROS levels in 200HRW and 500HRW groups were less than that of 200W and 500W, respectively. The epithelial degeneration, epithelial necrosis, and necrosis in muscle fibers in tissues of earthworm were less damaged in 200HRW and 500HRW groups compared to 200W and 500W, respectively. HRW groups significantly reduced the expression of 8-OHdG induced by nickel exposure and inflammatory cytokine response including TNF-α. The study showed that hydrogen-rich water could alleviate the toxic effects of nickel-induced oxidative and inflammatory damages in earthworms. The HRW treatment known for its cheap and eco-friendly propertıes without any negative effects on the ecosystem can be used as a green method for alleviating the toxification effects of heavy metals in contaminated soil and increasing cocoon production of earthworms.

Effects of hydrogen water and psychological treatment in a sample of women with panic disorder: a randomized and controlled clinical trial

Research suggests that inflammation is an important mediator in the pathophysiology of anxiety disorders. In addition, women are more likely to develop an anxiety and depression disorder, in comorbidity with a wide spectrum of diseases related to the immune system. In recent years, hydrogen-rich water has emerged as a promising therapeutic strategy to prevent and intervene in stress-related disorders, due to its antioxidant and anti-inflammatory properties. The present study aims to analyze the effects of psychological treatment and a hydrogen-rich drink on the severity of anxiety and depression, pro-inflammatory cytokine levels, the cortisol awakening response, and general health state in a sample of women with panic disorder. This is a completely randomized, placebo-controlled study. The treatment group simultaneously received psychological treatment and 1.5 L of hydrogenated water for three months, compared to the control group that received psychological treatment and placebo. The results show that the treatment group was not significantly better than the control group. But there was a further reduction in measured pro-inflammatory cytokine scores, improving body pain and physical health. When between-group treatment effects were removed, psychological treatment significantly decreased measured variables, including cytokines and cortisol. The results support the presence of a maladaptive inflammatory process in women with panic disorder.

Anti-inflammatory effect of a triterpenoid from Balanophora laxiflora: results of bioactivity-guided isolation

Balanophora laxiflora, a medicinal plant traditionally used to treat fever, pain, and inflammation in Vietnam, has been reported to possess prominent anti-inflammatory activity. This study examined the active constituents and molecular mechanisms underlying these anti-inflammatory effects using bioactivity-guided isolation in combination with cell-based assays and animal models of inflammation. Among the isolated compounds, the triterpenoid (21α)-22-hydroxyhopan-3-one (1) showed the most potent inhibitory effect on COX-2 expression in LPS-stimulated Raw 264.7 macrophages. Furthermore, 1 suppressed the expression of the inflammatory mediators iNOS, IL-1β, INFβ, and TNFα in activated Raw 264.7 macrophages and alleviated the inflammatory response in carrageenan-induced paw oedema and a cotton pellet-induced granuloma model. Mechanistically, the anti-inflammatory effects of 1 were mediated via decreasing cellular reactive oxygen species (ROS) levels by inhibiting NADPH oxidases (NOXs) and free radical scavenging activities. By downregulating ROS signalling, 1 reduced the activation of MAPK signalling pathways, leading to decreased AP-1-dependent transcription of inflammatory mediators. These findings shed light on the chemical constituents that contribute to the anti-inflammatory actions of B. laxiflora and suggest that 1 is a promising candidate for treating inflammation-related diseases.

Hydrogen-rich water ameliorates neuropathological impairments in a mouse model of Alzheimer's disease through reducing neuroinflammation and modulating intestinal microbiota

Hydrogen exhibits the potential to treat Alzheimer's disease. Stereotactic injection has been previously used as an invasive method of administering active hydrogen, but this method has limitations in clinical practice. In this study, triple transgenic (3×Tg) Alzheimer's disease mice were treated with hydrogen-rich water for 7 months. The results showed that hydrogen-rich water prevented synaptic loss and neuronal death, inhibited senile plaques, and reduced hyperphosphorylated tau and neurofibrillary tangles in 3×Tg Alzheimer's disease mice. In addition, hydrogen-rich water improved brain energy metabolism disorders and intestinal flora imbalances and reduced inflammatory reactions. These findings suggest that hydrogen-rich water is an effective hydrogen donor that can treat Alzheimer's disease. This study was approved by the Animal Ethics and Welfare Committee of Shenzhen University, China (approval No. AEWC-20140615-002) on June 15, 2014.

Therapeutic Effects of Hydrogen Gas Inhalation on Trimethyltin-Induced Neurotoxicity and Cognitive Impairment in the C57BL/6 Mice Model

Oxidative stress (OS) is one of the causative factors in the pathogenesis of various neurodegenerative diseases, including Alzheimer’s disease (AD) and cognitive dysfunction. In the present study, we investigated the effects of hydrogen (H₂) gas inhalation in trimethyltin (TMT)-induced neurotoxicity and cognitive dysfunction in the C57BL/6 mice. First, mice were divided into the following groups: mice without TMT injection (NC), TMT-only injection group (TMT only), TMT injection + lithium chloride-treated group as a positive control (PC), and TMT injection + 2% H₂ inhalation-treated group (H₂). The TMT injection groups were administered a single dosage of intraperitoneal TMT injection (2.6 mg/kg body weight) and the H₂ group was treated with 2% H₂ for 30 min once a day for four weeks. Additionally, a behavioral test was performed with Y-maze to test the cognitive abilities of the mice. Furthermore, multiple OS- and AD-related biomarkers such as reactive oxygen species (ROS), nitric oxide (NO), calcium (Ca²⁺), malondialdehyde (MDA), glutathione peroxidase (GPx), catalase, inflammatory cytokines, apolipoprotein E (Apo-E), amyloid β (Aβ)-40, phospho-tau (p-tau), Bcl-2, and Bcl-2- associated X (Bax) were investigated in the blood and brain. Our results demonstrated that TMT exposure alters seizure and spatial recognition memory. However, after H₂ treatment, memory deficits were ameliorated. H₂ treatment also decreased AD-related biomarkers, such as Apo-E, Aβ-40, p-tau, and Bax and OS markers such as ROS, NO, Ca²⁺, and MDA in both serum and brain. In contrast, catalase and GPx activities were significantly increased in the TMT-only group and decreased after H₂ gas treatment in serum and brain. In addition, inflammatory cytokines such as granulocyte colony-stimulating factors (G-CSF), interleukin (IL)-6, and tumor necrosis factor alpha (TNF-α) were found to be significantly decreased after H₂ treatment in both serum and brain lysates. In contrast, Bcl-2 and vascular endothelial growth factor (VEGF) expression levels were found to be enhanced after H₂ treatment. Taken together, our results demonstrated that 2% H₂ gas inhalation in TMT-treated mice exhibits memory enhancing activity and decreases the AD, OS, and inflammatory-related markers. Therefore, H₂ might be a candidate for repairing neurodegenerative diseases with cognitive dysfunction. However, further mechanistic studies are needed to fully clarify the effects of H₂ inhalation on TMT-induced neurotoxicity and cognitive dysfunction.

Hydrogen-Rich Water Improves Cognitive Ability and Induces Antioxidative, Antiapoptotic, and Anti-Inflammatory Effects in an Acute Ischemia-Reperfusion Injury Mouse Model

Background

Cerebral ischemia and its reperfusion injury facilitate serious neurodegenerative diseases such as dementia due to cell death; however, there is currently no treatment for it. Reactive oxygen species is one of the many factors that induce and worsen the development of such diseases, and it can be targeted by hydrogen treatment. This study examined the effect of molecular hydrogen in cerebral ischemia-reperfusion injury, which is emerging as a novel therapeutic agent for various diseases.

Methods

Ischemia-reperfusion injury was generated through bilateral common carotid artery occlusion in C57BL/6 mice. The test group received hydrogen-rich water orally during the test period. To confirm model establishment and the effect of hydrogen treatment, behavioural tests, biochemical assays, immunofluorescence microscopy, and cytokine assays were conducted.

Results

Open field and novel object recognition tests revealed that the hydrogen-treated group had improved cognitive function and anxiety levels compared to the nontreated group, while hematoxylin and eosin stain showed abundant pyknotic cells in a model mouse brain, and this was attenuated in the hydrogen-treated mouse brain. Total antioxidant capacity and thiobarbituric acid reactive substance assays revealed that hydrogen treatment induced antioxidative effects in the mouse brain. Immunofluorescence microscopy revealed attenuated apoptosis in the striatum, cerebral cortex, and hippocampus of hydrogen-treated mice. Western blotting showed that hydrogen treatment reduced Bax and TNFα levels. Finally, cytokine assays showed that IL-2 and IL-10 levels significantly differed between the hydrogen-treated and nontreated groups.

Conclusion

Hydrogen treatment could potentially be a future therapeutic strategy for ischemia and its derived neurodegenerative diseases by improving cognitive abilities and inducing antioxidative and antiapoptotic effects. Hydrogen treatment also decreased Bax and TNFα levels and induced an anti-inflammatory response via regulation of IL-2 and IL-10. These results will serve as a milestone for future studies intended to reveal the mechanism of action of molecular hydrogen in neurodegenerative diseases.

Antioxidant Properties of Hydrogen Gas Attenuates Oxidative Stress in Airway Epithelial Cells

Oxidative stress plays a crucial role in the development of airway diseases. Recently, hydrogen (H₂) gas has been explored for its antioxidant properties. This study investigated the role of H₂ gas in oxidative stress-induced alveolar and bronchial airway injury, where A549 and NCI-H292 cells were stimulated with hydrogen peroxide (H₂O₂) and lipopolysaccharide (LPS) in vitro. Results show that time-dependent administration of 2% H₂ gas recovered the cells from oxidative stress. Various indicators including reactive oxygen species (ROS), nitric oxide (NO), antioxidant enzymes (catalase, glutathione peroxidase), intracellular calcium, and mitogen-activated protein kinase (MAPK) signaling pathway were examined to analyze the redox profile. The viability of A549 and NCI-H292 cells and the activity of antioxidant enzymes were reduced following induction by H₂O₂ and LPS but were later recovered using H₂ gas. Additionally, the levels of oxidative stress markers, including ROS and NO, were elevated upon induction but were attenuated after treatment with H₂ gas. Furthermore, H₂ gas suppressed oxidative stress-induced MAPK activation and maintained calcium homeostasis. This study suggests that H₂ gas can rescue airway epithelial cells from H₂O₂ and LPS-induced oxidative stress and may be a potential intervention for airway diseases.

A novel strategy for treating cancer: understanding the role of Ca2+ signaling from nociceptive TRP channels in regulating cancer progression

Cancer is an aging-associated disease and caused by genomic instability that is driven by the accumulation of mutations and epimutations in the aging process. Although Ca²⁺ signaling, reactive oxygen species (ROS) accumulation, DNA damage response (DDR) and senescence inflammation response (SIR) are processed during genomic instability, the underlying mechanism for the cause of genomic instability and cancer development is still poorly understood and needs to be investigated. Nociceptive transient receptor potential (TRP) channels, which firstly respond to environmental stimuli, such as microbes, chemicals or physical injuries, potentiate regulation of the aging process by Ca²⁺ signaling. In this review, the authors provide an explanation of the dual role of nociceptive TRP channels in regulating cancer progression, initiating cancer progression by aging-induced genomic instability, and promoting malignancy by epigenetic regulation. Thus, therapeutically targeting nociceptive TRP channels seems to be a novel strategy for treating cancers.

Molecular Hydrogen as a Novel Antitumor Agent: Possible Mechanisms Underlying Gene Expression

While many antitumor drugs have yielded unsatisfactory therapeutic results, drugs are one of the most prevalent therapeutic measures for the treatment of cancer. The development of cancer largely results from mutations in nuclear DNA, as well as from those in mitochondrial DNA (mtDNA). Molecular hydrogen (H₂), an inert molecule, can scavenge hydroxyl radicals (·OH), which are known to be the strongest oxidizing reactive oxygen species (ROS) in the body that causes these DNA mutations. It has been reported that H₂ has no side effects, unlike conventional antitumor drugs, and that it is effective against many diseases caused by oxidative stress and chronic inflammation. Recently, there has been an increasing number of papers on the efficacy of H₂ against cancer and its effects in mitigating the side effects of cancer treatment. In this review, we demonstrate the efficacy and safety of H₂ as a novel antitumor agent and show that its mechanisms may not only involve the direct scavenging of ·OH, but also other indirect biological defense mechanisms via the regulation of gene expression.

New Approaches for Hydrogen Therapy of Various Diseases

Hydrogen therapy has recently received increasing attention as an emerging and promising therapeutic technology due to its selective antioxidant property and cell energy regulatory capability in vivo. To solve the low solubility issue of hydrogen, a variety of nanomaterials and devices for hydrogen supply have recently been developed, aiming to increase the concentration of hydrogen in the specific disease site and realize controlled hydrogen release and combined treatment. In this review, we mainly focus on the latest advances in using hydrogen-generating devices and nanomaterials for hydrogen therapy. These developments include sustained release of H2, controlled release of H2, versatile modalities of synergistic therapy, etc. Also, bio-safety issues and challenges are discussed to further promote the clinical applications of hydrogen therapy and the development of hydrogen medicine.

The Effects of Supersaturated Hydrogen-Rich Water Bathing on Biomarkers of Muscular Damage and Soreness Perception in Young Men Subjected to High-Intensity Eccentric Exercise

High-intensity eccentric exercise can cause a delayed onset of muscle soreness (DOMS), a short-term condition characterized by muscle damage and tenderness that might hold up recovery and jeopardize exercise routine. Previous studies indicated that hydrogen-rich water (HRW) might be a helpful topical intervention to boost recovery in musculoskeletal medicine, yet no data are available concerning the effectiveness and safety of whole-body bathing with supersaturated HRW after DOMS-inducing exercise. This study evaluates the effects of a single-session bathing with HRW on biochemical markers of muscular damage in healthy young men. The six volunteers who were exposed to DOMS-inducing eccentric exercise were assigned to either supersaturated HRW or control whole-body bathing in a double-blind crossover design. Immediately after an exercise session, the participants were immersed up to the neck into a 200 L bathtub with supersaturated HRW (8 mg of H₂ per L) or control water (no hydrogen) for 30 min. Blood biomarkers of inflammation and muscular damage and Visual Analogue Scale (VAS) scores for muscle soreness were assessed at baseline (before exercise) and at 24-hour follow-up. Two-way ANOVA revealed a significant difference between two groups in serum creatine kinase (CK) response over the period of intervention (P=0.04). A single-session bathing in HRW prevented a rise in circulating biomarkers of muscular damage induced by exercise at 24-hour follow-up, retaining the levels of all biomarkers similar to the baseline values (P > 0.05). On the other hand, serum CK, aldolase, and aspartate transaminase were significantly elevated at 24-hour follow-up as compared to the baseline levels after the control bath (342 ± 309 U/L vs. 465 ± 295 U/L; P > 0.05). HRW bath also induced a significant drop in VAS scores for muscle soreness in comparison with control water, both immediately after an intervention (32.7 ± 8.6% vs. 20.0 ± 12.8%; P=0.02) and at 24-hour follow-up (31.6 ± 24.3% vs. 22.4 ± 27.5%; P=0.03), respectively. No participants reported any major side effects during the trial. This pilot study suggests that the whole-body bathing in supersaturated HRW is a safe procedure that attenuates muscular damage and can ease sore muscles after high-intensity eccentric exercise.

Reactive oxygen species in cancer: a paradox between pro- and anti-tumour activities

Cancer constitutes a group of heterogeneous diseases that share common features. They involve the existence of altered cellular pathways which result in uncontrolled cell proliferation. Deregulation of production and/or elimination of reactive oxygen species (ROS) appear to be a relevant issue in most of them. ROS have a dual role in cell metabolism: they are compromised in normal cellular homeostasis, but their overproduction has been reported to promote oxidative stress (OS), a process that may induce the damage of cell structures. ROS accumulation is implicated in the activation of signaling pathways that promote cell proliferation and metabolic adaptations to tumour growth. One characteristic of cancer cells is the sensitivity to OS, which often results from the combination of high anabolic needs and hypoxic growth conditions. However, there is still no clear evidence about the levels of oxidant species that promote cellular transformation or, otherwise, if OS induction could be adequate as an antitumour therapeutic tool. There is a need for novel therapeutic strategies based on the new knowledge of cancer biology. Targeting oncogenic molecular mechanisms with non-classical agents and/or natural compounds would be beneficial as chemoprevention or new adjuvant therapies. In addition, epigenetics and environment, and particularly dietary factors may influence the development and prevention of cancer. This article will present a revision of the current research about molecular aspects proposed to be involved in the anticancer features of oxidant and antioxidant-based therapies targeting cancer cells, and their participation in the balance of oxidative species and cancer cell death.

Brain Metastases Completely Disappear in Non-Small Cell Lung Cancer Using Hydrogen Gas Inhalation: A Case Report

Lung cancer is the most common type of tumor, prone to contralateral lung, bone and brain metastasis. We report a 44-year-old woman diagnosed with lung cancer with multiple metastases in November 2015. Oral targeted drugs were initiated after the removal of brain metastases, and most lesions remained stable for 28 months. In March 2018, intracranial multiple metastases, as well as hydrocephalus accumulation in the third ventricle and lateral ventricles, and metastases in bone, adrenal gland, liver were noted. Hydrogen-gas monotherapy was started to control the tumor a month later. After 4 months, the size of multiple brain tumors was reduced significantly, and the amount of hydrocephalus in the third ventricle and lateral ventricles reduced significantly. After 1 year, all brain tumors had disappeared, and there were no significant changes in metastases in the liver and lung. These data show that, after standard treatments had failed, hydrogen-gas monotherapy elicited significant effective control of tumors (especially those in the brain), and survival time was lengthened.

A Gallbladder Carcinoma Patient With Pseudo-Progressive Remission After Hydrogen Inhalation

BACKGROUND

Hydrogen therapy has been reported to convert exhausted programmed cell death receptor (PD-1)+CD8+ T cells to PD-1-CD8+ T cells, in advanced colorectal cancer patients, which is associated with significantly prolonged survival.

CASE PRESENTATION

A 72-year-old female patient presented with metastatic gallbladder cancer and underwent symptomatic treatment combined with hydrogen therapy. The tumors were initially enlarged and displayed increased tumor marker expression following hydrogen inhalation therapy, after which they continued to remit, similar to the pseudo-progression that occurs after anti-PD-1 treatment. During one month of hydrogen therapy, the patient's gallbladder and liver tumors continued to progress, and intestinal obstruction occurred. The intestinal obstruction was gradually relieved after symptomatic treatment, and the metastases in the abdominal cavity gradually decreased in size, anemia and hypoalbuminemia were corrected, and both the lymphocyte and tumor marker levels returned to normal. The patient was able to resume normal life two and a half months after hydrogen inhalation and survived over 10 months.

CONCLUSION

This is the first report of pseudo-progression followed by sustained remission after hydrogen inhalation. This phenomenon is similar to the pseudo-progression-remission pattern that occurs following PD-1 antibody treatment. These findings suggest that hydrogen may have an inhibitory effect on PD-1 expression.

Hydrogen gas therapy induced shrinkage of metastatic gallbladder cancer: A case report

BACKGROUND

We present the case of a 72-year-old female patient with gallbladder cancer (GBC) who developed in situ recurrence and liver metastases 9 mo after irreversible electroporation ablation and oral tegafur (a fluoropyrimidine derivative) chemotherapy, which failed to control the progression of the disease. The patient further developed metastases in the lymph nodes around the head of the pancreas. The patient had severe anemia, requiring weekly blood transfusions. The gallbladder tumor invaded the descending part of the duodenum, causing intestinal leakage and hepatic colonic adhesion.

CASE SUMMARY

The patient refused other treatments and began daily hydrogen inhalation therapy. After 1 mo of treatment, the gallbladder and liver tumors continued to progress, and intestinal obstruction occurred. After continuous hydrogen therapy and symptomatic treatments including gastrointestinal decompression and intravenous nutrition support, the intestinal obstruction was gradually relieved. Three months after hydrogen therapy, the metastases in the abdominal cavity gradually reduced in size, her anemia and hypoalbuminemia were corrected, lymphocyte and tumor marker levels returned to normal, and the patient was able to resume normal life.

CONCLUSION

This is the first report of an efficacy and safety study about hydrogen therapy in patient with metastatic GBC and a critical general condition, who has remained stable for more than 4 months.

A New Approach for the Prevention and Treatment of Cardiovascular Disorders. Molecular Hydrogen Significantly Reduces the Effects of Oxidative Stress

Cardiovascular diseases are the most common causes of morbidity and mortality worldwide. Redox dysregulation and a dyshomeostasis of inflammation arise from, and result in, cellular aberrations and pathological conditions, which lead to cardiovascular diseases. Despite years of intensive research, there is still no safe and effective method for their prevention and treatment. Recently, molecular hydrogen has been investigated in preclinical and clinical studies on various diseases associated with oxidative and inflammatory stress such as radiation-induced heart disease, ischemia-reperfusion injury, myocardial and brain infarction, storage of the heart, heart transplantation, etc. Hydrogen is primarily administered via inhalation, drinking hydrogen-rich water, or injection of hydrogen-rich saline. It favorably modulates signal transduction and gene expression resulting in suppression of proinflammatory cytokines, excess ROS production, and in the activation of the Nrf2 antioxidant transcription factor. Although H2 appears to be an important biological molecule with anti-oxidant, anti-inflammatory, and anti-apoptotic effects, the exact mechanisms of action remain elusive. There is no reported clinical toxicity; however, some data suggests that H2 has a mild hormetic-like effect, which likely mediate some of its benefits. The mechanistic data, coupled with the pre-clinical and clinical studies, suggest that H2 may be useful for ROS/inflammation-induced cardiotoxicity and other conditions.