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Respiratory / COVID

The airways and lungs are among the more actively studied fields, not least through work from the COVID-19 period. Around 30 human studies exist — including controlled trials, pilot projects and case reports — alongside numerous reviews and preclinical investigations.

In humans, the studies mainly tested inhalation of H₂ (often as an H₂/O₂ mixture), and additionally hydrogen-rich water, for example in asthma, chronic obstructive pulmonary disease (COPD) and acute respiratory infections including COVID-19. They examined shortness of breath, cough, lung function as well as inflammation and oxygen values.

Several studies report good tolerability and possible relief of symptoms such as shortness of breath; the evidence, however, remains preliminary, as many papers are small, short and methodologically heterogeneous. An established therapeutic benefit is therefore not proven, and H₂ does not replace established respiratory therapy.

Human studies on molecular hydrogen for Respiratory / COVID. This page collects the 102 studies catalogued in this area — 7 randomized trials, 27 pilot/observational studies and 26 reviews. Listed newest first.

2026 · Nguyen Puente — Emerging Clinical Applications for Molecular Hydrogen

Respiratory care

Inhaled molecular hydrogen (H₂) has accumulated a growing body of encouraging clinical findings across neurological, cardiovascular, oncological and respiratory conditions — yet the evidence base remains constrained by small study sizes, inconsistent methodology, and a lack of standardised delivery systems.

2025 · Zajac — Molecular Hydrogen in the Treatment of Respiratory Diseases

International journal of molecular sciences

This review compiles twenty years of research on molecular hydrogen in respiratory medicine, covering allergies, asthma, COPD, pulmonary fibrosis, lung injury, respiratory infections, and lung cancer.

2025 · Neykhonji — Exploring the Potential of H₂ Therapy in Reducing Surgical Complications: A Review on Anti-inflammatory, Antioxidant, and Anti-fibrotic Mechanisms

Current pharmaceutical design

Molecular hydrogen shows anti-inflammatory, antioxidant, and anti-fibrotic properties that could make it a candidate for preventing post-surgical adhesions — one of the most common and debilitating complications after abdominal and pelvic surgery.

2024 · Dhillon — Hydrogen Water: Extra Healthy or a Hoax?—A Systematic Review

International Journal of Molecular Sciences

Hydrogen-rich water (HRW) — healthy or hype? A systematic review of 25 studies concludes: the antioxidant and anti-inflammatory effects are „encouraging“ in early clinical studies, but not yet conclusive — larger studies are needed.

2023 · Johnsen et al. — Molecular Hydrogen Therapy — A Review on Clinical Studies and Outcomes

Molecules (Basel, Switzerland)

This comprehensive review in Molecules analysed 81 identified clinical trials and 64 scientific publications on human studies of molecular hydrogen (H₂) therapy across a broad range of disease areas.

2023 · Li — Trend of research on the medical use of molecular hydrogen: a bibliometric analysis

Medical gas research

This bibliometric analysis of 1,126 PubMed publications on molecular hydrogen therapy (up to July 2021) shows a clear upward trend from 2007 onward.

2022 · Biswas — Electrocoagulation and electrooxidation technologies for pesticide removal from water or wastewater: A review

Chemosphere

This review covers electrochemical methods — electrocoagulation and electrooxidation — for removing pesticides from water, and notes that H₂ gas is generated as a byproduct at the cathode during electrocoagulation.

2022 · Zhang et al. — Molecular Hydrogen Is a Potential Protective Agent in the Management of Acute Lung Injury

Molecular medicine (Cambridge, Mass.)

Molecular hydrogen (H₂) may offer protective effects in acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) — two life-threatening conditions seen in critically ill patients, including those with severe COVID-19.

2022 · Ahmad et al. — Narrative on Hydrogen Therapy and its Clinical Applications: Safety and Efficacy

Current pharmaceutical design

This narrative review surveys the growing body of evidence on molecular hydrogen (H₂) as a therapeutic agent across cardiovascular, respiratory, neurological, metabolic, and infectious diseases — summarising both its proposed mechanisms and current safety data.

2022 · Fu — Molecular hydrogen is a promising therapeutic agent for pulmonary disease

Journal of Zhejiang University. Science. B

This review summarizes the growing body of evidence suggesting that molecular hydrogen can protect the lungs from a range of diseases — including acute lung injury, COPD, asthma, lung cancer, pulmonary hypertension, and pulmonary fibrosis — through its antioxidant, anti-inflammatory, and anti-apoptotic properties.

2021 · Qi — Perspective of Molecular Hydrogen in the Treatment of Sepsis

Current Pharmaceutical Design

In sepsis — the most common cause of death in intensive care units — molecular hydrogen (H₂) as a „medical gas“ shows a protective effect on several organs.

2021 · Alwazeer — Combating Oxidative Stress and Inflammation in COVID-19 by Molecular Hydrogen Therapy: Mechanisms and Perspectives.

Oxidative medicine and cellular longevity

This review systematically examines how molecular hydrogen (H₂) could theoretically address the oxidative stress and uncontrolled inflammation at the heart of severe COVID-19 — including its ability to suppress NF-κB signaling and activate the Nrf2 antioxidant pathway.

2021 · Bragina — Intestinal microbiota of athletes.

Voprosy pitaniia

This systematic review of 14 studies finds that athletes harbour a more diverse gut microbiome than sedentary individuals, with higher proportions of bacteria that ferment complex carbohydrates into short-chain fatty acids — including species that use hydrogen gas (H₂) and formate to drive fermentation.

2021 · Quan — Protective effects of molecular hydrogen on lung injury from lung transplantation.

Experimental biology and medicine (Maywood, N.J.)

This review synthesizes the experimental evidence showing that H₂ — administered via inhalation, drinking, injection, or topical bath — can reduce the oxidative stress and inflammation responsible for primary graft dysfunction after lung transplantation.

2021 · Hirano — Potential Therapeutic Applications of Hydrogen in Chronic Inflammatory Diseases: Possible Inhibiting Role on Mitochondrial Stress.

International journal of molecular sciences

This review proposes a mechanism by which molecular hydrogen (H₂) may inhibit NLRP3 inflammasome activation — a central driver of chronic inflammation — by reducing reactive oxygen species (ROS) produced inside mitochondria.

2021 · Chen et al. — Chemical and Biochemical Aspects of Molecular Hydrogen in Treating Kawasaki Disease and COVID-19.

Chemical research in toxicology

Kawasaki disease and COVID-19 both involve damaging vascular inflammation; this review explores the chemical and biochemical rationale for using inhaled molecular hydrogen (H₂) in both conditions.

2021 · Sano et al. — Hydrogen Gas Therapy: From Preclinical Studies to Clinical Trials.

Current pharmaceutical design

Hydrogen gas (H₂) has demonstrated broad therapeutic potential in preclinical and early clinical studies — from ischaemia-reperfusion injury to organ transplantation and emergency medicine — and appears safe, inexpensive, and easy to administer.

2021 · Ohta — Direct Targets and Subsequent Pathways for Molecular Hydrogen to Exert Multiple Functions: Focusing on Interventions in Radical Reactions

Current pharmaceutical design

Molecular hydrogen (H₂) is not simply a passive antioxidant — it actively intervenes in radical chain reactions, modifying lipid peroxides and downstream signaling cascades.

2021 · Lucas — Molecular hydrogen (H₂) as a potential treatment for acute and chronic fatigue

Archiv der Pharmazie

This review paper argues that molecular H₂ is well-suited for treating both acute and chronic fatigue, based on the premise that oxidative stress and mitochondrial dysfunction underlie many forms of fatigue.

2020 · Benoit — Molecular Hydrogen Metabolism: a Widespread Trait of Pathogenic Bacteria and Protists

Microbiology and molecular biology reviews : MMBR

Over 200 known pathogens carry genes for hydrogenases — enzymes that let bacteria consume or produce H₂ gas as part of their energy metabolism.

2018 · Chen — Research progress of hydrogen-rich saline for eye diseases.

[Zhonghua yan ke za zhi] Chinese journal of ophthalmology

This Chinese-language review summarizes the published research on hydrogen-rich saline (and hydrogen-rich water) for the treatment of eye diseases, including glaucoma, retinal ischemia, and other ocular conditions.

2016 · Zheng — Molecular Hydrogen Therapy Ameliorates Organ Damage Induced by Sepsis

Oxidative medicine and cellular longevity

This review summarises animal-based evidence suggesting that molecular hydrogen can reduce inflammatory cytokine release, oxidative stress, and organ damage in sepsis models, improving survival rates across brain, lung, liver, kidney, and intestinal tissues.

2013 · Lucas — Role of the Toll Like receptor (TLR) radical cycle in chronic inflammation: possible treatments targeting the TLR4 pathway

Molecular neurobiology

Activation of the Toll-like receptor 4 (TLR4) pathway — triggered by environmental factors such as ozone, particulate matter, ionizing radiation, and LPS from bacteria — may underlie a wide spectrum of chronic inflammatory and neuropsychiatric diseases.

2012 · Ohno et al. — Molecular hydrogen as an emerging therapeutic medical gas for neurodegenerative and other diseases.

Oxidative medicine and cellular longevity

This review surveys the research on molecular hydrogen (H₂) across 63 disease models and human diseases documented in the four and a half years after the landmark 2007 Nature Medicine paper.

2003 · Maier — Availability and use of molecular hydrogen as an energy substrate for Helicobacter species

Microbes and infection

This review summarises evidence that the gastric pathogen Helicobacter pylori and the liver pathogen H.

2025 · Shogenova — Efficiency and Safety of the Combined Use of Thermal Heliox, Nitric Oxide and Molecular Hydrogen in COPD Exacerbation with Respiratory Failure and Pulmonary Hypertension in the Post-COVID Period

Terapevticheskii arkhiv

In patients hospitalized with severe COPD exacerbation after COVID-19, combining three medical gases — thermal heliox, nitric oxide, and molecular hydrogen (H₂) — alongside standard therapy produced better improvements in breathing, gas exchange, and exercise tolerance than any single gas used alone.

2020 · Jin — Changes of nasal nitric oxide in the treatment of allergic rhinitis with hydrogen-rich saline lavage of nasal cavity

Lin chuang er bi yan hou tou jing wai ke za zhi (Journal of Clinical Otorhinolaryngology Head and Neck Surgery)

A nasal lavage with hydrogen-rich saline significantly changed the nitric-oxide value in the nose and could thus offer a starting point for treating allergic rhinitis (hay fever).

2016 · Gong et al. — Protective effect of hydrogen on the lung of sanitation workers exposed to haze.

Zhonghua jie he he hu xi za zhi = Zhonghua jiehe he huxi zazhi = Chinese journal of tuberculosis and respiratory diseases

1999 · Cole — Consequences of incomplete carbohydrate absorption from fruit juice consumption in infants.

Archives of pediatrics & adolescent medicine

In healthy infants aged ~5 months, consumption of pear juice (containing sorbitol and high fructose) caused carbohydrate malabsorption detectable by breath hydrogen testing, and was associated with increased physical activity and metabolic rate compared to infants who absorbed the carbohydrates normally.

2026 · Pozdnyakova — The combined use of inhaled nitric oxide and molecular hydrogen in patients with post-COVID-19 syndrome

Terapevticheskii arkhiv

Combined inhalation of nitric oxide (NO) and molecular hydrogen (H₂) relieves post-COVID syndrome better than NO alone.

2026 · Li — Adjunctive Molecular Hydrogen Capsule Therapy in Empyema Complicated by Chronic Inflammatory Demyelinating Polyneuropathy: A Case Report

In vivo (Athens, Greece)

A 76-year-old man with a rare combination of chest infection (Stage II empyema) and an autoimmune nerve disorder (CIDP) recovered after surgery plus adjuvant oral molecular hydrogen therapy.

2025 · Habet et al. — Hydrogen-FAST: Study Protocol for Inhaled Hydrogen Gas as Adjunctive Therapy in Refractory Cardiac Arrest (ECPR)

Trials

The Hydrogen-FAST trial is a phase 1 multicenter randomised controlled trial investigating whether inhaled 2 % hydrogen gas, delivered continuously for 72 hours during extracorporeal cardiopulmonary resuscitation (ECPR), is feasible and safe in patients with refractory cardiac arrest and underlying heart disease.

2025 · Lui et al. — Predicting Therapeutic Response to Molecular Hydrogen in Autoimmune Diseases via Immunophenotyping

APMIS : acta pathologica, microbiologica, et immunologica Scandinavica

Can we predict in advance which autoimmune patients will benefit from H₂ therapy? This prospective study in 25 patients (rheumatoid arthritis, lupus, and others) developed a novel prediction index — the HRPI — based on immune cell profiles.

2025 · Tsai et al. — Molecular Hydrogen as an Adjuvant Therapy in Comorbid Sjögren's Syndrome, SLE, and ILD: A Case Report on Immune Modulation and Fatigue Reduction

In vivo (Athens, Greece)

A 69-year-old woman with overlapping Sjögren's syndrome, systemic lupus erythematosus (SLE), and interstitial lung disease (ILD) — a difficult-to-treat triad — showed notable clinical improvements after adding molecular hydrogen therapy to her regimen.

2025 · Tu et al. — Molecular Hydrogen Therapy for SLE-PAH: Case Report on Immune Marker Modulation

In vivo (Athens, Greece)

SLE-associated pulmonary arterial hypertension (SLE-PAH) is one of the most life-threatening complications of lupus, and standard vasodilator treatments often fail to adequately control progression.

2024 · Pozdnyakova — Rehabilitation program of post-COVID-19 syndrome with the use of nitric oxide and molecular hydrogen

Terapevticheskii Arkhiv

The combined inhalation of nitric oxide and hydrogen improved complaints in post-COVID syndrome.

2024 · Lin — Molecular Hydrogen Therapy in Sjögren's Syndrome With Pulmonary Arterial Hypertension and Right-sided Heart Failure: A Case Report of Improved Immune Markers Including Treg, B Cells and Plasma Cell.

In vivo (Athens, Greece)

A 56-year-old woman with Sjögren's syndrome-associated pulmonary arterial hypertension and right-sided heart failure — unresponsive to five standard drugs — experienced clinical stabilisation and measurable immune improvement after starting daily hydrogen capsules as an add-on.

2024 · Mu — Hydrogen regulated pyroptosis through NLRP3-GSDMD pathway to improve airway mucosal oxidative stress injury induced by endotracheal tube cuff compression.

Free radical biology & medicine

Endotracheal tube cuffs compress airway tissue during anaesthesia, triggering oxidative stress and a form of inflammatory cell death (pyroptosis) — and hydrogen inhalation or hydrogen-rich saline in the cuff significantly reduced this damage.

2024 · Lui — Molecular Hydrogen as a Promising Therapy Could Be Linked With Increased Resting Treg Cells or Decreased Fas+ T Cell Subsets in a IgG4-PF-ILD Patient: A Case Report.

In vivo (Athens, Greece)

An 85-year-old woman with progressive fibrosing interstitial lung disease complicated by hospital-acquired pneumonia showed noticeable improvement in lung infiltrations on chest X-ray by day four of hydrogen-assisted therapy, alongside measurable immune changes: resting Treg cells rose, while Fas+ T cell subsets declined.

2024 · Liu — The Benefit of Hydrogen Gas as an Adjunctive Therapy for Chronic Obstructive Pulmonary Disease.

Medicina (Kaunas, Lithuania)

Six COPD patients who added hydrogen gas inhalation (30 min, three times daily for 30 days) to standard treatment showed significant improvements in symptom burden scores (CAT) and dyspnoea scale (mMRC) — but no changes in lung function, sleep quality, inflammation markers, or oxidative stress markers.

2021 · Danilova — Application of Molecular Hydrogen in Heart Surgery under Cardiopulmonary Bypass

Sovremennye tekhnologii v meditsine

During open-heart surgery on cardiopulmonary bypass, inhaling 1.5–2% hydrogen gas during anaesthesia reduced markers of lipid peroxidation (oxidative stress) compared to patients who did not receive H₂.

2020 · Wang et al. — Hydrogen gas (XEN) inhalation ameliorates airway inflammation in asthma and COPD patients.

QJM : monthly journal of the Association of Physicians

A single 45-minute inhalation of hydrogen-containing steam (2.4 % H₂) reduced key inflammatory cytokines in airways of 10 asthma and 10 COPD patients — including monocyte chemotactic protein 1 in both groups and IL-8 in asthma.

2016 · Maity et al. — Molecular hydrogen in human breath: a new strategy for selectively diagnosing peptic ulcer disease, non-ulcerous dyspepsia and Helicobacter pylori infection.

Journal of breath research

This study shows that breath H₂ excretion profiles are distinctly altered by H. pylori activity and can non-invasively differentiate between peptic ulcer disease and non-ulcerous dyspepsia — even after H.

1995 · Hundley et al. — Assessment of left-to-right intracardiac shunting by velocity-encoded, phase-difference magnetic resonance imaging

Circulation

MRI flow measurements in the major heart vessels agreed very well (r = 0.94) with invasive catheterisation data in detecting and quantifying left-to-right intracardiac shunts in 21 adults.

1994 · Parnes et al. — Chemotherapy-induced lactose intolerance in adults

Cancer

Chemotherapy caused measurable lactose malabsorption in 30% of cancer patients, but symptomatic lactose intolerance developed in only 11%.

1994 · Nakahara et al. — Evaluation of tracheal mucosal blood flow during an extended radical operation for esophageal carcinoma

Surgery today

Extended radical surgery for esophageal cancer significantly reduced tracheal mucosal blood flow, from 40 to 13 ml/100 g per minute, while preserving the right bronchial artery appeared protective.

1993 · Glamann et al. — Hydrogen inhalation for detecting intracardiac left-to-right shunting in adults

The American journal of cardiology

The hydrogen inhalation test reliably detected intracardiac left-to-right shunts in adults with perfect separation between the shunt and no-shunt groups (appearance times: 1.5 vs. 12 seconds).

1990 · Flores et al. — Assessment of the Sensitivity of Hydrogen Inhalation in the Detection of Left-to-Right Shunting

Catheterization and cardiovascular diagnosis

Inhaling a small amount of hydrogen gas and measuring its reappearance on the arterial side of the circulation is an extremely sensitive method for detecting left-to-right intracardiac shunts — far more sensitive than standard dye or oximetry techniques.

1987 · Niggemann et al. — Detection of Intracardiac Left-to-Right Shunting in Adults: A Prospective Analysis of the Variability of the Standard Indocyanine Green Technique

The American journal of cardiology

In 66 adult patients confirmed shunt-free by the ultrasensitive hydrogen inhalation method, the indocyanine green dye technique showed percentage „shunts“ ranging from −9 % to +26 % — establishing for the first time the normal variability range for this diagnostic test.

1959 · CLARK LC Jr — Left-to-right shunt detection by an intravascular electrode with hydrogen as an indicator.

Science (New York, N.Y.)

This 1959 paper from Science describes the foundational technique of using an intravascular platinum-tipped electrode to detect left-to-right intracardiac shunts with inhaled hydrogen as the indicator.

2026 · Jiao — Therapeutic Potential of Magnesium Diboride Nanosheets in PAH-Associated Right Heart Failure: Integrated Multi-Omics Analysis Reveals Ferroptosis Suppression via LC3/ATG5/NCOA4/FTH1 Pathway

Free radical biology & medicine

Magnesium diboride (MgB₂) nanosheets — which release H₂ upon contact with body fluids — were tested in an animal model of pulmonary arterial hypertension (PAH) and its resulting right heart failure.

2025 · Seya — Hydrogen-rich Gas Enhances Mitochondrial Membrane Potential and Respiratory Function Recovery in Caco-2 Cells Post-ischemia-reperfusion Injury

Biochemical and biophysical research communications

Hydrogen-rich gas restored mitochondrial function in human intestinal cells (Caco-2) after simulated ischemia-reperfusion injury, improving ATP production, mitochondrial membrane potential, and oxygen consumption while reducing cell death signals.

2025 · Li — Hydrogen promoted mitochondrial autophagy and alleviated CIH-induced vascular endothelial cell senescence by regulating oxidative stress.

European journal of pharmacology

Obstructive sleep apnoea (OSA) causes repeated oxygen deficits that accelerate ageing of the blood vessel lining — and molecular hydrogen (H₂) can protect vascular endothelial cells against this premature ageing by activating cellular clean-up processes (autophagy) and reducing oxidative stress.

2025 · Su — Multifaceted Immunomodulatory Nanocomplexes Target Neutrophilic-ROS Inflammation in Acute Lung Injury.

Advanced science (Weinheim, Baden-Wurttemberg, Germany)

A two-pronged nanoparticle system combining a neutrophil-inhibiting drug with hydrogen-releasing silicon nanoparticles significantly reduced lung injury in mouse models of sepsis-induced acute lung injury (ALI).

2025 · Jiang — Engineering probiotic biohydrogen micro-factories to initiate reductive stress for boosting tumor vulnerability.

Biomaterials

Probiotic bacteria (Enterobacter aerogenes) engineered into gel-based microcapsules produced continuous hydrogen inside tumours, inducing a state of „reductive stress“ — the opposite of oxidative stress — that disrupted cancer-cell metabolism and suppressed tumour growth.

2024 · Haribabu — Multifaceted exploration of acylthiourea compounds: In vitro cytotoxicity, DFT calculations, molecular docking and dynamics simulation studies.

International journal of biological macromolecules

Two newly synthesized acylthiourea compounds were characterized and tested for cytotoxicity against cancer cells, with molecular docking suggesting potential binding to viral proteases.

2024 · Li — Hydrogen-rich water alleviates asthma airway inflammation by modulating tryptophan metabolism and activating aryl hydrocarbon receptor via gut microbiota regulation.

Free radical biology & medicine

In asthmatic mice, hydrogen-rich water (HRW) shifted gut bacteria toward beneficial species and raised levels of a key bacterial metabolite that calmed airway inflammation via a specific receptor pathway.

2024 · Wang — Natural hydrogen gas and engineered microalgae prevent acute lung injury in sepsis

Materials Today Bio

Inhaled hydrogen gas protects the lung in sepsis — and a novel nanosystem of H₂-releasing particles plus microalgae (DQB@C) amplifies this protection in a mouse model by curbing inflammation, oxidative stress and „ferroptosis“ (iron-dependent cell death).

2023 · Aokage — Attenuation of pulmonary damage in aged lipopolysaccharide-induced inflammation mice through continuous 2 % hydrogen gas inhalation: A potential therapeutic strategy for geriatric inflammation and survival

Experimental gerontology

In aged mice (21–23 months) with LPS-induced systemic inflammation, continuous inhalation of 2 % hydrogen gas for 24 hours reduced lung inflammation, lowered senescence-related markers, and improved survival — while having no measurable effect on LPS-induced liver injury.

2021 · Yin et al. — Hydrogen Gas with Extracorporeal Cardiopulmonary Resuscitation Improves Survival after Prolonged Cardiac Arrest in Rats

Journal of translational medicine

In a rat model of prolonged cardiac arrest, adding hydrogen gas (H₂) to extracorporeal cardiopulmonary resuscitation (ECPR) dramatically improved 4-hour survival: 78% with H₂ versus 22% without.

2021 · Zhang — Molecular hydrogen alleviates asthma through inhibiting IL-33/ILC2 axis

Inflammation research : official journal of the European Histamine Research Society ... [et al.]

In an OVA-sensitised mouse model of asthma and a bronchial epithelial cell model, hydrogen/oxygen gas mixture inhalation markedly reduced allergic inflammation by suppressing the IL-33/ILC2 signalling axis.

2021 · V — Investigations of Dianhydro-D-glucitol adsorbed on AuNPs surface: In silico and in vitro approach based on anticancer activity studies against A549 lung cancer cell lines

Journal of molecular recognition : JMR

This in-vitro and computational chemistry study examined how attaching a lung-cancer drug (Dianhydro-D-glucitol) to gold nanoparticles affects its anticancer behaviour against A549 lung cancer cells.

2021 · Li — Hydrogen Attenuates Endotoxin-Induced Lung Injury by Activating Thioredoxin 1 and Decreasing Tissue Factor Expression

Frontiers in immunology

In a mouse model of endotoxin-induced lung injury, H₂ inhalation significantly improved survival, reduced pulmonary oedema, and decreased neutrophil infiltration — apparently by activating the antioxidant protein Thioredoxin 1 (Trx1), which in turn suppressed tissue factor (TF) and MMP-9.

2021 · Matsuura — Hydrogen Gas Therapy Attenuates Inflammatory Pathway Signaling in Septic Mice

The Journal of surgical research

In a mouse cecal ligation and puncture (CLP) sepsis model, continuous H₂ inhalation improved 7-day survival from 40% to 75% and suppressed systemic and organ-level inflammatory signalling.

2021 · Wang et al. — Hydrogen therapy as an effective and novel adjuvant treatment against COVID-19

QJM : monthly journal of the Association of Physicians

This short theoretical commentary proposes hydrogen therapy as a potential adjuvant approach in COVID-19 treatment. No abstract or experimental data are available for this publication.

2021 · Wang et al. — Response to: Hydrogen therapy as an effective and novel adjuvant treatment against COVID-19

QJM : monthly journal of the Association of Physicians

This is a response letter to a commentary proposing hydrogen therapy in COVID-19, published in the same journal issue. No abstract is available for this letter.

2020 · Ostojic — COVID-19 and Molecular Hydrogen Inhalation

Therapeutic advances in respiratory disease

This is a brief theoretical commentary exploring whether molecular hydrogen inhalation could play a supportive role in COVID-19 management, based on H₂'s known anti-inflammatory and antioxidant properties.

2020 · Li — Hydrogen Water Alleviates Paraquat-induced Lung Fibroblast Injury In Vitro by Enhancing Nrf2 Expression

Nan fang yi ke da xue xue bao = Journal of Southern Medical University

In human lung fibroblasts exposed to the herbicide paraquat, hydrogen-rich water treatment reduced cell damage markers and inhibited fibrosis-related collagen production — an effect that worked through upregulation of the antioxidant transcription factor Nrf2.

2020 · Meng — Hydrogen Gas Represses the Progression of Lung Cancer via Down-regulating CD47

Bioscience reports

In lung cancer cell lines and a mouse tumour model, hydrogen gas treatment reduced the expression of CD47 — a „don't eat me“ signal that cancer cells use to evade immune destruction — and thereby inhibited cancer cell growth, invasion, migration, and promoted macrophage-mediated tumour cell clearance.

2020 · Oh — Untethered Soft Robotics with Fully Integrated Wireless Sensing and Actuating Systems for Somatosensory and Respiratory Functions.

Soft robotics

This engineering study presents a wireless soft robotic hand that integrates flexible sensors — including a hydrogen gas sensor — for monitoring tactile pressure, temperature, and H₂ concentration via smartphone.

2020 · Niu — Hydrogen Attenuates Allergic Inflammation by Reversing Energy Metabolic Pathway Switch

Scientific Reports

Hydrogen curbs allergic airway inflammation by resetting a disturbed energy metabolism of the immune cells.

2019 · Chen et al. — Inhaling Hydrogen Ameliorates Early Postresuscitation EEG Characteristics in an Asphyxial Cardiac Arrest Rat Model.

BioMed research international

In a rat model of asphyxial cardiac arrest, breathing 2% hydrogen gas after resuscitation dramatically improved both survival (90% vs. 40%) and the recovery of brain electrical activity (EEG) within four hours.

2019 · Kröninger — Energy Conservation in the Gut Microbe Methanomassiliicoccus luminyensis Is Based on Membrane-Bound Ferredoxin Oxidation Coupled to Heterodisulfide Reduction

The FEBS journal

This in-vitro biochemistry study investigates how the gut-derived methanogenic archaeon Methanomassiliicoccus luminyensis generates cellular energy — using molecular hydrogen (H₂) as a reductant to form methane from methylamines.

2019 · Meng — Hyperoxygenated Hydrogen-Rich Solution Suppresses Lung Injury Induced by Hemorrhagic Shock in Rats.

The Journal of surgical research

In rats with hemorrhagic-shock-induced acute lung injury (ALI), intravenous infusion of a solution combining both extra oxygen and dissolved hydrogen (HOHS) outperformed standard resuscitation fluid and each component alone in protecting lung tissue.

2019 · Yu — Hydrogen gas reduces HMGB1 release in lung tissues of septic mice in an Nrf2/HO-1-dependent pathway.

International immunopharmacology

In septic mice (CLP model), 2 % hydrogen (H₂) gas inhalation reduced lung injury, improved survival, and decreased the release of HMGB1 — a late-phase danger signal in sepsis — through a pathway requiring the Nrf2 transcription factor and the enzyme HO-1.

2018 · Dong — Protective effects of hydrogen gas against sepsis-induced acute lung injury via regulation of mitochondrial function and dynamics

International immunopharmacology

In a mouse model of sepsis-induced acute lung injury (ALI), inhaling 2% hydrogen gas improved lung oxygenation, preserved mitochondrial membrane potential and ATP production, and reduced tissue damage compared to untreated septic animals.

2018 · Vasiliev — Reducing Humidity Response of Gas Sensors for Medical Applications: Use of Spark Discharge Synthesis of Metal Oxide Nanoparticles

Sensors (Basel, Switzerland)

This engineering study develops improved tin dioxide (SnO₂) nanoparticle gas sensors that are less sensitive to humidity and can detect hydrogen gas, lactate vapour, and ammonia — biomarkers respectively of gut infections, stomach cancer, and H.

2018 · Jiang — Therapeutic efficacy of hydrogen-rich saline alone and in combination with PI3K inhibitor in non-small cell lung cancer

Molecular medicine reports

In cultured human lung cancer cells (A549 line), hydrogen-rich saline reduced proliferation and promoted apoptosis; combining it with the PI3K inhibitor LY294002 enhanced these effects further by suppressing the PI3K/Akt signalling pathway.

2018 · Wang — Hydrogen gas inhibits lung cancer progression through targeting SMC3

Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie

In lung cancer cell lines and a mouse xenograft model, hydrogen gas (H₂) inhibited cell viability, migration, and invasion while promoting apoptosis — apparently by downregulating SMC3, a chromosome condensation regulator.

2017 · Zhao — Changes in IL-4 and IL-13 Expression in Allergic Rhinitis Treated with Hydrogen-Rich Saline in a Guinea-Pig Model

Allergologia et immunopathologia

Hydrogen-rich saline significantly reduced sneezing, scratching, IgE levels, and key allergy-driving cytokines (IL-4, IL-13) in guinea pigs with experimentally induced allergic rhinitis.

2016 · Wang — Hydrogen Metabolism in Helicobacter pylori Plays a Role in Gastric Carcinogenesis through Facilitating CagA Translocation

mBio

This animal and cell study shows that the bacterium Helicobacter pylori uses molecular hydrogen — produced by the gut microbiome — as an energy source to power delivery of its cancer-causing toxin CagA into stomach cells, promoting gastric cancer development in a gerbil model.

2016 · Muramatsu — Hydrogen-Rich Water Ameliorates Bronchopulmonary Dysplasia (BPD) in Newborn Rats

Pediatric pulmonology

Hydrogen-rich water given to pregnant and nursing rats reduced lung damage caused by a bacterial toxin in newborn animals.

2016 · Mohamed — Antioxidants and K⁺ Channel Agonists versus Hydrogen Therapy during Ex Vivo Lung Perfusion

European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery

This study compared different protective strategies — antioxidants, potassium channel agonists, and hydrogen therapy — applied during ex-vivo lung perfusion (EVLP), a technique used to preserve and assess donor lungs before transplantation.

2015 · Chen et al. — Molecular hydrogen protects mice against polymicrobial sepsis by ameliorating endothelial dysfunction via an Nrf2/HO-1 signaling pathway.

International immunopharmacology

In a mouse sepsis model, molecular hydrogen suppressed the inflammatory cascade and endothelial injury — both in cell culture and in live animals — by activating the Nrf2/HO-1 antioxidant pathway.

2015 · Hattori et al. — Maternal molecular hydrogen treatment attenuates lipopolysaccharide-induced rat fetal lung injury.

Free radical research

Drinking hydrogen-rich water (HRW) before lipopolysaccharide (LPS) injection significantly reduced inflammation, oxidative damage, and cell death in fetal rat lungs — suggesting that maternal H₂ intake could protect premature infants from inflammation-driven lung disease.

2011 · Terasaki — Hydrogen Therapy Attenuates Irradiation-Induced Lung Damage by Reducing Oxidative Stress

American journal of physiology. Lung cellular and molecular physiology

In irradiated human lung cells and in mice given whole-thorax irradiation, molecular hydrogen (H₂) — delivered as H₂-rich PBS, H₂-enriched drinking water, or 3% H₂ inhalation — significantly reduced oxidative stress markers, apoptosis, and lung fibrosis.

2009 · Kovala-Demertzi — Organotin meclofenamic complexes: Synthesis, crystal structures and antiproliferative activity of the first complexes of meclofenamic acid — novel anti-tuberculosis agents.

Journal of inorganic biochemistry

This in-vitro chemistry study synthesized and characterized organotin complexes of meclofenamic acid and tested them against cancer cell lines and Mycobacterium tuberculosis.

2008 · Benchimol — The hydrogenosome as a drug target.

Current pharmaceutical design

This in-vitro review/study describes hydrogenosomes — organelles found in certain parasitic microorganisms (such as Trichomonas) that produce molecular hydrogen — as potential drug targets for anti-parasitic therapies.

2008 · Ye — Inhibitory effect of electrolyzed reduced water on tumor angiogenesis.

Biological & pharmaceutical bulletin

This in-vitro study found that electrolyzed reduced water (ERW) reduced VEGF (vascular endothelial growth factor) gene expression and protein secretion in a human lung adenocarcinoma cell line, and inhibited in vitro formation of vascular tubules.

2005 · Maier — Use of molecular hydrogen as an energy substrate by human pathogenic bacteria

Biochemical Society transactions

Several pathogenic bacteria — including Helicobacter pylori (stomach), Helicobacter hepaticus (liver), and Salmonella — can use molecular hydrogen (H₂) produced in the gut as a respiratory fuel, and this ability significantly enhances their capacity to colonise and cause disease in animals.

1996 · Franić — Radiotoxicity of Tritiated Water and Tritiated Hydrogen

Arhiv za higijenu rada i toksikologiju

Tritiated water (HTO) is far more radiotoxic than tritiated hydrogen gas (HT): inhaling tritiated H₂ gas leads to partial oxidation into HTO in the lungs, meaning the effective dose is higher than previously assumed — and the official toxicity ratio of 1:25,000 (HT vs.