# Molecular Hydrogen as an Antioxidant and Radioprotector: Mechanistic Insights from Monte Carlo Radiation-Chemical Simulations.
> モンテカルロ放射線化学シミュレーションによる分子状水素の抗酸化・放射線防護メカニズムの解析


## Abstract

Using the IONLYS-IRT Monte Carlo track chemistry simulation code, this study modeled the time-dependent yields of reactive oxygen species (ROS) in a neutral, aerated aqueous solution under 300 MeV proton irradiation—conditions chosen to approximate low linear energy transfer (LET) radiation such as cobalt-60 gamma rays or fast electrons. Simulations incorporating varying concentrations of dissolved H₂ demonstrated that molecular hydrogen selectively scavenges hydroxyl radicals (•OH). However, its radical-quenching efficiency was quantitatively lower than that of cystamine, a sulfur-containing radioprotector with higher reactivity and faster •OH suppression. Despite this relative limitation, H₂ presents notable advantages including minimal toxicity, high tissue diffusivity, and biological compatibility, suggesting its potential utility in mitigating radiation-induced oxidative stress and inflammation.

### Mechanism

H₂ selectively scavenges hydroxyl radicals (•OH) generated by water radiolysis upon ionizing radiation exposure, thereby reducing oxidative damage to DNA, membrane lipids, and proteins. Its scavenging efficiency is lower than cystamine, but its low toxicity and high diffusivity are advantageous.

## Bibliographic

- **Authors**: Ria SA, Meesungnoen J, Jay-Gerin JP
- **Journal**: Antioxidants (Basel)
- **Year**: 2025 (2025-08-27)
- **PMID**: [41008961](https://pubmed.ncbi.nlm.nih.gov/41008961/)
- **DOI**: [10.3390/antiox14091054](https://doi.org/10.3390/antiox14091054)
- **PMC**: [PMC12466412](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12466412/)
- **Study type**: other
- **Delivery route**: in vitro
- **Effect reported**: positive

## Delivery context

This is basic research at the cellular or molecular level. For human application, inhalation is the most promising delivery route, but inhalation carries explosion risk and concentration matters (empirical LFL of 10%; high-concentration devices are not recommended).

## Safety notes

This is basic research at the cellular or molecular level. For human application, inhalation is the most promising delivery route, but inhalation carries explosion risk and concentration matters (empirical LFL of 10%; high-concentration devices are not recommended).

See also:
- [Inhalation concentration and LFL / UFL](https://h2-papers.org/en/safety-notes/inhalation-concentration)
- [Consumer Affairs Agency accident cases](https://h2-papers.org/en/safety-notes/accident-cases)
- [Inhalation safety threshold lineage](https://h2-papers.org/en/safety-notes/lineage)

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> **Cite as**: H2 Papers — PMID 41008961. https://h2-papers.org/en/papers/41008961
> **Source**: PubMed PMID [41008961](https://pubmed.ncbi.nlm.nih.gov/41008961/)