# Hydrogen as a new class of radioprotective agent.
> 放射線防護剤としての分子状水素の可能性：科学的・臨床的進展のレビュー


## Abstract

The majority of ionizing radiation-induced biological damage originates from hydroxyl radicals (·OH) generated through water radiolysis. Molecular hydrogen (H2) selectively scavenges ·OH and peroxynitrite (ONOO⁻), conferring antioxidant protection. This review consolidates evidence from in vitro and in vivo studies demonstrating H2's radioprotective properties, including findings from a randomized, placebo-controlled trial in which hydrogen-rich water consumption reduced radiation-induced oxidative stress responses without diminishing anti-tumor efficacy. Because H2 gas carries explosion risk, hydrogen-saturated solutions—such as physiological saline or pure water—are considered more practical for routine use. The review surveys key scientific and clinical progress supporting hydrogen-rich solutions as a novel class of radioprotective agents.

### Mechanism

H2 selectively neutralizes hydroxyl radicals (·OH) and peroxynitrite (ONOO⁻) produced during water radiolysis, thereby reducing oxidative damage to biomolecules caused by ionizing radiation.

## Bibliographic

- **Authors**: Qian L, Shen J, Chuai Y, Cai J
- **Journal**: Int J Biol Sci
- **Year**: 2013
- **PMID**: [24155664](https://pubmed.ncbi.nlm.nih.gov/24155664/)
- **DOI**: [10.7150/ijbs.7220](https://doi.org/10.7150/ijbs.7220)
- **PMC**: [PMC3805896](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3805896/)
- **Study type**: review
- **Delivery route**: mixed routes
- **Effect reported**: not assessed

## Delivery context

This study combines multiple delivery routes. As a general principle, the most efficient route for routine hydrogen intake is inhalation. Inhalation carries explosion risk (empirical LFL of 10%; high-concentration devices are documented in the Consumer Affairs Agency accident database and are not recommended).

## Safety notes

This study combines multiple delivery routes. As a general principle, the most efficient route for routine hydrogen intake is inhalation. Inhalation carries explosion risk (empirical LFL of 10%; high-concentration devices are documented in the Consumer Affairs Agency accident database and 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 24155664. https://h2-papers.org/en/papers/24155664
> **Source**: PubMed PMID [24155664](https://pubmed.ncbi.nlm.nih.gov/24155664/)