# Hydrogen therapy attenuates irradiation-induced lung damage by reducing oxidative stress.
> 水素による酸化ストレス軽減を介した放射線照射誘発肺障害の抑制効果


## Abstract

Molecular hydrogen (H2) selectively scavenges reactive oxygen species (ROS), including hydroxyl radicals and peroxynitrite, and rapidly crosses cell membranes. This study examined whether H2 could reduce radiation-induced lung damage. Human lung epithelial A549 cells exposed to 10 Gy irradiation were treated with H2-enriched PBS or medium; electron spin resonance and fluorescent indicators confirmed ROS reduction, while oxidative stress markers, apoptotic indices, and cell viability all improved. In C57BL/6J female mice receiving 15 Gy thoracic irradiation, combined 3% H2 gas inhalation and H2-enriched water intake reduced acute lung damage (oxidative stress and apoptosis) within one week, as assessed by immunohistochemistry and immunoblotting. At five months post-irradiation, chest computed tomography, Ashcroft scoring, and type III collagen deposition collectively indicated attenuation of pulmonary fibrosis. These findings suggest H2 administration may protect lung tissue from both acute and late radiation-induced injury without apparent toxicity.

### Mechanism

H2 directly scavenges hydroxyl radicals and peroxynitrite generated by irradiation, thereby reducing intracellular ROS levels, suppressing oxidative stress and apoptosis, and ultimately limiting both acute lung injury and late-stage fibrosis.

## Bibliographic

- **Authors**: Terasaki Y, Ohsawa I, Terasaki M, Takahashi M, Kunugi S, Dedong K, et al.
- **Journal**: Am J Physiol Lung Cell Mol Physiol
- **Year**: 2011
- **PMID**: [21764987](https://pubmed.ncbi.nlm.nih.gov/21764987/)
- **DOI**: [10.1152/ajplung.00008.2011](https://doi.org/10.1152/ajplung.00008.2011)
- **Study type**: animal study
- **Delivery route**: mixed routes
- **Effect reported**: positive
- **H2 concentration**: 3%

## 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 21764987. https://h2-papers.org/en/papers/21764987
> **Source**: PubMed PMID [21764987](https://pubmed.ncbi.nlm.nih.gov/21764987/)