# Antitumor Activity of Protons and Molecular Hydrogen: Underlying Mechanisms.
> 陽子と分子状水素の抗腫瘍活性：基礎的メカニズムの検討


## Abstract

This review examines the biological roles of protons (H⁺) and molecular hydrogen (H₂) in cellular processes, with a focus on their relevance to oncology. H₂, a biologically inert gas with low molecular weight, can rapidly cross cell membranes and access subcellular compartments including the nucleus and mitochondria. Reported effects include reduction of oxidative stress, suppression of inflammatory responses, and modulation of apoptotic pathways. Multiple delivery routes—inhalation, hydrogen-rich water ingestion, and hydrogen-rich saline infusion—are discussed in the context of cancer and other diseases. The review also addresses proton beam radiotherapy (PBT), which exploits the Bragg peak phenomenon to deliver precise radiation doses, and considers how H₂ and H₂-donor compounds may complement particle-based cancer approaches.

### Mechanism

H₂ diffuses across cell membranes to reach mitochondria and nuclear DNA, where it selectively scavenges reactive oxygen species such as hydroxyl radicals, thereby reducing oxidative stress and modulating inflammatory and apoptotic signaling pathways.

## Bibliographic

- **Authors**: Rochette L, Zeller M, Cottin Y, Vergely C
- **Journal**: Cancers (Basel)
- **Year**: 2021 (2021-02-20)
- **PMID**: [33672714](https://pubmed.ncbi.nlm.nih.gov/33672714/)
- **DOI**: [10.3390/cancers13040893](https://doi.org/10.3390/cancers13040893)
- **PMC**: [PMC7924327](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7924327/)
- **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 33672714. https://h2-papers.org/en/papers/33672714
> **Source**: PubMed PMID [33672714](https://pubmed.ncbi.nlm.nih.gov/33672714/)