# Molecular Hydrogen as a Novel Antitumor Agent: Possible Mechanisms Underlying Gene Expression.
> 抗腫瘍剤としての分子状水素：遺伝子発現調節を介した作用機序の考察


## Abstract

This review examines the antitumor potential and safety profile of molecular hydrogen (H₂). Cancer development is closely linked to mutations in both nuclear DNA and mitochondrial DNA (mtDNA), with hydroxyl radicals (·OH)—among the most potent oxidizing reactive oxygen species—identified as a key causative factor. H₂ selectively neutralizes ·OH and, unlike conventional antitumor agents, appears to lack significant side effects. Beyond direct radical scavenging, evidence suggests that H₂ may engage indirect biological defense pathways through modulation of gene expression. The review also addresses findings on H₂ efficacy in reducing adverse effects associated with cancer-related interventions, consolidating current knowledge on its mechanistic basis as a candidate antitumor agent.

### Mechanism

H₂ selectively scavenges hydroxyl radicals (·OH), thereby reducing oxidative DNA mutations in both nuclear and mitochondrial DNA. Additionally, indirect biological defense mechanisms involving gene expression regulation are proposed as contributing pathways.

## Bibliographic

- **Authors**: Hirano S, Yamamoto H, Ichikawa Y, Sato B, Takefuji Y, Satoh F
- **Journal**: Int J Mol Sci
- **Year**: 2021 (2021-08-13)
- **PMID**: [34445428](https://pubmed.ncbi.nlm.nih.gov/34445428/)
- **DOI**: [10.3390/ijms22168724](https://doi.org/10.3390/ijms22168724)
- **PMC**: [PMC8395776](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8395776/)
- **Study type**: review
- **Delivery route**: not specified
- **Effect reported**: not assessed

## Delivery context

The delivery route is not clearly identifiable from this paper. For hydrogen intake, inhalation is the most efficient route; inhalation, however, carries explosion risk (empirical LFL of 10%; high-concentration devices are not recommended).

## Safety notes

The delivery route is not clearly identifiable from this paper. For hydrogen intake, inhalation is the most efficient route; inhalation, however, carries explosion risk (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)

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> **Cite as**: H2 Papers — PMID 34445428. https://h2-papers.org/en/papers/34445428
> **Source**: PubMed PMID [34445428](https://pubmed.ncbi.nlm.nih.gov/34445428/)