# Molecular hydrogen: current knowledge on mechanism in alleviating free radical damage and diseases.
> フリーラジカル傷害および疾患における分子状水素の作用機序に関する現状知識のレビュー


## Abstract

Since molecular hydrogen was identified as a selective hydroxyl radical scavenger in 2007, beneficial effects have been documented across more than 170 disease models and human conditions, including ischemia-reperfusion injury, metabolic syndrome, inflammation, and cancer. Overproduction of reactive oxygen species is a common feature of these pathological states, and hydrogen has been consistently shown to act as a selective antioxidant. This review consolidates current knowledge on how hydrogen modulates biological systems at both the systemic and cellular levels. Topics covered include antioxidative, anti-inflammatory, and anti-apoptotic properties, protection of mitochondria and the endoplasmic reticulum, regulation of intracellular signaling cascades, and modulation of immune cell subset balance. The authors aim to provide a structured overview that supports deeper mechanistic investigation.

### Mechanism

Molecular hydrogen selectively scavenges hydroxyl radicals and exerts antioxidative, anti-inflammatory, and anti-apoptotic effects by protecting mitochondria and the endoplasmic reticulum, regulating intracellular signaling pathways, and balancing immune cell subtype composition.

## Bibliographic

- **Authors**: Tao G, Song G, Qin S
- **Journal**: Acta Biochim Biophys Sin (Shanghai)
- **Year**: 2019 (2019-12-13)
- **PMID**: [31738389](https://pubmed.ncbi.nlm.nih.gov/31738389/)
- **DOI**: [10.1093/abbs/gmz121](https://doi.org/10.1093/abbs/gmz121)
- **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 31738389. https://h2-papers.org/en/papers/31738389
> **Source**: PubMed PMID [31738389](https://pubmed.ncbi.nlm.nih.gov/31738389/)