# Role and mechanism of molecular hydrogen in the treatment of Parkinson's diseases.
> パーキンソン病における分子状水素の役割とメカニズムに関するレビュー


## Abstract

Parkinson's disease (PD) involves alpha-synuclein aggregation, oxidative stress, and neuroinflammation as core pathological features. This review systematically examines how molecular hydrogen may exert neuroprotective effects in PD and related neurodegenerative conditions. Evidence from preclinical models indicates that H2 can reduce oxidative damage, suppress inflammatory signaling, and inhibit neuronal apoptosis. However, clinical trials have produced inconsistent findings, with several reporting limited benefit. The review identifies critical knowledge gaps, including incomplete understanding of H2's influence on alpha-synuclein clearance and Nrf2-mediated immunomodulation. The authors call for large-scale, multicenter randomized trials to establish efficacy benchmarks and to develop individualized delivery strategies for H2 administration in PD.

### Mechanism

H2 selectively scavenges hydroxyl radicals and other reactive oxygen species, while activating Nrf2-mediated antioxidant pathways and suppressing neuroinflammation and apoptosis in dopaminergic neurons.

## Bibliographic

- **Authors**: Wang F, Zhang G, Zhai Q
- **Journal**: Front Neurosci
- **Year**: 2025
- **PMID**: [40336538](https://pubmed.ncbi.nlm.nih.gov/40336538/)
- **DOI**: [10.3389/fnins.2025.1576773](https://doi.org/10.3389/fnins.2025.1576773)
- **PMC**: [PMC12055789](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12055789/)
- **Study type**: review
- **Delivery route**: mixed routes
- **Effect reported**: mixed

## 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 40336538. https://h2-papers.org/en/papers/40336538
> **Source**: PubMed PMID [40336538](https://pubmed.ncbi.nlm.nih.gov/40336538/)