# Impact of molecular hydrogen treatments on the innate immune activity and survival of zebrafish (Danio rerio) challenged with Aeromonas hydrophila.
> 水素富化水浸漬がAeromonas hydrophila感染ゼブラフィッシュの自然免疫応答と生存率に及ぼす影響


## Abstract

This study examined the effects of hydrogen-rich water (HRW) immersion on zebrafish (Danio rerio) challenged with the pathogenic bacterium Aeromonas hydrophila. Fish subjected to HRW immersion showed improved post-infection survival rates compared to controls, and bacterial proliferation within the host was markedly reduced. Gene expression analysis in the spleen, kidney, and liver revealed downregulation of pro-inflammatory mediators including IL-1β, IL-6, and NF-κB, alongside upregulation of the anti-inflammatory cytokine IL-10. These findings represent the first investigation of HRW effects in bacterially infected fish and suggest potential applications of molecular hydrogen in aquaculture disease management.

### Mechanism

HRW suppresses pro-inflammatory gene expression (NF-κB, IL-1β, IL-6) while upregulating the anti-inflammatory cytokine IL-10 in multiple organs, thereby modulating innate immune responses and limiting bacterial proliferation in zebrafish.

## Bibliographic

- **Authors**: Hu Z, Wu B, Meng F, Zhou ZZ, Lu H, Zhao H
- **Journal**: Fish Shellfish Immunol
- **Year**: 2017
- **PMID**: [28630014](https://pubmed.ncbi.nlm.nih.gov/28630014/)
- **DOI**: [10.1016/j.fsi.2017.05.066](https://doi.org/10.1016/j.fsi.2017.05.066)
- **Study type**: animal study
- **Delivery route**: hydrogen-rich water
- **Effect reported**: positive

## Delivery context

Hydrogen-rich water is a low-risk delivery route, but the achievable systemic hydrogen dose is bounded. For clinical applications, inhalation is the most efficient route; inhalation, however, carries explosion risk, and concentration matters (empirical LFL of 10% applies to inhalation environments; high-concentration devices are documented in the Consumer Affairs Agency accident database and are not recommended).

## Safety notes

Hydrogen-rich water is a low-risk delivery route, but the achievable systemic hydrogen dose is bounded. For clinical applications, inhalation is the most efficient route; inhalation, however, carries explosion risk, and concentration matters (empirical LFL of 10% applies to inhalation environments; 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 28630014. https://h2-papers.org/en/papers/28630014
> **Source**: PubMed PMID [28630014](https://pubmed.ncbi.nlm.nih.gov/28630014/)