# Combined treatment with dissolved hydrogen molecule and platinum nanocolloid exerts carcinostatic/carcinocidal effects by increasing hydrogen peroxide generation and cell death in the human gastric cancer cell line NUGC-4.
> 溶存水素分子と白金ナノコロイドの併用がヒト胃癌細胞株NUGC-4において過酸化水素産生増加と細胞死を介して示す増殖抑制・殺細胞効果


## Abstract

This in vitro study investigated whether combined application of dissolved molecular hydrogen (H2) and platinum nanocolloid (Pt-nc) could suppress growth of human cancer cells. H2 plus Pt-nc inhibited proliferation of human promyelocytic leukemia HL60 cells and gastric adenocarcinoma-derived NUGC-4 cells, while normal human embryonic fibroblast OUMS-36 cells remained unaffected under transient exposure conditions, suggesting tumor-selective activity. In NUGC-4 cells, intracellular reactive oxygen species (ROS) levels rose approximately 200-fold relative to controls following combined treatment, and catalase co-treatment completely abolished the antiproliferative effect, implicating hydrogen peroxide as the key mediator. The combination also induced morphological alterations, cell death, and a reduction in DNA synthesis-positive cells. These findings indicate that H2 and Pt-nc together can drive carcinostatic and carcinocidal outcomes through intracellular ROS accumulation, particularly hydrogen peroxide, in human tumor cell lines.

### Mechanism

Combined H2 and platinum nanocolloid catalytically generates intracellular hydrogen peroxide, causing approximately 200-fold ROS elevation that drives DNA synthesis inhibition, morphological changes, and cell death selectively in tumor cells; catalase abolishes these effects, confirming H2O2 as the primary mediator.

## Bibliographic

- **Authors**: Saitoh Y, Kawasaki N, Eguchi N, Ikeshima M
- **Journal**: Free Radic Res
- **Year**: 2021
- **PMID**: [33929281](https://pubmed.ncbi.nlm.nih.gov/33929281/)
- **DOI**: [10.1080/10715762.2021.1902514](https://doi.org/10.1080/10715762.2021.1902514)
- **Study type**: in vitro study
- **Delivery route**: in vitro
- **Effect reported**: positive

## Delivery context

This is basic research at the cellular or molecular level. For human application, inhalation is the most promising delivery route, but inhalation carries explosion risk and concentration matters (empirical LFL of 10%; high-concentration devices are not recommended).

## Safety notes

This is basic research at the cellular or molecular level. For human application, inhalation is the most promising delivery route, but inhalation carries explosion risk and concentration matters (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)
- [Inhalation safety threshold lineage](https://h2-papers.org/en/safety-notes/lineage)

---

> **Cite as**: H2 Papers — PMID 33929281. https://h2-papers.org/en/papers/33929281
> **Source**: PubMed PMID [33929281](https://pubmed.ncbi.nlm.nih.gov/33929281/)