# The Role of Gaseous Molecules in Traumatic Brain Injury: An Updated Review.
> 外傷性脳損傷における気体分子（NO・CO・H₂S・H₂）の役割：最新レビュー


## Abstract

Traumatic brain injury (TBI) carries substantial mortality and poor prognosis, yet its underlying pathological mechanisms remain incompletely understood. Four endogenous gaseous molecules — nitric oxide (NO), carbon monoxide (CO), hydrogen sulfide (H2S), and molecular hydrogen (H2) — have been identified as important mediators in mammalian physiology and pathology. Because of their high membrane permeability, these molecules can readily penetrate the blood-brain barrier and exert neuroprotective effects across various central nervous system conditions. Accumulating experimental evidence suggests that each of these gases influences TBI progression through distinct but overlapping mechanisms. This review provides a broad overview of the roles these four gaseous molecules play in TBI development and their potential as intervention targets, highlighting molecular hydrogen among them for its selective antioxidant properties and favorable safety profile.

### Mechanism

Biological gaseous molecules including H2 cross the blood-brain barrier due to high membrane permeability, and are proposed to confer neuroprotection through suppression of oxidative stress, modulation of neuroinflammation, and inhibition of apoptotic pathways following traumatic brain injury.

## Bibliographic

- **Authors**: Che X, Fang Y, Si X, Wang J, Hu X, Reis C, et al.
- **Journal**: Front Neurosci
- **Year**: 2018
- **PMID**: [29937711](https://pubmed.ncbi.nlm.nih.gov/29937711/)
- **DOI**: [10.3389/fnins.2018.00392](https://doi.org/10.3389/fnins.2018.00392)
- **PMC**: [PMC6002502](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6002502/)
- **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 29937711. https://h2-papers.org/en/papers/29937711
> **Source**: PubMed PMID [29937711](https://pubmed.ncbi.nlm.nih.gov/29937711/)