Hydrogen Gas Inhalation Reduces Eye Allergy Symptoms in Mice

Effects of Inhalation of Hydrogen Gas on Allergic Conjunctivitis Model Mice

Research hubs: Eyes & Vision System · Immune System

Evidence type
Animal study (mouse)
Authors
Hideaki Sakata, Sho Kanzaki, Haruki Kai, Hikari Morii, Noriaki Haraoka, Shogo Takayama, Shimpei Seki, Yukio Sugimoto
Journal
Journal of Ocular Pharmacology and Therapeutics
Year
2026
DOI
10.1177/10807683261415800
Study Type
Mouse
Outcome
Positive
Peer Reviewed
Yes
Country
Japan
Health Condition
Allergic Conjunctivitis
Body System
Ocular

This research was done in animals. Results in animals often don't carry over to people.

TL;DR

Hydrogen gas inhalation reduced eye-scratching behavior and eosinophil accumulation in tears in a mouse model of allergic conjunctivitis, suggesting potential anti-itch and anti-inflammatory effects.

Key Finding

In mice with allergic conjunctivitis, inhaling hydrogen gas reduced eye-scratching behavior and decreased the number of eosinophils in tears.

Summary

Researchers created mice with allergic eye inflammation (similar to allergic conjunctivitis in humans) and tested whether breathing hydrogen gas would help. Mice that inhaled hydrogen gas showed less eye-scratching behavior and had fewer eosinophils (a type of immune cell) in their tears compared to untreated mice. The researchers believe hydrogen gas works by neutralizing harmful molecules called reactive oxygen species that contribute to allergic inflammation.

Practical Takeaway

This early animal study suggests hydrogen gas inhalation may help reduce allergic eye inflammation, but this is a mouse study only—human safety and effectiveness remain unknown. Much more research, including clinical trials in people, would be needed before hydrogen gas could be considered a treatment for allergic conjunctivitis.

Abstract (excerpt)

Purpose: Over the past decades, the prevalence of ocular allergies has increased worldwide. Molecular hydrogen is the lightest chemical element, and in recent years, there have been multiple reports on its therapeutic effects. Animal studies have also reported the effects of hydrogen gas on various…

Read the full abstract via DOI