Beneficial effects of hydrogen gas inhalation on a murine model of allergic rhinitis

Allergic rhinitis (AR) is a common chronic inflammatory condition. It has been previously indicated that oxidative stress may contribute to allergic inflammation, including AR. Although molecular hydrogen (H-2), an antioxidative agent, has been effective in treatment of numerous oxidative stress-associated diseases, the effect of inhalation of a high concentration of H-2 on AR remains unknown. In the current study, female BALB/c mice were sensitized with ovalbumin (OVA) followed by intranasal OVA challenge to establish an animal model of AR. Mice were subjected to exposure to H-2 and the inert gas helium at different frequencies and durations. The frequencies of sneezing/scratching and the body weights of mice were recorded. Histological analysis and multiplex cytokine assays were performed to evaluate the effects of H-2 on AR. Challenge with OVA induced significant nasal mucosa inflammation. H-2 inhalation reduced the infiltration of inflammatory cells into mucosa and lowered the levels of interleukin (IL)-5, IL-13 and monocyte chemoattractant protein-1 in serum. H-2 inhalation slightly increased the level of interferon-, however the difference was not statistically significant. Treatment with H-2 limited the weight increase in healthy mice and reversed the weight loss in mice with AR. Furthermore, H-2 inhalation induced a therapeutic effect on AR in a dose-dependent manner. The current results demonstrate that H-2 may demonstrate a therapeutic value for allergic diseases.