Aerosol inhalation of edaravone can improve inflammation, oxidative stress and pulmonary function of rats with smoke inhalation injury by down-regulating miR-320.

OBJECTIVE: To explore the protective effects and related mechanism of aerosol inhalation of edaravone on inflammation, oxidative stress and pulmonary function (PF) in rats with smoke inhalation injury.

METHODS: Twenty-four rats were stochastically and equally divided into four groups: group A (edaravone-preventing group), group B (model group), group C (low-dose group) and group D (high-dose group). The serum of rats was collected to determine the expression of miR-320, inflammatory mediators (TNF-α, IL-6, IL-10), oxidative stress indexes (MDA, SOD, MPO) and oxygenation index (OI). Pulmonary tissues of rats were collected to determine the total lung water (TLW), wet-to-dry ratio (W/D) and other parameters. HE staining was adopted for pathological evaluation.

RESULTS: Compared with group B, the levels of miR-320, TNF-α, IL-6, MDA, MPO, TLW and W/D in group A were significantly down-regulated, while IL-10, SOD and OI levels were significantly up-regulated, and the trend of this change was more obvious than that in group C and group D, with notably better improvement degree in group D than group C. In HE staining, the pulmonary tissue structure was basically normal in group A, and was better than that of the other three groups. In group B, the pulmonary tissue was seriously damaged, accompanied by a large number of inflammatory cells infiltration and alveolar wall thickening. The pathological condition of group C was notably ameliorated, the extent of this improvement was more pronounced in group D, and the degree of pathological improvement in group D was superior to that in group C.

CONCLUSION: Aerosol inhalation of edaravone in advance can reduce the levels of inflammatory factors and oxidative stress indexes in serum of smoke inhalation injury rats, thus protecting PF, which may be related to the down-regulation of miR-320 by edaravone.