Objective To study the protective effect of hesperitin on oxidative damage of rat lung tissue caused by trachea infusion of silica.

Methods A total of 54 Wistar male rats were randomly divided into 6 groups, namely negative control group (normal saline), silicon dioxide (SiO₂) (model group), SiO₂ treatment plus 100, 200 and 400 mg/kg hesperitin(3 groups), and SiO₂ treatment plus 100 mg/kg pirfenidone (positive control group). Each rat was given 1 mL of normal saline or 50 mg/mL of SiO₂ by trachea infusion. After 24 h, the rats in corresponding groups were given hesperitin or pirfenidone by intervention once daily. The rats were sacrificed after treatment for 28 days. The pathological examination of rat lung tissue was conducted, the content of malondialdehyde(MDA) and the activities of catalase(CAT), glutathione peroxide(GSH-Px), superoxide dismutase (SOD) and total antioxidant capacity(T-AOC) of the lung tissues were measured.

Results Histopathological examination showed that the lung tissue injury was relieved in pirfenidone and hesperitin treatment groups. Compared with the negative control group, the rat lung coefficient, MDA content and SOD activity in the SiO₂ model group were significantly increased (P < 0.05), while CAT, GSH-Px and T-AOC activities in the SiO₂ model group showed no significant difference(P > 0.05). After treatment with hesperidin or pirfenidone, the rat lung coefficient, alveolitis and fibrosis scores, and MDA content were decreased(P < 0.05), while CAT, SOD, GSH-Px, T-AOC activities were increased(P < 0.05).

Conclusion Hesperitin can relieve the damage of lung tissue in rats exposed to SiO₂ by changing the levels of various oxidation indicators, and then enhancing the antioxidant capacity.