ObjectiveTo explore the antioxidant effects of reduced glutathione on rat pulmonary fibrosis compared with traditional corticosteroid. MethodsOne-hundred and eight healthy SD rats were randomly divided into 6 groups,ie. a control group,a model group,a dexamethasone group,a low-dose glutathione group,a middle-dose glutathione group,and a high-dose glutathione group,with 18 rats in each group. The pulmonary fibrosis model was established by intratrachially instillation of bleomycin in all rats except the control group. The severity of lung fibrosis was evaluated by HE staining and Masson staining of collagen,and measurement of glutathione,hydroxyproline,superoxide dismutase (SOD),glutathion peroxidase (GSH-Px)in lung tissue homogenate by photocolorimetric method. ResultsOn 7th day and 14th day after bleomycin instillation, the severity of alveolitis in the model group,the dexamethasone group,and three glutathione intervention groups was significantly reduced compared with the control group (P<0.05). On 28 day, the severity of lung fibrosis was significantly reduced in the dexamethasone group and three glutathione intervention groups compared with the model group (P<0.05). On 7th day,lung glutathione content was significantly lower in the model group compared with the control group (P<0.05), significantly higher in the dexamethasone group and three glutathione intervention groups compared with the model group (P<0.05), significantly lower in the dexamethasone group and the low-dose glutathione group compared with the control group (P<0.05), and significantly higher in the high-dose glutathione group compared with the dexamethasone group (P<0.05). On 7th,14th,and 28th day,the hydroxyproline content in the dexamethasone group and three glutathione intervention groups decreased significantly compared with the model group (P<0.05). On 14th day,the hydroxyproline content in the middle-dose and high-dose glutathione groups was significantly lower than that in the dexamethasone group (P<0.05). SOD and GSH-Px were significantly reduced in the model group compared with the control group on all time points (P<0.05),but significantly increased after intervention by different doses of glutathione (P<0.05). ConclusionReduced glutathione can significantly reduce the degree of pulmonary fibrosis in rats,but has no obvious advantage over dexamethasone.