[Effects of Yiqi Huayu Hutan decoction on pulmonary fibrosis in rats and its mechanism].

OBJECTIVE: To investigate the effects of Yiqi Huayu Hutan decoction on pulmonary fibrosis of rats which induced by bleomycin. METHODS: The rat model of pulmonary fibrosis was induced by intratracheal injection of bleomycin hydrochloride (5 mg/kg). Sixty SD rats were randomly divided into the normal group (group N), the model group (group M), the positive control group (group Y), group of low concentration (group LC), group of medium concentration (group MC) and group of high concentration of Yiqi Huayu Hutan decoction (group HC). After 4 weeks, the experimental groups were treated with low concentration decoction, medium concentration decoction and high concentration decoction respectively, and the Y group was treated with hydrocortisone acetate, the Group N and group M were treated with saline by intragastric administration. Twelve weeks later, rats were killed and the pathomorphism of pulmonary tissues of each group was observed by HE staining and Masson staining. Further, the expressions of transforming growth factor-β1(TGF-β1), Snail1, E-cadherin and Fibronectin in pulmonary tissues of each group were detected by qTR-PCR and Western blot. RESULTS: Compared with the model group, the collagen sediment in the interstitial was reduced in the experimental groups, especially in the group of medium concentration, which was observed by HE staining and Masson staining .Compared with the model group, the expressions of TGF-β1, Snail1 and Fibronectin protein in pulmonary tissues of the treatment groups were decreased in the experimental group, especially in the group of medium concentration, which were detected by qRT-PCR and Western blot. CONCLUSION: Yiqi Huayu Hutan decoction can significantly improve the pulmonary fibrosis which is induced by bleomycin, and the mechanism is related to the inhibition of the expression of TGF-β/Snail pathway of transcription TGF-β1.