Effects of Xuanfei Huayu Formula on expression of TGF-β1/Smad in lung tissue of pulmonary fibrosis rats / 中草药

ABSTRACT

Objective: To investigate the effects of Xuanfei Huayu Formula (XFHY) on the expression of TGF-β1/Smad2 in pulmonary fibrosis rats. Methods: Sixty male SPF Wistar rats were randomly divided into six groups negative control group (group A), pulmonary fibrosis model group (group B), prednisone positive control group (group C, 0.167 mg/kg), the high doses of XFHY groups (group D, 14.38 g/kg), the medium doses of XFHY groups (group E, 7.19 g/kg), and the low doses of XFHY groups (group F, 3.60 g/kg) with ten rats in each group. The pulmonary fibrosis model was established by nasal instillation of bleomycin 7 μg/g (150 μL); In 8 h after the modle establishment, the rats in C, D, E, and F groups were respectively treated with prednisone acetate or XFHY once daily. Negative control group (group A) and model group (group B) were given equal volume physiological saline. The rats in different groups were executed 28 d after modeling for sampling. The HE and sirius red staining were used to observe alveolitis even pulmonary fibrosis changes in lung tissue under the microscope; The alkaline hydrolysis method was adopted to determine the content of hydroxyproline (Hyp) in lung tissue; The immunohistochemical method was used to determine the expression of alpha-SMA, Smad4, and Smad7 in rat lung tissues. The expression levels of TGF-β RII, Smad2, p-Smad2, and Smad7 proteins were detected by Western blotting. Results: The alveolar structure of the model group was severely damaged, and the interstitial hyperplasia, inflammatory cell infiltration, and collagen fibrosis were observed. Compared with the negative control group, the content of hydroxyproline and collagen staining was significantly increased in the model group. Compared with the model group, the expression of collagen fibers in the alveolar interval of three-dose group and prednisolone acetate group was significantly reduced, and the content of hydroxyproline was decreased significantly. Among them, the collagen fiber expression in XFHY high-dose group was less than XFHY low- and medium-dose group, and the hydroxyproline content was much lower. The above results showed that XFHY had a certain dose-effect relationship with the efficacy of pulmonary fibrosis. On this basis, the mechanism of the action of XFHY continues to it should be further explored. It was found that the protein content of TGF-β RII, Smad2, p-Smad2, Smad4, and α-SMA were decreased significantly, while the expression of Smad7 was higher in the XFHY group compared with the model group. Conclusion: XFHY can effectively prevent and treat pulmonary fibrosis, and its mechanism may relate to inhibit the over-expression of the α-SMA by regulating the TGF-β/Smad signaling pathway, thereby reducing the formation of collagen fibers.