Abstract: Objective To discuss the molecular mechanism and protective effect of Matrine on Blemycin-induced pulmonary fibrosis rat. Methods Rats were randomly divided into five groups, the control group, model group, Prednisone, Matrine low dose and high dose group.Pulmonary fibrosis model was made by adminstrated blecomin (5 mg/kg) through trachea. From 1st day after modeling, the rats were fed prednisone acetate (0.56mg/kg/d) or different dose matrine (50 and 100mg/kg/d). At the 7, 14, 28 days of modeling, the lung tissue biopsy sections are observed by HE and Masson staining pathology. The malondialdehyde (MDA) level and hydroxyproline (HYP) content in lung tissue was detected, and HO-1 mRNA was measured by RT-PCR, and production of TNF-α. The lung tissue biopsy sections are detected by HE and Masson staining pathology. Results In model group, inflammatory response was the main performance at 7d. At 28d, more lung fibroblast could be found. The collagen could be found more clearly, as demonstrated by Masson staining. Pathological changes in the in the matrine and prednisone treated group were less than the model group. The MDA and HYP content in model group was higher compared with normal control group (p<0.05), and decreased after matrine and prednisone treatment in 28d (p＜0.05). In the normal lung tissue, expression of HO-1 and production of TNF-αwere very low, and increased in the model group. After drug intervention, the levels of both TNF-α and HO-1 were decreased (p<0.05). Conclussions Matrine can alleviate the fibrosis status in rats, and the mechanism may be associate to regulate oxidative-antioxidant imbalance, and inhibition of TNF-α and HO-1 expression.

Key words: Matrine, Heme Oxygenase-1, TNF-α, Pulmonary fibrosis, Malondialdehyde, Hydroxyproline