Abstract: The aim was to evaluate the therapeutic effects and mechanisms of Qidan granule on blemycinA₅-induced pulmonary interstitial fibrosis (PIF)in rats. Altogether 40 rats we re divided into normal group, model group, Qidan group and Hydrocortisone group. Rat pulmonary f ibrosis was induced by blemycinA₅. They were treated with Qidan granule and Hy dr ocortisone respectively. The pathological changes and collagen protein dispositi on were observed by hematoxylin and eosin(HE) staining and Van Gieson(V.G)staini ng, and the expression of transforming growth factorβ(TGF-β)and tumor necrosi s factor α(TNF-α) proteins were measured by immunohistochemical technique. Af ter treatment, the pulmonary alveolitis and fibrosis were alleviated remarkable in the pathological section and collagen protein disposition in Qidan granule gr oup compared with those in the model group and hydrocortisone group (P<0.01) . The expression of TGF-β and TNF-αprotein were higher in Qidan granule grou p than those in normal group and were significantly less than those in the model group and in hydrocortisone group (P<0.01). Our studies suggest that Qidan granule would ameliorate the pulmonary alveolitis and fibrosis. TGF-β and TNF -α might play an important role in the development of alveolitis and fibrosis in rats.

Key words: pulmonary fibrosis, Qidan granule, TGF-β, TNF-α