Objective: To investigate whether Yangfei Huoxue prescription can inhibit lung inflammation of Pingyangmycin(PYM) -induced pulmonary fibrosis in rats. Method: PYM(5 mg·kg-1) was instilled into the rat trachea with a microliter injector to induce pulmonary fibrosis. Rats were randomLy divided into five groups: sham-operated group

control group

dexamethasone group

Huoxue group and Yangfei Huoxue group. Sham operated group and control group were given 0.5% carboxymethyl cellulose (CMC sodium) solution 1 mL/100 g weight. Dexamethasone group was given equal volume of dexamethasone solution. Huoxue group was given equal volume of Huoxue prescription. Yangfei Huoxue group was given equal volume of Yangfei Huoxue prescription for consecutive 28 days. The rats were anesthetized and killed by carotid exsanguination to calculate the lung index based on lung weight and body weight. The blood was separated at 3 000 r ·min-1 fot 10 min and obtained serum to examine IL-4

TNF-α and IFN-γ by radioimmunoassay. Left lungs were fixed

embedded

and 4um sections were prepared. Sections were stained with hematoxylin/eosin to assay alveolitis and score. TGF-beta and CTGF of the lung tissue were inspected by immunohistochemistry SABC and calculated the average gray scale. Result: Yangfei Huoxue prescription can significantly reduce the degree of alveolar inflammation and IL-4

TNF-α

IFN-γ in blood of PYM-induced lung injury in rats. Yangfei Huoxue prescription can significantly increase the gray scale of TGF-beta and CTGF. Conclusion: Yangfei Huoxue prescription can inhibit lung inflammation and PYM-induced pulmonary fibrosis in rats.