Abstract: AIM: To explore the inhibitory effects and mechanisms of tranilast on bleomycin-induced pulmonary fibrosis in rats.METHODS: Fourty-eight Sprague-Dauley rats were randomly divided into normal control group (Group N, n=16), pulmonary fibrosis model group (Group M, n=16), and tranilast treatment group (Group Q, n=16).Eight rats in each group were sacrificed on days 14 and 28 following the day of animal model establishment.The degree of airsacculitis and pulmonary fibrosis were detected by HE andMasson staining in each group rats.The concentrations of NF-κB, expressions of TGF-β₁ mRNA and concentrations of Hydroxyproline (HYP), SOD and MDA in lung tissue were detected by the immunohistochemical method, fluorescent quantitative PCR, allaki hydrolysis, DTNB and thiobarbituric acid method in each group, respectively.RESULTS: The concentrations of NF-κB, expressions of TGF-β₁ mRNA and concentrations of HYP, SOD andMDA in lung tissue were significantly higher in GroupM than in Group N (P<0.01) and was significantly lower in Q group than inM group (P<0.01).CONCLUSION: The anti-pulmonary fibrosis effect of tranilast may be achieved through inhibited the generation of oxygen free radicals and thus decreased the activity of NF-κB, thereby inhibited TGF-β mRNA expression.

Key words: pulmonary fibrosis, NF-κB, TGF-β₁, oxygen free radical, tranilast