Qom University of Medical Sciences Journal

Background and Objectives: Silymarin, the active principle of Silybum marianum, has antifibrotic effects in hepatic fibrosis by several mechanisms. Since the pathogenesis of fibroproliferative diseases is similar, the effect of silymarin in bleomycin-induced pulmonary fibrosis was evaluated in this study.

Methods: Silymarin (50 mg/kg, i.p.) was administered two days before the bleomycin instillation (3 U/kg) and throughout the test interval in mice. After two weeks, lung tissues of mice were evaluated for fibrosis by biochemical measurement of collagen deposition and histological analysis of pathological lung changes. Data were evaluated by one-way ANOVA and Dunnett analysis. P<0.05 was considered as significant.

Results: Pretreatment with Silymarin significantly (P<0.05) prevented the increase in lung collagen content and also partially inhibited the histologic changes induced by bleomycin. The wet lung weight in silymarin group was similar to that of control group and significantly lower than bleomycin group (P<0.001).    

Conclusion: The results of this study indicate that silymarin may prevent the collagen deposition and inflammation and may be protective in fibrogenic effects of bleomycin on lung.