[Effects of Cordyceps sinensis on dimethylnitrosamine-induced liver fibrosis in rats].

OBJECTIVE To study the effects of Cordyceps sinensis on dimethylnitrosamine-induced liver fibrosis in rats. METHODS SD rats were divided into normal control group, untreated group and Cordyceps sinensis-treated group. The rats in each group were fed with corresponding drug for 4 weeks. The rat's liver collagen deposition was observed with collagen staining. Hydroxyproline (Hyp) contents in liver tissue of the rats in 3 groups were determined with HCl hydrolysis. The tissue inhibitor of metalloproteinase-2 (TIMP-2) and type IV collagen contents were observed by Envision, and matrix metalloproteinases-2 (MMP-2) activity was detected by the method of enzyme-picture. Type I collagen was detected by Western blotting. RESULTS The contents of Hyp, TIMP-2, type IV collagen, and the expression of type I collagen in untreated group were significantly higher than those in the normal control group, while those in Cordyceps sinensis-treated group were significantly lower than those in the untreated group. The content of MMP-2 in untreated group was significantly lower than that in the normal control group, while that in Cordyceps sinensis-treated group was significantly higher than that in the untreated group. CONCLUSION Cordyceps sinensis can considerably relieve the liver fibrosis, and the mechanism may be related to promoting the degradation of the collagens.