Therapeutic effect of interleukin-10 on CCl4-induced hepatic fibrosis in rats

AIM: To study the therapeutic effect of exogenous interleukin-10 on CCl4-induced hepatic fibrosis in rats and its possible mechanisms. METHODS: Fourty-seven SD rats were randomly divided into control group (group N) and CCl4-included hepatic fibrosis model group (group C). After CCl4 was given for 9 wk, the model group was divided into three groups. Rats in group M were put to death immediately, rats in group T were treated with IL-10 for another three wk and then put to death, rats in group R recovered after three weeks and were then killed. The degree of hepatic fibrosis was measured by HE staining and histological activity index (HAI). Histological activity index (HAI), change of collagen types I and III were measured by Picrosirius staining. The expression of TNF-alpha, MMP-2 and TIMP-1 in liver tissue was measured by S-P immunohistochemistry. RESULTS: CCl4-induced experimental rat hepatic fibrosis model was established successfully. The degree of hepatic fibrosis was markedly lower in group T than in groups M and R, and there was no difference between the two groups. The expression of collagen types I and III was significantly suppressed in group T and was slightly suppressed in groups M and R. The positive levels of TNF-alpha, MMP-2 and TIMP-1 in group M increased significantly compared to those in group N (P < 0.01). The positive signals decreased significantly in groups T and R (P < 0.01), but positive score was significantly lower in group T than in group R (P < 0.01). CONCLUSION: Exogenous IL-10 can reverse CCl4-induced hepatic fibrosis in rats. IL-10 may exert its reversible effects on hepatic fibrosis by blocking CCl4-induced inflammation, inhibiting expression of MMP-2 and TIMP-1 and promoting resolution of collagen types I and III. (C) 2006 The WJG Press. All rights reserved.