Curcumin Protects against CCl4-Induced Liver Fibrosis in Rats by Inhibiting HIF-1α Through an ERK-Dependent Pathway

The ERK/HIF-1 alpha signaling pathway is believed to play an important role in the genesis of progressive fibrosis. An increasing expression of HIF-1 alpha and ERK accompanies CCl4-induced liver fibrosis in rats. Curcumin is verified to have antifibrotic effects in several kinds of liver fibrosis models. There is no specific evidence illustrating a connection between curcumin and the HIF-1 alpha/ERK pathway in rat liver fibrosis induced by CCl4. In this study, liver fibrosis was induced by CCl4 in treated rats. The data demonstrated that curcumin was able to attenuate liver fibrosis and inhibit the proliferation of HSC. Moreover, curcumin could remarkably elevate the hepatic function by decreasing serum levels of ALT, AST and ALP, and increasing levels of ALB, TP and alpha-SMA, Col III mRNA expression. Meanwhile, ECM status could also be reflected by curcumin treatment. The alleviation with curcumin treatment was associated with inhibition of HIF-1 alpha and phosphor-ERK. This study indicates that curcumin alleviates fibrosis by reducing the expression of HIF-1 alpha partly through the ERK pathway.