Effects of curcumin (Cur) on the expression of Smad2 and Smad3 proteins in rat liver tissue. (A, B) Immunohistochemical staining for Smad2 and Smad3 in the liver (original magnification, ×200). (C, D) Western blot analysis of hepatic Smad2 and Smad3 expression. Liver tissue was lysed and subjected to western blot analysis for Smad2 and Smad3 and the loading control GAPDH. Blots obtained from several experiments were analysed using densitometry, and the densitometric values were pooled from four animals per group and shown as means ± SD in the bar graph. *P < 0.05 for Cur/CCl4 vs. PBS/CCl4, **P < 0.01 for Cur/CCl4 vs. PBS/CCl4.