The Effect of Sal B on TGF-β1, TβRI, Smad2, p-Smad2 and p-Smad3 expression in kidneys of model rats. Western blot analysis showed significantly increased TGF-β1, TβR-I, p-Smad2 and p-Smad3 expressions in rats of the model group. In contrast, Sal B treatment attenuated HgCl2-induced upregulation of TGF-β1, TβR-I, p-Smad2 and p-Smad3 expressions. The values are represented as the density of TGF-β1 or TβR-I vs. GAPDH (%), or p-Smad2 vs. Smad2 (%), or p-Smad3 vs. Smad3 (%). **P < 0.01 vs. normal; *P < 0.05 vs. normal; ## P < 0.01 vs. model; #P < 0.05 vs. model.