Effects of PAP on DOX-induced protein level in the TGF-β/SMAD/ERK pathway. The protein levels of (A) TGF-β1, (B) SMAD2, p-SMAD2, (C) SMAD3, p-SMAD3, (D) ERK and p-ERK were detected by western blot. Bar images represent (E) TGF-β2 (F) p-SMAD2/SMAD2, (G) p-SMAD3/SMAD3 and (H) p-ERK/ERK levels, respectively.