Expression of pro-fibrotic cytokines and toll-like receptor 4 signaling pathway related-proteins is suppressed in sophocarpine-treated rats. Immunochemical analysis of the protein expression of α-SMA, TGF-β1, IL-6, TLR4 and ERK1/2 in the liver tissue of each group was performed as described in Materials and Methods. The results show the protein expression of α-SMA (× 200), TGF-β1 (× 200), IL-6 (× 200), TLR4 (× 200) and ERK1/2 (× 200) in the fibrotic livers of each group. TLR4: Toll-like receptor 4; IL-6: Interleukin-6; TGF-β: Transforming growth factor-β; SMA: Smooth muscle actin.