CCL4 and Hepatic fibrosis: Moreover, a recent study showed that Periplaneta americana extracts alleviated CCL4-induced hepatic fibrosis in rats via the inhibition of TGF-β1, nuclear factor kappa B (NF-κB), alpha-smooth muscle actin (α-SMA), and tissue inhibitor of metalloproteinases 1 (TIMP-1) [24].