Effect of bioactive peptide of Carapax Trionycis on TGF-β1-induced intracellular events in hepatic stellate cells

Ethnopharmacological relevance: In traditional Chinese medicines for hepatic fibrosis therapy, Carapax Trionycis is used usually as an indispensable component and has a long history of medical use in China. Previous studies have demonstrated that extracts of Carapax Trionycis were able to protect liver against fibrosis in CCl4 animal models. Aim of the study: The purpose of this study is to verify the inhibitory effect and the underlying mechanisms of Carapax Trionycis extract peptide (CTEP) on activated hepatic stellate cells which play a central role in liver fibrogenesis. Materials and methods: Hepatic stellate cells induced by TGF-beta(1) were applied to evaluate the anti-fibrotic effect of CTEP in vitro. MTS assay, enzyme-linked immunosorbent assay and western blotting were then used to further investigate the molecular mechanisms. Results: The results show that the contents of collagen I, collagen III and TIMP-1 were significantly inhibited and the level of collagen I, collagen III, p-Smad 3, TIMP-1 and alpha-SMA proteins decreased significantly in a concentration-dependence manner after treatment with CTEP. Interestingly, the level of Smad 3 protein was not different significantly. Conclusions: Our data indicate that CTEP efficiently inhibits cultured HSC-T-6 cell activation and proliferation via the TGF-beta(1)/Smad pathway as well as by the elimination of the extracellular matrix. Crown Copyright (C) 2013 Published by Elsevier Ireland Ltd. All rights reserved.