Abstract: Objective： To investigate the effects of tetrandrine (Tet) on proliferation and activation of rat cardiac fibroblasts. Methods： Firstly, the cell counting kit-8（cck-8） assay was applied to detect the effects of Tet with different concentrations on proliferation of cardiac fibroblasts. Secondly, transforming growth factor (TGF-β)with a concentration of 5 μg/L was used to induce the cardiac fibroblast activation, and Western blot was performed to measure the expression variation of βcatenin, vimentin (Vm), fibronectin (Fn) and smooth muscle α-actin (SMA). At last, the real-time PCR was conducted to mea-sure the expression change of collagen-1(Col-1) and collagen-3(Col-3). Results: The cck8 assay showed that the Tet with different concentrations respectively, which were 0.5 μmol/L, 1 μmol/L, 2 μmol/L, 4 μmol/L, and 8 μmol/L, significantly inhibited the proliferation of cardiac fibroblasts. The viability was decreased to 94.4%,84.9%,74.9%,63.8%and 50.3% respectively of the control group when the Tet concentration changed, and the difference was statistically significant, P=0.043，P<0.001，P<0.001，P<0.001，P<0.001 respectively. Western blot revealed that the expressions of β-catenin, Fn, SMA and Vm, were up-regulated by TGF-β(5 μg/L), the result showed that the difference was statistically significant, and the P values were 0.001，0.008，0.010，0.001 respectively. Then, the up-regulation of β-catenin, Fn and SMA was attenuated by pre-treatment of Tet, and the result also displayed that the difference was statistically significant, and the P values were 0.009，0.005，0.019,respectively. While there was no significant change in the expression of Vm, according to Western blotting, and P>0.05,at the same time, realtime PCR indicated that the up-regulations of Col-1 and Col-3 which were induced by TGF-β were blocked by pretreatment of Tet, the result showed that the difference was statistically significant, P<0.001. Conclusion: According to the experimental results, we can draw the conclusion that: the Tet can significantly inhibit the proliferation of cardiac fibroblasts, meanwhile, it can block the activation of cardiac fibroblasts, which is induced by TGF-β. It is supposed that the Tet may probably have anti myocardial fibrosis, which indicates that it may probably be a medicine which is used to block the cardiac remodeling.

Key words: Tetrandrine, Cardiac fibroblast, Cardiac remodeling