Inhibition of proliferation and induction of apoptosis by tetrandrine in HepG2 cells

Tetrandrine is a bisbenzylisoquinoline alkaloid derived from the root of Stephania tetrandra S. Moore, which has been reported to elicit in vitro cytotoxic effects on HeLa cells, and in vivo suppressive effects on mouse ascites tumors. In the present study, we examined the antiproliferative and apoptosis-inducing activity of tetrandrine in HepG2 cells, a human hepatoma cell line. Tetrandrine showed potent cytotoxic activity in HepG2 cells (IC50 = 9.0 +/- 1.0 muM) following incubation for 48 h. Dose-dependent induction of apoptosis was observed by agarose gel electrophoresis and flow cytometric analysis. Treatment of HepG2 cells with tetrandrine resulted in the activation of caspase-3 protease, and subsequent proteolytic cleavage of poly(ADP-ribose) polymerase. These results suggest that tetrandrine is potentially useful as a chemotherapeutic/chemopreventive agent in hepatocellular carcinoma. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.