Caudatin-2,6-dideoxy-3-O-methy-β-D-cymaropyranoside 1 induced apoptosis through caspase 3-dependent pathway in human hepatoma cell line SMMC7721.

Caudatin-2,6-dideoxy-3-O-methy-β-D-cymaropyranoside (CDMC), the C-21 steroidal glycoside recently extracted from the traditional Chinese medicinal plant, the root of Cynanchum auriculatum Royle ex Wight (Asclepiadaceae), has been shown to possess potent antitumor properties. However, the bioactivities of CDMC are still largely unknown, especially the antitumor effect and its mechanism. This study investigated the CDMC antitumor effects on human hepatoma cell line SMMC7721 cells by analysis of cell viability, cell cycle phases and apoptosis. The results showed that CDMC inhibited the growth of SMMC7721 cells in a time- and dose-dependent manner and resulted in cell cycle arrest in G(0)/G(1) phase. Furthermore, CDMC induced SMMC7721 cell apoptosis rather than necrosis through caspase 3 activation, and a caspase 3 inhibitor, Ac-DEVD-CHO, could attenuate the apoptosis induced by CDMC. The results suggested that the anticancer activity of CDMC could be attributed partially to its inhibition of cell proliferation and induction of apoptosis associated with caspase 3 activation.