Anti-cancer activity and mechanisms of 25-anhydrocimigenol-3-O-β-D- xylopyranoside isolated from Souliea vaginata on hepatomas

Our previous study first revealed the cytotoxicity and relative selectivity of 25-anhydrocimigenol-3-O-β-D-xylopyranoside (ACX) on HepG2 and R-HepG2 cells. In the present study, the anti-cancer activity and mechanisms of ACX isolated from S. vaginata were investigated both in vitro and in vivo. ACX showed significant, consistent anti-proliferative activity on hepatoma bel-7402 cells by MTT and clone formation assays with an IC50 value of 18 μmol/l. Morphological observation and flow cytometry results showed that apoptosis and G0/G1 cell cycle arrest contributed to the cytotoxic and cytostatic effects. Further studies showed that Bax and p21 protein expression were upregulated, Bcl-2 protein expression was downregulated, and poly(ADP-ribose) polymerase protein was cleaved. Moreover, ACX also exhibited a dose-dependent inhibition of tumor growth on mice implanted with H22 in vivo. These findings implicate ACX as a promising anti-cancer agent for chemotherapy of certain cancers. © 2006 Lippincott Williams & Wilkins.