Abstract: AIM: To explore the inhibitory effects of ambrolic acid (AA) and 20(s)-dammar-24-ene-3β, 20-diol-3β-acetate (DM) on five human digestive cancer cell lines and the mechanism of apoptotic induction effect of AA on human gastric cancer cell line SGC-7901.METHODS: MTT assay was used to observe the anti-proliferation effect of AA and DM on MKN-45, MKN-28, SGC-7901, PNAC-1 and HepG-2 cancer cell lines. The apoptosis rates of SGC-7901 treated by AA or DM were determined by flow cytometry (FCM). With western blotting, the levels of apoptotic-pathway related proteins were determined.RESULTS: AA and DM inhibited the proliferation of cancer cells in a dose-dependent manner. FCM analysis showed that cells co-incubated with AA were induced apoptosis dose-dependently, while DM had no ability to induce apoptosis. AA could down-regulate the levels of pro-caspase 3, 6, 8, 9 and Bcl-2 proteins and up-regulate the levels of Bax proteins.CONCLUSION: AA and DM have significant inhibitory activities in 5 human digestive cancer cell lines. The potential mechanism of apoptosis-induction effect caused by AA on SGC-7901 may due to its ability to regulate the levels of apoptotic-related proteins.

Key words: Forsythia suspense, Ambrolic acid, 20(s)-dammar-24-ene-3β, 20-diol-3β-acetate, Gastric cancer, Apoptosis