Triterpenoid saponins from Anemone flaccida induce apoptosis activity in HeLa cells.

Five triterpenoid saponins were isolated from Anemone flaccida Fr. Schmidt. Their structures were identified as glycoside St-I4a (1), glycoside St-J (2), anhuienoside E (3), hederasaponin B (4), and flaccidoside II (5). Compounds 1-2 were isolated from Anemone family for the first time, and compounds 3-4 were isolated from this plant for the first time. The inhibitory effects of saponins on proliferation of HeLa cells were studied by MTT assay, the apoptosis-induction activity was observed by cell-cycle analysis and caspase-3 expression assay. The antitumor activities of the saponins were ranked in the following order: 5 > 3 > 4 > 1 > 2. The data presented here indicated that naturally occurring triterpenoid saponins can be regarded as excellent structures for the potential development of new anticancer agents.