Antitumor activities of dammarane triterpene saponins from Bacopa monniera

Bioassay‐guided methods were used to test the antitumor activity of methanol extract of the whole plant of Bacopa monniera (L.) Wettst. and four different fractions (petroleum ether, CHCl 3 , EtOAc, and n ‐BuOH fractions) of the methanol extract. Among the five crude samples, n ‐BuOH fraction was noted to have the highest antitumor activity. The dammarane triterpene saponins isolated from n ‐BuOH fraction, bacopaside É (1) and bacopaside VII (3), had potential antitumor effect. 1 and 3 showed cytotoxicity of all the tested human tumor cell lines MDA‐MB‐231, SHG‐44, HCT‐8, A‐549 and PC‐3M in MTT assay in vitro , and showed 90.52 % and 84.13 % inhibition in mouse implanted with sarcoma S180 in vivo at the concentration of 50 μmol/kg, respectively. The remaining two compounds, bacopaside II (2) and bacopasaponin C (4) were found to be much less potent compared with 1 and 3. 1 and 3 significantly inhibited human breast cancer cell line MDA‐MB‐231 adhesion, migration and Matrigel invasion in vitro at the concentration of 50 μmol/L. Since no antitumor activities about the monomers from Bacopa monniera (L.) Wettst. have been reported, these results indicate that the mechanism of action of 1 and 3 needs further study. Copyright © 2009 John Wiley & Sons, Ltd.