In vitro inhibition of tumor cell growth by Miconia fallax

In vitro tumor growth inhibition by the ethanol extract of Miconia fallax DC. (Melastomataceae) was evaluated in culture media containing HeLa cells at the following concentrations: 5, 15, 25, 35, and 45 mu g/mL. Bioassay-guided fractionation of this extract furnished a mixture of ursolic and oleanolic acids. Both the ethanol extract and the mixture of the triterpenoid acids produced dose-dependent tumor growth inhibition. This antitumor activity was more pronounced when a mixture of the triterpene acids at a concentration of 45 mu g/mL was added to a HeLa cell culture medium.