Ninety samples from the extracts of plants from traditional Chinese medicines were screened for antitumor activity. Paeoniflorigenone (PFG) was isolated as an active ingredient from the root of moutan cortex， which showed the strongest activity. In addition， our data indicated that PFG was cytotoxic and induced apoptosis selectively in the cancer cell lines. These effects were cancelled by the addition of caspase inhibitor Z-VAD-FMK， suggesting that it was mediated by caspase-3 activation.
Ninety samples from the extracts of plants from traditional Chinese medicines were screened for antitumor activity. Paeoniflorigenone (PFG) was isolated as an active ingredient from the root of moutan cortex， which showed the strongest activity. In addition， our data indicated that PFG was cytotoxic and induced apoptosis selectively in the cancer cell lines. These effects were cancelled by the addition of caspase inhibitor Z-VAD-FMK， suggesting that it was mediated by caspase-3 activation.
