Dose-dependence and kinetics of caspase activation in response to eupatorin in human leukemia cells.

<p>(A) Caspase activation in response to eupatorin. Cells were treated with the indicated concentration of eupatorin and harvested at 24 h. Cell lysates were assayed for caspase-9, caspase-8, caspase-6 and caspase-3/7 activities using the LEHD-<i>p</i>NA, IETD-<i>p</i>NA, VEID-<i>p</i>NA and DEVD-<i>p</i>NA colorimetric substrates, respectively. The values represent fold induction of caspase activity relative to untreated control. (B) Kinetics of caspase activation in response to eupatorin. Cells were treated with 3 µM eupatorin, harvested at the indicated times, and cell lysates were assayed and the results are expressed as above. * indicates <i>P</i><0.05 for comparison with untreated control.