Figure 2

Apoptotic and cell-cycle effects of pyranocoumarins in MCF-7 cells. (a) Cell-cycle distribution: cells were treated with decursin (D), decursinol angelate (DA) or decursinol (DL) at different exposure concentrations (10 μM, 20 μM, 50 μM) for 24 hours in complete medium. Bar height represents average of duplicate flasks, variation less than 2%. (b) Apoptotic DNA nucleosomes detected by the Death ELISA kit in MCF-7 cells after 24 hours of treatment in complete medium. Bar height represents average of duplicate flasks, variation less than 2%. (c) Western blot analysis detection of cleaved poly(ADP-ribose) polymerase (c-PARP), estrogen receptors (ERs) and selected mitogen signaling and cell-cycle regulator proteins after 48 hours of treatment in complete medium. (d) Inhibition of decursin (50 μM)-induced apoptosis by 10 μM caspase inhibitors (CIs). PanI, Pan inhibitor (Q-VD-OPH); CI-3/7, zDEVDfmk; CI8, zIETDfmk; and CI9, zLEHDfmk (Enzyme Systems Products, Dublin, CA, USA). Inhibitors were added 2 hours prior to decursin treatment for an additional 24 hours. Mean ± standard deviation, triplicate determinations.