Effect of selected CGXs on apoptosis. Cells were treated for 60 min, 90 min, 120 min, 180 min with 2 μM CLV (lanes 2–5), 2 μM 3 (lanes 6–9), 2 μM 4 (lanes 10–13) and 80 μM 5 (lanes 14–17). Control cells treated with equal volume of DMSO are in lane 1. The cells were then collected and analyzed by WB to measure induction of apoptosis by caspase-3 (C3) activation. Both CLV and 3 show active caspase-3 starting at 90 min (lanes 3 and 7 respectively); 4 requires 120 min incubation to achieve comparable levels of activation; 5 induced caspase-3 activation only after 180 min incubation at 80 μM (lane 17). Tubulin (bottom line) was used as loading control.