Caspase-3 induced activity by compound 4l and 4o. Jurkat cells were incubated in the presence of 4l and 4o at 50 nM. After 24, 48, and 72 h of treatment, cells were harvested and stained with an antihuman active caspase-3 fragment monoclonal antibody conjugated with FITC: (upper panels) representative histograms of Jurkat cells incubated in the presence of 50 nM 4l and 4o for 48 h; (lower panel) percentage of caspase-3 active fragment positive cells after 24,48, and 72 h of treatment. Data are expressed as the mean ± SEM of three independent experiments.