Figure 2

Aloperine induces cell apoptosis in a dose-dependent manner. (A) U266 and MM.1S cells were treated with various concentrations of aloperine for 48 h, harvested, and analyzed by flow cytometry. (B) Aloperine activates caspases. Western blot analysis of lysates from U266 and MM.1S cells treated with 80 μM aloperine for the indicated durations with or without anti-caspase-8 or anti-caspase-9 antibodies. PF, full length; CF, cleaved fragment. Blots are representative of three independent experiments. β-Actin was assessed by Western blotting. All proteins levels were quantified densitometrically and are normalized to β-actin. (C) U266 cells were treated with 80 or 160 μM aloperine and the indicated agents for 48 h (as described in panel (B)) in the presence or absence of biochemical inhibitors of caspase-3, caspase-8, or caspase-9, and apoptosis was assessed using annexin V/propidium iodide staining. Data represent the mean ± SD. The results are from a representative experiment (n = 3) (^a,b P < 0.001 versus no inhibitors in MM cells).