Fig. 3

Effect of shikonin and TRAIL on antiapoptotic and proapoptotic protein expression in A549 cells. a and c A549 cells were pretreated with shikonin (4 μM) for 12 h and were then incubated with TRAIL (50 ng/ml) for another 12 h. Whole cell lysates were prepared and analyzed by Western blotting using the indicated antibodies. β-Actin was used as the loading control. b, d and e The data are presented as the means ± SDs of at least three independent experiments, and significant differences between the control group and other groups in each experiment are shown as **p < 0.01 and ***p < 0.001. S + T: Shikonin + TRAIL