Fig. 4.

Phosphorylation effect of shikonin and TRAIL on JNK, STAT3 and AKT. a Activation of JNK and inhibition of STAT3 and AKT were associated with the induction of apoptosis in A549 cells by shikonin and TRAIL cotreatment as described above. The expression of the total and phosphorylated forms of JNK, STAT3 and AKT were assessed using the corresponding antibodies via Western blotting. b The data are presented as the means ± SDs of at least three independent experiments, and significant differences between the control group and the other groups are shown as *p < 0.05, **p < 0.01 and ***p < 0.001. S + T: Shikonin + TRAIL