Fig. 4

ZALE induced ERK dependent apoptosis. a ZALE induced cytotoxicity to HeLa cells is ERK dependent. HeLa cells were treated with DMSO, ZALE, U0126 (ERK inhibitor), SP600125 (JNK inhibitor), or combination of inhibitor and ZALE. For combination treatment, cells were pretreated with the inhibitors 2 h prior to the treatment with ZALE (60 μg/ml). After 48 h viable cells were measured. The data represent the percentage growth compared with DMSO treated cells and show 1 representative result of 3 independent experiments with standard deviations. b Quantification of apoptotic nuclei observed after DAPI staining in the HeLa cells treated with either DMSO or ZALE or the MAPK inhibitors-ZALE combination for 48 h. c Immunblot showing the inhibition of activation of ERK, p38 and JNK by their respective inhibitors. Cells were treated with D (DMSO), Z (ZALE) or Z and the specific inhibitors