Figure 2

Saikosaponins and cisplatin co-treatment potentiates apoptosis in cancer cells. (A) HeLa cells were treated with cisplatin (8 μM) or saikosaponin-a (10 μM) or saikosaponin-d (2 μM) individually or combination of saikosaponin and cisplatin for 36 h and then stained with ethidium bromide and acridine orange; Cells were immediately observed and photographed under a fluorescence microscope. (B) HeLa cells were treated as indicated in (A), and then stained with annexin V and PI followed by flow cytometry analysis. Early apoptosis is defined by Annexin V⁺/PI^- staining (Q4) and late apoptosis is defined by Annexin V⁺/PI⁺ staining (Q2). (C) and (D) HeLa cells were treated with cisplatin (8 μM) or saikosaponin-a (10 μM) or saikosaponin-d (2 μM) individually or combination of saikosaponin and cisplatin for 24 h and 36 h. Caspase -3 and PARP were detected by western blot. β-actin was detected as an input control. (E) and (F) HeLa cells were pretreated with zVAD-fmk (20 μM) for 30 min or remained untreated and then treated with saikosaponin-a or -d and cisplatin for another 48 h. Cell death was measured as described in Fig. 1A.