Fig. 4. iso-PXA induces apoptosis in HeLa/VCR and HeLa cells. (a) AO/EB staining of HeLa/VCR and HeLa cells treated with iso-PXA (0, 0.25, 0.5 and 1 μM) and VCR (1 μM) for 48 h. (b) Densitometry of cell counts. (c) Annexin V/PI test of HeLa/VCR and HeLa cells treated with iso-PXA (0, 0.25, 0.5 and 1 μM) and VCR (1 μM) for 48 h by flow cytometry. (d) Densitometry of cell counts. Columns represent the means ± SD values of the apoptosis rate obtained from three individual experiments. *P < 0.05, **P < 0.01 HeLa/VCR vs. HeLa control.