Fig. 3

Measurement of apoptosis in HEK-293 cells treated with ZnO NPs. a Annexin V/PI staining in HEK-293 cells treated with ZnO NPs. The induction of apoptosis and necrosis was determined by flow cytometric analysis of Annexin V and PI staining. b Quantification of apoptotic cells with Annexin V-stained cells using flow cytometry. HEK-293 cells treated with different concentrations of ZnO NPs were assessed using Annexin V/PI staining. Cells were incubated with 0–25 μg/ml ZnO NPs for 24 h. *p < 0.05 versus control. The data are presented as the mean ± standard deviation of three independent experiments. c Western blotting for procaspase-3, cleaved-caspase-3 and Bax in HEK-293 cells. Cells were treated with 0–25 μg/ml ZnO NPs for 24 h