Fig. 4

Apoptosis analysis in HepG2 cells by Annexin V-FITC/PI. (a1–c1): change in membrane asymmetry, and (a2–c2): analysis of cell cycle in HepG2 cells after 48 h incubation with ZnO NPs. a Untreated (control); b treated cells with 50 μg/ml ZnO NPs; and c treated cells with 150 μg/ml ZnO NPs. d Percentages of apoptosis HepG2 cells. R5: G0 that refers to the proportion of apoptotic cells