Figure 1.

Effects of different concentrations of H₂O₂ on HUVEC viability. (a–e) Scatter plots of flow cytometric results with annexin V (horizontal axis) and 7-AAD (vertical axis). Cells were labeled with annexin V and 7-AAD after a 30 min incubation with different concentrations of H₂O₂. The conditions were as follows: (a) 0 μmol/L H₂O₂ (control), (b) 25 μmol/L H₂O₂, (c) 50 μmol/L H₂O₂, (d) 100 μmol/L H₂O₂, and (e) 200 μmol/L H₂O₂. Early apoptotic cells were defined as annexin V positive/7-AAD negative. (f) Quantitative analysis of cell apoptosis with different concentrations of H₂O₂ (mean ± SD of six separate experiments, ^∗p < 0.05 versus control, and one-way ANOVA followed by SNK post hoc test).