(a)
(b)
Figure 1: Cell viability, measured by flow cytometry as impermeability to PI, of NB4 cells treated with esculetin alone or combined with oxidants. (a) Viability of NB4 cells treated with esculetin alone or combined with H2O2. Cells (5 × 105/ml) were treated with 100 µM esculetin alone or in combination with 1 mM H2O2 for different times. (b) Viability of NB4 cells treated with esculetin alone or combined with t-BHP. Cells (5 × 105/ml) were treated with 100 M esculetin, 100, 250, and 500 µM t-BHP, or both compounds, for the indicated times. Data are expressed as mean ± SEM of three independent experiments. Treated versus untreated cells; ; . Treated with esculetin plus oxidant versus esculetin alone; ; . Treated with esculetin plus oxidant versus oxidant alone; .