Figure 2: Melatonin inhibits H2O2-induced ROS production and apoptosis in RPE cells. RPE cells were pretreated with different concentrations of melatonin (50 and 100 μM) for 48 h and exposed to 300 μM H2O2 for 4 h/24 h. ROS production was determined using the DCFDA assay (a, b). Cell apoptosis was analyzed with PI and annexin V (c, d). Values are the mean ± SD. versus the control group and versus H2O2-treated cells.