Figure 2: D-limonene inhibited H2O2-induced apoptosis in HLECs. (a) Annexin V/PI staining of HLECs incubated in 500, 1000, and 2000 μM D-limonene for 12 h and then treated with 100 μM H2O2 for 24 h is shown. The percentage of cells in each of the four quadrants is shown inside of each area. (b) The quantitative analysis of the apoptosis rate in HLECs is shown. , .