Figure 4. Astaxanthin inhibited hydrogen peroxide–induced intracellular generation of reactive oxygen species. A: The ARPE-19 cells were incubated with 10µM and 20µM astaxanthin (AST) for 24 h and then exposed to 200 µM hydrogen peroxide (H₂O₂) for 24 h. The intracellular reactive oxygen species (ROS) was measured with flow cytometry using 2′,7′-dichlorodihydrofluorescein diacetate (DCFH-DA). B: AST reduced the generation of ROS in ARPE-19 cells significantly. Data are shown as mean ± standard deviation (SD) (n=6); *p<0.05 versus control; # p<0.05 versus H₂O₂-induced cells without treatment with AST.