Figure 2. Astaxanthin prevented the decrease in retinal pigment epithelial cell viability induced by hydrogen peroxide. A: The ARPE-19 cells were incubated with different concentrations of astaxanthin (AST; 0, 5, 10, and 20 µM) for 24 h and then exposed to 200 µM hydrogen peroxide (H₂O₂) for 24 h. B: The ARPE-19 cells were treated with 20 µM AST for different lengths of time (6, 12, and 24 h) and then exposed to 200 µM H₂O₂ for 24 h. C: The ARPE-19 cells were treated with 20 µM AST for 24 h and then exposed to different concentrations of H₂O₂ (200 and 400 µM) for 24 h. Data are shown as mean ± standard deviation (SD) (n=6); *p<0.05 versus control. In all cases, the control is untreated retinal pigment epithelial (RPE) cells. # p<0.05 versus H₂O₂-induced cells without treatment with AST.