Figure 7. Dose effect of curcumin on catalase and Gpx-s messenger RNA (A) and protein (B) levels in ARPE-19 cells. Cells treated with various concentrations of curcumin (1–20 μΜ) for 6 h dose-dependently increased catalase, GPx-1, and GPx-4 at the messenger RNA (mRNA) and protein levels, compared with controls. Representative western blots of catalase (CAT), GPx-1, GPx-4, actin, and densitometric analysis of protein levels are shown in the upper and lower panels, respectively. Data represent mean±SEM from four separate samples. *p<0.05 versus control, **p<0.001 versus control.