Figure 5.

Protective effects of Cur and CurDD against oxidative stress occur through modulation of apoptotic MAPK p44/42 signalling pathway. ARPE-19 cells were pre-treated with 10 µM of Cur or CurDD for 24 h, followed by H₂O₂ treatment at appropriate concentrations (400 and 200 µM for undifferentiated and differentiate cells, respectively) for 6 h. Protein levels of phosphorylated P-p44/42 were assessed by immunoblotting in (A) undifferentiated and (B) differentiated ARPE-19 cells. GAPDH immunodetection was used as a loading control. Representative Western blots shown, with graphs presenting average normalised protein expression; (C) mRNA levels of p44/42 were analysed by qPCR. Graph represents average expression normalised against four housekeeping genes as described in Methods. (For both protein and mRNA, data is presented as mean ± SD values, n = 4; One-Way ANOVA test, * p ≤ 0.05 vs. control group, ^# p ≤ 0.05 vs. H₂O₂ group, and ^& p ≤ 0.05 vs. Cur + H₂O₂ group).