Figure 5.

Protective effect of PUN on UV-A-induced apoptosis in ARPE-19 cells. Cells were pre-treated with 10 μM PUN and incubated for 24 h, and then exposed to UV-A radiations for 1, 3, and 5 h. Protein levels of apoptotic hallmarks, Bax (left-panel) and Bcl-2 (right-panel), were determined by colorimetric cell-based ELISA kits (details in “Materials and Methods” section). Values obtained, normalized to GAPDH, were expressed as a percentage relative to unirradiated and not pre-treated cells (control 100%). Results are from two independent experiments, each including three replicates per experimental group; they are presented as the means ± SEM. One-way ANOVA analysis followed by post hoc Newman–Keuls was carried out. ** = p < 0.01 and *** = p < 0.001 vs. control; °° = p < 0.01 vs. PUN alone; § = p < 0.05 and §§§ = p < 0.001 vs. UV-A alone at the same experimental time.