B-ext, L-ext, their active components, and NAC improved metabolic activity reduction in 661 W cells. (A) Cytomorphology of 661 W cells after 24 h of blue LED light exposure. Small arrows indicate apoptotic cells. Scale bar, 50 μm. Inhibitory effects of B-ext (B), L-ext (C), NAC (D), delphinidin, cyanidin, malvidin (E), resveratrol, and procyanidin B2 (F) on blue LED light-induced reduction of metabolic activity in 661 W cells. Metabolic activity was assessed by incubating the cells with CCK-8 reagent for 2 h at 37°C; photometric data were obtained at 492/660 nm. Cells were treated with B-ext, L-ext, NAC, delphinidin, cyanidin, malvidin, trans- resveratrol, and procyanidin B2 for 1 h, and then exposed to 2500 lx of blue LED light for 6 h. Data are means ± SEM (n = 6). C, control; V, vehicle; B-ext, bilberry extract; L-ext, lingonberry extract; NAC, N-acetyl-l-cysteine; Dp, delphinidin; Cy, cyanidin; Mv, malvidin; PC, procyanidin B2; Res, trans-resveratrol. ##
p < 0.01 vs. control; *p < 0.05, **p < 0.01 vs. the vehicle-treated group (Dunnett’s multiple comparison test or Student’s t-test).