Fig. 1.

WEP induced HO-1 up-regulation at early time points only after UVA irradiation. a–d HO-1 expression level in NB1-RGB cells was evaluated using western blotting at each time point after initiating UVA irradiation (a) 3, (b) 6, (c) 12, and (d) 24 h. At all time points, WEP was applied at a concentration of 30 μg/mL. Mean ± SEM (n = 5–6), ^* P < 0.05 vs. control, ^** P < 0.01 vs. control, and ^‡ P < 0.01 vs. vehicle (Tukey’s test). (e) HO-1 expression level in NB1-RGB cells was evaluated using western blotting. WEP was applied at 3, 10, or 30 μg/mL 3 h after initiating UVA irradiation. Mean ± SEM (n = 6), control vs. vehicle (Student’s t-test), ^* P < 0.05 vs. vehicle (Dunnett’s test)