Figure 2.

Effect of unfractionated PE extract on UVB-induced COX-2 expression and PGE₂ production in HaCaT keratinocytes. HaCaT cells were sham irradiated or irradiated with 30 mJ/cm² UVB. (A) After irradiation the cells were treated with PE extract for 24 h before the PGE₂ concentration was measured in the cell culture supernatants. Data are expressed as mean ± SD of three independent experiments and the statistical significance was determined compared to the irradiated, untreated control (* p < 0.05; ** p < 0.01); (B) After irradiation the cells were treated with PE extract for 24 h. Then the cells were lysed and analyzed for COX-2 expression by western blotting. β-actin served as loading control.