Fig. 4

Effects of QAF on matrix metalloproteinases (MMP)-1 expression in UVB-stimulated HaCaT cells. The cells were pretreated with Quercus acuta Thunb. fruit (QAF) for 24 h, followed by UVB-irradiation. (A) Cells were seeded and pretreated with a range of concentrations of QAF (5, 10, 20, and 50 µg/mL) and 30 ng/ml EGF, followed by UVB irradiation and cultured for an additional 24 h. The level of MMP-1 released in the cell culture medium was measured using ELISA. (B) Protein expression of MMP-1 was analyzed using western blotting and band intensities were quantified. Cells were seeded and pretreated with a range of concentrations of QAF (5, 10, 20, and 50 μg/mL), followed by UVB irradiation and cultured for an additional 24 h. Data are expressed as the mean ± SD. #p < 0.05, ##p < 0.01, ###p < 0.001 versus control group; *p < 0.05, **p < 0.01, ***p < 0.001 versus UVB-treated group