FIGURE 2

FIGURE 2

Apigenin increases cellular tyrosinase activity and expression of melanogenic proteins. (A) Cellular tyrosinase activity was measured after treatment with apigenin (0, 1, 5, or 10 μM). (B) Mushroom tyrosinase activity was measured in a cell-free assay after treatment with apigenin (0, 1, 5, or 10 μM). (C) HEMCs were treated with apigenin (0, 1, 5, or 10 μM) for 48 h, and Western blotting was performed to assess protein levels of melanogenic markers. (D) Time-dependent changes in the expression levels of various proteins after treatment with apigenin (10 μM) for the indicated periods. (E) HEMCs were treated with apigenin (10 μM) for 4 h, and RT-qPCR was performed to measure MITF gene expression. (F) HEMCs were treated with apigenin (10 μM) for different time points, followed by Western blotting to assess MITF protein levels. Data are expressed as means ± SEM (n = 3). *p < 0.05, **p < 0.01, and ***p < 0.001 vs. untreated cells. HEMCs, human epidermal melanocytes; MITF, Melanocytes inducing transcription factor.