Effect of KZE on the protein levels of TRP-1 and TRP-2 in B16 cells. The cells were treated with 20 μg/ml of KZE for the indicated times. Western blot assays were performed to examine TRP-1 and TRP-2 expression levels. Results were normalized against β-actin expression. Results shown are means ± SEM and are representative of three independent experiments. Data were analyzed by One-Way Analysis of Variance (ANOVA) followed by post hoc Tukey test **P < 0.01, compared with control.