Effect of Cpc on cAMP/MAPK/ERK pathway and MITF expression at protein and mRNA levels. Immunoblot analysis was performed with cell extract proteins treated with (A) Cpc (0.1 mg/mL) at assigned time intervals for ERK1/2 (control (black); CPC-treated (grey)), and (B) different Cpc concentration (0.05, 0.1, 0.2 mg/mL) at 540 min for MEK. (C) Cell extract proteins at assigned time intervals treated with Cpc (0.1 mg/mL) were examined by Immunoblot analysis for MITF using β-actin as internal standards (control (black); CPC-treated (grey)). (D) Different levels of Cpc (0.05, 0.1, 0.2 mg/mL) treated MITF mRNA were analyzed by Q-PCR at 540 min. (E) Immunoblot analysis treated with Cpc (0.1 mg/mL), PD98059 (PD, 20 μM), and Cpc+PD at 72 hrs were performed for the evaluation of MITF and tyrosinase expression (MITF (black); tyrosinase (grey)). Data were expressed at mean ± SD from three different experiments. The asterisk (*) indicates a significant difference from control group (*, P < 0.05).