Effect of Cpc on viability of B16F10 melanoma cell, tyrosinase activity and melanin contents. Cells were treated with Cpc (0.05, 0.1, 0.2 mg/mL) for 72 hrs. (A) Cell viability was determined by MTT assay as described in Materials and Methods. (B) Tyrosinase activity (black) and melanin content (grey) were measured. (C) The expression of tyrosinase was determined by immunoblotting analysis (black) and RT-PCR (grey), using β-actin and GAPDH as internal standards, respectively. Data were expressed at mean ± SD from three different experiments. The asterisk (*) indicates a significant difference from control group (*, P < 0.05; **, P < 0.01).