Figure 4.
Effect of OISEA on the levels of melanogenesis related mRNA and proteins in melan-a cells. (A) Cells (5 × 105 cells/mL) were cultured for 24 h; the medium was replaced with fresh medium containing the indicated concentration of OISEA or arbutin for 24 h, and the mRNA was extracted using TRIzol. mRNA expression was analyzed by reverse transcription-polymerase chain reactions. (B) Cells (5 × 105 cells/mL) were cultured for 24 h; the medium was replaced with fresh medium containing the indicated concentrations of OISEA or arbutin for 3 days. Total cell lysates were extracted and assayed by Western blotting using antibodies against tyrosinase, TYRP-1, TYRP-2, and MITF. Equal amounts of protein loading were confirmed using β-actin. (C) Statistical analysis of the band intensity of tyrosinase, TYRP-1, TYRP-2, and MITF obtained by Western blot analysis. Results are presented as means ± SD. * p < 0.05, ** p < 0.01, versus the non-treated group.