Abstract: Objective To study the effects of paeonol on the tyrosinase activity and melanogenesis in co-culture model of human melanocytes and keratinocytes.Methods Melanocytes and the co-culture model of human melanocytes and keratinocytes were cultivated and the proliferation of melanocytes and the co-cultures was measured by MTT colorimetric assay.The tyrosinase activity and melanin level were measured by enzymic method.Results The melanin synthesis and tyrosinase activity were markedly suppressed by paeonol in a dose-dependent manner at the concentrations of 50μmol/L,100μmol/L,and 200μmol/L in both melanocytes and co-cultures.The significant stronger suppression was observed with 100μmol/L and 200μmol/L of paeonol than that with controls (P< 0.01).Conclusion Paeonol exhibits dose-dependent inhibitory effects on melanin synthesis and tyrosinase activity in co-cultures of human melanocytes and keratinocytes.

Key words: Paeonol, Melanocyte, Keratinocytes