Abstract:

Zhang Lingling, Xu Wen, Xu Ai′e Department of Dermatology, Third Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou 310009, China Corresponding author: Xu Ai′e, Email: xuaiehz@msn.com 【Abstract】 Objective To evaluate the effect of puerarin on melanogenesis in melanocytes, and to explore its possible mechanisms. Methods Third- to fifth-passage melanocytes isolated from human foreskin were treated with different concentrations （1, 5, 10, 20, 40, 80 and 160 μmol/L） of puerarin for 24 hours, with those receiving no treatment as the normal control group. Methyl thiazolyl tetrazolium （MTT） assay was performed to evaluate the proliferative activity of melanocytes, a sodium hydroxide solubilization method was used to measure melanin content, and reverse transcription PCR （RT-PCR） and Western blot analysis were performed to quantify the mRNA and protein s of microphthalmia-associated transcription factor （MITF）, tyrosinase （TYR） and tyrosinase-related protein-1 （TRP-1） respectively. Results There were no significant differences in the proliferative activity of melanocytes between the puerarin （1 - 40 μmol/L） groups and normal control group （P > 0.05）, and 40 μmol/L was chosen as the concentration of puerarin for subsequent experiments. Compared with the normal control group, the 40-μmol/L puerarin group showed increased melanin content as well as mRNA and protein s of MITF, TYR and TRP-1 （all P < 0.05）. Concretely speaking, the protein s of MITF, TYR and TRP-1 in the 40-μmol/L puerarin group were increased by 8.69%, 10.28% and 10.58% compared with the normal control group respectively （all P < 0.05）, and their mRNA s were 2.48, 1.91 and 1.63 times higher in the 40-μmol/L puerarin group than in the normal control group respectively （all P < 0.05）. Conclusion Puerarin can increase the mRNA and protein s of MITF, TYR and TRP-1, and promote melanogenesis in melanocytes.