Research On The Melanin Synthesis Mechanism Of Two Phytoestrogens Regulation A375 Cells

Objective By studying the biological characteristic effects of two traditional Chinese medicine phytoestrogens which include Bavachinin and Corylin on human melanoma and the key enzyme in the process of melanin secretion regulation and intervention of ER and MAPK signal pathway, to analyze the inhibition effects of phytoestrogens on melanin formation in the process of chloasma formation, to clarify the potential mechanisms of two phytoestrogens for the treatment of chloasma, and to provide theoretical basis for rational use of traditional Chinese medicine phytoestrogens in preventing and treating chloasma and skin pigmentation disease.Methods The A375 cell lines were treated with phytoestrogens respectively. MTT test, NaOH schizolysis method and L-dopa oxidation method were respectively used to detect the cell proliferation, the content of melanin and the activity of tyrosinase(TYR) to analyze the intervention effects of five phytoestrogens on melanin formation. RT-PCR and Wesrern bloting were applied to measure the mRNA and protein expression levels of tyrosinase(TYR), and tyrosinase related proteins, and the mRNA or protein expression levels of ERK1、ERK2 and JNK2 which were the key protein kinases of ER-MAPK signal pathway, to discuss the molecular mechanisms of phytoestrogens inhibiting melanin secretion.Results Bavachinin and Corylin(100μmol?L-1、10μmol?L-1) can significantly inhibit the A375 cell proliferation(P﹤0.05), which showed significant cytotoxity on human melanoma and didn’t fit for the next research. Bavachinin and Corylin(1μmol?L-1、10-1μmol?L-1、10-2μmol?L-1), can inhibit melanin synthesis(P﹤0.05) and TYR activities(P﹤0.05) in different degrees. Bavachinin and Corylin(1μmol?L-1) can variously restrain the mRNA expressions of TYR, TRP-1 and TRP-2(P ﹤ 0.05). Bavachinin and Corylin(1μmol?L-1) can in varying degrees control the mRNA or protein expressions of ERK1、ERK2 and JNK2(P﹤0.05), but this effect will be weakened by ICI182780 and SP600125.Conclusion The results show that phytoestrogens can significantly inhibit the activity of TYR and the key enzyme and to have the effect of inhibiting melanin synthesis in A375 cell lines. The possible molecular mechanism of phytoestrogens inhibiting melanin synthesis may be by cutting TYR, TRP-1 and TRP-2 mRNA and protein expression quantity and/or inhibiting ER-MAPK signal pathway.