Tyrosinase activity and melanogenic effects of Lespedeza bicolor extract in vitro and in vivo

Lespedeza bicolor (L. bicolor) is used for medicinal purposes because of its various biological and pharmacological activities. In this study, the effects of L. bicolor ethanol extract on the treatment of vitiligo were investigated. The determination of melanin content in melanocytes was measured using B16 melanoma cells and C57BL/6J Ler-vit/vit mice. Finally, the quercetin content in L. bicolor were qualitatively analyzed using HPLC. The results obviously indicated that the L. bicolor extract enhanced melanogenesis and increased tyrosinase activity in cultured melanoma cells and C57BL/6J Ler-vit/vit mice. Treatment with L. bicolor extract led to a higher content of melanin and eumelanin in C57BL/6J Ler-vit/vit mice hair than in control (untreated) mice, which demonstrated the therapeutic effect of hair-graying associated with vitiligo. There was a notable increase in melanocytes in the skin of C57BL/6J Ler-vit/vit mice treated with L. bicolor extract compared with the control. L. bicolor extract was a potent tyrosinase and melanin synthesis activator in B16 melanoma cells. C57BL/6J Ler-vit/vit mice treated with L. bicolor extract had significantly higher melanin content in hair than the untreated control. The results suggest that L. bicolor extract is a potential alternative treatment for improvement of vitiligo.