ABSTRACT
Aim To investigate the inhibitory effect of polyphenol from Cortex Mori( CMP) on melanogenesis in mouse melanoma B16 cells and its possible mecha- nism. Methods Melanoma B16 cells with high ex-pression melanin were induced by α-melanocyte-stimu-lating hormone ( α-MSH) to establish cell model. Cell viability was detected by MTT assay. The melanin syn-thesis and tyrosinase activity were measured by NaOH and L-Dopa assays, respectively. The tyrosinase (TYR), tyrosinase-related protein-1 (TRP-1), tyrosi-nase-related protein-2 ( TRP-2 ) and microphthalmia associated transcription factor ( MITF ) protein and mRNA levels were measured by Western blot and qRT-PCR, respectively. Results CMP could inhibit the melanin synthesis and tyrosinase activity in α-MSH stimulated B16 cells in a dose-dependent manner ( P<0.05) . The melanin content and tyrosinase activity significantly decreased by 52.95% , 32.85% at 20 mg ·L-1of CMP, respectively. Treatment of 100 mg· L-1of arbutin reduced the melanin content and tyrosi- nase activity by 17.29% , 16.75% , respectively. Based on the results of this study, CMP showed a stronger anti-melanogenesis activity than that of positive control arbutin. After treated by CMP, the protein and mRNA levels of TYR, TRP-1, TRP-2 and MITF were significantly inhibited compared to the α-MSH group ( P<0.05) . Conclusions CMP could suppress the melanogenesis in α-MSH stimulated B16 cells, and its mechanism may be related to its regulation of the pro-tein and mRNA expressions of TYR, TRP-1, TRP-2 and MITF, and the inhibition of tyrosinase activity.