Abstract: Objective To study the effects of ethanol extracts from six traditional Chinese medicines for treating vitiligo on the expression of mRNA for tyrosinase (TYR),tyrosinase-related protein (TRP)-1,and TRP-2 in B 16 melanoma cells.Methods Ethanol extracts were prepared from six traditional Chinese medicines,i.e.Cremastra appendiculata (D.Don) Makino,Mentha haplocalyx Briq.,Sophora flavescens Ait.,Prunella vulgaris L.,Sesamum indicum L.,and Eclipta prostrata L..B16 melanoma cells were treated respectively with ethanol extracts at a concentration of 10 or 20μg/mL for 72 h,with culture media and 8-methoxypsoralen (8-MOP) served as blank and positive control,respectively.The expression of mRNA for TYR,TRP-1,and TRP-2 was measured by semiquantitative reverse transcription PCR.Results The ethanol extracts from Sophora flavescens Ait.significantly upregulated the expression of mRNA for both TYR and TRP-2 (both P<0.05).The expression of TYR mRNA was also significantly upregulated by extracts from Cremastra appendiculata (D.Don) Makino,Sesamum indicum L.,and Eclipta prostrata L. (all P<0.05),whereas none of the extracts affected TRP-1 mRNA expression (P>0.05).Conclusions The results indicate that Cremastra appendiculata (D.Don) Makino,Sophora flavescens Ait.,Sesamum indicum L.and Eclipta prostrata L.can upregulate the expression of TYR mRNA.Moreover,Sophora flavescens Ait can also upregulate TPR-2 mRNA expression.These may partially account for the therapeutic mechanisms of these Chinese herbal drugs in vitiligo.

Key words: Drugs, Chinese herbal, Melanoma, experimental, Tyrosinase, Tyrosinase-related protein 1/2