Abstract: The mechanism of whitening activity of Tricholoma matsutake TMSP-5II was studied in this paper.The evaluation of whitening activity was performed by Tyrosinase Inhibitory Activity (TIA) and melanin determination.The results showed that TMSP-5II can inhibit tyrosinase activity,and the inhibition rate was 56% with the concentration of 125 μg/mL.In addition,TMSP-5II can significantly inhibit the melanin production of B16 in a dose dependent way,and the inhibitory activity was better than that of arbutin. MITF, POMC and TYR were selected to perform the real-time quantitative PCR (RT-PCR) experiments in order to determine the possible targeting gene of TMP-5II and the results indicated that TMSP-5II played an important role in the reduction of expression levels of MITF, POMC and TYR, leading to a decreased melanin production.Therefore,TMSP-5II reduced the gene expression of the proteins that play an essential role in the production of melanin.

Key words: TMSP-5Ⅱ, whitening, melanin, genes