ABSTRACT
Down-regulation of melanin synthesis and\or melanin transfer are/is required for recovery of pigmentary disorders. It is known that direct inhibitors of tyrosinase, the key enzyme in melanin synthesis, such as hydroquinone with a phenol structure, suppress melanin synthesis. We screened some herbal monomers using human melanocytes and found that paeonol, a major phenolic component of Moutan Cortex, down-regulated melanin synthesis. The melanin synthesis and tyrosinase activity were inhibited by paeonol in a dose-dependent manner. The expression levels of tyrosinase mRNA and protein were also reduced by paeonol. We further studied the inhibitory effects of paeonol on melanin transfer in co-culture of melanocytes and keratinocytes. More than 50% of inhibition of melanin transfer was observed at concentration of 200 microM of paeonol and the increased melanin transfer induced by SLIGRL, the PAR-2 activating peptide, was also reduced by paeonol. However, paeonol did not influence the expression level of PAR-2 mRNA in co-culture cells. These results indicate that the depigmenting effect of paeonol might be due to its down-regulation of melanogenesis and melanin transfer.
Subject(s)
Acetophenones/pharmacology , Down-Regulation/drug effects , Melanins/metabolism , Cell Survival/drug effects , Cells, Cultured , Coculture Techniques , Dose-Response Relationship, Drug , Humans , Keratinocytes/drug effects , Keratinocytes/metabolism , Male , Melanins/genetics , Melanocytes/drug effects , Melanocytes/metabolism , Monophenol Monooxygenase/genetics , Monophenol Monooxygenase/metabolism , RNA, Messenger/metabolismABSTRACT
Itraconazole has been used to treat superficial candidal infections in China for 12 years with promising efficacy and safety. This article retrospectively reviewed literatures published in the mainstream journals in China with an attempt to find a reasonable therapy for Chinese populations.
