title: Inhibitory effect of p-coumaric acid by Rhodiola sachalinensis on melanin synthesis in B16F10 cells.
abstract: Rhodiola has been widely used in traditional Asian medicine. In this study, we tested the hypopigmentation effects of R. sachalinensis and its active compounds including catechin, chlorogenic acid, p-coumaric acid, and p-tyrosol. Results have shown that only p-coumaric acid inhibits melanin synthesis in B16F10 cells. However, p-coumaric acid did not inhibit tyrosinase activity when L-DOPA was used as a substrate. Instead, p-coumaric acid inhibited tyrosinase activity when L-tyrosine was used as a substrate. We further analyzed the changes of cAMP responsive element binding protein (CREB) phosphorylation and tyrosinase gene expression. The results indicate that p-coumaric acid does not affect CREB phosphorylation or tyrosinase protein production. In turn, these findings demonstrate that p-coumaric acid has no effect on the upstream regulation of tyrosinase gene expression, although p-coumaric acid showed a significant inhibitory effect on melanogenesis. Because p-coumaric acid showed different effects on tyrosinase activity according to different substrates, we tested whether tyrosinase can utilize p-coumaric acid as a substrate. Our findings revealed that competitive inhibition occurs between p-coumaric acid and tyrosine. Consequently, this finding could be a primary mechanism for the hypopigmenting action of p-coumaric acid.
authors.affiliation: Department of Dermatology, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: So-Hee
authors.initials: SH
authors.lastname: Park
authors.forename: Dong-Seok
authors.initials: DS
authors.lastname: Kim
authors.forename: Seo-Hyoung
authors.initials: SH
authors.lastname: Park
authors.forename: Jung-Won
authors.initials: JW
authors.lastname: Shin
authors.forename: Sang-Woong
authors.initials: SW
authors.lastname: Youn
authors.forename: Kyoung-Chan
authors.initials: KC
authors.lastname: Park
mesh_terms: D015153:Blotting, Western; D002392:Catechin / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects; D002726:Chlorogenic Acid / Q000494:pharmacology; D003373:Coumaric Acids / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000494:pharmacology*; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D006801:Humans; D007980:Levodopa / Q000378:metabolism; D008543:Melanins / Q000037:antagonists & inhibitors* / Q000096:biosynthesis*; D008546:Melanoma, Experimental / Q000378:metabolism; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors; D010626:Phenylethyl Alcohol / Q000031:analogs & derivatives / Q000494:pharmacology; D010766:Phosphorylation; D011422:Propionates; D029771:Rhodiola / Q000737:chemistry*; D014443:Tyrosine / Q000037:antagonists & inhibitors / Q000494:pharmacology; D000521:alpha-MSH / Q000494:pharmacology
chemical_list: D003373:Coumaric Acids; D017362:Cyclic AMP Response Element-Binding Protein; D008543:Melanins; D011422:Propionates; C011867:4-hydroxyphenylethanol; D002726:Chlorogenic Acid; D014443:Tyrosine; D007980:Levodopa; D000521:alpha-MSH; D002392:Catechin; D014442:Monophenol Monooxygenase; C495469:p-coumaric acid; D010626:Phenylethyl Alcohol