title: Quercetin inhibits α-MSH-stimulated melanogenesis in B16F10 melanoma cells.
abstract: Quercetin is known to inhibit tyrosinase activity and melanin production in melanocytes. However, several reports suggest that quercetin has different and opposite effects on melanogenesis. This study examined the precise effects of quercetin on melanogenesis using cell-free assay systems and melanocytes. Quercetin inhibited the monophenolase and diphenolase activities of tyrosinase, and melanin synthesis in cell-free assay systems. Quercetin induced mild stimulation of the tyrosinase activity and dihydroxyphenylalaminechrome tautomerase (TRP-2) expression but only at low concentrations (<20 μm) in B16F10 melanoma cells. In contrast, the addition of 50 μm quercetin to the cells led to a significant decrease in the activity and synthesis of tyrosinase, as well as a decrease in the expression of tyrosinase-related protein-1 and TRP-2 proteins, regardless of the presence or absence of α-melanocyte stimulating hormone (α-MSH). Quercetin also reduced the intracellular cAMP and the phosphorylated protein kinase A levels in α-MSH-stimulated B16F10 cells. Moreover, quercetin (20 μm) diminished the expression and activity of tyrosinase, and melanin content in cultured normal human epidermal melanocytes. These effects were not related to its cytotoxic action. Although the in vivo effects of quercetin are still unclear, these results suggest that quercetin could play important roles in controlling melanogenesis.
authors.affiliation: Institute of Oral Biosciences and BK21 Program, Chonbuk National University, Jeonju, South Korea.
authors.forename: Yeon-Mi
authors.initials: YM
authors.lastname: Yang
authors.forename: Young-Ok
authors.initials: YO
authors.lastname: Son
authors.forename: Seung-Ah
authors.initials: SA
authors.lastname: Lee
authors.forename: Young-Mi
authors.initials: YM
authors.lastname: Jeon
authors.forename: Jeong-Chae
authors.initials: JC
authors.lastname: Lee
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D048708:Cell Growth Processes / Q000187:drug effects; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D006801:Humans; D019746:Intramolecular Oxidoreductases / Q000096:biosynthesis; D008543:Melanins / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D008544:Melanocytes / Q000187:drug effects / Q000378:metabolism; D008546:Melanoma, Experimental / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors / Q000378:metabolism; D010088:Oxidoreductases / Q000096:biosynthesis; D010766:Phosphorylation; D010858:Pigmentation / Q000187:drug effects; D011794:Quercetin / Q000494:pharmacology*; D014407:Tumor Cells, Cultured; D000521:alpha-MSH / Q000037:antagonists & inhibitors* / Q000494:pharmacology
chemical_list: D008543:Melanins; D000521:alpha-MSH; D011794:Quercetin; D000242:Cyclic AMP; D010088:Oxidoreductases; C064056:tyrosinase-related protein-1; D014442:Monophenol Monooxygenase; D017868:Cyclic AMP-Dependent Protein Kinases; D019746:Intramolecular Oxidoreductases; C042501:dopachrome isomerase