title: Silymarin inhibits melanin synthesis in melanocyte cells.
abstract: OBJECTIVE
  The aim was to search for inhibitors of melanogenesis from natural resources.
  
  
  METHODS
  The inhibitory effect of silymarin on melanogenesis in a spontaneously immortalized mouse melanocyte cell line, Mel-Ab, was studied.
  
  
  RESULTS
  Silymarin significantly prevented melanin production in a dose-dependent manner with an IC50 value (concentration producing 50% maximal inhibition) of 28.2 microg/ml, without effects on cell viability. Also, silymarin inhibited L-DOPA oxidation activity of tyrosinase, the rate-limiting melanogenic enzyme, in cell based-systems but it did not directly affect cell-free tyrosinase activity. Furthermore, Western blot analysis indicated that silymarin decreased the expression of tyrosinase protein.
  
  
  CONCLUSIONS
  This study suggests that the depigmenting effect of silymarin might be attributable to inhibition of tyrosinase expression and that silymarin may be useful as a natural skin-lightening agent.
authors.affiliation: Functional Metabolomics Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Korea.
authors.forename: Soo-Jin
authors.initials: SJ
authors.lastname: Choo
authors.forename: In-Ja
authors.initials: IJ
authors.lastname: Ryoo
authors.forename: Young-Hee
authors.initials: YH
authors.lastname: Kim
authors.forename: Guang-Hwa
authors.initials: GH
authors.lastname: Xu
authors.forename: Won-Gon
authors.initials: WG
authors.lastname: Kim
authors.forename: Ki-Ho
authors.initials: KH
authors.lastname: Kim
authors.forename: Seong-Joon
authors.initials: SJ
authors.lastname: Moon
authors.forename: Eui-Dong
authors.initials: ED
authors.lastname: Son
authors.forename: KiHwan
authors.initials: K
authors.lastname: Bae
authors.forename: Ick-Dong
authors.initials: ID
authors.lastname: Yoo
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D015153:Blotting, Western; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D007980:Levodopa / Q000378:metabolism; D008543:Melanins / Q000037:antagonists & inhibitors* / Q000096:biosynthesis*; D008544:Melanocytes / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D012838:Silymarin / Q000494:pharmacology*; D012880:Skin Pigmentation / Q000187:drug effects
chemical_list: D000975:Antioxidants; D008543:Melanins; D012838:Silymarin; D007980:Levodopa; D014442:Monophenol Monooxygenase