title: Anemonin is a natural bioactive compound that can regulate tyrosinase-related proteins and mRNA in human melanocytes.
abstract: BACKGROUND
  Melanin is the pigment responsible for skin color. Melanin synthesis occurs with the participation of the tyrosinase (TYR) family of proteins including TYR, tyrosinase-related protein 1 (TRP1), and tyrosinase-related protein 2(TRP2/DCT).
  
  
  OBJECTIVE
  The effect of a newly isolated natural compound that inhibits hyperpigmentation on the regulation of the TYR family of proteins was examined.
  
  
  METHODS
  The natural compound, anemonin, was isolated from Clematis crassifolia Benth and was used to inhibit cellular TYR activity; it was found to have a low cytotoxicity (cell viability > 80%) in human melanocytes.
  
  
  RESULTS
  In human melanocytes, anemonin showed both time- and dose-dependent inhibition (IC(50) 43.5 microM) of TYR. Western blot analysis and immunocytochemical staining revealed that expression of TYR, TRP1, and TRP2 was decreased in anemonin-treated melanocytes. Additionally, reverse transcription and quantitative real-time polymerase chain reaction analyses revealed that expression of mRNAs for MITF, TYR, TYRP1, and TYRP2 was also suppressed by anemonin.
  
  
  CONCLUSIONS
  The natural compound, anemonin, an active compound of C. crassifolia, inhibits pigmentation synthesis in human melanocytes. Anemonin inhibits melanin synthesis by inhibiting the transcription of the genes encoding MITF, TYR, TRP1, and TRP2. This natural compound may be a candidate for cosmetic use.
authors.affiliation: Department of Biochemistry and Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan.
authors.forename: Yen-Hua
authors.initials: YH
authors.lastname: Huang
authors.forename: Tzong-Huei
authors.initials: TH
authors.lastname: Lee
authors.forename: Kuei-Jung
authors.initials: KJ
authors.lastname: Chan
authors.forename: Feng-Lin
authors.initials: FL
authors.lastname: Hsu
authors.forename: Yu-Chih
authors.initials: YC
authors.lastname: Wu
authors.forename: Mei-Hsien
authors.initials: MH
authors.lastname: Lee
mesh_terms: D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D039324:Clematis / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation; D004791:Enzyme Inhibitors / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D005663:Furans / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D006801:Humans; D020128:Inhibitory Concentration 50; D019746:Intramolecular Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D008543:Melanins / Q000378:metabolism; D008544:Melanocytes / Q000187:drug effects* / Q000201:enzymology; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D051739:Microphthalmia-Associated Transcription Factor / Q000378:metabolism; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D010936:Plant Extracts / Q000494:pharmacology; D018515:Plant Leaves; D012333:RNA, Messenger / Q000378:metabolism*; D013997:Time Factors; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D004791:Enzyme Inhibitors; D005663:Furans; C497234:MITF protein, human; D008543:Melanins; D008562:Membrane Glycoproteins; D051739:Microphthalmia-Associated Transcription Factor; D010936:Plant Extracts; D012333:RNA, Messenger; D010088:Oxidoreductases; C489799:TYRP1 protein, human; D014442:Monophenol Monooxygenase; D019746:Intramolecular Oxidoreductases; C042501:dopachrome isomerase; C028304:anemonin