Anemonin is a natural bioactive compound that can regulate tyrosinase-related proteins and mRNA in human melanocytes.
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.
Huang
Yen-Hua
YH
Department of Biochemistry and Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan.
Lee
Tzong-Huei
TH
Chan
Kuei-Jung
KJ
Hsu
Feng-Lin
FL
Wu
Yu-Chih
YC
Lee
Mei-Hsien
MH
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
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