Stimulation of melanogenesis by scoparone in B16 melanoma cells.
OBJECTIVE
The effect of coumarin derivatives on melanogenesis was investigated in B16 murine melanoma cells.


METHODS
Melanin content and tyrosinase activity were analyzed spectrophotometrically. The expression of tyrosinase, tyrosinase-related protein-1 (TRP-1) and tyrosinase-related protein-2 (TRP-2) were measured either by reverse transcription-polymerase chain reaction (RT-PCR) or Western blot.


RESULTS
Among the coumarin derivatives studied, scoparone (6,7- dimethoxycoumarin) was the most potent; the 6- or 7-methoxy group was found to be essential for the stimulation of melanogenesis. The melanin content was greatly increased by scoparone in a dose-dependent manner; there was no cytotoxicity at the effective concentrations. Scoparone increased enzyme activity as well as protein and mRNA expression of tyrosinase. In addition, mRNA of TRP-1 and TRP-2 were also increased after treatment with scoparone. H-89, an inhibitor of protein kinase A (PKA), completely inhibited the scoparone-induced increase of melanogenesis and the tyrosinase protein.


CONCLUSIONS
These results suggest that scoparone-induced stimulation of melanogenesis is likely to occur at the transcriptional level of melanogenesis-related enzymes through PKA signaling.
Yang
Jeong-yeh
JY
Department of Biochemistry, Dental School, Chonbuk National University, Jeonju 561-756, Korea.
Koo
Jeung-hyun
JH
Song
Young-gil
YG
Kwon
Kang-beom
KB
Lee
Ju-hyung
JH
Sohn
Hee-sook
HS
Park
Byung-hyun
BH
Jhee
Eun-chung
EC
Park
Jin-woo
JW
D000818:Animals; D045744:Cell Line, Tumor; D003374:Coumarins / Q000008:administration & dosage / Q000494:pharmacology*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors; D004305:Dose-Response Relationship, Drug; D019746:Intramolecular Oxidoreductases / Q000096:biosynthesis / Q000235:genetics; D007546:Isoquinolines / Q000494:pharmacology; D008543:Melanins / Q000378:metabolism*; D008546:Melanoma, Experimental / Q000378:metabolism* / Q000473:pathology; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000235:genetics; D051379:Mice; D014442:Monophenol Monooxygenase / Q000378:metabolism*; D010088:Oxidoreductases / Q000096:biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013449:Sulfonamides / Q000494:pharmacology
D003374:Coumarins; D007546:Isoquinolines; D008543:Melanins; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D013449:Sulfonamides; D010088:Oxidoreductases; C079621:Tyrp1 protein, mouse; D014442:Monophenol Monooxygenase; D017868:Cyclic AMP-Dependent Protein Kinases; D019746:Intramolecular Oxidoreductases; C042501:dopachrome isomerase; C018145:scoparone; C063509:N-(2-(4-bromocinnamylamino)ethyl)-5-isoquinolinesulfonamide