Silymarin inhibits melanin synthesis in melanocyte cells.
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.
Choo
Soo-Jin
SJ
Functional Metabolomics Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Korea.
Ryoo
In-Ja
IJ
Kim
Young-Hee
YH
Xu
Guang-Hwa
GH
Kim
Won-Gon
WG
Kim
Ki-Ho
KH
Moon
Seong-Joon
SJ
Son
Eui-Dong
ED
Bae
KiHwan
K
Yoo
Ick-Dong
ID
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
D000975:Antioxidants; D008543:Melanins; D012838:Silymarin; D007980:Levodopa; D014442:Monophenol Monooxygenase