Active constituents from Sophora japonica exhibiting cellular tyrosinase inhibition in human epidermal melanocytes.
OBJECTIVE
There is greater consumer awareness of plant-based skin-care products. Sophora japonica L. (Fabaceae) has been used traditionally as a hemostatic agent and also has skin-care and whitening benefits. The effect of the isolated active compounds of Sophora japonica L. (Fabaceae) that inhibits tyrosinase activity in human epidermal melanocytes (HEMn) was examined.


METHODS
We used the mushroom tyrosinase inhibitory assay to isolate active constituents from the extracts. The structures of these constituents were characterized by physical and spectroscopic analyses. Cellular tyrosinase kinetics were analyzed and showed by Lineweaver-Burk plot.


RESULTS
A new compound, N-feruloyl-N'-cis-feruloyl-putrescine (8), together with four flavonoids and three putrescine derivatives were obtained after assay-guided isolation of S. japonica. In HEMn, compound 8 was minimally cytotoxic (cell viability >90% at 100 microM) and the IC(50) value for suppression of cellular tyrosinase activity was estimated as 85.0 microM. Zymography analysis demonstrated the compound's concentration-dependent effects and the kinetic analysis indicated the compound's mixed-inhibitory action.


CONCLUSIONS
We concluded that the new compound 8 is the most potent component of S. japonica yet discovered. Its pigment inhibition activity may be exploitable cosmetically.
Lo
Yuan-Hsin
YH
Department of Dermatology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei 111, Taiwan.
Lin
Rong-Dih
RD
Lin
Yi-Pei
YP
Liu
Yan-Ling
YL
Lee
Mei-Hsien
MH
D000363:Agaricales / Q000201:enzymology; D002470:Cell Survival / Q000187:drug effects; D000078404:Epidermal Cells; D004817:Epidermis / Q000187:drug effects; D006801:Humans; D007202:Indicators and Reagents; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D008544:Melanocytes / Q000187:drug effects / Q000201:enzymology*; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors*; D011700:Putrescine / Q000737:chemistry; D029909:Sophora / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
D007202:Indicators and Reagents; D014442:Monophenol Monooxygenase; D011700:Putrescine