title: Crude ethanol extracts from grape seeds and peels exhibit anti-tyrosinase activity.
abstract: This study aimed to evaluate the anti-tyrosinase activities of ethanol extracts from the peels and the seeds of Kyoho grapes and Red Globe grapes (KG-PEE, KG-SEE, RGG-PEE, and RGG-SEE). The total phenolic content in KG-SEE and RGG-SEE was 400 +/- 11 and 339 +/- 7 mg gallic acid equivalent/g, respectively, about 22 times and 13 times that in KG-PEE and RGG-PEE, respectively. Both seed extracts showed significantly higher anti-tyrosinase activity than the peel extracts due to their high total phenolic content. The gallic acid content in RGG-SEE was twice that in KG-SEE, and gallic acid showed high anti-tyrosinase activity; thus, RGG-SEE had higher anti-tyrosinase activity than KG-SEE. Lineweaver-Burk plots revealed that the inhibitory mechanism of the ethanol extracts from the grapes was a mix-type inhibition. Grape seed has a greater total phenolic content and has potential as a skin-lighting agent.
authors.affiliation: Department of Food Science, National Chiayi University, No.300, Syuefu Rd., Chiayi City 60004, Taiwan, ROC. ckhsu@mail.nycu.edu.tw
authors.forename: Cheng-Kuang
authors.initials: CK
authors.lastname: Hsu
authors.forename: Su-Tze
authors.initials: ST
authors.lastname: Chou
authors.forename: Pai-Jane
authors.initials: PJ
authors.lastname: Huang
authors.forename: Mei-Chin
authors.initials: MC
authors.lastname: Mong
authors.forename: Chien-Kuo
authors.initials: CK
authors.lastname: Wang
authors.forename: Yu-Pin
authors.initials: YP
authors.lastname: Hsueh
authors.forename: Jyun-Kai
authors.initials: JK
authors.lastname: Jhan
mesh_terms: D004791:Enzyme Inhibitors / Q000302:isolation & purification / Q000494:pharmacology*; D000431:Ethanol / Q000737:chemistry; D007700:Kinetics; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D010636:Phenols / Q000302:isolation & purification / Q000494:pharmacology*; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology*; D012639:Seeds / Q000737:chemistry; D027843:Vitis / Q000737:chemistry*
chemical_list: D004791:Enzyme Inhibitors; D010636:Phenols; D010936:Plant Extracts; D000431:Ethanol; D014442:Monophenol Monooxygenase