title: Inhibitory properties of aqueous ethanol extracts of propolis on alpha-glucosidase.
abstract: The objective of the present study was to evaluate the inhibitory properties of various extracts of propolis on alpha-glucosidase from baker's yeast and mammalian intestine. Inhibitory activities of aqueous ethanol extracts of propolis were determined by using 4-nitrophenyl-D-glucopyranoside, sucrose and maltose as substrates, and acarbose as a positive reference. All extracts were significantly effective in inhibiting α-glucosidase from baker's yeast and rat intestinal sucrase in comparison with acarbose (P < 0.05). The 75% ethanol extracts of propolis (75% EEP) showed the highest inhibitory effect on α-glucosidase and sucrase and were a noncompetitive inhibition mode. 50% EEP, 95%, EEP and 100% EEP exhibited a mixed inhibition mode, while water extracts of propolis (WEP) and 25% EEP demonstrated a competitive inhibition mode. Furthermore, WEP presented the highest inhibitory activity against maltase. These results suggest that aqueous ethanol extracts of propolis may be used as nutraceuticals for the regulation of postprandial hyperglycemia.
authors.affiliation: Bee Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100093, China ; National Research Center of Bee Product Processing, Ministry of Agriculture, Beijing 100093, China.
authors.forename: Hongcheng
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Bee Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100093, China.
authors.forename: Guangxin
authors.initials: G
authors.lastname: Wang
authors.affiliation: Department of Food Science, University of Manitoba, Winnipeg, MB, Canada R3T 2N2.
authors.forename: Trust
authors.initials: T
authors.lastname: Beta
authors.affiliation: Bee Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100093, China ; National Research Center of Bee Product Processing, Ministry of Agriculture, Beijing 100093, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Dong