title: A high-throughput assay for quantification of starch hydrolase inhibition based on turbidity measurement.
abstract: A high-throughput method for rapid determination of starch hydrolase inhibition was developed using a 96-well microplate UV-vis reader to monitor the turbidity decrease over time. The area under the curve of turbidity measured over time was used to quantify the inhibitory effect of polyphenolic compounds on porcine pancreatic amylase, rat intestine α-glucosidase, and fungal amyloglucosidase. Acarbose equivalence (AE) was introduced for the first time and defined as IC50 of acarbose divided by the IC50 of the sample measured under the same 96-well plate. This way, the run-to-run variations are canceled out. Among the plant extracts tested, grape seed extracts (1,440 μmolAE/g) and cinnamon bark extracts (1600 μmolAE/g) are the most active in inhibiting rat intestine α-glucosidase. For porcine α-amylase inhibition, grape seed extracts (5710 μmol AE/g) are close to four times more active (equal weight basis) than acarbose (1550 μmolAE/g).
authors.affiliation: Food Science and Technology Program, Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Republic of Singapore.
authors.forename: Tingting
authors.initials: T
authors.lastname: Liu
authors.forename: Lixia
authors.initials: L
authors.lastname: Song
authors.forename: Hongyu
authors.initials: H
authors.lastname: Wang
authors.forename: Dejian
authors.initials: D
authors.lastname: Huang
mesh_terms: D020909:Acarbose / Q000494:pharmacology; D000818:Animals; D002935:Cinnamomum zeylanicum / Q000737:chemistry; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005638:Fruit / Q000737:chemistry; D005087:Glucan 1,4-alpha-Glucosidase / Q000037:antagonists & inhibitors*; D065089:Glycoside Hydrolase Inhibitors; D009391:Nephelometry and Turbidimetry / Q000379:methods*; D055292:Pancreatic alpha-Amylases / Q000037:antagonists & inhibitors*; D024301:Plant Bark / Q000737:chemistry; D010936:Plant Extracts / Q000494:pharmacology; D059808:Polyphenols / Q000494:pharmacology; D051381:Rats; D012639:Seeds / Q000737:chemistry; D013552:Swine; D027843:Vitis / Q000737:chemistry
chemical_list: D004791:Enzyme Inhibitors; D065089:Glycoside Hydrolase Inhibitors; D010936:Plant Extracts; D059808:Polyphenols; D055292:Pancreatic alpha-Amylases; D005087:Glucan 1,4-alpha-Glucosidase; D020909:Acarbose