title: Antihypertensive properties of flavonoid-rich apple peel extract.
abstract: Hypertension is a major public health problem rising across the globe. Inhibition of angiotensin converting enzyme (ACE) is identified as a main therapeutic target in controlling high blood pressure. The present study investigated the ACE inhibitory property of a flavonoid-rich apple peel extract (FAE), its constituents, selected flavonoids and some quercetin metabolites using a biochemical assay of ACE inhibition and a human umbilical vein endothelial cell (HUVEC) model. FAE, all the tested flavonoids except genistein, and two quercetin metabolites (quercetin-3-O-glucuronic acid and quercetin-3-O-sulfate) significantly (p<0.05) inhibited ACE. Enzyme kinetic analysis revealed that flavonoids are competitive inhibitors of ACE. In the HUVEC model, FAE, quercetin-3-O-glucoside and quercetin-3-O-glucuronic acid inhibited significantly (p<0.05) ACE activity. Overall, FAE and most of the flavonoids tested showed ACE inhibition in vitro which needs further investigations using animal and human clinical trials.
authors.affiliation: Department of Environmental Sciences, Nova Scotia Agricultural College, Truro, NS, Canada B2N 5E3.
authors.forename: Nileeka
authors.initials: N
authors.lastname: Balasuriya
authors.forename: H P Vasantha
authors.initials: HP
authors.lastname: Rupasinghe
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000737:chemistry*; D000818:Animals; D000959:Antihypertensive Agents / Q000737:chemistry*; D005419:Flavonoids / Q000737:chemistry*; D005638:Fruit / Q000737:chemistry; D061307:Human Umbilical Vein Endothelial Cells / Q000201:enzymology; D006801:Humans; D007700:Kinetics; D027845:Malus / Q000737:chemistry*; D007703:Peptidyl-Dipeptidase A / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry*; D011817:Rabbits
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents; D005419:Flavonoids; D010936:Plant Extracts; D007703:Peptidyl-Dipeptidase A