title: Inhibition of human intestinal α-glucosidases by calystegines.
abstract: Calystegines are polyhydroxylated nortropane alkaloids found in Convolvulaceae, Solanaceae, and other plant families. These plants produce common fruits and vegetables. The calystegine structures resemble sugars and suggest interaction with enzymes of carbohydrate metabolism. Maltase and sucrase are α-glucosidases contributing to human carbohydrate degradation in the small intestine. Inhibition of these enzymes by orally administered drugs is one option for treatment of diabetes mellitus type 2. In this study, inhibition of maltase and sucrase by calystegines A3 and B2 purified from potatoes was investigated. In silico docking studies confirmed binding of both calystegines to the active sites of the enzymes. Calystegine A3 showed low in vitro enzyme inhibition; calystegine B2 inhibited mainly sucrose activity. Both compounds were not transported by Caco-2 cells indicating low systemic availability. Vegetables rich in calystegine B2 should be further investigated as possible components of a diet preventing a steep increase in blood glucose after a carbohydrate-rich meal.
authors.affiliation: Institute of Pharmacy, Faculty of Sciences I, Martin-Luther-University Halle-Wittenberg , Hoher Weg 8, 06120 Halle (Saale), Germany.
authors.forename: Nebojša
authors.initials: N
authors.lastname: Jocković
authors.forename: Wiebke
authors.initials: W
authors.lastname: Fischer
authors.forename: Matthias
authors.initials: M
authors.lastname: Brandsch
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Brandt
authors.forename: Birgit
authors.initials: B
authors.lastname: Dräger
mesh_terms: D001665:Binding Sites; D018938:Caco-2 Cells; D065089:Glycoside Hydrolase Inhibitors; D006801:Humans; D007421:Intestine, Small / Q000737:chemistry / Q000201:enzymology*; D015394:Molecular Structure; D010936:Plant Extracts / Q000737:chemistry* / Q000302:isolation & purification; D011485:Protein Binding; D011198:Solanum tuberosum / Q000737:chemistry*; D014326:Tropanes / Q000737:chemistry* / Q000302:isolation & purification; D000520:alpha-Glucosidases / Q000737:chemistry / Q000378:metabolism
chemical_list: D065089:Glycoside Hydrolase Inhibitors; D010936:Plant Extracts; D014326:Tropanes; C055033:calystegin; D000520:alpha-Glucosidases