Cocoa polyphenols inhibit sucrose hydrolysis in Caco‐2 cells

Abstract

Disaccharidase enzymes bound to the microvilli of intestinal epithelial cells are essential in the liberation of glucose from dietary carbohydrates. Glucose uptake from the lumen of the small intestine is facilitated by transporters located in the apical membrane of enterocytes; subsequent diffusion into capillary blood occurs at the basolateral surface similarly facilitated by transporters.Attenuation of enzyme and transporter activity may decrease post‐prandial blood glucose levels thereby providing a more uniform supply of glucose to the cells rather than an initial peak followed by rapid decline. This may have positive consequences not only for healthy subjects but also for individuals suffering from impaired glucose tolerance and type‐2 diabetes.Using Caco‐2 cells, passages 36 to 40, the rate of sucrose hydrolysis has been determined in the absence and presence of cocoa extracts and various polyphenols present in chocolate and cocoa. Using sucrose as the substrate, kinetic parameters were: a maximum reaction rate (Vmax) of 4.5 μmol min−1 and a Michaelis‐Menten constant (Km) of 33 mM.The addition of cocoa extract inhibited sucrose hydrolysis by Caco‐2 cells. (−)‐Epicatechin, (+)‐catechin and procyanidin B2, major components of cocoa, also diminished sucrose hydrolysis in Caco‐2 cells substantially.These results show that intestinal hydrolysis of sucrose by alpha‐glucosidase enzymes may be inhibited by cocoa polyphenols thereby reducing the rate of liberation of glucose. This would subsequently limit the uptake of glucose into the blood thereby reducing post‐prandial blood glucose levels.This work was funded by a BBSRC industrial case award to Nestlé, York UK.