C-glucosidic ellagitannins and galloylated glucoses as potential functional food ingredients with anti-diabetic properties: a study of α-glucosidase and α-amylase inhibition. (30th May 2020)

• Record Type: Journal Article
• Authors: Cardullo, Nunzio; Muccilli, Vera; Pulvirenti, Luana; Cornu, Anaëlle; Pouységu, Laurent; Deffieux, Denis; Quideau, Stéphane; Tringali, Corrado
• Is Part Of: Food chemistry. Volume 313(2020)
• Publication Date: 2020-05-30
• Subjects: Hydrolyzable tannins -- Hypoglycemic activity -- α-Glucosidase inhibition -- α-Amylase inhibition -- Intrinsic fluorescence -- Inhibition kinetics; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2019.126099
• Languages: English
• ISSNs: 0308-8146

Abstract

Abstract: Diabetes mellitus is a metabolic disorder characterized by hyperglycemia, which can be counteracted by inhibition of α-glucosidase and α-amylase, both involved in the carbohydrate metabolism. Fourteen C -glucosidic ellagitannins and three galloylated glucoses were studied as potential α-glucosidase and α-amylase inhibitors. Most of the compounds were found to be moderate inhibitors of α-amylase, but potent inhibitors of α-glucosidase, showing low-micromolar IC50 values, far lower than that of the antidiabetic drug acarbose. This selectivity can be an advantage for their possible application as functional food ingredients with anti-diabetic properties because strong α-amylase inhibition generally causes undesired side effects. The best inhibitors were selected for further studies. Intrinsic fluorescence measurements confirmed their high affinity towards α-glucosidase, highlighting a static quenching mechanism . Circular dichroism measurements and kinetics of inhibition indicated that the most active C -glucosidic ellagitannin roburin D (RobD ) is a competitive inhibitor, whereas α-pentagalloylglucose (α-PGG ) acts as a mixed-type inhibitor.