Evaluation of the Inhibition of Carbohydrate Hydrolyzing Enzymes, the Antioxidant Activity, and the Polyphenolic Content ofCitrus limettaPeel Extract

Abstract

Type 2 diabetes mellitus is one of the most frequent causes of death in Mexico, characterized by chronic hyperglycemia. One alternative strategy for this metabolic abnormality is inhibiting the enzymes responsible for the metabolism of carbohydrates. We evaluated whether the aqueousCitrus limettapeel extract could inhibit the metabolism of carbohydrates. We found that this extract inhibited primarily the enzymeα-amylase by 49.6% at a concentration of 20 mg/mL and to a lesser extent the enzymeα-glucosidase with an inhibition of 28.2% at the same concentration. This inhibition is likely due to the high polyphenol content in theCitrus limettapeel (19.1 mg GAE/g). Antioxidant activity of theCitrus limettapeel demonstrated dose-dependent antioxidant activity, varying from 6.5% at 1.125 mg/mL to 42.5% at 20 mg/mL. The study of these polyphenolic compounds having both antihyperglycemic and antioxidant activities may provide a new approach to the management of type 2 diabetes mellitus.