Determination of Glycemic Index, Antidiabetic and Antioxidant Activities of Palmyra/Borassus abellifer Treacle

Abstract

B. abellifer treacle is a well-known local traditional sweetener. This study was performed to determine the glycaemic-index ( GI), antidiabetic, and antioxidant activities of methanolic(ME) and aqueous extract(AE) of B. abellifer treacle. Healthy undergraduates of KAATSU University were selected as subjects(n=30). The food containing 50g of carbohydrates was consumed by fasted volunteers. Capillary blood was taken at fasting, 15,30,45,60, and 120 min after the meal. The GI was calculated by dividing the incremental area under the curve for the treacle by the glucose and multiplying by 100. To determine the antidiabetic properties, glucose absorption by yeast cells (GAYC), and glucose adsorption capacity (GAC) assays were performed, and Metformin served as the standard. Ferric- Reducing Antioxidant Power (FRAP) assay and H2O2 scavenging were performed to determine the antioxidant activity, and ascorbic acid served as the standard. Absorbance was measured, and IC50 values were calculated. GI of the treacle was 61.72 17.44, and the glycemic load was 42.03. In GAYC, it showed IC50=0.4609 gmL􀀀1 and IC50=0.2119 gmL-1 for AE and ME respectively, compared to metformin IC50=0.0819 gmL􀀀1. AE and ME adsorbed 74.44%, and 71.60% of, 100M glucose. In H2O2 scavenging, AE and ME showed IC50=0.1204 gmL􀀀1 and IC50=0.3559 gmL-1 respectively, compared to ascorbic acid IC50=4.421 gmL􀀀1. In the FRAP assay, AE and ME showed IC50=0.02783 gmL􀀀1, and IC50=0.02716 gmL􀀀1 respectively, compared to ascorbic acid IC50=0.02971 gmL􀀀1. The study revealed that B. abellifer treacle should be classi ed as medium GI food, with high antidiabetic and antioxidant activities. Further studies are recommended to study the adaptability of treacle for the diet of diabetic subjects, and subjects at risk.