The effect of abrus precatorius methanol leaves extract in inhibiting glucose absorption in in vitro study

Abstract

Abrus precatorius leaves have been used traditionally for treatment of Type II diabetes in Malaysia. In this study, the potential of the 80% methanolic extract of Abrus precatorius leaves has been studied for its a-glucosidase inhibitory activity and its glucose diffusion effect. The extract of this plant at varying concentrations (6.25, 12.5, 25, 50 mg/ml) were tested using in vitro methods. An inhibitory a-glucosidase activity was determined spectrophotometrically in a 96-well microtiter plate. The results of a- glucosidase inhibition assay revealed that Abrus precatorius leaves extract showed strong inhibition (65.4% and 84.6%) at the concentrations of 25 and 50 mg/ml, respectively, and represent less inhibition (25% and 28.2%) at the concentration of 6.25 and 12.5 mg/ml respectively when compared to control. Whereas, the effects of Abrus precatorius leaves extract on glucose movement across the sealed dialysis tube was measured spectrophotometrically using the glucose oxidase method. The results of inhibition of glucose diffusion in vitro assay indicated that, Abrus precatorius leaves extract shows a slight inhibitory effect on glucose diffusion at the concentrations of 12.5, 25 and 50 mg/ml after 16 hours, and the concentration of 50 mg/ml showed more effect after 24 hours. Nonetheless, the plant extract did not show any statistically significant effect on glucose movement after 0, 4, 8, 12, 16, 20 and 24 hours when compared to control. Therefore, it is considered that, the concentrations higher than 50 mg/ml may show a significant inhibitory effect on glucose diffusion. Overall, these results suggest that, Abrus precatorius leaves extract have significant inhibitory effects on glucose absorption due to the ability of plant to inhibit intestinal a-glucosidase enzyme.