AnIn Vitrostudy on the inhibitory activities ofEugenia jambolanaseeds against carbohydrate hydrolyzing enzymes

Abstract

Herbal medicines have been used since prehistoric times by different cultures worldwide for treatment of diabetes. In the present investigation, the effect of untreated and heat-treated aqueous extracts from Eugenia jambolana Lam (Myrtaceae) seeds on carbohydrate hydrolyzing enzymes, namely, porcine pancreatic α-amylase, rat intestinal α-glucosidase, and sucrase, have been studied using in vitro model systems. Untreated E. jambolana extract (EJU) signiÞ cantly inhibited (p ≤ 0.01) α-amylase, α-glucosidase, and sucrase activities in a dosedependent manner, with the exception of sucrase, where the increased sample concentration did not increase the sucrase inhibitory activity. Heat treatment of the sample resulted in a signiÞ cant increase (p ≤ 0.01) in the α-amylase inhibitory activity of the sample, while a marginal increase in the α-glucosidase and sucrase inhibitory activities were observed, however, they did not reach statistical signiÞ cance. EJU showed IC50 values of 3.4%, and 68 and 56 μg mL-1 for α-amylase, α-glucosidase, and sucrase, respectively, while the IC50 values for heat-treated E. jambolana extract (EJH) were 2.4%, and 66 and 54 μg mL-1, respectively. Further, a signiÞ cant correlation (p ≤ 0.01; r = 0.833) was observed between α-amylase, α-glucosidase, and sucrase inhibitory activities of both EJU and EJH. These Þ ndings emphasize that inhibition of carbohydrate hydrolyzing enzymes is one of the mechanisms through which E. jambolana exerts its hypoglycemic effect in vivo. Key words : Α-amylase, α-glucosidase, sucrase.