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.
