Phytochemicals and Human Pancreatic α-amylase-Amylase Inhibitory Activities of Fresh and Boiled Elephant Apple (Dillenia indica) Fruit Extracts

Abstract

Fruits of elephant apple (Dillenia indica) are edible and also used for treatment of diabetes by action as the inhibitor of carbohydrate hydrolyzing enzyme. In this research, the aqueous extracts from edible parts of fresh and boiled fruits of D. indica were determined the presence of phytochemicals; including total phenolic, flavonoid and condensed tannin contents, evaluated of human pancreatic α-amylase inhibitory activity and studied of the stability of active phytochemicals. The results showed that the boiled fruit extract contained more total phenolic, flavonoid and condensed tannin contents than the fresh fruit extract.  In addition, the boiled fruit extract (% inhibition = 100.00 ± 0.00, IC₅₀ = 25.40 ± 2.42mg/ml) had a higher capacity to inhibit the human pancreatic α-amylase than the fresh fruit extract (% inhibition = 98.17 ± 3.96, IC₅₀ = 51.39 ± 2.65 mg/ml). Moreover, the active phytochemicals were stable under dark condition at –20 ºC for 3 months. These results suggested that fruits of D. Indic are suitable to develop as a nutraceuticals for diabetes management.