Abstract
Aqueous extracts of different seasonal as well as less popular but edible indigenous fruits of West Bengal, India were studied for their α-glucosidase and α-amylase inhibitory properties. Of the 22 different species of fruits, sixteen fruits inhibited both the carbohydrate digesting enzymes. Concentrations of the extracts are presented as fresh weight of fruit used to make extract / ml. Very high α-amylase (IC50 value = 5.0 μg/ml) and α-glucosidase (IC50 value = 9.0 μg/ml) inhibitory activity was shown by extracts of Phoenix sylvestris. Achras sapota also showed high α-amylase (IC50 value = 53.0 μg/ml) and α-glucosidase (IC50 value = 56.0 μg/ml) inhibitory activities. During the present study, no correlation could be established between total phenol / flavonoid content and α-amylase / α-glucosidase inhibitory activity. Unweighted pair-group average (UPGA) dendrogram showing interrelationships between the investigated species shows that the fruits can be grouped into two high level clusters. The cluster I brought together Borassus flabellifer and Physalis peruviana having very low α-glucosidase inhibitory activity. The cluster II included fruits with moderate to high α- glucosidase inhibitory activity.
Keywords: α-amylase, α-glucosidase, fruits, antidiabetic, phenols, flavonoids, achras sapota, phoenix sylvestris, hyperglycemia, Mammalian starch