Assessment of the anti-diabetic potential of the Cratoxylum formosum subsp. formosum extracts via carbohydrate hydrolyzing enzymes inhibitory activities

Introduction: This research aims to evaluate the anti-diabetic activity of the extracts from different parts of Cratoxylum formosum subsp. formosum. Methods: The in vitro inhibitory activities of the hexane (HEX), dichloromethane (DCM) and ethyl acetate (EtOAc) extracts from the flowers, leaves, roots and stems on pancreatic α-amylase (pAA), Saccharomyces α-glucosidase (SAG), rat intestinal maltase (rIM), and sucrase (rIS) were investigated. Results: The DCM and EtOAc extracts from the flowers (IC۵۰ ۵.۴ ± ۱.۵ and ۱۰.۵ ± ۰.۶ µg/mL) displayed the similar inhibitory activities as acarbose (IC۵۰ ۷.۲ ± ۰.۴ µg/mL) in the pAA assay. The inhibitory activities of the DCM and EtOAc extracts from the flowers (IC۵۰ ۵۶.۷ ± ۸.۹ and ۲۰.۴ ± ۰.۴ µg/mL), EtOAc extract from leaves (IC۵۰ ۴۵.۰ ± ۳.۵ µg/mL), DCM and EtOAc extracts from roots (IC۵۰ ۳۵.۰ ± ۶.۷ and ۱۶.۷± ۳.۶ µg/mL), and EtOAc extract from stems (IC۵۰ ۳۱.۱ ± ۷.۳ µg/mL) were more potent than acarbose (IC۵۰ ۴۳۱.۴ ± ۱۶.۷ µg/mL) on SAG inhibitory assay (P<۰.۰۵). In the rIM assay, DCM and EtOAc extracts from the flowers (IC۵۰ ۸.۵ ± ۰.۲ and ۱۲.۴ ± ۰.۳ µg/mL) exhibited stronger inhibitory activity than acarbose (IC۵۰ ۳۸.۵ ± ۷.۲ µg/mL) (P<۰.۰۵). Moreover, the inhibitory activity of DCM extract from the flowers (IC۵۰ ۱۶.۹ ± ۱.۵ µg/ mL) was comparable to the acarbose (IC۵۰ ۱۵.۵ ± ۱.۲ µg/mL) on rIS assay. Conclusion: The DCM and EtOAc extracts from the flowers were more active than the leaves, roots and stems in the inhibition of our defined target enzymes.