In Vitro Inhibitory Effect on Digestive Enzymes and Antioxidant Potential of Commonly Consumed Fruits

Dietary inhibitors of fats and carbohydrates degrading enzymes can reduce obesity and type 2 diabetes. In this study, we screened crude extracts from 30 commonly consumed fruits to test their in vitro inhibitory effect against key enzymes relevant for obesity (pancreatic lipase) and type 2 diabetes (alpha-glucosidase and alpha-amylase), total phenolic content (Folin-Ciocalteu method), and antioxidant capacity (ABTS and FRAP). The IC50 values of the fruits tested varied from 39.91 to >400 mg/mL, from 1.04 to >80 mg/mL, and from 0.72 to 135.07 mg/mL against alpha-glucosidase, alpha-amylase, and pancreatic lipase, respectively. Antioxidant capacity ranged from 0.66 to 124.66 mu mol of TE/g of fruit and strongly correlated with phenolic content, while the enzyme inhibition was poorly correlated with total phenolic and antioxidant capacity. Among fruits tested, blue honeysuckle and red gooseberry exhibited the highest inhibitory activity with respect to the carbohydrate degrading enzymes, while lingonberry had the strongest anti-lipase activity.