Food applications in the obesity prevention: Lipid and carbohydrate digestive enzyme inhibitors found naturally in foods

In this study, some foods and food components that show inhibitory properties of intestinal enzymes responsible for macronutrient digestion were discussed. Inhibitory effects on lipid and carbohydrate digestive enzymes of food sources (apple, black grapes, cinnamon, puncture vine, chickpea, sage, rosemary), which are rich in bioactive compounds (procyanidins, anthocyanins, saponins, carnosic acid), which are known for their inhibitory effects on lipid and carbohydrate digestive enzymes, were determined with lipase, α-amylase and α-glucosidase enzyme inhibition analyses. Total procyanidins, total anthocyanins, total saponins and carnosic acid contents of the chosen food samples were determined before and after in vitro digestion to calculate how much bioactive compounds reach to absorption cells (bioaccessibility). While the highest total anthocyanin content was found in red grape (164.76 ± 2.51 mg/100 g), the highest procyanidin content was found in cinnamon (6432.54±177.31 mg/100 g) among the selected food samples (p<0.05). The anthocyanin bioaccessibilities were found as 10.23±1 %, 8.23±0.64 %, and 8.73±0.70 % in apple, red grape, and cinnamon, respectively. The procyanidin bioaccessibilities of apple, red grape, and cinnamon were found as 17.57±0.71 %, 14.08±0.74 % and 18.75±1.49 %, respectively. The saponin content of chickpea (24.08±2.01 mg/g) was found to be higher than the saponin content of puncture vine (Tribulus terrestris) (13.16±0.89 mg/g) (p<0.05). On the other hand, the bioaccessibility of saponin in Tribulus terrestris (% 51.84±2.85) was higher compared to the saponin bioaccesibility in chickpea (% 39.98±2.97) (p<0.05). The carnosic acid content in rosemary (18.72±0.33 mg/g) was higher than sage (3.76±0.13 mg/g) (p<0.05). The bioaccesibilities of carnosic acid in rosemary and sage were found to be % 45.10±1.88 ve % 38.32±0.2, respectively. Rosemary provided highest α-glucosidase and lipase inhibition and it had the lowest IC50 values (76.80±1.68 μg/mL for α-glucosidase, 4.31±0.62 μg/mL for lipase) compared to the other samples analyzed in this study. Moreover, the highest α-amylase inhibition was observed for the cinnamon, which had the lowest IC50 values for α-amylase (3.54±0.86 μg/mL). Furthermore, to the best of our knowledge, this is the first work that standard equivalent inhibition capacities for food samples were determined and these values were in agreement with the IC50 values. In summary, the present study provides the evidence that these food samples (apple, black grapes, cinnamon, puncture vine, chickpea, sage, rosemary) are potent inhibitors against α-amylase, α-glucosidase and lipase in vitro and they can play an important role with a low calorie diet to control body weight.