Polyphenols from guaraná after in vitro digestion: Evaluation of bioacessibility and inhibition of activity of carbohydrate-hydrolyzing enzymes

Guaraná (Paullinia cupana) is a typical product from Amazon biota that exerts antioxidant capacity due to the presence of phenolic compounds, such as catechin, epicatechin and proanthocyanidins. The objective of this study was to evaluate the potential inhibitory activity of guaraná extracts, after digestion in vitro, on carbohydrates-metabolism enzymes and to assess the bioacessibility of guaraná polyphenols. The guaraná samples before and after enzymatic digestion, were compared for total phenolic content and phenolic profile. Furthermore, we investigated the uptake of polyphenols from guarana, using Caco-2 cells, and the effect of digested guaraná on carbohydrate metabolism enzymes. The amount of total phenolic compounds extracted from guaraná decreased after digestion in vitro, and native phenolics were not identified after cell permeation. On the other hand, polyphenols from guaraná were able to inhibit α-glucosidase and α-amylase activities. In conclusion, guaraná can be considered as a dietary source with anti-hyperglycemic potential.