Abstract

Introduction: Dietary polyphenols are widely known by its antioxidant property. However, few reports have confirmed this notion by measuring redox impact in living cells and even less connect the antioxidant impact with an anti-inflammatory effect. Our proposed hypothesis is that the anti-inflammatory effect of dietary polyphenols on a cellular model of human intestinal epithelium is a consequence of the antioxidant impact achieved. Methods: By expressing HyPer, a redox biosensor in Caco-2 cells, we monitored the biological impact of five polyphenols [quercetin, 5 µM; kuromanin, 5 µM; caffeic acid, 10 µM; neochlorogenic acid, 5 µM and procyanidin B1, 5 µM] on redox state in the cytoplasm of living cells. To investigate the potential anti-inflammatory impact of polyphenols, we exposed established Caco-2 monolayers to 500 M of H2O2 by 30 minutes, which provoked an increment in IL-1 mRNAa suitable strategy to examine if these polyphenols decrease the proinflammatory effect induced by H2O2. Results: Quercetin and neochlorogenic acid (24h) showed significant decrease in basal measurements of HyPer, whereas caffeic acid had an opposite effect incrementing the basal. By exposing transiently control cells to 50 M H2O2, HyPer signal increased by 39 ± 2%. Cells treated with procyanidin, caffeic acid and kuromanin elicited significant reduction in the biosensor response. The pre-treatment with polyphenols for 24 hours interferes with the H2O2-induced increase of IL-1β. Conclusions: Our experimental approach allows us to suggest a connection between redox impact and cytokines production, offering an attractive path to investigate molecular candidates for the expected benefits of some dietary polyphenols.