Chronic supplementation with dietary proanthocyanidins protects from diet-induced intestinal alterations in obese rats.
Increased attention has been paid to the link between altered intestinal function and elevated incidence of metabolic disorders, such as in obesity. This study investigated in obese rats the role of grape seed proanthocyanidin extract (GSPE) chronic treatment, taken in a low, moderate, or high dose, on obesity-associated intestinal alterations in response to a cafeteria diet (CAF). To evaluate the degree of intestinal inflammation, reactive oxygen species (ROS) production and myeloperoxidase (MPO) activity were measured as well as the expression of inflammatory-related genes. The barrier integrity was assessed by quantifying the gene expression of tight-junction components and measuring the plasma LPS. GSPE decreased the ROS levels and MPO activity, without substantial differences among the doses. The supplementation with moderate and high GSPE doses significantly decreased iNOS expression compared to the CAF group, and the same pattern was observed in the low-dose animals with respect to IL-1β expression. Moreover, the results show that GSPE significantly increases zonulin-1 expression with respect to the CAF animals. This study provides evidence for the ameliorative effect of a proanthocyanidin extract on high-fat/high-carbohydrate diet-induced intestinal alterations, specifically reducing intestinal inflammation and oxidative stress and suggesting a protection against a barrier defect.