Protective Effects of Grape Seed Extract on Lipopolysaccharide Exposure and Radiation-Induced Intestinal Mucosal Damage: Insights from an In Vitro Study

Backgrounds and aim: Protective effects of natural compounds have been suggested in the prevention and treatment of radiation-induced mucositis or bacterial infections. In this study, the protective effects of proanthocyanidin-rich grape seed extract (GSE) on bacterial Lipopolysaccharide (LPS) and radiation-induced epithelial barrier damage and Reactive Oxygen Species (ROS) production were investigated in an in vitro model. Methods: Human intestinal epithelial cells Caco-2, previously treated with LPS, GSE, or LPS + GSE, were irradiated with 10 Gy divided into five daily treatments. Epithelial barrier integrity and ROS production were measured before and after each treatment. Results: Irradiation, at different doses, significantly increased intestinal permeability and ROS production; pretreatment with GSE was able to significantly prevent the increased intestinal permeability (4.63 ± 0.76 vs. 15.04 ± 1.5; p < 0.05) and ROS production (12.9 ± 1.08 vs. 1048 ± 0.5; p < 0.0001) induced by irradiation treatment. When the cells were pretreated with LPS, the same results were observed: GSE cotreatment was responsible for preventing permeability alterations (5.36 ± 0.16 vs. 49.26 ± 0.82; p < 0.05) and ROS production (349 ± 1 vs. 7897.67 ± 1.53; p < 0.0001) induced by LPS exposure when added to the irradiation treatment. Conclusions: The results of the present investigation demonstrated, in an in vitro model, that GSE prevents the damage to intestinal permeability and the production of ROS that are induced by LPS and ionizing radiation, suggesting a potential protective effect of this extract on the intestinal mucosa during irradiation treatment.