A Gastrointestinally Digested Ribes nigrum L. Fruit Extract Inhibits Inflammatory Response in a Co-culture Model of Intestinal Caco-2 Cells and RAW264.7 Macrophages

Blackcurrant fruits are a rich source of polyphenolic compounds with high antioxidant capacity and potent anti-inflammatory properties. In this study, blackcurrant extract digested in an artificial gastrointestinal tract and its intestinal permeable fraction were investigated for their ability to suppress inflammatory responses induced in a two-component cell culture system of intestinal epithelial cells and macrophages. The obtained results showed the capacity of the extract at a concentration of 1 mg of freeze-dried blackcurrant powder per mL to down-regulate the expression of inflammatory mediators, such as IL-8 (54 ± 7%) and COX-2 (17 ± 6%) in intestinal cells and IL-1α (76 ± 4%), IL-1β (91 ± 2%), and IL-6 (61 ± 5%) in macrophages stimulated with lipopolysaccharides. Inhibited COX-2 (44 ± 6%) and iNOS (15 ± 7%) expression played a role in reducing the production of prostaglandin E2 (40 ± 20%) and NO (31 ± 9%), respectively. Decreased TNF-α secretion (24 ± 5%) by activated macrophages was also observed...