Intestinal anti-inflammatory activity of the polyphenolic-enriched extract Amanda® in the trinitrobenzenesulphonic acid model of rat colitis

Alternative herbal therapy is increasingly used for inflammatory bowel disease (IBD), but it is essential to prove its safety and efficacy. We have assayed the anti-inflammatory effects of Amanda®, a standardized water extract of Spanish Marcona almond skin very rich in polyphenols, in the trinitrobenzenesulphonic acid (TNBS) model of rat colitis. Amanda® reduced the inflamed/ulcerated colonic area and preserved the mucosal architecture. The extract decreased the inflammatory infiltrate and the myeloperoxidase activity, as well as improved the oxidative state by increasing the glutathione content. Amanda® also modulated the expression of pro-inflammatory cytokines and inducible nitric oxide synthase. Besides, Amanda® improved the epithelial barrier function by restoring the levels of villin and mucin MUC3. Thus, the data from this work prove that Amanda® extract possesses therapeutic activity in TNBS-induced colitis in rats, targeting different pathological factors of IBD like oxidative stress, neutrophil mucosal infiltration and loss of intestinal epithelial barrier function.