Apple peel polyphenols: A key player in the prevention and treatment of experimental inflammatory bowel disease.
Clin Sci (Lond). 2016 Sep 14. Epub 2016 Sep 14. PMID: 27630205
Marie Claude Denis
Diets rich in fruits and vegetables may reduce oxidative stress and inflammation via several mechanisms. These beneficial effects may be due to their high polyphenol content. The aims of the present study are to evaluate the preventive and therapeutic aspects of polyphenols in dried apple peel extract (DAPP) on intestinal inflammation while elucidating the underlying mechanisms and clinical benefits. Induction of intestinal inflammation in mice was performed by oral administration of the inflammatory agent DSS at 2.5% for 10 days. Physiological and supraphysiological doses of DAPP (200 and 400 mg/kg/day, respectively) were administered by gavage for 10 days pre- and post-DSS treatment. DSS-mediated inflammation caused weight loss, shortening of the colon, dystrophic detachment of the epithelium, and infiltration of mono- and polymorphonuclear cells in the colon. DSS induced an increase in lipid peroxidation, a down-regulation of antioxidants, an augmented MPO and COX2, an elevated PGE2 and a shift in mucosa-associated microbial composition. However, DAPP normalized these abnormalities in preventive or therapeutic situation in addition to lowering inflammatory cytokines while stimulating antioxidant transcription factors and modulating other potential healing pathways. The supraphysiological dose of DAPP in therapeutic situation also improved mitochondrial dysfunctions. Relative abundance of Peptostreptococcaceae and Enterobacteriaceae bacteria was slightly decreased in DAPP-treated mice. In conclusions, DAPP exhibit powerful anti-oxidant and anti-inflammatory actions in the intestine and are associated with the regulation of cellular signaling pathways and changes in microbiota composition. Evaluation of preventive and therapeutic effects of DAPP may be clinically feasible in individuals with intestinal inflammatory bowel diseases.