Polyphenol-rich grape pomace extracts protect against dextran sulfate sodium-induced colitis in rats.

BACKGROUND: Several studies have reported that polyphenols may exert beneficial effects on inflammatory bowel disease. This study aimed to evaluate the effects of preventive consumption of polyphenol-rich red grape pomace extracts (GPEs) on dextran sulfate sodium (DSS)-induced colitis in rats. Rats were fed for 21 days with a semi-synthetic diet enriched with a GPE (Alicante-S, Alicante-P or Pinot-S) and colitis was induced by DSS administration in drinking water (40 g L(-1) ) during the last 7 days of experimentation. RESULTS: GPEs attenuated clinical signs and colon shortening and Alicante GPEs limited histological lesions induced by DSS. GPEs curbed the increase in myeloperoxidase activity and modulated antioxidant enzyme activities. Moreover, GPEs prevented the DSS-induced increase in pro-inflammatory cytokine levels and the up-regulation of various genes implicated in colitis such as intercellular adhesion molecule 1 (ICAM-1) and matrix metalloproteinase 9 (MMP-9). CONCLUSION: These results suggest that polyphenol-rich red GPEs could provide prevention against colon inflammation.