Dietary unsaponifiable fraction from extra virgin olive oil supplementation attenuates acute ulcerative colitis in mice

Extra virgin olive oil (EVOO) has demonstrated immunomodulatory and antiinflammatory properties in murine experimental ulcerative colitis (UC). In addition to its high monounsaturated fatty acid content, evidences have accumulated on the favorable properties of minor, although highly bioactive, components present in the unsaponifiable fraction (UF). The present study was designed to evaluate the effects of dietary EVOO's UF supplementation on acute UC. C57BL/6 mice were fed from weaning with sunflower oil (SD), EVOO diet and UF-enriched SD at 5% oil (SD+UF). After 30 days, mice were exposed to 3% dextran sulfate sodium (DSS) for 5 days developing acute colitis. After 4 days of DSS removal, animals were sacrificed and colons were histological and biochemically processed. Disease activity index and microscopic damage score were significantly improved in EVOO and SD+UF dietary groups versus SD group. In addition, both dietary treatments significantly induced decreases in MCP-1 and TNF-alpha, levels, iNOS and COX-2 overexpression and p38 MAPKs activation in colon mucosa. Moreover, an upregulation of I kappa B expression was also observed after feeding the animals with both diets. However, no statistically differences between data from mice fed with EVOO or UF+SD diets were observed. Dietary enrichment with EVOO's UF reduces the damage in acute colitis model, alleviating the oxidative events and returning proinflammatory proteins expression to basal levels probably through p38 MAPK and NF kappa B signalling pathways. EVOO's UF diet might provide a basis for developing a new strategy in dietary supplementation for the prevention of UC. (C) 2012 Elsevier B.V. All rights reserved.