Previous studies proposed a protective role of the dietary intake of (n-3) PUFA in human
inflammatory bowel disease (IBD), but almost no studies have been performed using
olive oil. The aims of the present study were to test the beneficial effects of an
olive oil-based diet with or without
fish oil, rich in (n-3) PUFA, in the
dextran sodium sulfate (DSS) model of rat
colitis and to elucidate the mechanisms involved in their potential beneficial effects, with special attention to the production of some of the mediators involved in the intestinal inflammatory response, such as
leukotriene B(4) (LTB(4)),
tumor necrosis factor alpha (
TNFalpha) and
nitric oxide (NO). Rats were fed the different diets for 2 wk before
colitis induction and thereafter until colonic evaluation 15 d later. Colitic rats fed the
olive oil-based diet had a lower colonic inflammatory response than those fed the
soybean oil diet, and this beneficial effect was increased by the dietary incorporation of (n-3) PUFA. A restoration of colonic
glutathione levels and lower colonic
NO synthase expression occurred in all colitic rats fed an
olive oil diet compared with the control colitic group that consumed the
soybean oil diet. However, (n-3) PUFA incorporation into an
olive oil diet significantly decreased colonic
TNFalpha and LTB(4) levels compared with colitic rats that were not supplemented with
fish oil. These results affirm the benefits of an
olive oil diet in the management of IBD, which are further enhanced by the addition of (n-3) PUFA.