Dietary polyunsaturated fatty acids improve histological and biochemical alterations in rats with experimental ulcerative colitis

The aim of the present study was to determine whether dietary intake of monounsaturated (MUFA) and/or polyunsaturated fatty acids (PUFA) of the (n-3) and (n-6) series could improve intestinal damage and reduce inflammation in experimental ulcerative colitis (UC). Rats were treated with 80 mg/kg body of 2,4,6-trinitrobenzenesulfonic acid and fed for 1 or 2 wk diets enriched in olive oil (00), fish oil (FO), or purified pig brain phospholipids (BPL), as sources of monounsaturated and PUFA of the (n-3) and (n-3) + (n-6) series. Evaluation of macroscopic and microscopic colonic damage was assessed. Ultrastructural and histologic changes were analyzed as well as plasma and colonic mucosa fatty acid profiles and some biochemical markers of injury and inflammation [alkaline phosphatase (AP), mieloperoxidase (MPO), prostaglandin E-2 (PGE(2)) and leukotriene B-4]. Fatty acid profiles of both plasma and mucosa mostly reflected the dietary fatty acid composition. Plasma MUFA proportions were higher in UC animals fed the 00 diet compared with FO or BPL groups 1 and 2 wk and (n-3) long chain PUFA (LC-PUFA) were higher in the FO than in the 00 and BPL groups. At 1 wk, UC led to lower MUFA mucosa levels and (n-3)LC-PUFA were higher in the FO group compared with the 00 and BPL groups. Rats with UC fed FO at 1 wk showed significantly less macroscopic and microscopic colonic damage. They also have lower AP and MPO activities and PGE(2) levels compared with the 00 and BPL groups and showed enhanced histological repair, less necrotic areas within the mucosa, and more goblet cells with mature mucin granules. These results suggest that the use of balanced diets containing (n-3) LC-PUFA could ameliorate the inflammation and mucosal damage in UC.