Beneficial effects of n-9 eicosatrienoic acid on experimental bowel lesions

Dietary fortification of n-9 polyunsaturated fatty acids (PUFA) or 5,8,11-eicosatrienoic acid (ETrA) as well as n-3 PUFA might contribute to the suppression of leukotriene B4 (LTB4) synthesis and thereby reduce inflammatory bowel lesions. As a result, the effect of an ETrA-enriched diet on experimental bowel lesions was examined in this study. In Expt. 1, rats were freely fed either an ETrA-enriched or a standard diet. After 7 days of feeding, acute bowel lesions were induced by the subcutaneous injection of 10 mg/kg indomethacin. In Expt. 2, chronic bowel lesions were made by performing subcutaneous injections of 7.5 mg/kg indomethacin twice. After the first injection, the rats were freely fed either an ETrA-enriched or a standard diet for 7 days. In both experiments, the rats fed an ETrA-enriched diet showed increased levels of ETrA in the plasma and intestinal mucosa, and a decreased inflammation score. However, there was no significant decrease in plasma and intestinal mucosal LTB4 in the ETrA-enriched diet-fed rats. These results suggest that the dietary supplementation of ETrA may have both prophylactic and therapeutic effects on experimentally produced bowel lesions. Further investigations are necessary to clarify the effects of ETrA on bowel lesions and its mechanisms.