1997 Volume 50 Issue 4 Pages 279-285
The effects of dietary oils containing a considerable amount of n-3 fatty acid, i. e., perilla oil and fish oil, on ulcerative colitis were compared with those of corn oil in rats. Male 6-week-old SD rats were intracolonically administered trinitrobenzene sulfonic acid (TNBS) dissolved in 50% ethanol after a oneweek feeding period. The rats were fed the experimental diets for one additional week and then decapitated. The severity of ulcerative colitis induced by TNBS was assessed according to the method of Morris et al. The average damage score was higher in the group fed perilla oil than in that fed corn oil. Both the level of arachidonic acid in phospholipid, and leukotriene B4 production by neutrophils were lower in the perilla oiland fish oil-fed groups than in the corn oil-fed group. However, an anti-inflammatory effect of n-3 fatty acids was not observed. Furthermore, the damage score was increased by administration of indomethacin in the fish oil-fed group. These results suggest that the production of arachidonic acid metabolites via the cyclooxygenase pathway, rather than through depression of leukotriene B4, is essential for protection of the colonic mucosa.
