Effect of dietary fats and sesamin on the lipid metabolism and immune function of Sprague-Dawley rats

We examined the effect of three dietary fats, safflower oil (SAF) rich in linoleic acid, borage oil (BOB) rich in gamma-linolenic acid, and perilla oil PER) rich in alpha-linolenic acid, on the lipid metabolism, and chemical mediator and immunoglobulin levels in sprague-Dawley rats, as well as the dietary effect of sesame-derived antioxidative sesamin. The serum cholesterol, phospholipid, triglyceride, prostaglandin E2 level and splenic leukotriene B4 level were lower in the rats fed on BOB or PER than in those fed on SAP. SES feeding suppressed the expression of the lipid-decreasing effect of BOR, but not in the rats fed on PER. In respect of the fatty acid composition of the liver and spleen, PER feeding gave a lower arachidonic acid level, add higher eicosapentaenoic and docosahexaenoic acid levels than SAF feeding did, while the effect of BOB feeding was marginal. The effect of SES feeding on fatty acid composition was much smaller than that of dietary rats. In respect of immunoglobulin production, PER+SES feeding gave the lowest IgE productivity in the mesenteric lymph node lymphocytes. These results suggest the PER feeding regulated lipid metabolism and exerted an anti-allergic effect by a different mechanism from that with BOB feeding