Dietary docosahexaenoic acid but not eicosapentaenoic acid suppresses lipopolysaccharide-induced interleukin-1 beta mRNA induction in mouse spleen leukocytes

Mice were fed a diet supplemented either with beef tallow (BT), BT plus eth yl eicosapentaenoate (EPA) or BT plus ethyl docosahexaenoate (DHA) for 9 we eks. EPA and DHA supplementation increased the content of the respective fa tty acid in spleen leukocyte lipids, which was associated with the reductio n in the arachidonate content. IL-1 beta mRNA induction upon lipopolysaccha ride (LPS) stimulation in spleen leukocytes in the DHA diet group was signi ficantly lower than in the BT diet group, but the EPA diet was without any significant effect. The amount of prostaglandin E2 (PGE2) released from LPS -stimulated spleen leukocytes was significantly lower in both the EPA and D HA groups than in the BT group. Thus, dietary EPA and DHA inhibited arachid onate metabolism similarly but had different effects on Il-lp mRNA inductio n in mouse spleen leukocytes. (C) 2000 Harcourt Publishers Ltd.