Comparison of the effects of dietary alpha-linolenic, stearidonic, and eicosapentaenoic acids on production of inflammatory mediators in mice.

The effects of dietary stearidonic acid (18:4n-3) on inflammatory mediator release in whole blood and splenocytes was investigated in Balb/c mice, and the effects were compared with those of two other n-3 PUFA: alpha-linolenic acid (18:3n-3) and EPA (20:5n-3). TAG mixtures containing 10% of 18:4n-3, 18:3n-3, or 20:5n-3 as the respective sole n-3 PUFA were enzymatically synthesized. Diets containing synthesized TAG mixtures were fed to Balb/c mice for 3 wk. The release of prostaglandin F2 (PGE2) and tumor necrosis factor (TNF) were measured in whole blood and splenocytes stimulated with lipopolysaccharide. In whole blood, the production of TNF was suppressed by all dietary n-3 PUFA (18:3n-3, 18:4n-3, and 20:5n-3) as compared with the control diet, which contained TAG prepared from safflower oil. PGF2 production was not significantly changed. Differences among the n-3 PUFA (18:3n-3, 18:4n-3, and 20:5n-3) were not observed. In splenocytes, PGE2 production was suppressed by dietary n-3 PUFA, but TNF production was not. GC analysis of plasma and splenocyte FA profiles showed an increase in the levels of 20:4n-3, 20:5n-3, and 22:6n-3 in mice fed the diet containing 18:4n-3.