Docosahexaenoic acid and other dietary polyunsaturated fatty acids suppress leukotriene synthesis by mouse peritoneal macrophages

The efficacy of individual omega-3 polyunsaturated fatty acids (PUFA) in altering eicosanoid synthesis in peritoneal macrophages was studied by feeding mice for 10 days a diet containing 2 wt % fat, which included 0.5 wt % ethyl esters of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) or linolenic acid (LNA). Upon stimulation with calcium ionophore A23187, macrophages from these animals produced significantly lower amounts of leukotriene C4, leukotriene B4 and 12-hydroxyeicosatetraenoic acid, prostaglandin E2 and 6-keto prostaglandin F1 alpha compared with those obtained from animals on the diets containing olive oil or safflower oil. The decrease in leukotriene synthesis was similar in the animals fed DHA, EPA or LNA diets. This depression of eicosanoids by DHA and EPA was associated with decreased levels of arachidonic acid (AA); however, LA that altered eicosanoids did not have the same effect on AA levels.