Docosahexaenoic acid exerts anti-inflammatory action on human eosinophils through peroxisome proliferator-activated receptor-independent mechanisms.

Background: Despite the fact that previous studies have indicated the significant roles of polyunsaturated fatty acids (PUFAs) in the immune system through peroxisome proliferator-activated receptor alpha (PPARα) and PPARγ, the biological functions and the mechanisms of action in eosinophils are poorly understood.

Methods: We investigated the functional effects of docosahexaenoic acid (DHA, n-3 PUFA) on human peripheral blood eosinophils, using in vitro systems to test the hypothesis that DHA negatively regulates eosinophil mechanisms through PPARα and PPARγ.

Results: Eosinophil apoptosis that spontaneously occurs under normal culture conditions was accelerated in the presence of DHA.