Decreased proinflammatory cytokines and increased antioxidant enzyme gene expression by ω−3 lipids in murine lupus nephritis

Enrichment of diet with ω−3 lipid rich-menhaden fish oil (FO) when fed ad libitum to autoimmune lupus-prone NZB/NZW F₁ (B/W) female mice delayed the onset and slowed progression of renal disease while significantly extending life-span compared to ω-6 lipid rich-corn oil (CO)-fed mice. Northern blot analysis of kidneys from FO-fed mice revealed no detectable levels of IL-1α IL−6 and TNFα mRNA contrasted to levels that were easily detected in CO-fed mice. In contrast to the cytokines, FO-fed mice showed higher renal levels of the antioxidant enzymes-catalase, glutathione peroxidase (GSH-Px), superoxide dismutase (SOD)-mRNAs compared to CO-fed mice. The results suggest that dietary supplementation with FO, as compared to CO, inhibits the production of pro-inflammatory cytokines and ameliorates immune-complex-mediated kidney injury possibly by enhancing the ability of cells to dispose of harmful reactive oxygen intermediates.