Fish oil-supplemented parenteral nutrition prolongs survival while beneficially altering phospholipids' Fatty Acid composition and modulating immune function in rat sepsis.

We investigated the therapeutic effects of parenteral fish oil (FO) on survival and fatty acid profile in plasma and erythrocyte membranes, T-lymphocyte subsets, and plasma cytokines in a rat model of sepsis. Adult male Sprague-Dawley rats were subjected to cecal ligation and puncture-induced sepsis. For recovery, central venous catheterization was performed 2 days before sepsis was induced. Rats were randomly assigned to receive normal saline (n = 20) or total parenteral nutrition (PN) containing a standard soybean oil emulsion (n = 20) or FO-supplemented TPN (n = 20) at the onset of sepsis for 5 days. In the control group, rats were challenged by sham operation and underwent appropriate control treatment (n = 10). Sepsis led to a high mortality and body weight loss compared with sham operation. Total PN supplemented with FO, but not without FO, improved the survival compared with normal saline. Furthermore, parenteral infusion of FO increased the concentrations of eicosapentaenoic acid and docosahexaenoic acid, as well as the ratio of (eicosapentaenoic acid + docosahexaenoic acid) to arachidonic acid both in plasma and erythrocyte membrane. In addition, FO-supplemented TPN improved the percentages of CD3 and CD3CD4 T cells, as well as the CD4/CD8 ratio in spleen. Meanwhile, the percentage of regulatory T cells (CD4CD25Foxp3) among CD4 T cells was reduced by FO-supplemented TPN. Fish oil-supplemented TPN attenuated the production of high-mobility group box 1 and IL-10 in plasma. Moreover, parenteral FO decreased the bacterial loads in peritoneal lavage, blood, lung, and spleen. The present study suggests that FO-supplemented TPN initiated at the onset of sepsis improves survival, beneficially alters the lipids profile in plasma and erythrocyte membrane, modulates immune function, and regulates inflammatory response in a rat model.