Eicosapentanoic acid prolongs survival and attenuates inflammatory response in an experimental model of lethal trauma

In an attempt to define the efficacy of intravenously administered n-3 polyunsaturated fatty acids (PUFAs) in an animal model of lethal trauma following femur fracture, an intravenous solution of eicosapentanoic acid (EPA) - one n-3 PUFA - was administered in 25 rabbits; 13 were controls and 12 were treated with EPA 30 min after fracture. Vital signs were recorded and serum concentrations of tumor necrosis factor-alpha (TNFalpha) and respiratory burst of neutrophils were assessed. Survival of controls was 7.7% and of animals treated with EPA 50% (log-rank: 5.162; p: 0.023). Vital signs of both groups did not differ. Oxidative burst of neutrophils was greater among EPA-treated animals compared with controls at 48 h (p: 0.010). Serum levels of TNFalpha of the former group were decreased compared with the latter at 48 h (p: 0.019). Bacterial growth of enterobacteriaceae from liver and spleen after death or euthanasia was lower among EPA-treated rabbits than controls. These results suggest that EPA possesses considerable immunomodulatory activities improving survival in a model of lethal trauma. Restoration of oxidative burst conferring efficient phagocytosis of evading bacteria seems the most probable mechanism of action.