In vivo effects of olive oil-based lipid emulsion on lymphocyte activation in rats

Numerous studies suggest that immune function may be compromised by lipid emulsions rich in polyunsaturated fatty acids, especially linoleic acid. In our study, we compared the effect of a new olive oil-based lipid emulsion (ClinOleic®) containing 18% linoleic acid, and an emulsion based on soybean oil (Ivelip®; 52% linoleic acid) on lymphocyte functions. Weaning Wistar rats (n= 24) were fed for 4 weeks on an oral diet that contained 12% of total energy as lipids from soybean oil. Then they received, during 6 days, a total parenteral nutrition (260 kcal/kg/d) in which 12% of total energy was brought by one of the two lipid emulsions. The fatty acid profile of spleen lymphocyte phospholipids reflected lipid intakes, with a higher content of oleic acid in ClinOleic® group and linoleic acid in Ivelip® group. A greater proportion of cells expressed the interleukin-2 receptor a-chain (CD25) after administration of ClinOleic® when compared to Ivelip® (55.43 ± 3.47 vs 45.48 ± 3.26%, P 0.05). Moreover, the CD25 expression was positively correlated with oleic acid content of spleen lymphocyte phospholipids (r= 0.500,P 0.018). These results show that ClinOleic® is able to induce, in vivo, a greater proportion of cells expressing CD25, and suggest that oleic acid could have a role in the observed effects.