Excessive dietary linoleic acid induces proinflammatory markers in rat

Fautrel U991International audienceFollowing the historical dietary recommendations, the substitution of polyunsaturated fatty acids (PUFA) for saturated fatty acids (SFA) resulted in a dramatic increase of linoleic acid (LA) in the western diet. While pro-atherogenic properties of SFA have been described, the involvement of LA on the inflammatory process remains controversial. Herein, we evaluated the effects of an excessive LA intake on the cytokine-induced expression of endothelial adhesion molecules, vascular cell adhesion molecule-1 (VCAM-1) and intercellular cell adhesion molecule-1 (ICAM-1), through the nuclear factor (NF)-κB pathway, in comparison with a control diet and regarding a “positive” SFA-diet. Wistar rats were fed experimental diets: a control diet or diets enriched with LA or SFA for 11 weeks. Plasma lipid parameters and proinflammatory cytokine production such as interleukin (IL)-1β and tumor necrosis factor (TNF)-α were analysed. Expression of endothelial adhesion molecules and NF-κB was determined by immunohistochemical analysis. No difference was observed in body weight. The enriched diets did not affect triglyceride and total cholesterol levels in plasma. Our results demonstrated that excessive dietary LA intake increased TNF-α levels (p<0.05) in plasma. Rats fed the LA-enriched diet showed a significant higher expression of VCAM-1, ICAM-1 and NF-κB in aortas. In addition, our results demonstrated that an excess of LA is more efficient to activate endothelial molecular process than an excess of SFA. The present study provides further support for the proinflammatory properties of LA and suggests a LA-derivatives pathway involved in the inflammatory proces