Effect of dietary oils on oxidative stress and cytokine production by murine macrophages

Abstract

Many studies have shown that the nature of the lipid consumed in the diet significantly affects the prevalence of coronary, inflammatory or autoimmune diseases (1,2) . The present study was conducted to compare the impact of feeding mice on diets enriched with edible oils (150 g/kg diet; fish oil (FO), olive oil (OVO) and orujo olive oil (ORO)) with that of a basal diet (BD) enriched with 20 g maize oil/kg on the ability to modulate oxidative reactive species and pro-inflammatory mediator generation by stimulated murine macrophages. Swiss male mice were fed on the different diets for 8 weeks. Diets were formulated according to American Institute of Nutrition (AIN) recommendations (3) . Peritoneal macrophages were isolated from these mice and stimulated. Reactive oxygen (O 2 -and H 2 O 2 ) and nitrogen (NO 2 -) species, PGE 2 , TNFa and IL-6 were measured in the supernatant fractions from 10 6 cells. All test diets down regulated NO generation compared with the BD (Fig.1); in contrast, FO increased H 2 O 2 generation whereas OVO and ORO group diets significantly inhibited this ROS production compared with the BD. In addition, ORO was able to decrease O 2 -formation compared with the BD group (Fig.1). Finally, both OVO and FO groups significantly decreased PGE 2 and cytokine production (Fig. 2). These results are in agreement with those of other authors in that a diet enriched in olive oil was found to show a protective effect against oxidative stress and inflammation (4,5) and they confirm the preventive anti-inflammatory properties of FO (6) . Moreover, the results provide important additional data about the ability of ORO to prevent oxidative damage to cells.