Objective

Many studies have shown that the nature of the lipid consumed in the diet significantly affects the development of inflammatory diseases. In this study, we compared the effect of diets supplemented with 15% by weight of fish oil (FO), refined olive oil (ROO), and pomace olive oil (POO) with that of a low-fat diet, 2% by weight of corn oil, considered as the basal diet (BD), on the ability to modify reactive oxidative species and proinflammatory mediator generation by stimulated murine macrophages.

Methods

Mice were fed the different oil-enriched diets for 8 wk. Peritoneal macrophages were isolated from these mice and subsequently stimulated. Reactive oxygen species and proinflammatory mediators were measured in the corresponding supernatants. Data were statistically treated by one-way analysis of variance and Tukey's multiple comparison post hoc test.

Results

The ROO and POO significantly reduced the hydrogen peroxide production compared with BD, whereas FO stimulated its production. Moreover, the generation of nitric oxide was significantly prevented in all the experimental oil-enriched dietary groups. The ROO and FO groups showed significantly reduced cytokine (tumor necrosis factor-alpha, interleukin-1beta, interleukin-6) and prostaglandin E(2) production.

Conclusion

These results confirm the prevention action on proinflammatory mediator generation exerted by FO and demonstrate the protective antioxidant properties not only of olive oil but also of POO. The consumption of these olive oils may help to prevent cellular oxidative stress and inflammation.