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Br J Nutr. 2007 Feb;97(2):389-98.

Eicosapentaenoic acid actions on adiposity and insulin resistance in control and high-fat-fed rats: role of apoptosis, adiponectin and tumour necrosis factor-alpha.

Pérez-Matute P, Pérez-Echarri N, Martínez JA, Marti A, Moreno-Aliaga MJ.
Department of Physiology and Nutrition, University of Navarra, 31008 Pamplona, Spain.

n-3 PUFA have shown potential anti-obesity and insulin-sensitising properties. However, the mechanisms involved are not clearly established. The aim of the present study was to assess the effects of EPA administration, one of the n-3 PUFA, on body-weight gain and adiposity in rats fed on a standard or a high-fat (cafeteria) diet. The actions on white adipose tissue lipolysis, apoptosis and on several genes related to obesity and insulin resistance were also studied. Control and cafeteria-induced overweight male Wistar rats were assigned into two subgroups, one of them daily received EPA ethyl ester (1 g/kg) for 5 weeks by oral administration. The high-fat diet induced a very significant increase in both body weight and fat mass. Rats fed with the cafeteria diet and orally treated with EPA showed a marginally lower body-weight gain (P = 0.09), a decrease in food intake (P < 0.01) and an increase in leptin production (P < 0.05). EPA administration reduced retroperitoneal adipose tissue weight (P < 0.05) which could be secondary to the inhibition of the adipogenic transcription factor PPARgamma gene expression (P < 0.001), and also to the increase in apoptosis (P < 0.05) found in rats fed with a control diet. TNFalpha gene expression was significantly increased (P < 0.05) by the cafeteria diet, while EPA treatment was able to prevent (P < 0.01) the rise in this inflammatory cytokine. Adiposity-corrected adiponectin plasma levels were increased by EPA. These actions on both TNFalpha and adiponectin could explain the beneficial effects of EPA on insulin resistance induced by the cafeteria diet.


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And MUFAs NF-kappaB.


Atherosclerosis. 2007 Oct;194(2):e141-6.

The chronic intake of a Mediterranean diet enriched in virgin olive oil, decreases nuclear transcription factor kappaB activation in peripheral blood mononuclear cells from healthy men.

Perez-Martinez P, Lopez-Miranda J, Blanco-Colio L, Bellido C, Jimenez Y, Moreno JA, Delgado-Lista J, Egido J, Perez-Jimenez F.

Lipids and Atherosclerosis Research Unit, Hospital Universitario Reina Sofía, Avenida Menéndez Pidal s/n, 14004-Córdoba, Spain.

OBJECTIVE: Nuclear transcription factor kappaB (NF-kappaB) plays a key role in the inflammatory response and can be modulate by dietary fat. We have examined the effect of three diets, with different fat composition, on the activation of NF-kappaB on peripheral blood mononuclear cells (PBMCs). METHODS: Sixteen healthy men followed three 4-week diets, in a randomised crossover design: a Western diet, rich in saturated fat (SFA) [22% SFA, 12% monounsaturated fat (MUFA) and 0, 4 alpha-linolenic acid]; a Mediterranean diet [<10% SFA, 24% MUFA and 0.4% alpha-linolenic acid], and a low fat diet enriched in alpha-linolenic acid [<10% SFA, 12% MUFA and 2% alpha-linolenic acid]. NF-kappaB (electrophoretic mobility shift assay) in mononuclear cells and plasma concentrations (ELISA) of soluble vascular cellular adhesion molecule 1 (VCAM-1) were examined after either diets. RESULTS: Western diet increased 2.7-fold NF-kappaB compared with the Mediterranean diet (p=0.038) and 1.79-fold with the alpha-linolenic acid diet (p=0.07). No differences were found between the last two. Furthermore, an increase on plasma VCAM-1 was observed with the Western diet (p<0.05). CONCLUSIONS: The Mediterranean diet diminished NF-kappaB activation in mononuclear cells, compared with Western diet, supporting its cardioprotective properties. The effect of the n-3 enriched diet was intermediate.


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