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

Abstract

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.

• Authors: Patricia Pérez-Matute, Nerea Pérez-Echarri, J Alfredo Martínez, Amelia Marti, María J Moreno-Aliaga
• Journal: The British journal of nutrition (Br J Nutr) Vol. 97 Issue 2 Pg. 389-98 (Feb 2007) ISSN: 0007-1145 [Print] England
• PMID: 17298710 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Adiponectin
• Dietary Fats
• Insulin
• Leptin
• PPAR gamma
• RNA, Messenger
• Tumor Necrosis Factor-alpha
• Eicosapentaenoic Acid

Topics

• Adiponectin (genetics, metabolism)
• Adipose Tissue (metabolism)
• Animals
• Apoptosis (physiology)
• Dietary Fats (administration & dosage)
• Dietary Supplements
• Eating (physiology)
• Eicosapentaenoic Acid (administration & dosage)
• Gene Expression
• Insulin (blood)
• Insulin Resistance (physiology)
• Leptin (blood)
• Lipolysis (physiology)
• Male
• PPAR gamma (genetics)
• RNA, Messenger (analysis)
• Rats
• Rats, Wistar
• Tumor Necrosis Factor-alpha (genetics)
• Weight Gain (physiology)