Abstract

Scope: Dietary n-3 long-chain PUFAs (n-3 LCPUFAs) supplementation was studied in an HFD-induced (HFD is high-fat diet) steatosis and inflammation in relation to peroxisome proliferator-activated receptor alpha (PPAR-alpha) and nuclear factor kappa B (NF-kappa B) signaling. Methods and results: Male C57BL/6J mice received (i) control diet (10% fat, 20% protein, 70% carbohydrate), (ii) control diet plus n-3 LCPUFAs (daily doses of 108 mg/kg body weight of eicosapentaenoic acid plus 92mg/kg body weight of docosahexaenoic acid), (iii) HFD (60% fat, 20% protein, 20% carbohydrate), or (iv) HFD plus n-3 LCPUFAs for 12 wk. PPAR-alpha, tumor necrosis factor alpha (TNF-alpha), and IL-1 beta mRNA expression, acyl-CoA oxidase 1 (ACOX1), and carnitine-acyl-CoA transferase 1 (CAT-I) protein contents, and NF-kappa B DNA binding activity were measured. HFD significantly decreased liver PPAR-alpha, ACOX1, and CAT-I levels with NF kappa B activation, higher TNF-alpha and IL-1 beta expression, and steatosis development. These changes were either reduced or normalized to control values in animals subjected to HFD plus n-3 LCPUFAs, with establishment of an inverse association between NF-kappa B activation and PPAR-alpha mRNA expression (r=-0.66, p < 0.0001). Conclusion: Data presented indicate that n-3 LCPUFAs supplementation prevents liver steatosis and inflammation induced by HFD, with underlying mechanisms involving enhanced PPAR-alpha signaling and diminished NF-kappa B activation.