Hypercholesterolaemia alters the responses of the plasma lipid profile and inflammatory markers to supplementation of the diet with n-3 polyunsaturated fatty acids from fish oil

• Published in: European journal of clinical investigation Vol. 36; no. 11; pp. 788 - 795
• Main Authors: Bravo, E., Napolitano, M., Lopez-Soldado, I., Valeri, M., Botham, K. M., Stefanutti, C.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-11-2006; Blackwell
• Subjects: Animals; Biological and medical sciences; Cytokines - blood; Dietary Fats, Unsaturated - metabolism; Dietary Fats, Unsaturated - pharmacology; Disorders of blood lipids. Hyperlipoproteinemia; Fatty Acids, Omega-3 - metabolism; Fatty Acids, Omega-3 - pharmacology; Fish Oils - administration & dosage; General aspects; Hepatocyte Nuclear Factor 4; Hypercholesterolaemia; Hypercholesterolemia - metabolism; Hypercholesterolemia - physiopathology; inflammation; Lipid Peroxides - blood; Lipids - blood; Male; Medical sciences; Metabolic diseases; n-3 polyunsaturated fatty acids; plasma lipids; Rats; Rats, Wistar; RNA, Messenger - blood; Nutrition; Polyunsaturated fatty acid; Biological marker; Metabolic diseases; Biological indicator; Lipids; Hyperlipoproteinemia; Inflammation; Lipoprotein; n-3 fatty acid; Fish oil; plasma lipids; Cholesterol; Profile; Blood plasma; Medicine; Hypercholesterolemia; Diet; n-3 polyunsaturated fatty acids; Supplementation; Dyslipemia; Hypercholesterolaemia
• ISSN: 0014-2972; 1365-2362
• DOI: 10.1111/j.1365-2362.2006.01726.x

Background  The influence of supplementing the diet with long‐chain n‐3 polyunsaturated fatty acids (PUFA) from fish oil on plasma lipids and lipid peroxides and the production of pro‐inflammatory mediators in normolipidaemic and hypercholesterolaemic rats were studied.
Materials and methods  Rats were divided into four groups and fed one of the following diets: a control diet (containing 4% corn oil); an n‐3 PUFA diet [containing 4% eicospentaenoic (EPA) + docosahexaenoic (DHA)]; a hypercholesterolaemic diet (HCH); or a HCH + n‐3 PUFA diet over a 4‐week period. Plasma lipids, lipid peroxides, cytokines [tumour necrosis factor (TNF)α, interleukin (IL)‐6, interferon (IFN)γ] and mRNA for hepatic nuclear factor‐4α (HNF4α) were determined.
Results  Plasma triglyceride (TG), but not cholesterol, levels were decreased by the n‐3 PUFA as compared with the control diet (P < 0·001), but the addition of n‐3 PUFA to the HCH diet decreased both the TG (P < 0·01) and cholesterol (P < 0·05) concentrations. Plasma lipid peroxides and expression HNF4α mRNA were increased by n‐3 PUFA in the normolipidaemic (P < 0·05), but not in the hyperlipidaemic rats. Compared with the control diet group, plasma concentrations of TNFα and IL‐6 were increased in the n‐3 PUFA (P < 0·05) and HCH diet (P < 0·05, P < 0·01, respectively) groups, but not in animals given the HCH + n‐3 PUFA diet, whereas IFNγ levels were increased in hypercholesterolaemia (P < 0·05), but were unaffected by n‐3 PUFA.
Conclusion  These results demonstrate that the major effect of fish oil n‐3 PUFA is to lower the TG levels in both normo‐ and hyperlipidaemia. Furthermore, in the hypercholesterolaemic state, fish oil n‐3 PUFA induces additional beneficial changes in the immune and peroxidation responses.