A fish oil-rich diet reduces vascular oxidative stress in apoE^–/– mice

Abstract

Oxidative stress contributes to lipid peroxidation and decreases nitric oxide (NO) bioavailability in atherosclerosis. While long-chain (n-3) polyunsaturated fatty acids (PUFA) are easily oxidized in vitro, they improve endothelial function. Hence, this study postulates that long-chain (n-3) PUFA decrease atherogenic oxidative stress in vivo. To test this, apoE^–/– mice were fed a corn oil- or a fish oil (FO)-rich diet for 8, 14 or 20 weeks and parameters related to NO and superoxide (O₂^.–) plus markers of lipid peroxidation and protein oxidative damage in the aortic root were evaluated. The FO-rich diet increased NO production and endothelial NO synthase (NOS) expression and lowered inducible NOS, p22^phox expression and O₂^.–production after 14 and 20 weeks of diet. Protein lipoxidative damage (including 4-hydroxynonenal) was decreased after a long-term FO-diet. This supports the hypothesis that a FO-rich diet could counteract atherogenic oxidative stress, showing beneficial effects of long-chain (n-3) PUFA.

Keywords::

• Atherosclerosis
• 4-hydroxynonenal
• polyunsaturated fatty acids
• nitric oxide
• superoxide anion
• aortic root

Acknowledgements

We thank Nuria Clos and Susana Castells from the Scientific and Technical Department of the University of Barcelona and María del Puy Sáiz for their technical support. The authors thank the Language Service at the University of Barcelona for English language revision.

Declaration of interest: The study was supported by the Spanish Comisión Interministerial de Cienciay Tecnología (PM 98-0182, AGL2006-12433), Spanish Ministry of Health (network RD06/0045-PREDIMED), the Generalitat de Catalunya (2005GR269), by Croatian Ministry of Science and by the COST Action B35 Lipid Peroxidation Associated Disorders. The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.

This paper was first published online on Early Online on 20 May 2010.