Abstract
Background: Fish oil with an abundance of omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) has been known as a beneficial dietary supplement for improvement of metabolic disorders, including nonalcoholic fatty liver disease. However, the detailed molecular mechanism still remains unknown in fish oil-ameliorated lipid metabolism disorders. The aim of this study is to investigate the beneficial effect and the possible molecular mechanism of fish oil on lipometabolism of liver and skeletal muscle in high-fat-diet-fed rats.
Methods: High fat diets were applied to induce defects of lipid metabolism in male Sprague-Dawley rats. After administering high fat diets supplemented with or without fish oil for eight weeks, the blood, liver and skeletal muscle tissues were harvested from sacrificed experimental animals. Lipometabolism-related protein expressions and gene expressions were analyzed by Western blot and real-time quantitative reverse transcription polymerase chain reaction, respectively.
Results: Diet supplementation with fish oil showed an efficient improvement in imbalance of plasma and hepatic lipid profiles in high-fat diet-fed rats. In addition, fish oil supplementation significantly activated adenosine monophosphate (AMP)-activated protein kinase (AMPK) phosphorylation in both livers and skeletal muscles. Moreover, fish oil supplementation was also able to activate downstream lipid catabolism-related protein expression (PPAR-alpha) and gene expression (LPL) in liver and skeletal muscle, respectively.
Conclusion: These results suggest that diet supplementation of fish oil exerts a beneficial improvement in lipometabolism of liver and skeletal muscle via AMPK and downstream lipid catabolism-related signals activation.
