Effects of fish oil containing eicosapentaenoic acid and docosahexaenoic acid on dystrophic mdx mice hearts at later stages of dystrophy.

OBJECTIVE

In the present study, we investigated whether omega-3 would be effective against dystrophic cardiomyopathy at later stages (13 and 17 mo) of the disease.

METHODS

Mdx mice (8 mo old) received omega-3 oil (commercially available fish oil; FDC vitamins; omega-3) for 5 mo. Untreated-mdx mice received mineral oil. Heart and diaphragm muscle were evaluated by morphometric (fibrosis), molecular (western blot, inflammatory markers), biochemical (creatine kinase), and functional (electrocardiogram) analyses.

RESULTS

Mdx mice presented elevated plasma levels of cardiac creatine kinase (41.2 U/L in normal × 119.6 U/L in untreated-mdx mice), which were significantly decreased by omega-3 treatment. Heart fibrosis was significantly ameliorated by omega-3 treatment at 17 mo of age (untreated-mdx: 20.8% of fibrosis; omega-3-treated: 15.7% of fibrosis in right ventricle). Omega-3 improved some electrocardiogram parameters. Markers of inflammation (tumor necrosis factor alpha, matrix metalloprotease-9, and tissue inhibitor of metalloprotease 1) in mdx heart were significantly decreased by omega-3 treatment. Omega-3 increased β-dystroglycan levels in mdx heart and did not affect the levels of the profibrotic transforming growth factor beta. Omega-3 ameliorated the dystrophic diaphragm in almost all of the parameters evaluated (fibrosis, transforming growth factor beta, metalloprotease-9, and tissue inhibitor of metalloprotease 1).

CONCLUSIONS

The present study suggests that omega-3 may be useful in ameliorating dystrophic cardiomyopathy and diaphragm dystrophy in mdx mice at later stages of the disease, further supporting the use of omega-3 in DMD clinical trials.