Marine n-3 PUFA protects hearts from I/R injury via restoration of mitochondrial function.

OBJECTIVES: Overwhelming evidence shows that dietary supplementation with n-3 polyunsaturated fatty acids (PUFAs) elicits protective effects on patients with cardiovascular disease. However, the detailed mechanisms underlying n-3 PUFA-mediated cardioprotection are unknown, and examined in the present study. METHODS: We evaluated heart performances with Langendorff perfusion apparatus. Meanwhile, whole mitochondria were purified from non-perfused hearts for functional assessment, and lipid peroxidation level was measured as well. RESULTS: Compared with control groups, hearts from n-3 PUFA-supplemented rats showed improved functional recovery and reduced tissue injury following ischemia/reperfusion (I/R). Furthermore, the mitochondrial function of PUFA-treated hearts was significantly enhanced, as demonstrated by biochemical analysis of respiratory chain activity. In addition, thiobarbituric acid-reactive substance or TBARS assay revealed that lipid peroxidation product, malondialdehyde or MDA, in the mitochondria was significantly reduced by PUFA treatment. CONCLUSION: Taken together, our data indicate that marine n-3 PUFA could improve cardiac performance after I/R injury by restoring mitochondrial respiratory activities and attenuating lipid peroxidation.