Cardioprotective role of long-term kefir and omega-3 fatty acid supplementation on myocardial apoptosis via oxidative stress-mediated lysosomal cathepsin release in isoproterenol-induced myocardial infarction rat model

Objective: The antiapoptotic and antioxidative role of long-term kefir and omega-3 fatty acids and their relationship with cysteine proteases on isoproterenol (ISO) induced myocardial infarction (MI) experimental model was investigated in our study. Material and Methods: Fifty male Sprague-Dawley rats were evenly divided into five distinct groups (n=10): Control, MI, kefir +MI, omega-3+MI, and kefir+omega 3+MI groups. Kefir 10% (with drinking water) and omega-3 fatty acid (30 mg/day per 100g body weight into the standard chow) were administrated during 30 days. ISO was subcutaneously injected into the rats (100 mg/ kg b.w.) on the 29th and 30th days. Myocardial tissue and blood samples were taken 12 hours after the last ISO dose. Creatine kinase MB (CK-MB) activities were measured in serum samples. Caspase-3, superoxide dismutase (SOD), malondialdehyde (MDA), nitric oxide (NO), DNA fragmentation, cathepsin B and L levels, were measured in myocardial tissue. Results: Serum CK-MB (p<0.05) and cardiac tissue MDA (p>0.05), NO (p<0.01), caspase 3 (p<0.01), DNA fragmentation (p<0.001), cathepsin B (p<0.05) and L (p<0.05) activities were increased and SOD (p<0.001) activities were decreased in MI group compared to control group. The preventive effects of long-term therapy with kefir and omega-3 fatty acids have been demonstrated on apoptosis, oxidative stress markers, and cysteine protease enzymes. Conclusion: Our results showed that long-term administration of kefir and omega-3 fatty acids might be effective in reducing myocardial apoptosis through oxidative stress-mediated release of cysteine proteases in myocardial infarction, especially in the kefir and combined therapy groups.