Cardioprotective effects of ozone oxidative preconditioning in an in vivo model of ischemia/reperfusion injury in rats

Background. Several studies have demonstrated the beneficial effects of ozone oxidative preconditioning in several pathologies characterized by cellular oxidative and inflammatory burden. The present study was designed to investigate the cardioprotective effects of oxidative preconditioning in ischemia/reperfusion (I/R) injury. Methods. Rats were randomly assigned into five groups. Groups 1 and 2 were normal and I/R groups, respectively. Two of the other groups received two different doses of ozone therapies by rectal insufflations. The last group received vehicle (oxygen). Rats were subjected to myocardial I/R (40min/10min). Heart rate and ventricular arrhythmias were recorded during I/R progress. At the end of reperfusion, plasma creatine kinase-MB (CK-MB) activity and total nitrate/nitrite (NOx) were determined. In addition, lactate, adenine nucleotides, thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH) and myeloperoxidase (MPO) activity were estimated in the heart left ventricle. Histological examination was also performed to visualize the protective cellular effects. Results. Both doses of ozone therapy were equally protective in reducing CK-MB release. However, the higher dose was more effective in reducing oxidative stress, lactate accumulation, elevated MPO activity and plasma NOx as well as preserving myocardial adenine nucleotides. Histological examination also revealed better improvement with a higher dose of ozone therapy compared to the I/R group. Conclusion. Ozone therapy can afford significant cardioprotection against biochemical and histological changes associated with I/R injury.