Effect of medical ozone therapy on diabetes-induced cardiac dysfunction

Diabetic metabolic dysregulation is accompanied by oxidative stress that could possibly lead to dysfunction in cardiac myocytes. The aim of this study was to elucidate the effect of controlled medical ozone therapy to diabetic rats on ischemia reperfusion insult in isolated rat hearts. Both long-term [12 weeks duration] and short-term [20 days duration] treatment were investigated. Rats of each duration were divided into non-diabetic control group and streptozotocin-induced diabetic group, the latter group being further divided into two subgroups, namely, a group receiving medical ozone and the other remaining untreated. Long-term groups were studied for the cardiac responses before and after ischemia reperfusion. Short-term groups were used to assess the degree of leukocytic adhesion to coronary endothelium. In both durations, serum levels of CPK and TNF-alpha were determined. Long-term ozone therapy to diabetic rats improved myocardial depression before and after ischemia reperfusion, with reduction in ischemia reperfusion injury. Short-term therapy resulted in an attenuating effect on leukocyte adherence to coronary vascular endothelial cells after ischemia-reperfusion. The present data show the cardioprotective effect of medical ozone therapy on ischemia reperfusion injury in diabetic rats. The reduction in TNF-alpha may represent a mechanism for such protection. Prohibiting leukocyte-endothelial adhesion and transmigration may be useful in decreasing leukocyte-dependent post-reperfusion injury

Oxidative preconditioning of medical ozone

Cardiac ischemic reperfusion injury is gaining importance due to rising of cardiac intervention procedures invoking transient ischemia, which requires trials of preconditioning strategies, A possible beneficial one could be the use of medical ozone, which is known to play a vital role in our well -being Therefore, the effect of small dose medical ozone on heart muscle and its possible protective effect on subsequent ischemia/ reperfusion injury was evaluated. Animals included in the present study were allocated into three groups: unconditioned control rats [group I], two months-ozonepreconditioned rats [group II], and three months-ozone-preconditioned rats [group III]. Rats were injected i.p. with small doses of ozone twice weekly. At the end of the experimental period, half the rats in each group were injected with heparin, a blood sample was taken for determination of plasma malondialdehyde [MDA] and the heart excised and used for isolated heart study. A blood sample was collected from the other half in each group for determination of serum glucose and the heart excised and sent for histological examination. Isolated heart study was carried out according to modified Langendorff technique. After recording basal cardiac activity, global ischemia was induced by stoppage of perfusion for 30 minutes followed by resumption of flow for another 30 minutes, and cardiac activity then recorded. The results revealed signifcant reduction in intrinsic inotropy of hearts isolated from unconditioned control rats after ischemia/ reperfusion [I/R], evidenced by significant decrease in tension generation per unit time [PT/t] after I/R in these rats, together with prolongation, of half relaxation time, insignificant change of intrinsic chronotropic activity and myocardial flow rate after I/R. Two months-medical ozone-preconditioning resulted in correction of the impaired intrinsic inotropy after I/R seen in unconditioned control rats, with enhancement of diastolic function. However, three months- medical-ozone preconditioning did not protect the hearts isolated from these rats from systolic dysfunction after I/R, though the diastolic function was significantly improved after I/R compared to unconditioned control rats. Serum glucose was decreased and plasma malondialdehyde was significantly increased in both the two-and three-months ozone-preconditioned rats. Histological examination of heart muscle revealed increased mitochondria! density in ozone preconditioned rats which was more marked in the two months-ozone-treated rats