Prophylactic and therapeutic effects of oleuropein on reperfusion-induced arrhythmia in anesthetized rat

Background: This study was conducted to reveal that whether i.v. injection of oleuropein, the most potent polyphenolic antioxidant in olive leaf, has any effect on the magnitude of reperfusion arrhythmia in anesthetized rats or not

Methods: Eighty male Wistar rats were divided into 8 groups of 10 each: groups 1 and 5 were assigned as the prophylac c and treatment control groups, groups 2 and 6 as the prophylac c and treatment groups with lidocaine [10 mg/kg], groups 3 and 4 as the prophylac c groups with 10 and 50mg/kg oleuropein [i.v.], and groups 7 and 8 as the treatment groups with 10 and 50 mg/kg oleuropein [i.v.], respectively. Reperfusion injury was induced by 5-min regional ischemia and 15-min reperfusion of left anterior descending coronary artery. Heart rate, blood pressure, and electrocardiogram were monitored throughout the procedure

Results: blood pressure was significantly decreased by infusion of 50 mg/kg oleuropein in groups 4 and 8, but unlike the lidocaine as a standard anti-arrhythmic drug in groups 2 and 5 had not significant effect on heart rate. The onset of arrhythmia in groups received oleuropein [groups 3, 4, 7, and 8] was significantly delayed. The mortality rate due to irreversible ventricular fibrillation was also significantly reduced in groups 3, 4, 7, and 8. The effect of lidocaine in groups 2 and 5 was more potent than that in oleuropein group

Conclusion: These findings indicate that i.v. injection of oleuropein possibly through its antioxidant activity reduces the magnitude of reperfusion-induced arrhythmia

Effects of ecstasy on mouse cardiac histopathology, electrocardiogram and blood cell counts

Background and Aims: ecstasy or 3-4-methylenedioxymethamphetamine [MDMA] is a brain stimulant and a hallucinogenic material prepared by chemical changes in amphetamine. The aim of this study was to evaluate the changes induced by this drug in mouse cardiac histopathology, electrocardiogram [ECG] and blood cell counts

Materials and Methods: in this experiment, 3 groups [n=10] of mice were enrolled. Group 1, as control, received placebo. Group 2 mice were given single daily low dose [20 mg/kg/d for 28 days] of intraperitoneal MDMA, and group 3 were given single daily high dose [40 mg/kg/d for 28 days] of intraperitoneal MDMA. An AVF lead ECG record was obtained, a blood sample was taken for complete blood counts, and the heart was removed for microscopic study of tissue sections with routine staining

Results: the group 3 showed significant decrease in erythrocyte indices, myocarditis in 7 cases and monocyte infiltration around cardiac myocytes in 6 cases. In group 2, lower degree of myocardial injury was observed, but significant increase in QT and QTc durations was observed in ECG. In high dose group, red blood count, hematocrit, mean cell volume and mean corpuscular hemoglobin concentration showed significant changes in comparison with the control group

Conclusion: ecstasy can affect red blood cell index and lead to anemia. Many monocytes may be seen around cardiac cells, and increased ventricular depolarization and repolarization can lead to increase in QRS-QT interval. Combination of myocarditis, arrhythmia and sinus tachycardia reflect change in cardiac function and myocardial structure. Cardiac injury due to hypoxia and ischemia may cause myocardial infarction

Prolonged oral administration of oleuropein might protect heart against aconitine-induced arrhythmia

In this study, it was surveyed to know whether an oral single dose of oleuropein could mimic the cardiac preconditioning in rats' hearts or whether its prolonged oral administration could protect the heart against the aconitine-induced arrhythmia in rats. Eighty male Wistar rats were divided into two series [n = 8 in each group]. In the first series, all groups [except the control [Con] group] were given a single oral dose of oleuropein [20 mg/Kg] 1, 3, 24 and 48 h before the infusion of aconitine. In the second series, except the Con group, the other four groups were given oral oleuropein [20 mg/Kg/day] for 3, 7, 14 and 28 days, before the infusion of aconitine. Electrocardiogram was recorded to monitor arrhythmia. Data of the first series showed that the initiation time of arrhythmia, the initiation of ventricular tachycardia [VT], the numbers of reversible ventricular fibrillation [VF] and the death time had no significant difference compared with Con group. In the second series, a significant protection was occurred only in the 28 days group that was evident with increased initiation time of arrhythmia, increased initiation time of VT, and increased the number of reversible VF and death time in compared to the Con group. The findings of this study show that the oral administration of a single dose of oleuropein could not mimic the preconditioning effects in rat hearts, but the prolonged administration of oleuropein for about four weeks could protect the heart against aconitine-induced arrhythmia