Effects of Oleuropein on Endothelial Functions in Aortas of Rats with Chronic Myocardial Infarction

Rat model of chronic myocardial infarction and heart failure is associated with endothelial dysfunction, which has partly been attributed to increased oxidative stress.
This study aimed to examine the effects of oleuropein on vascular endothelial dysfunction in rats with chronic myocardial infarction.
The rats were subjected to coronary artery ligation or sham operation. On the next day, they were divided into a sham and a coronary-ligated group receiving distilled water (1 mL/day) and two coronary artery-ligated groups receiving 10 or 20 mg/kg/day oleuropein. Five weeks later, hemodynamic variables were measured, isolated aortic studies were performed, and serum concentrations of superoxide dismutase and malondialdehyde were determined. The data were entered into Sigmastat Statistical Software and were analyzed using one-way ANOVA followed by Duncan’s Multiple Range. P ≤ 0.05 was considered to be statistically significant.
The rats with myocardial infarction receiving vehicle had a significantly lower left ventricular systolic pressure (P = 0.04), rate of rise (P = 0.03), decrease of left ventricular pressure (P = 0.03), relaxation response to acetylcholine (P = 0.01), and serum levels of superoxide dismutase (P = 0.01). Oleuropein treatment prevented the reduction of these variables. Moreover, the myocardial infarction group receiving vehicle had a significantly higher contraction response to phenylephrine (P = 0.03) and serum levels of malondialdehyde (P = 0.02) compared to the sham group. Treatment with oleuropein prevented the increase of these variables. There was no significant difference among the study groups regarding heart rate.
The findings indicated that chronic myocardial infarction resulted in heart failure and was associated with endothelial dysfunction. They also demonstrated that oleuropein attenuated endothelial dysfunctions, possibly, by antioxidative effects.