Preventive effects of oleuropein against cardiac remodeling after myocardial infarction in Wistar rat through inhibiting angiotensin-converting enzyme activity.

OBJECTIVE: Myocardial infarction remains the major cause of global death due to cardiovascular diseases. This study aimed to assess the protective role of oleuropein in attenuating the cardiac remodeling in isoproterenol-induced myocardial infarction in rats. METHODS AND RESULTS: Male Wistar rats were randomly divided into four groups, control, isoproterenol (Isop) and pretreated animals with oleuropein at two different doses (20 and 40 mg/kg) orally for 7 days and intoxicated with isoproterenol (Isop+Oleu20) and (Isop+Oleu40) groups. The subcutaneous injection of isoproterenol (100 mg/kg body weight) to untreated rats for two consecutive days showed significant increases in ST-segment elevation, heart weight index and alteration in the ECG pattern and hemodynamic function. Else, serum levels of cardiac troponin-T, creatine kinase isoenzyme (CK-MB), lactate dehydrogenase (LDH) and alanine aminotransferase (ALT) underwent a notable rise in serum of Isop group by (345, 82, 73 and 106%, respectively) as compared to normal rats. Isoproterenol-induced myocardial injury was evidenced by alteration in serum lipids profile and increased activities of pancreatic lipase by 94% and angiotensin-converting enzyme (ACE) by 78% which reflects the occurrence of cardiac remodeling process. The histopathological findings of the infarcted group showed myocardium necrosis and cells inflammatory infiltration. However, the treatment with oleuropein gave a good protection of the myocardium by decreasing cardiac injury markers specially troponin-T, restoring hemodynamic parameters and attenuating cardiac remodeling process through inhibition of ACE activity. CONCLUSION: Oleuropein offers high preventive effects from cardiac remodeling process in rats with acute myocardial infarction.

Protective Effect of Hydroxytyrosol Against Cardiac Remodeling After Isoproterenol-Induced Myocardial Infarction in Rat.

The present study aimed to investigate the cardioprotective effect of hydroxytyrosol (HT) against isoproterenol-induced myocardial infarction in rats. Male rats were randomly divided into four groups, control, isoproterenol (Isop) and pretreated animals with HT in two different doses (2 and 5 mg/kg) orally for 7 days and intoxicated with isoproterenol (Isop + HT1) and (Isop + HT2) groups. Myocardial infarction in rats was induced subcutaneously by isoproterenol (100 mg/kg, s.c.) at an interval of 24 h on 6th and 7th day. On 8th day, electrocardiographic (ECG) pattern, gravimetric and biochemical parameters were assessed. Isoproterenol exhibited changes in ECG pattern, including significant ST-segment elevation and increase in the serum troponin-T level by 317 % as compared to control rats. Moreover, cardiac injury markers (creatine kinase-MB, lactate dehydrogenase, alanine aminotransferase) underwent a notable rise in serum of infarcted animals. Else, a disturbance in lipids profile and significant increase in lipase and angiotensin-converting enzyme (ACE) activities and heart weight ratio were observed in isoproterenol group. However, pre- and co-treatment with HT (2 and 5 mg/kg) improved the myocardium injury, restored the hemodynamic function and inhibited the ACE activity that prevent cardiac hypertrophy and remodeling. Overall, these findings demonstrated that HT exerted a potent cardioprotective effect against isoproterenol-induced myocardial infarction.