The effects of essential oil of Lavandula angustifolia on isoproterenol-induced myocardial infarction in rats

Abstract

Background: Myocardial infarction is a common presentation of ischemic heart disease and is a leading cause of morbidity and mortality worldwide. Lavandula angustifolia known in Iran as “ Ostokhoddus “ native to the western Mediterranean regions, is a herbaceous plant (Lamiaceae) with antioxidative and anti-inflammatory effects. Aim: This study was designed to investigate the cardioprotective effects of L. angustifolia essential oil on isoproterenol-induced myocardial infarction in rats. Methods: The dried sample (100g) was subjected to hydrodistillation by using a Clevenger and the oils were dried over anhydrous Na2SO4. Male wistar rats were assigned to 6 groups of control, sham, isoproterenol and treatment with 5, 10, 20 mg/kg of the essential oil. MI was induced by subcutaneous injection of Isoproterenol (100mg/kg) for 3 consecutive days at an interval of 24h. The essential oil was injected intraperitonealy for 2 consecutive days with an interval of 24h. Following anaesthesia, hemodynamic parameters were measured. After sacrificing the animals heart to body weight ratio and histopathological examinations were done. Myeloperoxidase (MPO) and Malondialdehyde (MDA) were measured for quantifying the activity of neutrophils, and to determine the lipid peroxidation in myocardium, respectively. Results: Essential oil significantly amended the ECG (ST-segment elevation and suppressed R-amplitude) and myocardial necrosis along with histopathological changes (P<0.001). The essential oil (10mg/kg) increased (P<0.001) LVdp/dtmax from 2793±210 to 4488±253mmHg/sec and decreased the heart to body weight ratio from 4.1±0.21 to 2.6±0.12 (P<0.001). Treatment with 20mg/kg of L. angustifolia lowered the LVEDP from 14±3.43mmHg to 4.3±0.85 and suppressed the elevation of MDA, also decreased the MPO activity in myocardium from 4095±334.52mU/g tissue to 2130±183 (P<0.001). Conclusion: The results demonstrated that L. angustifolia essential oil protects myocardium against isoproterenol-induced MI and it could be related to its antioxidant activities.