Cardioprotective Effect of Olive Oil Against Ischemia Reperfusion-induced Cardiac Arrhythmia in Isolated Diabetic Rat Heart.

Ishfaq A Bukhari,Bassem Y Sheikh,Fahim Vohra,Abdulrahman A Almotrefi,Sibtain Afzal,Osama Y Mohamed,Omnia Nayel

doi:10.7759/cureus.7095

Abstract

BackgroundOlive oil is rich in monounsaturated fatty acids and has been reported for a variety of beneficial cardiovascular effects, including blood pressure lowering, anti-platelet, anti-diabetic, and anti-inflammatory effects. Diabetes is a major risk factor for cardiac dysfunctions, and olive oil prevents diabetes-induced adverse myocardial remodeling.ObjectiveThe study aimed to evaluate the effects of olive oil against streptozotocin-induced cardiac dysfunction in animal models of diabetes and ischemia and reperfusion (I/R)-induced cardiac arrhythmias.MethodsDiabetes was induced in male rats with a single intraperitoneal injection of streptozotocin (60 mg/kg i.p), rats were treated for five, 15, or 56 days with olive oil (1 ml/kg p.o). Control animals received saline. Blood glucose and body weight were monitored every two weeks. At the end of the treatment, rats were sacrificed and hearts were isolated for mounting on Langedorff’s apparatus. The effect of olive oil on oxidative stress and histopathological changes in the cardiac tissues were studied.ResultsThe initial blood glucose and body weight were not significantly different in the control and olive-treated animals. Streptozotocin (60 mg/kg i.p) caused a significant increase in the blood glucose of animals as compared to saline-treated animals. The control, saline-treated diabetic animals exhibited a 100% incidence of I/R-induced ventricular fibrillation, which was reduced to 0% with olive oil treatment. The protective effects of olive oil were evident after 15 and 56 days of treatment. Diltiazem, a calcium channel blocker (1 µm/L) showed similar results and protected the I/R-induced cardiac disorders. The cardiac tissues isolated from diabetic rats exhibited marked pathological changes in the cardiomyocytes, including decreased glutathione (GSH) and increased oxidative stress (malondialdehyde; MDA). Pretreatment of animals with olive oil (1 ml/kg p.o) increased GSH and decreased MDA levels. Olive oil also improved the diabetic-induced histopathological changes in the cardiomyocytes.ConclusionOlive oil possesses cardiac protective properties against I/R-induced cardiac arrhythmias in rats. It attenuated oxidative stress and diabetes-induced histopathological changes in cardiac tissues. The observed cardiac protectiveness of olive oil in the present investigation may be related to its antioxidant potential.

Highlights

Olive oil is the primary source of fat in the Mediterranean diet, which is associated with low morbidity and mortality for cardiovascular disease [1]
The control, saline-treated diabetic animals exhibited a 100% incidence of ischemia and reperfusion (I/R)-induced ventricular fibrillation, which was reduced to 0% with olive oil treatment
Similar to non-diabetic control animals, the incidence of ventricular fibrillation (VF) was 100% in diabetic rats, which was reduced to 0% with olive oil treatment for 56 days

Summary

Introduction

Olive oil is the primary source of fat in the Mediterranean diet, which is associated with low morbidity and mortality for cardiovascular disease [1]. Several studies have shown that the chronic administration of edible oils, including olive oil, reduced blood pressure, attenuated the loss of hypertension-induced left ventricular cardiomyocytes, and deceased adverse myocardial remodeling in spontaneously hypertensive and streptozotocin (STZ) diabetic rats [10,11]. The preventive role of olive oil against atrial fibrillations has been studied clinically [12] Other edible oils, such as marine fish oil, prevented ischemia-induced ventricular fibrillation in rats [13]. Owing to the beneficial cardiovascular effects of edible oils against ischemia-reperfusion-induced cardiac arrhythmias and the diverse medicinal benefits of olive oil in cardiovascular disorders, the aim of our current project was to assess the effects of acute and chronic administration of olive oil against ischemia reperfusion-induced cardiac arrhythmias in isolated diabetic and non-diabetic rat hearts. Diabetes is a major risk factor for cardiac dysfunctions, and olive oil prevents diabetes-induced adverse myocardial remodeling

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Conclusion