The effects of dietary hempseed on cardiac ischemia/reperfusion injury in hypercholesterolemic rabbits

Exp Clin Cardiol. 2006 Fall;11(3):198-205.

Abstract

Background: Hempseed is a novel functional food that contains several health-promoting polyunsaturated fatty acids (PUFAs). PUFAs, such as those found in flaxseed and fish, have been shown to protect the heart against arrhythmias following ischemia/reperfusion.

Objective: TO INVESTIGATE THE POTENTIAL OF DIETARY HEMPSEED AS A CARDIOPROTECTIVE AGENT AGAINST GLOBAL ISCHEMIA AND SUBSEQUENT REPERFUSION BY ASSESSING SEVERAL MEASUREMENTS OF CARDIAC PERFORMANCE: QT interval duration, left ventricular pressure, arrhythmia incidence and arrhythmia duration.

Methods: MALE NEW ZEALAND WHITE RABBITS WERE FED ONE OF SIX DIETS: a control diet; or one supplemented with 10% hempseed, 10% delipidated hempseed, 0.5% cholesterol, 0.5% cholesterol plus 10% hempseed or 5% coconut oil. After eight weeks on their respective diets, the hearts were excised and subjected to 30 min of global ischemia and 45 min of reperfusion. Electrocardiogram traces were recorded throughout the experiment and were subsequently analyzed for QT interval duration, left ventricular pressure, arrhythmia incidence and arrhythmia duration. Plasma and cardiac tissue were analyzed for fatty acid content and composition.

Results: Cholesterol-fed animals exhibited significantly higher PUFA levels in their plasma, but this did not directly translate into higher PUFA levels in their cardiac fractions. There were no significant differences among the groups in the incidence or duration of ischemia-derived arrhythmias. During reperfusion, there was a significant decrease in the incidence of fibrillation in the hearts obtained from cholesterol-fed and hempseed- plus cholesterol-fed rabbits compared with the hearts from delipidated hempseed-fed rabbits.

Conclusions: Dietary hempseed induced limited beneficial effects on cardiac function during ischemia/reperfusion challenge. The present study does not support the use of dietary hempseed to protect the heart during ischemic insult in this experimental model.

Keywords: Functional food; Ischemia; Polyunsaturated fatty acids; Reperfusion.