Abstract
The aim of this work is to study the effect of aqueous extract of whole plant of Crataegus aronia on the force of contraction and heart rate of isolated rabbit's heart. Six Isolated rabbit's hearts were perfused through aorta in a Langendorff mode. Heart rate and contractility were determined for 5 min in the presence of 8 concentrations of C. aronia aqueous extract (1, 2, 5, 10, 20, 40, 100 and 200 mg/ml) or adrenaline (0.05 mM) as control drug. The changes after each treatment were compared with their baseline values. Data were collected with the help of PowerLab data acquisition and analyzed by Labchart Pro 7 software. At all time intervals recorded, there were no significant changes in the force of contraction nor the heart rate (HR) after infusion of low concentrations of the extract (1, 2, 5 and 10 mg/ml). The maximum increase in force of contraction occurred at a dose of 40 mg/ml, while the maximum decrease in HR occurred at a dose of 20 mg/ml (P < 0.01). The highest doses of the extract (100 and 200 mg/ml) caused hardening of the heart, stopping of the perfusion fluid from entering and stopped the beating of the heart. Therefore, the aqueous extract of whole plant of C. aronia syn: azarolus (L) showed a positive inotropic and negative chronotropic effects on isolated rabbit's heart.