effect of aqueous-ethanolic extract from rosa damascena on guinea pig isolated heart

objective(s) in the present study, the effects of aqueous-ethanolic extract from rosa damascena on heart rate and contractility were examined. materials and methods isolated guinea-pig hearts were perfused through aorta in a langendorff mode. heart rate (hr) and contractility were determined in the presence of four concentrations of the extract (0.1, 0.2, 0.4 and 1.0 mg %) and isoprenaline (1, 10, 100 nm and 1 μm) in comparison with baseline values in the presence and absence of propranolol (n= 10 for each group). results both isoprenaline and the extract caused increase in heart rate and contractility (p< 0.05 to p< 0.001). the percent increased in hr due to the final concentration of isoprenaline in the absence of propranolol was significantly greater than that of the extract (p< 0.01). propranolol caused significant reduction in both hr and contractility (p< 0.05 for both) but this effect was significantly reversed by isoprenaline and the extract (p< 0.05 to p< 0.001). the percent increased in heart contractility due to the final concentration of the extract in the absence and presence of propranolol was significantly greater than that of isoprenaline (p< 0.05 for both cases). there was significant correlation between both hr and heart contractility with concentration of isoprenaline and the extract (p< 0.05 to p< 0.001). conclusion in conclusion this study showed a relatively potent inotropic and chornotropic effect for rosa damascena on isolated guinea-pig heart.