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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). ResultsBoth 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). ConclusionIn conclusion this study showed a relatively potent inotropic and chornotropic effect for Rosa damascena on isolated guinea-pig heart.