RESUMEN
The present study was conducted to investigate the effects of aqueous methanolic extract of Morus nigra L. fruiton frog’s heart.Force of contraction and heart rate were measured by force displacement transducer attached to Power Lab data acquisition system. Lab chart Pro 5 software was used for the acquisition and analysis of data. The extract was also screened for various phytochemical constituents using standard methods. The results indicated that the extract produced a significant dose dependent decrease in heart rate without affecting the contractility of the heart. Phytochemical analysis also revealed that the extract contained flavonoids, cardiac glycosides,alkaloids, saponins and phenolic compounds.It is conceivable therefore; that the negative chronotropic effectsof aqueous methanolic extract of Morus nigra L. fruit may be attributed to the presence of certain pharmacologically active compounds.