RESUMEN
Paullinia pinnata L. is a plant widely used in African traditional medicine especially in the treatment of erectile dysfunction. This study aims to evaluate the cardiotoxicity of 50% hydroalcoholic extract of the roots of P. pinnata. The result of the acute toxicity test has shown a LD50 greater than 5000 mg/kg. During the 28 days subchronic administration, P. pinnata has increased significantly the relative weight of kidney. P. pinnata has induced also a microcytosis and an isolated hypochromia. Renal injuries were observed with doses of 400 mg/kg and 800 mg/kg; and are noted by the increase in blood urea, creatinine, potassium and chlorine. Cardiac disorders characterized by the increase of creatinine phosphokinase with P. pinnata at 800 mg/kg has been noted; as well as cholestasis, characterized by an increase in the ALP at 200, 400 and 800 mg/kg. The study conducted on the isolated auricle of guinea pigs, has shown that P. pinnata, at increasing concentrations (0.5 to 2.5 mg/mL) has caused an increase in the force of contraction (positive inotropic effect) and simultaneously a decrease in heart rate (negative chronotropic effect). The positive inotropic effect observed could justify the traditional use of this plant as an aphrodisiac.