Sedative and cardiovascular effects of <i>Aloysia citriodora</i> Palau, on mice and rats

<i>Aloysia citriodora</i> Palau, Verbenaceae ("cedrón") is widely used as infusion or decoction in South America to treat indigestion, tachycardia and anxiety. We previously demonstrated its antispasmodic effect on rat duodenum. Now, its aqueous extract (AEC) from 1 to 10 mg/kg was sedative in mice on the open-field, effect which was potentiated by diazepam and sensitive to flumazenil. In normotensive rats, 1 to 30 mg AEC/kg induced a transitory hypotension, insensitive to atropine and L-NAME. Regarding an effect on α-adrenergic receptors, AEC non-competitively blocked the phenylephrine contraction on vas deferens. In isolated rat hearts, AEC induced negative inotropism, as well as vitexin, the main component. Then, the benzodiazepine-like sedation, negative inotropism and antispasmodic effect preclinically justify its popular use for abdominal cramps and as coadjuvant for anxiety and angor. Colegio de Farmacéuticos de la Provincia de Buenos Aires