In vivo hypotensive effect of a chemically characterised extract from the leaves of Lippia alba (Mill.) N.E.Br.

Lippia alba (erva-cidreira) is often mentioned in Brazilian ethnopharmacological studies. Although its leaves have been used to treat hypertension, few studies have evaluated its hypotensive effects. This work aimed to evaluate the haemodynamic effects of Lippia alba methanolic extract and to characterise its chemical composition. Normotensive rats received an intravenous injection of L. alba extract. Systolic, diastolic, mean arterial pressures, and electrocardiographic data were analysed. ¹ H-qNMR and LC-MS were used to assess the chemical composition. L. alba extract had significant hypotensive effects on systolic, diastolic, and mean arterial pressure. Acteoside was identified as major compound (292.6 ± 2.7 mg/g). Sixty-one other compounds were tentatively identified, mainly phenylethanoids, flavonoids, and iridoids. L. alba extract reduces systolic, diastolic, mean arterial pressure, and appears to be associated with a reduction in heart rate. Acteoside, a known hypotensive compound, may be responsible for these effects, but other structurally similar minority compounds may also contribute.