Comparative Hypotensive Effects of Compounds Extracted from Lippia multiflora Leaves

Abstract

The marked hypotensitive effects of the methanolic extract evidenced in Lippia multiflora leaves prompted us to search for the active principle responsible for such an activity in anaesthetized rats. The methanolic extract was then fractionated according to a scheme of processes and by means of various solvents. Data obtained under the experimental conditions adopted, showed that the hypotensive principle of Lippia multiflora leaves are not flavonic: they are rather phenolic. From the phenolic fraction, two pure products were isolated: inactive verbascoside and Li 1, a cafeic acid ester, linked to 3,4-dihydroxyphenylethanol, the chemical structure of which has not been elucidated yet. Li 1 exhibited a marked and long-lasting hypotensive effect. The study of dose-response curves of the phenolic fraction and Li 1 showed that Li 1 could be one of the major - if not the only one - active principles responsible for the hypotensive action of Lippia multiflora leaves.