The vasorelaxant effect of gallic acid involves endothelium-dependent and -independent mechanisms.

The mechanisms of action involved in the vasorelaxant effect of gallic acid (GA) were examined in the isolated rat thoracic aorta. GA exerted a relaxant effect in the highest concentrations (0.4-10mM) in both endothelium-intact and endothelium-denuded aortic rings.

Long-lasting endothelium-dependent relaxation of isolated arteries caused by an extract from the bark of Combretum leprosum.

Objective: To describe and to characterize the relaxing effect of an extract of the bark of Combretum leprosum on isolated arterial rings from different animals.

Methods: Rings (3 to 4mm) from rabbit, rat, or porcine arteries rings were suspended in an organ bath (Krebs, 37°C, 95%O2/5%CO2) to record isometric contractions. After the stabilization period (2 to 3 hours) contractions were induced by the addition of phenylephrine (0.