Perillyl Alcohol Promotes Relaxation in Human Umbilical Artery.

Background Perillyl alcohol (POH) is a monoterpenoid found in plant essential oils and has been shown to relax murine vessels, but its effect on human vessels remains poorly studied.Objective The study aimed to characterize the effect of POH on human umbilical arteries (HUA).Methods Rings of HUA were obtained from uncomplicated patients and suspended in an organ bath for isometric recording. The vasorelaxant effect of POH in HUA was evaluated on basal tone and electromechanical or pharmacomechanical contractions, and possible mechanisms of action were also investigated.Results POH (1-1000 mu M) altered the basal tone of HUA and completely relaxed HUA rings precontracted with KCl (60 mM) or 5-HT (10 mu M), obtaining greater potency in the pharmacomechanical pathway (EC50 110.1 mu M), suggesting a complex interference in the mobilization of extra- and intracellular Ca2+. POH (1000 mu M) inhibited contractions induced by BaCl2 (0.1-30 mM) in a similar way to nifedipine (10 mu M), indicating a possible blockade of L-type VOCC. In the presence of potassium channel blockers, tetraethylammonium (1 mM), 4-aminopyridine (1 mM), or glibenclamide (10 mu M), an increase in the EC50 value of the POH was observed, suggesting a modulation of the activity of BKCa, KV, and KATP channels.Conclusion The data from this study suggest that POH modulates Ca2+ and K+ ion channels to induce a relaxant response in HUA.