title: Relaxant activity of methanolic extract from seeds of Peganum harmala on isolated rat aorta.
abstract: The activity of methanolic extract from the seeds of Peganum harmala L. (MEP) on vascular smooth muscle (rat aorta) was investigated. MEP induced relaxation in aorta precontracted with noradrenaline (10(-6) M) or KCl (80 mM) (IC50 = 14.49 +/- 1.15 and 5.93 +/- 1.26 micrograms/mL, respectively) in a dose-dependent manner and this relaxant effect was not endothelium-dependent. The vasodilatory effects were potentiated by isoprenaline (10(-9) M) (1.08 +/- 0.14 micrograms/mL) and negatively affected by a non-specific inhibitor of phosphodiesterase, IBMX (10(-4) M) (20.81 +/- 1.06 micrograms/mL). Pretreatment with MEP (3, 6, 18 micrograms/ml) shifted the phenylephrine-induced dose-response curves to the right and the maximum response was attenuated, indicating that the antagonist effect of MEP on alpha 1-adrenoceptors was non-competitive. These results suggest that MEP exerts a vasodilatory effect not related to the presence of endothelium and the main mechanism may be related to the inhibition of cyclic AMP phosphodiesterase.
authors.affiliation: Departament of Pharmacology, Faculty of Pharmacy, C/Profesor García González s/n, 41012 Sevilla, Spain.
authors.forename: H
authors.initials: H
authors.lastname: Berrougui
authors.forename: M D
authors.initials: MD
authors.lastname: Herrera-Gonzalez
authors.forename: E
authors.initials: E
authors.lastname: Marhuenda
authors.forename: A
authors.initials: A
authors.lastname: Ettaib
authors.forename: M
authors.initials: M
authors.lastname: Hmamouchi
mesh_terms: D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D000432:Methanol; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D032443:Peganum / Q000737:chemistry*; D010936:Plant Extracts / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D012639:Seeds / Q000737:chemistry; D012997:Solvents; D014662:Vasoconstrictor Agents / Q000037:antagonists & inhibitors / Q000494:pharmacology
chemical_list: D010936:Plant Extracts; D012997:Solvents; D014662:Vasoconstrictor Agents; D000432:Methanol