title: Hydro-ethanolic Extract ofPortulaca oleraceaAffects Beta-adrenoceptors of Guinea Pig Tracheal Smooth Muscle.
abstract: Thestimulatory effect of the extract ofPortulaca oleracea(P. olerace) on β-adrenoceptor of tracheal smooth muscle was examined.To examine β-adrenoceptor stimulatory effect, concentration response curve to isoprenaline was obtained in pre-contracted tracheal smooth muscle in the presence of three concentrations of aqueous-ethanolic extract, propranolol, and saline. Values of EC50(the effective concentration of isoprenaline, causing 50% of maximum response) and dose ratio-1(CR-1) were measured. This effect was tested innon-incubated tracheal smooth muscle (group 1) and incubated tissues with chlorpheniramine (group 2). Concentration-response curves to isoprenaline in the presence of two higher concentrations of the extract in group 1 and all three concentrations in group 2 showed leftward shifts compared to isoprenaline curves produced in the presence of saline in both groups. EC50obtained in the presence of propranolol was significantly higher than that of saline in both groups of experiments (p<0.05 for both cases). However, the EC50obtained in the presence of two higher concentrations of the extract in group 1 and lower concentration in group 2 were non-significantly but those obtained of medium and high extract concentrations in the group 2 were significantly (p<0.05 for both cases)lower than those of saline. The values of (CR-1) obtained in the presence of all concentrations of the extract in groups1 and 2 were significantly lower than that of propranolol (p<0.05 to p<0.001).The results indicated a stimulatory effect of theP. oleraceextract on ß2-adrenoceptors of tracheal smooth muscle.
authors.affiliation: Neurogenic Inflammation Research Centre and Department of Physiology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Mohammad Hossein
authors.initials: MH
authors.lastname: Boskabady
authors.affiliation: Neurogenic Inflammation Research Centre and Department of Physiology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Milad
authors.initials: M
authors.lastname: Hashemzehi
authors.affiliation: pharmaceutical Research Center and Department of Physiology School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Khazdair
authors.affiliation: Student Research Committee, Faculty of Pharmacy, Mashhad University of MedicalSciences, Mashhad, Iran.
authors.forename: Vahid Reza
authors.initials: VR
authors.lastname: Askari
keywords: Guinea pig; Hydroalcoholic extract; Portulaca oleracea; Tracheal smooth muscle; β-adrenoceptor