title: Mechanisms underlying the endothelium-dependent vasodilatory effect of an aqueous extract of Elaeis Guineensis Jacq. (Arecaceae) in porcine coronary artery rings.
abstract: This study was undertaken to investigate the vasodilatory effect of an aqueous extract of Elaeis guineensis Jacq (EGE) in the porcine coronary artery and elicit its possible mechanism(s) of action. Vascular effects of crude extract of dried and powdered leaves of Elaeis guineensis were evaluated on isolated coronary arteries on organ chambers. Determination of eNOS expression and the phosphorylation level of eNOS were determined by Western blot analysis. In the presence of indomethacin, EGE caused pronounced relaxations in endothelium-intact but not in endothelium-denuded coronary artery rings. Relaxations to EGE were significantly reduced by N(ω)-nitro-L-arginine (L-NA, a competitive inhibitor of NO synthase), slightly but not significantly by charybdotoxin plus apamin (two potent inhibitors of EDHF-mediated responses) and abolished by the combination of L-NA and charybdotoxin plus apamin. Relaxations to EGE were abolished by the membrane permeant, SOD mimetic, MnTMPyP, and significantly reduced by wortmannin, an inhibitor of PI3-kinase. Exposure of endothelial cells to EGE increased the phosphorylation level of eNOS at Ser1177 in a time and concentration-dependent manner. MnTMPyP abolished the EGE-induced phosphorylation of eNOS.In conclusion, the obtained data indicate that EGE induces pronounced endothelium-dependent relaxations of the porcine coronary artery, which involve predominantly NO. The stimulatory effect of EGE on eNOS involves the redox-sensitive phosphorylation of eNOS at Ser1177 most likely via the PI3-kinase pathway.
authors.affiliation: Laboratoire de Pharmacologie, Université Cheikh Anta Diop, BP 5005, Dakar, Sénégal. mndiaye10@orange.sn
authors.forename: Mamadou
authors.initials: M
authors.lastname: Ndiaye
authors.forename: Eric
authors.initials: E
authors.lastname: Anselm
authors.forename: Madièye
authors.initials: M
authors.lastname: Séne
authors.forename: Williams
authors.initials: W
authors.lastname: Diatta
authors.forename: Amadou Moctar
authors.initials: AM
authors.lastname: Dièye
authors.forename: Babacar
authors.initials: B
authors.lastname: Faye
authors.forename: Valérie B
authors.initials: VB
authors.lastname: Schini-Kerth
mesh_terms: D000818:Animals; D028023:Arecaceae / Q000737:chemistry*; D001685:Biological Factors / Q000494:pharmacology*; D015153:Blotting, Western; D003331:Coronary Vessels / Q000166:cytology / Q000187:drug effects*; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects*; D045462:Endothelium-Dependent Relaxing Factors / Q000494:pharmacology*; D066298:In Vitro Techniques; D009569:Nitric Oxide / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism; D010084:Oxidation-Reduction; D010766:Phosphorylation; D010936:Plant Extracts / Q000494:pharmacology; D018515:Plant Leaves; D013552:Swine; D014664:Vasodilation / Q000187:drug effects* / Q000502:physiology; D014867:Water
chemical_list: D001685:Biological Factors; D045462:Endothelium-Dependent Relaxing Factors; D010936:Plant Extracts; C067410:endothelium-dependent hyperpolarization factor; D014867:Water; D009569:Nitric Oxide; D052250:Nitric Oxide Synthase Type III