Vasorelaxant response induced by Sida santaremnensis H. Monteiro ethanol extract on rat superior mesenteric artery

• Published in: African journal of biotechnology Vol. 10; no. 65; pp. 14587 - 14597
• Main Authors: Daniel, Dias Rufino Arcanjo, Nelma, Neylanne Pinho Muniz Oliveira, Edson, Santos Ferreira Filho, Danielly, Albuquerque da Costa, Mariana, Helena Chaves, Antocirc nio, Carlos Romatilde o Borges, Aldeiacute dia, Pereira de Oliveira, Rita, de Caacute ssia Meneses Oliveira
• Format: Journal Article
• Language: English
• Published: 24.10.2011
• ISSN: 1684-5315; 1684-5315
• DOI: 10.5897/AJB11.1429

The aim of this work was to characterize the vasorelaxant effect produced by Sida santaremnensis ethanol extract (Ssan-EtOH) in rat superior mesenteric artery. Ssan-EtOH showed neither acute toxicity nor hemolytic activity. In the other hand, it induced a concentration-dependent vasorelaxant effect on phenylephrine (10 mu mol/L) or KCI (80 mmol/L)-induced pre-contractions in endothelium-intact rat mesenteric artery rings, which attenuated after endothelium removal, without changes in maximum effect. N super(G)-nitro-L-arginine methyl ester (L-NAME) (100 mu mol/L), indomethacin (10 mu mol/L), atropine (1 nmol/L), KCI (20 mmol/L) or tetraethylammonium (3 mmol/L) pretreatment also induced a response attenuation. The endothelium-derived hyperpolarizing factor (EDHF) involvement in Ssan-EtOH-induced vasorelaxant response was verified after L-NAME (100 mu mol/L) plus Indomethacin (10 mu mol/L) plus tetraethylammonium (3 mmol/L) pretreatment and this vasorelaxation was decreased. In endothelium-denuded rings, Ssan-EtOH was able to inhibit phenylephrine-induced contractions (10 super(-9) to 10 super(-5) mol/L) in a concentration-dependent manner. In a nominally without Ca super(2+) depolarizing Tyrode solution, Ssan-EtOH inhibited CaCfc (10 super(-6) - 3 x 10 super(-2) mol/L)-induced contractions in a concentration-dependent manner. The endothelium-dependent Ssan-EtOH-induced vasorelaxant effect probably involves the participation of the nitric oxide synthase (NOS) and cyclooxygenases (COX) pathways, as well muscarinic receptors and EDHF and the endothelium-independent effect probably occurs by Ca super(2+) influx inhibition through voltage-operated calcium channels.