Nitric oxide-dependent vasodilatation by ethanolic extract of Hancornia speciosa via phosphatidyl-inositol 3-kinase.
The vasodilator effect of the ethanolic extract of leaves from Hancornia speciosa Gomes (HSE) was studied in rat aortic rings. HSE produced a concentration-dependent vasodilatation (pIC(50)=5.6+/-0.1), which was completely abolished in endothelium-denuded vessels. The endothelium-dependent vasodilatation induced by HSE was abolished by l-NAME (100 microM), a nitric oxide (NO) synthase inhibitor, but not atropine (1 microM; pIC(50)=5.6+/-0.2), a muscarinic receptor antagonist, nor indomethacin (10 microM; pIC(50)=5.4+/-0.2), a cyclooxygenase inhibitor. The concentration-response curve of HSE was significantly shifted to the left by superoxide dismutase (SOD; 300U/mL). In addition, while SOD displaced the 3-morpholino-sidnonimine (SIN-1; P<0.05) concentration-effect curve to the left, HSE (50 microg/mL) had no effect. Finally, wortmannin (0.3 microM), an inhibitor of phosphatidyl-inositol 3-kinase (PI3K), dramatically reduced the vasodilator effect of HSE. Together, these findings lead us to conclude that HSE induces a NO- and endothelium-dependent vasodilatation in rat aortic preparations, likely by a mechanism dependent on the activation of PI3K.
Ferreira
Herick C
HC
Departamento de Farmacologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antonio Carlos 6627, 31270-901 Belo Horizonte, Brazil.
Serra
Carla P
CP
Lemos
Virginia S
VS
Braga
Fernão C
FC
Cortes
Steyner F
SF
D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects; D029062:Apocynaceae / Q000737:chemistry*; D001938:Brazil; D004305:Dose-Response Relationship, Drug; D000431:Ethanol; D066298:In Vitro Techniques; D008297:Male; D008519:Medicine, Traditional; D008981:Molsidomine / Q000031:analogs & derivatives / Q000494:pharmacology; D009569:Nitric Oxide / Q000502:physiology*; D010656:Phenylephrine / Q000494:pharmacology; D019869:Phosphatidylinositol 3-Kinases / Q000502:physiology*; D024301:Plant Bark / Q000737:chemistry; D010936:Plant Extracts / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D012997:Solvents; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects*; D014665:Vasodilator Agents / Q000494:pharmacology
D010936:Plant Extracts; D012997:Solvents; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D010656:Phenylephrine; D009569:Nitric Oxide; D000431:Ethanol; C002385:linsidomine; D008981:Molsidomine; D019869:Phosphatidylinositol 3-Kinases