Antispasmodic effects of <i>Aloysia polystachya</i> and <i>A. gratissima</i> tinctures and extracts are due to non-competitive inhibition of intestinal contractility induced by acethylcholine and calcium

 

Autores
Consolini, Alicia E.; Berardi, Andrea Beatriz; Rosella, María Adelaida; Volonté, María Guillermina
Tipo de recurso
artículo
Estado
Versión publicada
Año de publicación
2011
País
Argentina
Institución
Universidad Nacional de La Plata
Repositorio
SEDICI (UNLP)
Descripción
The antispasmodic effects of acqueous extracts (AE) and tinctures (T) of Aloysia polystachya (Griseb.) Moldenke and Aloysia gratissima (Gillies & Hook.) Tronc., Verbenaceae, were studied on rat isolated ileum and duodenum. These plants are used for gastrointestinal disorders and as eupeptic in South America. Both AE non-competitively inhibited the dose-response curves (DRC) of ACh and the DRC of Ca2+ in high-[K+]o, as well as the T. The T of A. polystachya and A. gratissima respectively inhibited the ACh-DRC at the IC50 of 3.15±0.57 and 6.46±2.28 mg leaves/mL. The Ca2+-antagonist activity of both T occurred with IC50 respectively similar to those of the ACh-DRC, and was potentiated by the depolarization produced by 10 mM TEA, a blocker of K+-channels. The spasmolytic effect of T does not involve DA release and binding to D2, since it was not reduced by 10 μM metoclopramide. Also, T induced dose-dependent relaxation on the tonic contracture produced by high-[K+]o and ACh. By TLC there were detected in the leaves the presence of carvone, and flavonoids such as quercetin and hesperidin. By HPLC there were not found vitexin nor isovitexin, identified in A. citriodora. The monoterpene (-)-carvone non-competitively inhibited the ACh-DRC (pD ́2 of 4.0±0.1) and the DRC of Ca2+ (pD ́2 of 3.86±0.19), suggesting that the Ca2+-influx blockade is the mechanism of its antispasmodic effect. Results suggest that the antispasmodic effect of A. polystachya and A. gratissima are mostly explained by the non-competitive blockade of Ca+2 influx. It could be associated to the presence of flavonoids, and in the tinctures to some spasmolytic components of the essential oil such as carvone.
Idioma
inglés
OAI Identifier
oai:sedici.unlp.edu.ar:10915/37521
Enlace del recurso
http://sedici.unlp.edu.ar/handle/10915/37521
http://hdl.handle.net/10915/37521
http://www.scielo.br/pdf/rbfar/v21n5/aop12811.pdf
Nivel de acceso
Acceso abierto
Materia
Ciencias Exactas
Farmacia
acetylcholine
calcium
carvone
hesperidin
isovitexin
quercetin
depolarization
aloysia
antispasmodic
Ca antagonist
verbenaceae