|
Antispasmodic and bronchodilator activities of Taxodium
mucronatum Ten leaf extract
Alma Rosa Cortés-Arroyo1*, Adriana M.
Domínguez-Ramírez1, Martín Gómez-Hernández1,
José R. Medina López1, Marcela Hurtado y de la
Peña1 and Francisco J. López-Muñoz2.
1Departamento
Sistemas Biológicos, Universidad Autónoma
Metropolitana-Xochimilco, Calzada del Hueso 1100, Colonia
Villa Quietud. C.P. 04960, México, D.F., México.
2Departamento
de Farmacobiología, Centro de Investigación y de Estudios
Avanzados-Unidad Sur, Calzada Tenorios 235, Colonia Granjas
Coapa. C.P. 14330, México, D.F., México.
*Corresponding author:
E-mail:
cortesar@correo.xoc.uam.mx. Tel: (5255)54837213. Fax:
(5255)54837237.
Accepted 2 November, 2010 |
|
The
relaxant effects of the Taxodium mucronatum Ten leaf
hexane extract on intestinal and tracheal smooth muscle were
evaluated in vitro by testing spontaneous
contractions of rabbit jejunum and agonist-induced
contractions of guinea pig ileum and rat trachea. The
extract produced a concentration-dependent relaxation of the
spontaneous contractions of rabbit jejunum (EC50:
4.9
±
0.5 µg/ml) that was equipotent to papaverine.
Following incubation of guinea pig ileum with the extract,
the concentration-response curves to acetylcholine,
histamine, 5-hydroxytryptamine and Ca2+ were
displaced to the right and the maximum response was
significantly reduced. K+-induced contraction of
the ileal tissue was completely abolished with 31.6 µg/ml of
the extract. In rat tracheal rings, the extract inhibited
both 1 µM carbachol (EC50: 33.9
± 2.5 µg/ml) and 60 mM K+ (EC50: 20.6
±
1.1 µg/ml)-induced contractions. It also caused the
concentration-response to Ca2+ curves to shift to
the right in a non-competitive manner. These results
demonstrate a non-specific relaxant effect that could be
mediated through inhibition of calcium influx via both
voltage- and receptor-gated calcium channels. The relaxant
activity induced by this extract provides a rational basis
for the traditional use of T. mucronatum to treat
disorders of the gastrointestinal and respiratory tracts.
Key
words:
Taxodium mucronatum, Cupresaceae, muscular relaxant,
antispasmodic, bronchodilator. |
