Planta Med 2002; 68(5): 467-469
DOI: 10.1055/s-2002-32092
Letter
© Georg Thieme Verlag Stuttgart · New York

Inhibitory Effect of Xanthomicrol and 3α-Angeloyloxy-2α-hydroxy-13,14Z-dehydrocativic Acid from Brickellia paniculata on the Contractility of Guinea-Pig Ileum

Mariana Meckes1 , Fernando Calzada1 , Daniel Paz1 , Jaime Rodríguez1 , Héctor Ponce-Monter2
  • 1Unidad de Investigación Médica en Farmacología de Productos Naturales, Hospital de Pediatría, Centro Médico Nacional Siglo XXI, IMSS, México
  • 2Unidad de Investigación Médica en Farmacología, Hospital de Especialidades, Centro Médico Nacional Siglo XXI, IMSS, México
Further Information

Publication History

June 27, 2001

January 20, 2002

Publication Date:
07 June 2002 (online)

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Abstract

Chemical fractionation of Brickellia paniculata methanolic extract by monitoring its inhibitory effect on K+-induced contraction in guinea-pig ileum in vitro led to the isolation of 5,4′-dihydroxy-6,7,8-trimethoxyflavone (xanthomicrol) and the labdane-diterpene 3α-angeloyloxy-2α-hydroxy-13,14Z-dehydrocativic acid (AAHDD). Both compounds inhibited the tonic contraction the effect being highly potent when a mixture in a proportion of 3 : 1 (xanthomicrol/AAHDD) was assayed. The phasic component of the contractile response with K+ was also reduced by the compounds. Xanthomicrol depressed the spasms induced with ACh, Hist, and BaCl2 and its effect on Ca2+ concentration-response curve showed a type of non-surmountable calcium blocking action; unlike the flavonoid, AAHDD produced a parallel rightward shift of the concentration-response curve to calcium, suggesting a competitive antagonism with an estimated pA2 of 4.66. Obtained results support, in part, the popular use of B. paniculata as a spasmolytic remedy.

References

Mariana Meckes

Unidad de Investigación Médica en

Farmacología de Productos Naturales

Hospital de Pediatría

CMN Siglo XXI, IMSS

Av. Cuauhtémoc 330

Cp. 06750 México D.F.

Fax: +7-61-0952

Email: meck7707@prodigy.net.mx