title: Relaxant effect of xanthomicrol and 3alpha-angeloyloxy-2alpha-hydroxy-13,14z-dehydrocativic acid from Brickellia paniculata on rat uterus.
abstract: Brickellia paniculata has been used as spasmolytic in Mexican traditional medicine. Xanthomicrol and 3alpha-angeloyloxy-2alpha-hydroxy-13,14Z-dehydrocativic acid (AAHDD) are two of the main leaf components with antispasmodic activity. However, their mechanism of action remains unknown. An in vitro comparative study between xanthomicrol and AAHDD on rat uterus precontracted by either KCl (60 mM) or oxytocin (10 mIU/ml) was carried out to investigate the mechanism of action of these compounds on smooth muscle. Relaxant effect was measured as median inhibitory concentration (IC(50)) and maximal effect as maximal relaxant response (R(max)). Xanthomicrol was significantly more potent than AAHDD in inhibiting contractions induced by KCl 60 mM, whereas AAHDD was more potent than xanthomicrol in inhibiting contractions induced by oxytocin 10 mIU/ml. These results suggest that xanthomicrol induces a greater blocking effect on voltage-operated calcium channels than on receptor-operated gates.
authors.affiliation: ICSA, Universidad Autónoma del Estado de Hidalgo, Hildago, México.
authors.forename: Hector
authors.initials: H
authors.lastname: Ponce-Monter
authors.forename: Salud
authors.initials: S
authors.lastname: Perez
authors.forename: Miguel Angel
authors.initials: MA
authors.lastname: Zavala
authors.forename: Cuauhtemoc
authors.initials: C
authors.lastname: Perez
authors.forename: Mariana
authors.initials: M
authors.lastname: Meckes
authors.forename: Arturo
authors.initials: A
authors.lastname: Macias
authors.forename: María
authors.initials: M
authors.lastname: Campos
mesh_terms: D000818:Animals; D019659:Asteraceae; D004958:Estradiol / Q000031:analogs & derivatives / Q000494:pharmacology; D005260:Female; D047309:Flavones / Q000494:pharmacology*; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009281:Naphthalenes / Q000494:pharmacology*; D010121:Oxytocin / Q000494:pharmacology; D010421:Pentanoic Acids / Q000494:pharmacology*; D010936:Plant Extracts / Q000494:pharmacology*; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D014599:Uterus / Q000187:drug effects / Q000502:physiology*
chemical_list: C462037:3-angeloyloxy-2-hydroxy-13,14-dehydrocativic acid; D047309:Flavones; D009281:Naphthalenes; D010421:Pentanoic Acids; D010936:Plant Extracts; C074283:estradiol 3-benzoate; C462036:xanthomicrol; D004958:Estradiol; D010121:Oxytocin; D011433:Propranolol; D019331:NG-Nitroarginine Methyl Ester