title: Relaxant effects of a hydroalcoholic extract of Ruta graveolens on isolated rat tracheal rings.
abstract: BACKGROUND
  Ruta graveolens L. (R. graveolens) is a medicinal plant employed in non-traditional medicines that has various therapeutic properties, including anthelmintic, and vasodilatory actions, among others. We evaluated the trachea-relaxant effects of hydroalcoholic extract of R. graveolens against potassium chloride (KCl)- and carbachol-induced contraction of rat tracheal rings in an isolated organ bath.
  
  
  RESULTS
  The results showed that the airway smooth muscle contraction induced by the depolarizing agent (KCl) and cholinergic agonist (carbachol) was markedly reduced by R. graveolens in a concentration-dependent manner, with maximum values of 109 ± 7.9 % and 118 ± 2.6 %, respectively (changes in tension expressed as positive percentages of change in proportion to maximum contraction), at the concentration of 45 μg/mL (half-maximal inhibitory concentration IC50: 35.5 μg/mL and 27.8 μg/mL for KCl- and carbachol-induced contraction, respectively). Additionally, the presence of R. graveolens produced rightward parallel displacement of carbachol dose-response curves and reduced over 35 % of the maximum smooth muscle contraction.
  
  
  CONCLUSIONS
  The hydroalcoholic extract of R. graveolens exhibited relaxant activity on rat tracheal rings. The results suggest that the trachea-relaxant effect is mediated by a non-competitive antagonistic mechanism. More detailed studies are needed to identify the target of the inhibition, and to determine more precisely the pharmacological mechanisms involved in the observed biological effects.
authors.affiliation: Center of Neurosciences and Peptides Biology (CEBIOR-BIOREN), Faculty of Medicine, University of La Frontera, Temuco, Chile. luis.aguila.paredes@gmail.com.|School of Veterinary Medicine, Unit of Nutrition, and Animal Production, Faculty of Natural Resources, and Veterinary Medicine, Santo Tomás University, Temuco, Chile. luis.aguila.paredes@gmail.com.
authors.forename: Luis
authors.initials: L
authors.lastname: Águila
authors.affiliation: Center of Neurosciences and Peptides Biology (CEBIOR-BIOREN), Faculty of Medicine, University of La Frontera, Temuco, Chile. jennyruedlinger@gmail.com.
authors.forename: Jenny
authors.initials: J
authors.lastname: Ruedlinger
authors.affiliation: Center of Neurosciences and Peptides Biology (CEBIOR-BIOREN), Faculty of Medicine, University of La Frontera, Temuco, Chile. karina.mansilla@gmail.com.
authors.forename: Karina
authors.initials: K
authors.lastname: Mansilla
authors.affiliation: Center of Neurosciences and Peptides Biology (CEBIOR-BIOREN), Faculty of Medicine, University of La Frontera, Temuco, Chile. jordenesmora@gmail.com.
authors.forename: José
authors.initials: J
authors.lastname: Ordenes
authors.affiliation: Center of Neurosciences and Peptides Biology (CEBIOR-BIOREN), Faculty of Medicine, University of La Frontera, Temuco, Chile. raul.salvatici@ufrontera.cl.
authors.forename: Raúl
authors.initials: R
authors.lastname: Salvatici
authors.affiliation: Department of Physiology, Cardiovascular Division, Federal University of Sao Paulo, São Paulo, Brazil. rui.camposjr@unifesp.br.
authors.forename: Rui Ribeiro
authors.initials: RR
authors.lastname: de Campos
authors.affiliation: Center of Neurosciences and Peptides Biology (CEBIOR-BIOREN), Faculty of Medicine, University of La Frontera, Temuco, Chile. fernando.romero@ufrontera.cl.|Center of Genetic and Immunologic Studies (CEGIN), Faculty of Medicine, University of La Frontera, Temuco, Chile. fernando.romero@ufrontera.cl.
authors.forename: Fernando
authors.initials: F
authors.lastname: Romero
mesh_terms: D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D018678:Cholinergic Agents / Q000494:pharmacology; D002853:Chromatography, Liquid; D011564:Furocoumarins / Q000032:analysis; D066298:In Vitro Techniques; D020128:Inhibitory Concentration 50; D009119:Muscle Contraction / Q000187:drug effects; D009129:Muscle Tonus / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects*; D009467:Neuromuscular Depolarizing Agents / Q000494:pharmacology*; D010276:Parasympatholytics / Q000494:pharmacology*; D035261:Plant Components, Aerial / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D011189:Potassium Chloride / Q000494:pharmacology; D011794:Quercetin / Q000032:analysis; D017207:Rats, Sprague-Dawley; D032105:Ruta / Q000737:chemistry*; D012431:Rutin / Q000032:analysis; D014132:Trachea / Q000187:drug effects* / Q000601:surgery
chemical_list: D018678:Cholinergic Agents; D011564:Furocoumarins; D009467:Neuromuscular Depolarizing Agents; D010276:Parasympatholytics; D010936:Plant Extracts; D012431:Rutin; D011189:Potassium Chloride; D002217:Carbachol; D011794:Quercetin