title: Relaxant effects of Artemisia ludoviciana on isolated rat smooth muscle tissues.
abstract: BACKGROUND
  Artemisia ludoviciana spp. mexicana (Willd. Ex.) Spring D.D. Keck (Asteraceae), known as "estafiate" is employed for the treatment of diarrhea, dysentery, parasites, abdominal pain, vomiting, stomach ache, and also as antispasmodic agent. The aim of the present study was to evaluate the relaxant effect of hexanic (HEAl), dichloromethanic (DEAl) and methanolic (MEAl) extracts on isolated trachea, ileum and aorta rat rings, and to establish the tracheo-relaxant mode of action of DEAl.
  
  
  METHODS
  All extracts were investigated based on their capacity of to inhibit the rat ileum spontaneous contraction, to relax contraction induced by noradrenaline (0.1 μM) on endothelium-intact and endothelium-denuded thoracic aorta rat rings, and also to inhibit contraction provoked by carbachol (1 μM) on rat trachea.
  
  
  RESULTS
  Organic extracts had no spasmolytic action on ileum strips compared to positive control (papaverine, p<0.05). On the other hand, all extracts induced a significant concentration- and partial endothelium-dependent vasorelaxant activity. Extracts also showed significant relaxant effect on pre-contracted tracheal tissue in a concentration-dependent manner. In last two experiments, DEAl was the most potent and efficient extract; however, it was less potent than papaverine and theophylline, used as positive controls (p<0.05). In tracheal preparation, DEAl shifted to the right, in a parallel manner, the concentration-response curves induced by carbachol (p<0.05). Also, DEAl induced a significant relaxant effect on the contraction produced by potassium chloride (KCl, 80 mM). Pre-incubation with 1-H-[1,2,4]-oxadiazolo-[4,3a]-quinoxalin-1-one (ODQ, 10 μM), indomethacin (10 μM), N(ω)-nitro-L-arginine methyl ester (L-NAME, 10 μM), glibenclamide (10 μM) and 2-aminopyridine (2-AP, 100 μM) did not modify the DEAl-relaxant curves.
  
  
  CONCLUSIONS
  Functional experiments suggest that the most active extract, DEAl, induced its relaxant effect by possible muscarinic receptors antagonism and calcium channel blockade in tracheal rings. On the other hand, significant vasorelaxant activity showed by DEAl is partially endothelium-dependent. Finally, spasmolytic activity induced by the extracts in the rat ileum was not significant, which suggests that the antidiarrheic effect of the plant is related to antimicrobial and antiparasitic properties previously described.
authors.affiliation: Facultad de Farmacia, Universidad Autónoma del Estado de Morelos, Morelos, Mexico. enoch@uaem.mx
authors.forename: Samuel
authors.initials: S
authors.lastname: Estrada-Soto
authors.forename: Amanda
authors.initials: A
authors.lastname: Sánchez-Recillas
authors.forename: Gabriel
authors.initials: G
authors.lastname: Navarrete-Vázquez
authors.forename: Patricia
authors.initials: P
authors.lastname: Castillo-España
authors.forename: Rafael
authors.initials: R
authors.lastname: Villalobos-Molina
authors.forename: Maximiliano
authors.initials: M
authors.lastname: Ibarra-Barajas
mesh_terms: D000818:Animals; D019306:Artemisia; D002121:Calcium Channel Blockers / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000187:drug effects; D007082:Ileum / Q000187:drug effects; D008297:Male; D018727:Muscarinic Antagonists / Q000494:pharmacology; D009126:Muscle Relaxation / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D009466:Neuromuscular Blocking Agents / Q000737:chemistry / Q000494:pharmacology*; D010276:Parasympatholytics / Q000737:chemistry / Q000494:pharmacology*; D035261:Plant Components, Aerial; D028321:Plant Preparations / Q000737:chemistry / Q000494:pharmacology*; D010946:Plants, Medicinal; D051381:Rats; D017208:Rats, Wistar; D012997:Solvents / Q000737:chemistry; D014132:Trachea / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects*
chemical_list: D002121:Calcium Channel Blockers; D018727:Muscarinic Antagonists; D009466:Neuromuscular Blocking Agents; D010276:Parasympatholytics; D028321:Plant Preparations; D012997:Solvents