title: Relaxant effects of the essential oil of Mentha pulegium L. in rat isolated trachea and urinary bladder.
abstract: OBJECTIVE
  We evaluated the relaxant activity of the essential oil of Mentha pulegium L. (EOMP) and pulegone in rat isolated tracheal and bladder smooth muscles.
  
  
  METHODS
  ISOMETRIC contractions of isolated tracheal and bladder strips from male Wistar rats were induced by KCl (K60; 60 mm) or acetylcholine (ACh; 10 µm). EOMP and its majory compound pulegone were incubated, after contracting agent, with the tissues in cumulating concentrations.
  
  
  RESULTS
  EOMP (3-300 µg/ml) inhibited the contractions induced by ACh and K60 in both tissues, but was more effective against the contractions induced by K60 in trachea (IC50 = 40.47 ± 3.27 µg/ml) compared with ACh. Its relaxant action rules out ganglia and NO participation. Pulegone (10(-7) to 10(-3 ) m) inhibited the contractions induced by ACh and K60 in both tissues. EOMP concentration-dependently inhibited the contractions evoked by addition of CaCl(2) in depolarised trachea, suggesting inhibition of extracellular calcium entry.
  
  
  CONCLUSIONS
  These findings suggests that EOMP induced relaxant responses in pre-contracted smooth muscles of rat trachea and bladder, which are likely to be mediated via inhibition of calcium entry, mainly by its major compound, pulegone. These effects are coherent with the popular use of EOMP as an antispasmodic agent.
authors.affiliation: Departamento de Morfologia, Universidade Federal do Ceará, Fortaleza-CE, Brasil. pedrogsoares@yahoo.com.br
authors.forename: Pedro Marcos Gomes
authors.initials: PM
authors.lastname: Soares
authors.forename: Alana
authors.initials: A
authors.lastname: de Freitas Pires
authors.forename: Emmanuel Prata
authors.initials: EP
authors.lastname: de Souza
authors.forename: Ana Maria Sampaio
authors.initials: AM
authors.lastname: Assreuy
authors.forename: David Neil
authors.initials: DN
authors.lastname: Criddle
mesh_terms: D000109:Acetylcholine; D000818:Animals; D002122:Calcium Chloride / Q000378:metabolism; D000081005:Cyclohexane Monoterpenes; D004305:Dose-Response Relationship, Drug; D020128:Inhibitory Concentration 50; D008297:Male; D031335:Mentha pulegium / Q000737:chemistry*; D039821:Monoterpenes / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects* / Q000502:physiology; D009822:Oils, Volatile / Q000494:pharmacology*; D010276:Parasympatholytics / Q000494:pharmacology*; D010936:Plant Extracts / Q000494:pharmacology; D011189:Potassium Chloride; D051381:Rats; D017208:Rats, Wistar; D014132:Trachea / Q000187:drug effects* / Q000502:physiology; D001743:Urinary Bladder / Q000187:drug effects* / Q000502:physiology
chemical_list: D000081005:Cyclohexane Monoterpenes; D039821:Monoterpenes; D009822:Oils, Volatile; D010276:Parasympatholytics; D010936:Plant Extracts; C039648:pulegone; D011189:Potassium Chloride; D002122:Calcium Chloride; D000109:Acetylcholine