title: Antispasmodic effects and composition of the essential oils from two South American chemotypes of Lippia alba.
abstract: Lippia alba (Mill.) N. E. Brown (Verbenaceae) is an aromatic species used in Central and South America as eupeptic for indigestion. In Argentina, it is used by the "criollos" from the Chaco province. There are several chemotypes which differ in the chemical composition of the essential oils. Nowadays, it is experimentally cultivated in some countries of the region, including Argentina.
  
  
  OBJECTIVE
  To compare the chemical composition and pharmacology of the essential oils from two chemotypes: "citral" (CEO) and "linalool" (LEO), in isolated rat duodenum and ileum.
  
  
  METHODS
  Contractile concentration-response curves (CRC) of acetylcholine (ACh) and calcium in 40mM K(+)-medium (Ca(2+)-CRC) were done in isolated intestine portions, in the absence and presence of CEO or LEO at different concentrations.
  
  
  RESULTS
  Likewise verapamil, CEO and LEO induced a non-competitive inhibition of the ACh-CRC, with IC50 of 7.0±0.3mg CEO/mL and 37.2±4.2mg LEO/mL. l-NAME, a NO-synthase blocker, increased the IC50 of CEO to 26.1±8.7mg CEO/mL. Likewise verapamil, CEO and LEO non-competitively inhibited the Ca(2+)-CRC, with IC50 of 6.3±1.7mg CEO/mL, 7.0±2.5mg LEO/mL and 0.24±0.04mg verapamil/mL (pIC50: 6.28). CEO was proved to possess limonene, neral, geranial and (-)-carvone as the major components, while LEO was rich in linalool.
  
  
  CONCLUSIONS
  Results suggest that CEO has five times more potency than LEO to inhibit muscarinic contractions. The essential oils of both chemotypes interfered with the Ca(2+)-influx, but with an IC50 about 28 times higher than that of verapamil. Moreover, CEO partially stimulated the NO production. These results show the medicinal usefulness of both Lippia alba chemotypes, thus validating its traditional use, potency and mechanism of action.
authors: Cátedra de Farmacología y Magister en Plantas Medicinales, Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, La Plata, Argentina; Bioquímica y Fitoquímica, Facultad de Ciencias Agrarias y Forestales, Universidad Nacional de La Plata, La Plata, Argentina.
authors: Marcos A
authors: MA
authors: Blanco
authors: Germán A
authors: GA
authors: Colareda
authors: Catalina
authors: C
authors: van Baren
authors: Arnaldo L
authors: AL
authors: Bandoni
authors: Jorge
authors: J
authors: Ringuelet
authors: Alicia E
authors: AE
authors: Consolini
mesh_terms: D000818:Animals; D001118:Argentina; D004305:Dose-Response Relationship, Drug; D004386:Duodenum / Q000187:drug effects; D005260:Female; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D032411:Lippia / Q000737:chemistry*; D008297:Male; D008519:Medicine, Traditional; D009119:Muscle Contraction / Q000187:drug effects; D009822:Oils, Volatile / Q000737:chemistry / Q000494:pharmacology; D010276:Parasympatholytics / Q000737:chemistry / Q000494:pharmacology; D010938:Plant Oils / Q000737:chemistry / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013035:Spasm / Q000188:drug therapy
chemical_list: D009822:Oils, Volatile; D010276:Parasympatholytics; D010938:Plant Oils
keywords: ACh; Antispasmodic; CEO; CRC; Ca(2+)-blocker; Chemotypes; EC(50); EO; Essential oil; GC-FID-MS; IC(50); LEO; Lippia alba; Rat intestine; acethylcholine; citral chemotype essential oil; concentration–response curve; effective concentration at 50%; essential oil; gas chromatograph with flame ionization and mass spectrometry detectors; inhibitory concentration to 50%; linalool chemotype essential oil