title: Evaluation of the analgesic and anti-inflammatory effects of the essential oil of Lippia gracilis leaves.
abstract: OBJECTIVE
  The aim of the present study is to investigate the antinociceptive, anti-inflammatory, and antioxidant activities of essential oil (EO) of Lippia gracilis Schauer (Verbenaceae) leaves to support the medicinal uses claimed by folklore practitioners in the caatinga region (semi-arid) of Northeastern Brazil.
  
  
  METHODS
  The chemical composition and antinociceptive and anti-inflammatory activities of the EO of Lippia gracilis leaves (50-200 mg/kg) were investigated. Antinociceptive activity of the EO was evaluated by writhing test. Anti-inflammatory activity of the EO was evaluated using paw oedema and peritonitis methods.
  
  
  RESULTS
  Oral treatment with the EO of Lippia gracilis leaves elicited inhibitory activity on acetic acid effect at 50, 100, and 200 mg/kg (30.33+/-2.36, 25.20+/-1.48, and 21.00+/-1.54 abdominal writhes, respectively, P<0.05), as compared with the control group (36.73+/-1.92 writhes). The compound acetylsalicylic acid (ASA, 300 mg/kg) inhibited the acetic acid-induced writhing (12.67+/-0.50 abdominal writhes, P<0.001). Carrageenan-induced oedema formation was reduced with the EO of Lippia gracilis leaves at 200 mg/kg (0.72+/-0.06 mL h, P<0.001) and by the reference compound ASA (300 mg/kg, 0.85+/-0.04 mL h, P<0.001), as compared with the control group (1.76+/-0.06 mL h). Leukocyte migration into the peritoneal cavity induced by carrageenan was reduced with the EO of Lippia gracilis leaves at 50, 100, and 200 mg/kg (13.81+/-0.61, 11.77+/-0.91, and 10.30+/-0.60 leukocytes x 10(6)/mL, respectively, P<0.01), and by the compound dexamethasone (2 mg/kg, 5.34+/-0.33 leukocytes x 10(6)/mL, P<0.001), as compared with the control group (16.71+/-0.54 leukocytes x 10(6)/mL). The analyses of the essential oil allowed the identification of Lippia gracilis as a thymol-p-cymene chemotype (32.68% and 17.82%, respectively).
  
  
  CONCLUSIONS
  The EO of Lippia gracilis leaves shows antinociceptive and anti-inflammatory activities.
authors.affiliation: Department of Physiology, Federal University of Sergipe, São Cristóvão, Sergipe, Brazil.
authors.forename: S S
authors.initials: SS
authors.lastname: Mendes
authors.forename: R R
authors.initials: RR
authors.lastname: Bomfim
authors.forename: H C R
authors.initials: HC
authors.lastname: Jesus
authors.forename: P B
authors.initials: PB
authors.lastname: Alves
authors.forename: A F
authors.initials: AF
authors.lastname: Blank
authors.forename: C S
authors.initials: CS
authors.lastname: Estevam
authors.forename: A R
authors.initials: AR
authors.lastname: Antoniolli
authors.forename: S M
authors.initials: SM
authors.lastname: Thomazzi
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000302:isolation & purification / Q000494:pharmacology*; D000975:Antioxidants / Q000302:isolation & purification / Q000494:pharmacology*; D002634:Chemotaxis, Leukocyte / Q000187:drug effects; D004487:Edema / Q000188:drug therapy; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D007958:Leukocyte Count; D032411:Lippia / Q000737:chemistry*; D008297:Male; D051379:Mice; D009822:Oils, Volatile / Q000302:isolation & purification / Q000494:pharmacology*; D010146:Pain / Q000188:drug therapy*; D010529:Peritoneal Cavity / Q000166:cytology; D010538:Peritonitis / Q000188:drug therapy / Q000276:immunology; D018515:Plant Leaves / Q000737:chemistry; D010938:Plant Oils / Q000302:isolation & purification / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D000975:Antioxidants; D009822:Oils, Volatile; D010938:Plant Oils