title: Evaluation of the antinociceptive, anti-inflammatory and gastric antiulcer activities of the essential oil from Piper aleyreanum C.DC in rodents.
abstract: BACKGROUND
  Piper aleyreanum is a small tree that is widely distributed in tropical and subtropical regions, mostly in North and South America, and is used as an immunomodulator, analgesic and antidepressant in folk medicine.
  
  
  OBJECTIVE
  This study was designed to investigate the antinociceptive, anti-inflammatory and gastric antiulcer activities of the essential oils from the aerial parts of Piper aleyreanum (EOPa) in rodents.
  
  
  METHODS
  The antinociceptive and anti-inflammatory effects of orally administered EOPa were evaluated in mice subjected to the formalin and pleurisy models, respectively. We also pretreated the rats with EOPa before acute ethanol-induced gastric lesions and measured gastric lesion extension and mucus and glutathione (GSH) levels in the gastric mucosa. Finally, we performed a phytochemical analysis of EOPa.
  
  
  RESULTS
  The chemical composition of EOPa was analyzed by gas chromatography and mass spectrometry (GC/MS), which identified 35 compounds, representing 81.7% of total oil compounds. Caryophyllene oxide (11.5%), β-pinene (9%), spathulenol (6.7%), camphene (5.2%), β-elemene (4.7%), myrtenal (4.2%), verbenone (3.3%) and pinocarvone (3.1%) were the major oil constituents. The oral administration of EOPa (10-1000 mg/kg) significantly inhibited the neurogenic and inflammatory phases of formalin-induced licking, with ID50 values of 281.2 and 70.5 mg/kg, respectively. The antinociception caused by EOPa (100 mg/kg, p.o.) was not reversed by naloxone (1 or 5 mg/kg, i.p.) in the formalin test. EOPa (100-300 mg/kg, p.o.) did not affect animal motor coordination in an open-field model. In carrageenan-induced pleurisy, EOPa (1-100 mg/kg, p.o.) significantly decreased the total cell count, neutrophils and mononuclear cells with mean ID50 values of 53.6, 21.7 and 43.5 mg/kg, respectively. In addition, EOPa (1-30 mg/kg, p.o.) protected the rats against ethanol-induced gastric lesions with an ID50 value of 1.7 mg/kg and increased the mucus and GSH levels of the gastric mucosa to levels similar to those of the non-lesioned group.
  
  
  CONCLUSIONS
  These data show for the first time that EOPa has significant antinociceptive and anti-inflammatory actions, which do not appear to be related to the opioid system. EOPa also has interesting gastroprotective effects related to the maintenance of protective factors, such as mucus production and GSH. These results support the widespread use of Piper aleyreanum in popular medicine and demonstrate that this plant has therapeutic potential for the development of phytomedicines with antinociceptive, anti-inflammatory and gastroprotective properties.
authors.affiliation: Department of Medicine, Federal University of Rondônia, Porto Velho, RO 78900-500, Brazil.
authors.forename: Daniella K S
authors.initials: DK
authors.lastname: Lima
authors.forename: Laudir J
authors.initials: LJ
authors.lastname: Ballico
authors.forename: Fernanda
authors.initials: F
authors.lastname: Rocha Lapa
authors.forename: Hilda P
authors.initials: HP
authors.lastname: Gonçalves
authors.forename: Lauro Mera
authors.initials: LM
authors.lastname: de Souza
authors.forename: Marcello
authors.initials: M
authors.lastname: Iacomini
authors.forename: Maria Fernanda de Paula
authors.initials: MF
authors.lastname: Werner
authors.forename: Cristiane Hatsuko
authors.initials: CH
authors.lastname: Baggio
authors.forename: Isabela Tiemy
authors.initials: IT
authors.lastname: Pereira
authors.forename: Luisa Mota
authors.initials: LM
authors.lastname: da Silva
authors.forename: Valdir A
authors.initials: VA
authors.lastname: Facundo
authors.forename: Adair Roberto Soares
authors.initials: AR
authors.lastname: Santos
mesh_terms: D000700:Analgesics / Q000627:therapeutic use*; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use*; D000897:Anti-Ulcer Agents / Q000627:therapeutic use*; D002351:Carrageenan; D000431:Ethanol; D005557:Formaldehyde; D005978:Glutathione / Q000378:metabolism; D008297:Male; D051379:Mice; D009043:Motor Activity / Q000187:drug effects; D009822:Oils, Volatile / Q000627:therapeutic use*; D010146:Pain / Q000139:chemically induced / Q000188:drug therapy; D008517:Phytotherapy; D031701:Piper; D010998:Pleurisy / Q000139:chemically induced / Q000188:drug therapy; D051381:Rats; D017208:Rats, Wistar; D013276:Stomach Ulcer / Q000139:chemically induced / Q000188:drug therapy / Q000378:metabolism
chemical_list: D000700:Analgesics; D000893:Anti-Inflammatory Agents; D000897:Anti-Ulcer Agents; D009822:Oils, Volatile; D005557:Formaldehyde; D000431:Ethanol; D002351:Carrageenan; D005978:Glutathione