title: Protective effect of Chresta martii extract on ethanol-induced gastropathy depends on alpha-2 adrenoceptors pathways but not on nitric oxide, prostaglandins or opioids.
abstract: BACKGROUND
  Species of Chresta genus- are recognized by the population of northeastern Brazil as traditional herbs used to treat gastric diseases and other disorders.
  
  
  OBJECTIVE
  This work aimed to find out the action mechanism of Chresta martii hydro alcoholic extract gastro protective effect in the model of ethanol-induced gastropathy.
  
  
  METHODS
  Gastropathy was assessed by percentual damaged area determination in photographs of mice opened stomachs. Fasted mice treated with ethanol 99.9% (0.2 ml/animal, p.o.) were pre-treated with Chresta martii hydro alcoholic extract (HAE) (50, 100 or 200 mg/kg, p.o.), ranitidine (80 mg/kg, p.o.) or saline (5 ml/kg; p.o.) in different experimental sets, in which pharmacological tools (naloxone, indomethacin, N(ω)-Nitro-L-arginine methyl ester hydrochloride (L-NAME) or yohimbine) were added in order to clarify a possible action mechanism. Animals were sacrificed 30 min after ethanol challenge to stomach analysis. Determination of non-protein sulfhydryl groups and tissue hemoglobin, besides histological assessment (H&E) were taken to fully characterize the HAE gastro protective effect.
  
  
  RESULTS
  HAE (100 and 200 mg/kg) was able to protect mucosa against ethanol gastropathy in presence of three (naloxone, indomethacin and L-NAME) of four antagonist/inhibitor tools. The HAE effect was reversed only by yohimbine, showing the alpha-2 adrenoceptors participation on gastro protective effect of this extract. HAE histological characteristics, NP-SH and Hb were compatible with the protective effects.
  
  
  CONCLUSIONS
  HAE possesses gastroprotective effects in an ethanol-induced gastropathy model in mice, corroborating the traditional use of this family of plants to treat gastric disorders. This activity is mediated by alpha-2 adrenoceptors activation, but not by nitric oxide release, opioid receptor activation or prostaglandin synthesis. HAE also has antioxidant activity that is thought to either play a role in this biological activity or to be a byproduct of alpha-2 adrenergic complex activation.
authors.affiliation: Laboratory of Pharmacology of Sobral-LaFS, Federal University of Ceará. Av. Comandante Maurocélio Rocha Pontes 100, Derby, CEP 62.042-280, Sobral, Ceará, Brazil. alfredodentista@gmail.com
authors.forename: Antonio Alfredo
authors.initials: AA
authors.lastname: Rodrigues e Silva
authors.forename: Mirna
authors.initials: M
authors.lastname: Marques Bezerra
authors.forename: Hellíada
authors.initials: H
authors.lastname: Vasconcelos Chaves
authors.forename: Vicente
authors.initials: V
authors.lastname: de Paulo Teixeira Pinto
authors.forename: Eryvelton
authors.initials: E
authors.lastname: de Souza Franco
authors.forename: Angela
authors.initials: A
authors.lastname: Magalhães Vieira
authors.forename: Edeline
authors.initials: E
authors.lastname: Barbosa Araújo
authors.forename: Lívia
authors.initials: L
authors.lastname: Cunha Rios
authors.forename: Ana Catarina
authors.initials: AC
authors.lastname: Resende Leite
authors.forename: Maria Bernadete
authors.initials: MB
authors.lastname: de Sousa Maia
mesh_terms: D058647:Adrenergic alpha-2 Receptor Agonists / Q000494:pharmacology; D000701:Analgesics, Opioid; D000818:Animals; D019659:Asteraceae; D003000:Clonidine / Q000494:pharmacology; D000431:Ethanol; D035264:Flowers; D006454:Hemoglobins / Q000378:metabolism; D008297:Male; D051379:Mice; D009569:Nitric Oxide; D010936:Plant Extracts / Q000627:therapeutic use*; D018515:Plant Leaves; D011453:Prostaglandins; D020011:Protective Agents / Q000627:therapeutic use*; D018341:Receptors, Adrenergic, alpha-2 / Q000378:metabolism*; D013272:Stomach Diseases / Q000139:chemically induced / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D013438:Sulfhydryl Compounds / Q000378:metabolism
chemical_list: D058647:Adrenergic alpha-2 Receptor Agonists; D000701:Analgesics, Opioid; D006454:Hemoglobins; D010936:Plant Extracts; D011453:Prostaglandins; D020011:Protective Agents; D018341:Receptors, Adrenergic, alpha-2; D013438:Sulfhydryl Compounds; D009569:Nitric Oxide; D000431:Ethanol; D003000:Clonidine