title: Diuretic effects and urinary electrolyte excretion induced by Aspidosperma subincanum Mart. and the involvement of prostaglandins in such effects.
abstract: BACKGROUND
  Aspidosperma subincanum Mart. is a medicinal herb known for its diuretic properties and used for the treatment of cardiovascular-related illnesses. Although our earlier study has shown that the ethanol extract of Aspidosperma subincanum (EEAS) induces hypotension and vasodilation, no scientific data have been recorded to evaluate the diuretic effects of this Brazilian medicinal plant. The aim of this study was to evaluate the diuretic activity of EEAS, and possible mechanism of action, using Wistar rats.
  
  
  METHODS
  EEAS (60 and 120mg/kg), furosemide (20mg/kg) or saline (control) were orally administered to rats individually held in metabolic cages for urine collection 1, 2, 4, 6, 8, 12 and 24h after treatment. In order to evaluate the involvement of prostaglandins in the diuretic action of EEAS, the animals received piroxicam (5mg/kgi.p.), a nonselective inhibitor of cyclooxygenase, before treatment with EEAS at 120mg/kg. The control groups received only saline (NaCl, 0.9%), or saline and piroxicam. Urinary volume, electrolyte excretion and pH were measured.
  
  
  RESULTS
  Oral administration of EEAS 60 and 120mg/kg significantly increased diuresis and electrolyte excretion of Na(+) and K(+) on a continuous basis throughout the study period. Both EEAS 60 and 120mg/kg caused a relative increase of around 77% and 142%, respectively, in cumulative diuresis compared with the control group. From 4th hour until the end of the experiment, the group treated with EEAS 120mg/kg provided a greater excretion of Na(+) than the furosemide group. The diuretic effects of EEAS were neutralized by piroxicam between 4 and 8h after treatment.
  
  
  CONCLUSIONS
  The results suggest that EEAS could present compound(s) responsible for diuretic activities, and the mechanism could involve the prostaglandin system.
authors.affiliation: Faculty of Pharmacy, Federal University of Goias, Avenida Universitária s/n, 74605-220 Goiânia, GO, Brazil.
authors.forename: Emmeline Flor
authors.initials: EF
authors.lastname: Ribeiro
authors.affiliation: Faculty of Pharmacy, Federal University of Goias, Avenida Universitária s/n, 74605-220 Goiânia, GO, Brazil.
authors.forename: Carolina
authors.initials: C
authors.lastname: de Fátima Reis
authors.affiliation: Institute of Chemistry, Federal University of Goias, Campus Samambaia, Caixa Postal 131, 74001-970 Goiânia, GO, Brazil.
authors.forename: Flávio Silva
authors.initials: FS
authors.lastname: de Carvalho
authors.affiliation: Institute of Chemistry, Federal University of Goias, Campus Samambaia, Caixa Postal 131, 74001-970 Goiânia, GO, Brazil.
authors.forename: João Pedro Silva
authors.initials: JP
authors.lastname: Abreu
authors.affiliation: Institute of Chemistry, Federal University of Goias, Campus Samambaia, Caixa Postal 131, 74001-970 Goiânia, GO, Brazil.
authors.forename: Andréa Fernandes
authors.initials: AF
authors.lastname: Arruda
authors.affiliation: Faculty of Pharmacy, Federal University of Goias, Avenida Universitária s/n, 74605-220 Goiânia, GO, Brazil.
authors.forename: Clévia Ferreira Duarte
authors.initials: CF
authors.lastname: Garrote
authors.affiliation: Faculty of Pharmacy, Federal University of Goias, Avenida Universitária s/n, 74605-220 Goiânia, GO, Brazil. Electronic address: matheusroch@yahoo.com.br.
authors.forename: Matheus Lavorenti
authors.initials: ML
authors.lastname: Rocha
mesh_terms: D000818:Animals; D030009:Aspidosperma; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D004232:Diuretics / Q000494:pharmacology*; D005260:Female; D010894:Piroxicam / Q000494:pharmacology; D024301:Plant Bark; D010936:Plant Extracts / Q000494:pharmacology*; D011188:Potassium / Q000652:urine; D011453:Prostaglandins / Q000378:metabolism; D017208:Rats, Wistar; D012964:Sodium / Q000652:urine
chemical_list: D016861:Cyclooxygenase Inhibitors; D004232:Diuretics; D010936:Plant Extracts; D011453:Prostaglandins; D010894:Piroxicam; D012964:Sodium; D011188:Potassium
keywords: Aspidosperma subincanum; Diuretic; Electrolytes; Hypertension; Prostaglandins