title: Acute toxicity, antinociceptive activity and indole alkaloids of aqueous extract from bark of Aspidosperma cuspa (Kunth) Blake.
abstract: ETNOPHARMACOLOGICAL RELEVANCE: Aspidosperma cuspa (Kunth) Blake (Apocynaceae) is popularly known as "amargosa" or "cuspa", and its bark is used in folk medicine primarily for pain.
  
  
  OBJECTIVE
  In the present study the acute toxicity, antinociceptive effect and alkaloids of the aqueous decoction extract of the Aspidosperma cuspa bark in mice was investigated.
  
  
  METHODS
  Acute toxicity was tested using a variation of the method described by Lichfield and Wilcoxon. The antinociceptive activity was evaluated using the acetic acid induced writhing and tail-flick tests. The phytochemical analysis was performed.
  
  
  CONCLUSIONS
  Oral administration of the extract did not cause animal death (LD(50)>4 g/kg), and the histological analysis showed an absence of alterations in all organs examined. TD(50) of the extract was 0.5521 g/kg for male mice and 1.1565 g/kg for females. The aqueous extract at doses 276 mg/kg (p.o.) did not produce a significant inhibition of acetic acid-induced writhes, but showed a significant effect in tail-flick test. Naloxone, an opioid receptor antagonist, pretreatment inhibited significantly the antinociceptive activity of the extract. It is suggested that the aqueous decoction extract of the bark of Aspidosperma cuspa has an antinociceptive effect, and this may be mediated by opioid receptors. Three indole alkaloids (aspidocarpine, 11-methoxytubotaiwine and picraline) were isolated from the aqueous extract. The antinociceptive activity of the extract is presumed to be due to these compounds.
authors: Laboratorio de Productos Naturales, Facultad de Farmacia, Apartado 40109, Universidad Central de Venezuela, Caracas 1040-A, Venezuela. nery.perez@ucv.ve
authors: Nery M
authors: NM
authors: Pérez
authors: Fátima B
authors: FB
authors: Torrico
authors: Abelardo
authors: A
authors: Morales
mesh_terms: D019342:Acetic Acid; D000701:Analgesics, Opioid / Q000627:therapeutic use* / Q000633:toxicity; D000818:Animals; D030009:Aspidosperma; D005260:Female; D006358:Hot Temperature; D026121:Indole Alkaloids / Q000032:analysis / Q000627:therapeutic use* / Q000633:toxicity; D008297:Male; D051379:Mice; D009270:Naloxone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D010146:Pain / Q000139:chemically induced / Q000188:drug therapy* / Q000503:physiopathology; D008517:Phytotherapy; D024301:Plant Bark; D010936:Plant Extracts / Q000737:chemistry / Q000627:therapeutic use* / Q000633:toxicity; D014867:Water / Q000737:chemistry
chemical_list: D000701:Analgesics, Opioid; D026121:Indole Alkaloids; D009292:Narcotic Antagonists; D010936:Plant Extracts; D014867:Water; D009270:Naloxone; D019342:Acetic Acid