title: Antipsychotic and sedative effects of the leaf extract of Crassocephalum bauchiense (Hutch.) Milne-Redh (Asteraceae) in rodents.
abstract: BACKGROUND
  Crassocephalum bauchiense (Hutch.) Milne-Redh (Asteraceae) has been used as a medicine for the treatment of epilepsy, insomnia, dementia and psychotic disorders in Cameroonian traditional medicine.
  
  
  OBJECTIVE
  This study was designed to examine whether the aqueous extract and the alkaloid fraction prepared from the leaves of Crassocephalum bauchiense possess antipsychotic and sedative properties in rodents.
  
  
  METHODS
  The rectal temperature of mice was recorded with a probe thermometer at a constant depth. Novelty-induced rearing behavior is used to evaluate a central excitatory locomotor behavior in mice. The antipsychotic effects of the extracts were assessed using the apomorphine animal model of psychosis. The catalepsy test was tested based on the ability of the leaves extracts of Crassocephalum bauchiense to alter the duration of akinesia by placing the naive mice with both forelegs over a horizontal bar. The extracts of Crassocephalum bauchiense effects were evaluated on sodium pentobarbital-induced sleeping time. In addition, gamma-aminobutyric acid concentrations in the brain treated mice were also estimated.
  
  
  RESULTS
  The aqueous extract and the alkaloid fraction from Crassocephalum bauchiense caused dose-dependent inhibition of novelty-induced rearing behavior, decreased the apomorphine-induced stereotypy and fighting, and had significant fall of the body temperature. The aqueous extract prolonged the sodium pentobarbital sleeping time. This prolongation was not reversed by bicuculline, a light-sensitive competitive antagonist of GABA(A) receptors complex. However, the effect of the aqueous extract on sodium pentobarbital-induced sleeping time was blocked by N-methyl-β-carboline-3-carboxamide, a partial inverse agonist of the benzodiazepine site in the GABA(A) receptor complex and flumazenil, a specific antagonist of the benzodiazepine site in the GABAA receptor complex. In biochemical experiments, the concentration of the inhibitory amino acid, gamma-aminobutyric acid, was significantly increased in the brain of animals treated with the aqueous extract of Crassocephalum bauchiense and sodium valproate.
  
  
  CONCLUSIONS
  The results show that the antipsychotic and sedative properties of Crassocephalum bauchiense are possibly mediated via the blockade of dopamine D-2 receptors and GABAergic activation, respectively. However, pharmacological and chemical studies are continuing in order to characterize the mechanism(s) responsible for these neuropharmacological actions and also to identify the active substances present in the extracts of Crassocephalum bauchiense.
authors: Department of Zoology and Animal Physiology, Faculty of Science, University of Buea, P.O. Box 63 Buea, Cameroon. taiwe_sotoing@yahoo.fr
authors: Germain
authors: G
authors: Sotoing Taïwe
authors: Elisabeth
authors: E
authors: Ngo Bum
authors: Emmanuel
authors: E
authors: Talla
authors: Amadou
authors: A
authors: Dawe
authors: Fleur Clarisse
authors: FC
authors: Okomolo Moto
authors: Gwladys
authors: G
authors: Temkou Ngoupaye
authors: Neteydji
authors: N
authors: Sidiki
authors: Bernard
authors: B
authors: Dabole
authors: Paul Désiré
authors: PD
authors: Djomeni Dzeufiet
authors: Théophile
authors: T
authors: Dimo
authors: Michel
authors: M
authors: De Waard
mesh_terms: D000818:Animals; D014150:Antipsychotic Agents / Q000494:pharmacology / Q000627:therapeutic use*; D001058:Apomorphine; D019659:Asteraceae; D001522:Behavior, Animal / Q000187:drug effects; D001831:Body Temperature / Q000187:drug effects; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D002375:Catalepsy / Q000188:drug therapy / Q000378:metabolism; D004195:Disease Models, Animal; D018492:Dopamine Antagonists / Q000494:pharmacology / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D005260:Female; D005442:Flumazenil / Q000494:pharmacology; D018682:GABA Agents / Q000494:pharmacology / Q000627:therapeutic use; D006993:Hypnotics and Sedatives / Q000494:pharmacology / Q000627:therapeutic use*; D008297:Male; D016488:Medicine, African Traditional; D051379:Mice; D008815:Mice, Inbred Strains; D009043:Motor Activity / Q000187:drug effects; D010424:Pentobarbital; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology / Q000627:therapeutic use; D018515:Plant Leaves; D011618:Psychotic Disorders / Q000188:drug therapy* / Q000378:metabolism; D017207:Rats, Sprague-Dawley; D011963:Receptors, GABA-A / Q000378:metabolism; D012890:Sleep / Q000187:drug effects*; D014635:Valproic Acid / Q000494:pharmacology; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
chemical_list: D014150:Antipsychotic Agents; D018492:Dopamine Antagonists; D018682:GABA Agents; D006993:Hypnotics and Sedatives; D010936:Plant Extracts; D011963:Receptors, GABA-A; D005442:Flumazenil; D005680:gamma-Aminobutyric Acid; D014635:Valproic Acid; D010424:Pentobarbital; D001058:Apomorphine