Ethanol Extracts of Terminalia ivorensis (Chev A.) Stem Bark Attenuates the Positive, Negative and Cognitive Symptoms of Psychosis in Experimental Animal Models
Benneth Ben-Azu *
Department of Pharmacology and Therapeutics, College of Medicine, University of Ibadan, Ibadan, Oyo State, Nigeria.
Adegbuyi Oladele Aderibigbe
Department of Pharmacology and Therapeutics, College of Medicine, University of Ibadan, Ibadan, Oyo State, Nigeria.
Olusegun Adebayo Adeoluwa
Department of Pharmacology and Therapeutics, College of Medicine, University of Ibadan, Ibadan, Oyo State, Nigeria and Department of Pharmacology and Therapeutics, College of Medicine and Health Sciences, Afe Babalola University, Ado Ekiti, Ekiti State, Nigeria.
Ezekiel Oluwagbenga Iwalewa
Department of Pharmacology and Therapeutics, College of Medicine, University of Ibadan, Ibadan, Oyo State, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Aims: This study was undertaken to evaluate the antipsychotic property of the ethanol extract of T. ivorensis (EETI) stem bark in mice
Study Design: The study used experimental animal models predictive of human psychosis in mice
Place and Duration of Study: Neuropharmacology Laboratory, Department of Pharmacology and Therapeutics, Faculty of Basic Medical Sciences, University of Ibadan, Oyo State, Nigeria, between June 2013 and July 2014.
Methodology: Antipsychotic activity of EETI [125-1000 mg/kg, per os (p.o.)] was assessed based on the inhibition of stereotyped behavior induced by apomorphine (1 mg/kg, i.p.) or ketamine (10 mg/kg, i.p.) and ketamine-induced hyperactivity for positive symptoms in mice. Ketamine-enhanced immobility in forced swim test (FST) and reversal treatment of ketamine-induced cognitive dysfunction for negative and cognitive symptoms in mice respectively, and drug-induced ptosis and catalepsy in mice were also employed to further evaluate the antipsychotic property of EETI.
Results: EETI (125-1000 mg/kg, p.o.) significantly (p<0.05) inhibited apomorphine or ketamine-induced stereotypy, and ketamine-induced hyperactivity. Moreover, EETI significantly (p<0.05) attenuated the enhanced immobility and ameliorated the cognitive dysfunction by ketamine (30 and 20 mg/kg, i.p.), respectively in mice. EETI also dose dependently depleted the monoamine as indexed by the ptosis paradigm, however did not demonstrate cataleptic behavior as indexed on the catalepsy scale which suggest lack of expyramidal symptoms.
Conclusion: This study provides valuable evidence which suggests that T. ivorensis contain biologically active constituents that possess antipsychotic activity. Thus, justifying its ethnomedicinal claims in the management of psychotic disorders.
Keywords: Psychosis, schizophrenia, antipsychotics, Terminalia ivorensis.