African Journal of

  • Abbreviation: Afr. J. Biotechnol.
  • Language: English
  • ISSN: 1684-5315
  • DOI: 10.5897/AJB
  • Start Year: 2002
  • Published Articles: 12300

Full Length Research Paper

Neuropharmacological evaluation of Annona senegalensis leaves

Okoli, C. O., Onyeto, C. A., Akpa, B. P., Ezike, A. C.*, Akah, P. A. and Okoye, T. C.
  Department of Pharmacology and Toxicology, Faculty of Pharmaceutical Sciences, University of Nigeria, Nsukka 410001, Enugu State, Nigeria.  
Email: [email protected]

  •  Accepted: 27 August 2010
  •  Published: 06 December 2010




The neuropharmacological activities of methanol leaf extract (ME) of Annonasenegalensis Pers (Annonaceae) and its bioactive fractions (MF and F7) were studied in rodents using pentylenetetrazol (PTZ)-induced seizures, pentobarbitone-induced sleep, apomorphine-induced stereotypy, open field, elevated plus maze (EPM) and rotarod performance tests. The extract and fractions inhibited PTZ-induced seizures, prolonged pentobarbitone-induced sleep, reduced stereotypic behaviour induced by apomorphine, decreased the frequency of line crossing and centre square entries and increased rearing in the air in the open field. The frequency of grooming and rearing against the wall were decreased, whereas the duration of grooming increased. Also, the extract and fractions increased the duration of stay in the open arm when compared to the closed arm of the EPM, and reduced the average time spent on the rotarod. Acute toxicity test showed an oral LD50 of ME greater than 5 g/kg in mice. Phytochemical analysis showed that ME tested positive for carbohydrates, reducing sugar, resins, saponins, tannins, steroids, terpenoids, alkaloids, flavonoids and glycosides; MF tested positive for saponins, steroids, terpenoids, alkaloids, carbohydrates, reducing sugar, flavonoids and glycosides; while F7 tested positive for flavonoids. These findings suggest that leaves of A. senegalensis possess anticonvulsant, central depressant and anxiolytic-like properties attributable to flavonoids.



Key words: Annona senegalensis, anticonvulsant, anxiolytic, sedative, stereotypy.


Abbreviations: AST, Aspartate transaminase; ALT, alanine transaminase; ACP,acid phosphatise; ALP, alkaline phosphatise; LDH, lactate dehydrogenase; PHF,polyherbal formulation.