PHARMACOLOGICAL RATIONALE FOR THE USE OF SOME MEDICINAL PLANTS AS ANTIEPILEPTIC AGENTS IN ZARIA, NIGERIA
PHARMACOLOGICAL RATIONALE FOR THE USE OF SOME MEDICINAL PLANTS AS ANTIEPILEPTIC AGENTS IN ZARIA, NIGERIA
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Date
2008-07
Authors
YA’U, JAMILU
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Abstract
The effects of the hydro-alcoholic root bark extracts of C. edulis and B. aegyptiaca were
studied on pentylenetetrazole (PTZ) and Maximal electroshock (MES)-induced seizures in
animal models. The effects of Flumazenil and Naloxone were studied on the anticonvulsant
activity of the plant extracts to determine their possible mechanisms of anticonvulsant
action. The intraperitoneal LD50 of the hydro-alcoholic root bark extracts of C. edulis and
B. aegyptiaca were found to be 282.8 mg/Kg and 1131.3 mg/Kg respectively, this suggests
that the extracts are mildly toxic by this route. Oral LD50 of the extracts were both greater
than 5000 mg/Kg, suggesting non toxic profile. The C. edulis extract produced 40% while
B. aegyptiaca offered 20% protection against seizures induced by PTZ when given
intraperitoneally while the standard anticonvulsant drug used, diazepam offered 60%
protection at 0.5 mg/kg and 100% protection at 1 mg/kg. Similarly, in the oral route no
protection was obtained in both extracts. In MES-induced seizures, C. edulis extract
protected the chicks by 90% while B. aegyptiaca showed no protection. Flumazenil and
Naloxone reversed the anticonvulsant activities of both C. edulis and B. aegyptiaca extracts
suggesting involvement of GABAA-BDZ receptors and opioid receptors in the extracts
anticonvulsant activities. C. edulis extract fractions aqueous portion (AP), diethyl ether
filtrate (BP), diethyl ether precipitate (CS), ethyl acetate (EA) and n-butanol (NB) were
found to have varied anticonvulsant activities; AP fraction showed 80%, BP 40%, CS 40%,
EA 40% protection in a non dose dependent manner and NB offered no protection against
PTZ-induced seizures in mice while fraction CS 60% seizure protection in an inverse dose
dependent pattern, fractions AP, BP, EA and NB CS did not produce any significant
seizure protection against MES-induced seizures in chicks, similarly phenytoin, standard
anticonvulsant drug used produced 100% protection. There was no significant difference
between the fractions treated and the control groups in the duration of seizure. All the C.
edulis fractions when tested against 4-aminopyridine-induced seizures showed no
protection indicating lack of activity on potassium channels. Various phytochemical
constituents such as anthraquinones, tannins, saponins, glycosides were found to be present
and consistently alkaloids were absent in the extracts and the fractions. The results suggest
the presence of bioactive component(s) that possess anticonvulsant activities. The data may
provide pharmacological basis for the use of the plants in the management of epilepsy in
Zaria, Nigeria.
Description
A THESIS SUBMITTED TO THE POSTGRADUATE SCHOOL, AHMADU BELLO
UNIVERSITY, ZARIA, IN PARTIAL FULFILLMENT FOR THE AWARD OF
MASTERS OF SCIENCE DEGREE IN PHARMACOLOGY
DEPARTMENT OF PHARMACOLOGY AND CLINICAL PHARMACY
FACULTY OF PHARMACEUTICAL SCIENCES
AHMADU BELLO UNIVERSITY
ZARIA, NIGERIA
JULY, 2008
Keywords
PHARMACOLOGICAL, RATIONALE, MEDICINAL, PLANTS, ANTIEPILEPTIC, ANTIEPILEPTIC, ZARIA,, NIGERIA