Evaluation of Anticonvulsant Activity of Methanol Leaf Extract of Peristrophe bicalyculata (Acanthaceae) in Experimental Animals

Abstract

Abstract
Peristrophe bicalyculata (Retz) Nees, a perennial herb found throughout tropical Africa, is used in Nigerian ethnomedicine for the management of pain and convulsions. The objective of this study is to screen for the anticonvulsant activity of methanol leaf extract of P. bicalyculata at doses of 200, 400 and 800 mg/kg in experimental animals. Preliminary phytochemical screening and acute toxicity studies were carried out. The extract was evaluated for anticonvulsant activity using maximal electroshock induced seizure test in day-old chicks, pentylenetetrazole- (PTZ), strychnine-, 4-aminopyridine- and picrotoxin induced seizures models in mice. Phytochemical screening showed the presence of alkaloids, anthraquinones, glycosides, cardiac glycosides, saponins, steroids, triterpenes, tannins and flavonoids, while the intraperitoneal median lethal dose was estimated to be 3800 mg/kg in mice. P. bicalyculata extract at 200 mg/kg protected 30% of chicks against tonic hind limb extension. In the PTZ test, the extract at 800 mg/kg offered 66.67% protection against seizures. It also significantly (p<0.01) increased the mean onset of seizures at 200 mg/kg when compared to control. However, the extract offered no protection against strychnine, 4-aminopyridine and picrotoxin-induced seizures. The results revealed that, the methanol leaf extract of Peristrophe bicalyculata possess anticonvulsant activity and therefore lend some scientific support for its ethno-medical use in the management of convulsions.