Abstract

Epilepsy is a chronic neurological disorder of the brain function that is characterized by a periodic and unpredictable occurrence of seizures. Carica papaya infusion has been used to treat epilepsy by traditional medicine practitioners in many communities of Kaduna State, Nigeria. Present work aimed to evaluate the anticonvulsant effects produced by acute administration of 70% methanol leaves extract of Carica papaya (CPLE) using two experimental models: Pentylenetetrazole-induced seizures (PTZ) and Maximal Electroshock-induced seizures (MES) in mice and chicks respectively. Phenytoin 20mg/kg and Valproate 200mg/kg body weight were used as standard drugs for MES seizures and PTZ induced seizures respectively. In MES induced seizures, CPLE increased the time of onset of Tonic Hind Limb Extension (THLE) at doses of 200 and 400mg/kg body weight. Extract caused an insignificant decrease (p > 0.05)in duration of THLE. Percentage protection of MES seizures with dose of 400 mg/kg body weight was 100%. In PTZ induced convulsion, CPLE at 400 mg/kg dose significantly increased (p ≤ 0.05) mean latency period. Percentage protection of PTZ induced seizures at 200 and 400 mg/kg doses were 60% and 80% respectively, which implied a dose-dependent activity. Phenytoin in MES-induced seizures and Valproate in PTZ induced seizures produced 100% seizure protection. CPLE suppressed seizures induced by MES, however a significant difference (p≤0.05) was observed in PTZ-induced seizure. The LD50 of CPLE was ≥ 2000 mg/kg body weight. Preliminary phytochemical screening showed presence of flavonoids, Triterpenes, Saponins and Alkaloids. Results therefore, provided evidence of anticonvulsant effects by CPLE. Hence, CPLE may be developed as a safe and cheaper alternative drug for long-term use in therapeutic management of neurological disorders characterized by convulsions.