Pharmacological Evaluation of the Central Nervous System Activity of Aframomum melegueta Seed Extract in Mice

Abstract

Objective: To study the effects of intraperitoneal injection of aqueous seed extract of Aframomum melegueta (AM) on the central nervous system (CNS) in mice. Materials and methods: The study sought to evaluate the effects of the extract on the general behaviour of the animals (Irwin test), on pentobarbitone-induced sleeping time, on methamphetamine-induced stereotyped behaviour, on motor coordination, and on convulsive seizures induced by isoniazid and picrotoxin. AM was tested at a dose range of 5-400 mg/kg. Results: AM (50-200 mg/kg) produced a significant decrease in spontaneous motor activity and also caused a dose-related prolongation of pentobarbital-induced sleeping time. At a dose range of 100-400 mg/kg, a significant inhibition of methamphetamine (35 mg/kg, i. p) induced stereotyped behaviour was observed. Furthermore, it offered a significant protection against convulsions induced by isoniazid (200 mg/kg, i.p). However, it failed to modify the convulsive action of picrotoxin (10 mg/kg, i.p) and did not cause any significant effect in the motor coordination of animals on the rota-rod machine. Conclusion: The results of this study suggest that A. melegueta seed extract possesses central nervous system depressant activity.