Some Central Nervous System Effects of the aqueous Extract of the Leaves of Phyllanthus Amarus Schum, (Euphorbiaceae).

Abstract

The leaves of Phyllanthus amarus is used in Southern Nigeria to treat variety of diseases including epilepsy. The aqueous extract of the leaves of Phyllanthus amarus was investigated for some central nervous system effects. Two animals models (maximal electroshock and pentylenetetrazol-induced convulsion), were used for the anticonvulsant screening in mice. The influences of the extract on barbiturate-induced sleeping time and on motor coordination were investigated in rats and mice respectively. The extract protected the animals against maximal electroshock-induced convulsion at the doses of 100mg/kg and 200mg/kg that were used, but could not protect the animals against pentylenetetrazol-induced convulsion at these two doses. However, higher doses of 500mg/kg and 1000mg/kg only provided a marginal protection of 20% and 40% to the animals against pentylenetetrazol-induced convulsion. The extract neither prolonged barbiturate-induced sleeping time nor did it impair the motor co-ordination ability of the animals on the Ugo Basile rotarod rotating at 6rpm. The results have shown that the aqueous extract of the leaves of Phyllanthus amarus contains some active principles that have anticonvulsant effect and protect mainly against maximal electroshock-induced convulsion, without depressing the central nervous system.

Key Words: Phyllanthus amarus, Anticonvulsant Activity, Sleeping Time, Sedation