Evaluation of the anticonvulsant activity of aqueous leaf extract of Emilia praetermissa Milne-Redh (Asteraceae) in rats and mice

Background: Emilia praetermissa has been used for the treatment of convulsive disorders in children by herbalists in Eastern Nigeria. It is also used for the treatment of ulcers, fever, splenomegaly, filarial infections, bacterial infections and ringworms. Objective: This objective was to investigate the inhibitory property of the aqueous leaf extract of E. praetermissa (AEP) against electrically and chemically induced convulsions in rats and mice. Methodology: Groups of rats were administered 5, 10 and 20 mg/kg aqueous leaf extract of E. praetermissa and after one hour they were subjected to maximal electroshock. Groups of mice treated with same doses of the extract were subjected to chemically-induced convulsion using pentylentetrazol or strychnine. Phenobarbitone (30 mg/kg) and/or diazepam (0.5 mg/kg) were used as standards. Comparisons were made by use of Student’s t-test. All data were analyzed using GraphPad Instat software (USA). P < 0.05 indicated statistically significant difference. Results: The doses of aqueous leaf extract of E. praetermissa significantly (P< 0.05) reduced the extensor seizure latency in maximal electroshock model, and onset of tonic convulsion in the chemical models. Aqueous leaf extract of E. praetermissa (20mg/kg; P< 0.007) was significantly superior to diazepam (0.5 mg/kg; P< 0.04) in reducing the onset of strychnine-induced seizure. Conclusion: These results suggest that the ethnomedicinal application of E. praetermissa in Eastern Nigeria has scientific basis that requires further investigation. Key words: Emilia praetermissa, aqueous extract, anticonvulsant activity