Evaluation of anticonvulsant activity of the aqueous and total crude extracts of Vernonia amygdalina Delile in pentylenetetrazole-induced seizures in wistar albino rats

Abstract

Introduction: Seizures due to abnormal electrical activity in the brain leading to convulsions and hence epilepsy have continued to be a serious problem among the population globally including in Uganda. Medicinal plants such as Vernonia amygdalina are commonly used in the management of epilepsies in local communities of Uganda with limited scientific information on its anticonvulsant activity. Aim: Study assessed the anticonvulsant activity of Vernonia amygdalina in pentylenetetrazoleinduced seizures in Wistar albino rats. Methods: A laboratory based experiment was conducted to evaluate anticonvulsant activity of the aqueous and total crude extracts of Vernonia amygdalina in pentylenetetrazole-induced seizures in Wistar albino rats. 200mg/kg and 1000mg/kg of each of the extracts were administered to 8 groups of 6 animals each. After 30 minutes, seizures were induced in each of the rats in all 10 groups by dosing them with 35mg/kg of PTZ. Each of the animals was then observed for 30 minutes and latency to onset of seizures, frequency and duration of seizures and latency to mortality and mortality rate were observed and recorded. Their behavior was also recorded based on the Racine scale. Data was analyzed using STATA version 13. Means were compared using ANOVA at 95% CI. Study was approved by MAK SBS REC (SBS-2022-219). Results: All the root and leaf extracts of Vernonia amygdalina reduced frequency of PTZ-induced seizures in Wistar albino rats as compared to the negative control. The best reduction in frequency was seen in the groups treated with aqueous leaf extract 1000mg/kg and total crude extract 1000mg/kg in which two animals each of these groups were totally protected against seizures and only one seizure each for the other four animals as compared to two or three seizures for the animals in the negative control group. The groups treated with aqueous leaf extract (1000mg/kg) and total crude root extract (1000mg/kg) showed a significant (p<0.05) reduction of seizure duration to 10.8s and 11.3s as compared to the negative control at 55.4s. The root and leaf aqueous and total crude extracts of Vernonia amygdalina did not increase latency to onset of PTZ-induced seizures in Wistar albino rats. 1000mg/kg of the aqueous leaf extract and the both doses (200mg/kg and 1000mg/kg) of the total crude root extract of Vernonia amygdalina totally protected the animals against death from PTZ-induced seizures in Wistar albino rats as compared to 16.7% mortality rate in the negative control group. In the group treated with aqueous root extract (1000mg/kg) one animal (16.7%) died but there was a significant increase in latency to mortality to 2597s as compared to 1217s in the negative control group. The total crude root extract (1000mg/kg) significantly (p<0.05) reduced the mean Racine score of seizures to 2.2s as compared to 2.7s in the negative control. Conclusion: Aqueous and total crude extracts of the leaf and root of Vernonia amygdalina had significant anticonvulsant properties.