Anti-Convulsant Activity of Different Extracts of Centella asiatica and Bacopa monnieri in Animals

Objective: To evaluate anti-convulsant profile of different extracts of Centella asiatica and Bacopa monnieri in rats. Materials and methods: The effects of single oral administration of different preparations of C.asiatica and B.monnieri were evaluated for their anticonvulsant profile in the Maximal Electroshock Seizure (MES) in rats at 1, 3, 6, and 24 h after administration and Pentylene tetrazole (PTZ) test in mice and rats. The ED50 dose of Phenytoin (30 mg/kg) was used for comparison. Results: The crude drug of C.asiatica (500 mg/kg) showed mild to moderate anticonvulsant activity, from 1 h to 24 h. The methanolic extract of C.asiatica (CA-I) showed higher activity than the crude drug at 3 and 6 h, but there was no anti-convulsant activity at 1 h. The solubulised extract of C.asiatica (CA-II) (using Cresmer RH 40 and propylene glycol) at 500 and 1000 mg/kg, also showed a similar profile of activity which was dose-dependent. The crude drug of B.monnieri (500 mg/kg) showed mild to moderate activity from 1 h to 6 h but there was no activity at 24 h. The methanolic extract of B.monnieri (BM-I) (which was later partitioned between butanol and water) showed a lesser degree of activity only at 3 h and 6 h. The solubilised extract of B.monnieri (BM-II) (500 mg/kg) showed mild to moderate activity at 3 h and 6 h with minimal activity at 24 h. At 1000 mg/kg, a comparatively higher degree of activity was seen at 1 h - 6h but not at 24 h. The activity of B.monnieri was almost equivalent to Phenytoin at 6 h. In the Pentylenetetrazol (PTZ) chemoshock seizure test, no activity was detected for both plants (500 mg/kg). Conclusion: Overall, B.monnieri has a faster onset of action and time/dose responses were qualitatively similar to Phenytoin, while C.asiatica had quantitatively lesser activity but had a longer duration of action.