Evaluation of Anticonvulsant Effects of Nimodipine and Ascorbic Acid on Pentylenetetrazole- Induced Seizures in Mice

Introduction: The mechanisms underlying the vulnerability of the brain to seizures remains unknown. Calcium ions influx and oxidative stress have been implicated in a variety of acute and chronic epileptogenic conditions. The present study was aimed at investigating the effects of nimodipine and ascorbic acid (vitamin C) alone and in combination on pentylenetetrazole (PTZ) - induced seizures in mice.Material and methods: The animals received nimodipine (0.5, 1, 1.5, 2 mg/Kg, i.p.), ascorbic acid (30, 100, 300 mg/Kg, i.p.) alone and in combination with sodium valproate (100 mg/Kg, i.p.), 15 and 30min prior to intra-peritonral injection of PTZ (60 mg/Kg) and the acute seizure parameters such as seizure latency, duration and protection percent were studied in each group.Results: Ascorbic acid alone did not have any effects on the seizure parameters and the number of mice convulsing ( P>0.05). Nimodipine in 2 mg/kg dose had full protective effect on PTZ- induced seizure parameters, and in lesser doses it exerted partial protective effects. The combination of ascorbic acid (300 mg/Kg) with nimodipine (1.5 mg/Kg) or sodium valproate had a significant synergistic protective effect against PTZ- induce seizures in comparison with controls( P<0.001).Conclusion: Ascorbic acid potentiates the anticonvulsive effects of nimodipine on PTZ-induced seizure in mice