Evaluation of anticonvulsant effects of nimodipine and ascorbic acid on pentylenetetrazole- induced seizures in mice

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. 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. 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). Ascorbic acid potentiates the anticonvulsive effects of nimodipine on PTZ-induced seizure in mice.