Anticonvulsive effect of vitamin C on pentylenetetrazol-induced seizures in immature rats

Abstract

Vitamin C helps to prevent brain oxidative stress and participate in the synthesis of progesterone. It also possesses a progesterone-like effect and acts synergistically with progesterone on the brain. Progesterone and its metabolites, but also vitamin C have been associated with anticonvulsant effects. We evaluated the progesterone concentration 30min and 24h after the last administration of vitamin C (500mg/kg, i.p. for five days). We also evaluated how vitamin C altered pentylenetetrazol (PTZ)-induced seizures by measuring the onset latency of seizures, percentage of incidence and mortality as well as amino acid levels after seizures. Vitamin C treatment alone increased basal progesterone concentrations to 531% after 30min compared to 253% after 24h. Furthermore, vitamin C significantly increased the latency to the first myoclonic, clonic and tonic seizure induced by PTZ (80mg/kg, i.p.) and decreased the percentage of incidence of clonic and tonic seizures as well as the mortality rate. Changes in tissue concentration of amino acids were primarily observed at 24h after vitamin C treatment. Our results suggest that vitamin C together with progesterone and/or its metabolites are involved in the protection against PTZ-induced seizures in immature rats.