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In the present study, we investigated the effect of seizures on rat performance in the Morris water maze task, as well as on choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) activities in rat hippocampus. Wistar rats were treated with 0.9% saline (i.p., control group) and pilocarpine (400 mg/kg, i.p., pilocarpine group). After the treatments all groups were observed for 1 h. The changes on reference and working spatial memory caused by pilocarpine administration were observed in seized rats. The ChAT and AChE activities were measured using spectrophotometric methods and the results compared to values obtained from saline animals. Its activities were also determined after behavioral task. Results showed that seizures alter reference memory when compared to saline-treated animals. In the working memory task, we observed a significant day's effect with significant differences between control and pilocarpine-induced seizures. In pilocarpine group, it was observed a significant decreased in ChAT and AChE activities, when compared to control group. Our findings suggest that seizures caused cognitive dysfunction and a decrease of ChAT and AChE activities that might be related, at least in part, to the neurological problems presented by seizures induced by pilocarpine.

Temporal lobe epilepsy is the most common form of epilepsy in humans. Oxidative stress is a mechanism of cell death induced by seizures. Buspirone presents anxyolitic and antidepressant effects due to their ability to stimulate 5-HT(1A) receptor. We studied the buspirone effects on oxidative stress in rat hippocampus after seizures and status epilepticus (SE) induced by pilocarpine. In pilocarpine group there was a significant increase in lipid peroxidation and nitrite levels. However, no alteration was observed in superoxide dismutase and catalase activities. Buspirone pretreatment produces significantly reduction of the lipid peroxidation level (60%) and nitrite content (44%) as well as increased the superoxide dismutase (47%) and catalase (40%) activities in rat hippocampus after seizures, when compared with the pilocarpine group. The intraperitoneal injection of buspirone prior to pilocarpine suppressed the behavioral seizure occurrence. According to our results, the oxidative stress is present during seizures. Buspirone exerted anticonvulsant effects associated with the inhibition of the development of oxidative stress. These results suggest a therapeutic use potential of buspirone in epilepsy treatment., (Copyright 2009 Elsevier Inc. All rights reserved.)

In the present study we investigated the effects of lipoic acid (LA) on delta-aminolevulinic dehydratase (delta-ALA-D) and Na(+), K(+)-ATPase activities in rat brain after seizures induction by pilocarpine. Wistar rats were treated with 0.9% saline (i.p., control group), lipoic acid (10mg/kg, i.p., LA group), pilocarpine (400mg/kg, i.p., pilocarpine group), or the combination of LA (10mg/kg, i.p.) with pilocarpine (400mg/kg, i.p.), 30 min before administration of LA (LA plus pilocarpine group). After the treatments all groups were observed for 1h. The enzyme activities (delta-ALA-D and Na(+), K(+)-ATPase) were measured using spectrophotometric methods, and the results were compared with that obtained from saline and pilocarpine-treated animals. Neuroprotective effects of LA against seizures were evaluated based on those enzyme activities. The pilocarpine group showed a reduction in delta-ALA-D and Na(+), K(+)-ATPase activities after seizures. In turn, LA plus pilocarpine abolished the appearance of seizures and reversed the decreased in delta-ALA-D and Na(+), K(+)-ATPase activities produced by seizures, when compared to the pilocarpine seizing group. The results from the present study demonstrate that preadministration of LA abolished seizure episodes induced by pilocarpine in rat, probably by increasing delta-ALA-D and Na(+), K(+)-ATPase activities in rat brain during seizures., ((c) 2009 Elsevier Inc. All rights reserved.)

Recent researches have shown that antioxidant compounds may have certain neuroprotective effect against the neurotoxicity of seizures at cellular level. Ubiquinone (UQ), an antioxidant compound, exhibits a wide range of therapeutic effects that are attributed to its potent antioxidant capacity. The objective of the present study was to evaluate the neuroprotective effects of UQ in rats, against the observed oxidative stress during seizures induced by pilocarpine. Wistar rats were treated with either 0.9% saline (i.p., control group), UQ (5, 10 or 20 mg/kg, i.p., UQ5, UQ10 and UQ20 groups), pilocarpine (400 mg/kg, i.p., P400 group), or co-administration of pilocarpine with UQ group rats 30 min prior to UQ administration. After the treatments all groups were observed for 24 h. The antioxidant enzymatic activities as well as the hydroperoxide concentrations were measured using spectrophotometric methods and the results were analyzed. In pilocarpine group there was a significant increase in hydroperoxides concentration and glutathione peroxidase activity. However, no alteration was observed in superoxide dismutase and catalase activities. Antioxidant treatment significantly reduced the hydroperoxide content and increased the superoxide dismutase, catalase and glutathione peroxidase activities in rat hippocampus during seizures induced by pilocarpine. Our findings strongly support the hypothesis that oxidative stress in hippocampus occurs during seizures induced by pilocarpine, which indicates that brain damage induced by the oxidative process plays a crucial role in seizures pathogenic consequences. Our result also suggests that ubiquinone can exert significant neuroprotective effects that might be useful in the treatment of neurodegenerative diseases., (2009 Elsevier B.V. All rights reserved.)

Ascorbic acid has many nonenzymatic actions and is a powerful water-soluble antioxidant. It protects low density lipoproteins from oxidation and reduces harmful oxidants in the central nervous system. Pilocarpine-induced seizures have been suggested to be mediated by increases in oxidative stress. Current studies have suggested that antioxidant compounds may afford some level of neuroprotection against the neurotoxicity of seizures. The objective of the present study was to evaluate the neuroprotective effects of ascorbic acid (AA) in rats, against the observed oxidative stress during seizures induced by pilocarpine. Wistar rats were treated with 0.9% saline (i.p., control group), ascorbic acid (500 mg/kg, i.p., AA group), pilocarpine (400 mg/kg, i.p., pilocarpine group), and the association of ascorbic acid (500 mg/kg, i.p.) plus pilocarpine (400 mg/kg, i.p.), 30 min before of administration of ascorbic acid (AA plus pilocarpine group). After the treatments all groups were observed for 6h. The enzyme activities as well as the lipid peroxidation and nitrite concentrations were measured using spectrophotometric methods and the results compared to values obtained from saline and pilocarpine-treated animals. Protective effects of ascorbic acid were also evaluated on the same parameters. In pilocarpine group there was a significant increase in lipid peroxidation and nitrite level. However, no alteration was observed in superoxide dismutase and catalase activities. Antioxidant treatment significantly reduced the lipid peroxidation level and nitrite content as well as increased the superoxide dismutase and catalase activities in hippocampus of adult rats after seizures induced by pilocarpine. Our findings strongly support the hypothesis that oxidative stress in hippocampus occurs during seizures induced by pilocarpine, proving that brain damage induced by the oxidative process plays a crucial role in seizures pathogenic consequences, and also imply that a strong protective effect could be achieved using ascorbic acid.