Status epilepticus (SE) is a neurological emergency with an associated mortality of 10-12% [1]. Pilocarpine-induced seizure models have provided information on the behavioral and neurochemical characteristics associated with seizure activity [2,3]. Other studies suggest permanent changes in different biochemical systems during SE. An increase in lipid peroxidation, a decrease in GSH content, and excessive free radical formation may occur during SE induced by pilocarpine [4,5].This model can be used to investigate the development of neuropathology in SE [6]. Despite numerous studies clearly indicating the importance of enzyme activity in the epileptic phenomenon, the mechanisms by which these enzymes influence SE are not completely understood [7,8]. Therefore, we decided to study enzymatic activity related to oxidative stress mechanisms during SE [9].Oxidative stress, which is defined as the over-production of free radicals, can dramatically alter neuronal function and has been related to SE [10,11]. It is particularly facilitated in the brain, as the brain contains large quantities of oxidizable lipids and metals, and, moreover, has fewer antioxidant mechanisms than other tissues [8].Free radicals are chemical entities characterized by an orbital containing an unpaired electron [12]. This electron confers on these molecules a strong propensity to react with target molecules by giving or withdrawing one electron from the target molecules to complete their own orbital [13]. Superoxide, a free radical, can be generated in the brain by several mechanisms such as The role of oxidative stress in pilocarpine-induced status epilepticus was investigated by measuring lipid peroxidation level, nitrite content, GSH concentration, and superoxide dismutase and catalase activities in the hippocampus of Wistar rats. The control group was subcutaneously injected with 0.9% saline. The experimental group received pilocarpine (400 mgAEkg )1 , subcutaneous). Both groups were killed 24 h after treatment. After the induction of status epilepticus, there were significant increases (77% and 51%, respectively) in lipid peroxidation and nitrite concentration, but a 55% decrease in GSH content. Catalase activity was augmented 88%, but superoxide dismutase activity remained unaltered. These results show evidence of neuronal damage in the hippocampus due to a decrease in GSH concentration and an increase in lipid peroxidation and nitrite content. GSH and catalase activity are involved in mechanisms responsible for eliminating oxygen free radicals during the establishment of status epilepticus in the hippocampus. In contrast, no correlations between superoxide dismutase and catalase activities were observed. Our results suggest that GSH and catalase activity play an antioxidant role in the hippocampus during status epilepticus.Abbreviations ROS, reactive oxygen species; SE, status elipticus.

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RESUMO:A procura de novos agentes terapêuticos provenientes de plantas medicinais para doenças psiquiátricas tem progredido signifi cativamente na última década. Isso refl ete num grande número de preparações herbárias para as quais o potencial psicoterapêutico tem sido avaliado em diversos modelos animais. O intuito desta revisão é fornecer uma ampla visão das plantas medicinais que apresentam efeitos terapêuticos signifi cantes em modelos animais de doenças psiquiátricas, especifi camente os distúrbios da ansiedade. Um considerável número de constituintes herbários cujos efeitos comportamentais e ações farmacológicas têm sido bem caracterizados podem ser bons candidatos para futuras investigações que podem resultar em uso clínico, merecendo, portanto, uma maior atenção em estudos posteriores.Unitermos: Plantas medicinais, distúrbios da ansiedade, modelos animais de ansiedade. ABSTRACT: "Medicinal plants and their bioactive constituents:A scientifi c review of bioactivity and potential benefi ts in the anxiety disorders in animal models". A search for novel pharmacotherapy from medicinal plants for psychiatric illnesses has progressed signifi cantly in the past decade. This is refl ected in the large number of herbal preparations for which psychotherapeutic potential has been evaluated in a variety of animal models. The aim of this review is to provide an overview of medicinal plants that have signifi cant therapeutic effects in animal models of psychiatric illnesses, specifi cally anxiety disorders. A considerable number of herbal constituents whose behavioral effects and pharmacological actions have been well characterized may be good candidates for future investigations that may result in clinical use, thus deserving increased attention in future studies.

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: Oxidative stress has been implicated in a large number of human degenerative diseases, including epilepsy. Levetiracetam (LEV) is a new antiepileptic agent with broad-spectrum effects on seizures and animal models of epilepsy. Recently, it was demonstrated that the mechanism of LEV differs from that of conventional antiepileptic drugs. Objectifying to investigate if LEV mechanism of action involves antioxidant properties, lipid peroxidation levels, nitrite-nitrate formation, catalase activity, and glutathione (GSH) content were measured in adult mice brain. The neurochemical analyses were carried out in hippocampus of animals pretreated with LEV (200 mg/kg, i.p.) 60 min before pilocarpine-induced seizures (400 mg/kg, s.c.). The administration of alone pilocarpine, 400 mg/kg, s.c. (P400) produced a significant increase of lipid peroxidation level in hippocampus. LEV pretreatment was able to counteract this increase, preserving the lipid peroxidation level in normal value. P400 administration also produced increase in the nitrite-nitrate formation and catalase activity in hippocampus, beyond a decrease in GSH levels. LEV administration before P400 prevented the P400-induced alteration in nitrite-nitrate levels and preserved normal values of catalase activity in hippocampus. Moreover, LEV administration prevented the P400-induced loss of GSH in this cerebral area. The present data suggest that the protective effects of LEV against pilocarpine-induced seizures can be mediated, at least in part, by reduction of lipid peroxidation and hippocampal oxidative stress.

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This work studied the antinociceptive effects of the hydroalcoholic extracts (HAEs) from Erythrina velutina (Ev) and Erythrina mulungu (Em) in three experimental models of nociception in mice. The extract was administered intraperitoneally to female mice at the doses of 200 and 400 mg/kg. Inhibitions of abdominal contractions were observed with the doses of 200 (88.6%; 86.8%) and 400 (95.5%; 83.5%) mg/kg of E. velutina and E. mulungu, respectively, as compared to controls. E. velutina and E. mulungu, at both doses, reduced the nociception produced by formalin in the 1st and 2nd phases and this effect was not reversed by the pretreatment with naloxone. In the hot plate test an increase of the reaction time was observed only at 60 (Ev=18.0+/-2.2; Em=20.8+/-2.52) and 90 min (Ev=20.4+/-1.71; Em=23.7+/-2.32) after the treatment with E. velutina and E. mulungu at the dose of 400 mg/kg as compared to controls (T60=11.1+/-0.74; T90=11.9+/-0.86). This effect was not reversed by naloxone. We conclude that E. velutina and E. mulungu presents antinociceptive effects, which are independent of the opioid system.

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