Neuroscience Letters 416 (2007) 227–230 Effects of the vitamin E in catalase activities in hippocampus after status epilepticus induced by pilocarpine in Wistar rats D.O. Barros a , S.M.L. Xavier a , C.O. Barbosa a , R.F. Silva a , R.L.M. Freitas a , F.D. Maia a , A.A. Oliveira a , R.M. Freitas a,∗ , R.N. Takahashi b a Curso de Farm´ acia, Faculdade Cat´ olica Rainha do Sert ˜ ao, Rua Juvˆ encio Alves, 660, Centro, Quixada, 63900-00, CE, Brasil b Universidade Federal de Santa Catarina, Centro de Ciˆ encias Biol ´ ogicas, Coordenadoria Especial de Farmacologia. Rua Ferreira Lima, 82, Centro, 88015420 - Florian´ opolis, SC – Brasil Received 10 January 2007; received in revised form 25 January 2007; accepted 26 January 2007 Abstract Experimental manipulations suggest that in vivo administration of exogenous antioxidants agents decreases the concentration of free radical in the brain. Neurochemical studies have proposed a role for catalase in brain mechanisms responsible by development to status epilepticus (SE) induced by pilocarpine. The present study was aimed at was investigating the changes in catalase activities after pilocarpine-induced SE. Animals were treated with vitamin E (VIT E) 200 mg/kg (intraperitoneally (i.p.)) and, 30 min later, they received pilocarpine hydrochloride, 400 mg/kg, subcutaneous (s.c.) (P400). Other three groups received VIT E (200 mg/kg, i.p.), pilocarpine (400 mg/kg, s.c.) or 0.9% NaCl (control) alone. Animals were closely observed for behavioral changes, tremors, stereotyped movements, seizures, SE and death, for 24 h following the pilocarpine injection. The brains were dissected after decapitation. The results have shown that pilocarpine administration and resulting SE produced a significant increase in hippocampal catalase activity of (88%). In the group pre-treated which VIT E in hippocampal catalase activity was increase of 67% and 214% when compared with P400 and control group, respectively. Our results demonstrated a direct evidence of an increase in the activity of the hippocampal catalase of rat adults during seizure activity and after the pre-treated which VIT E that could be responsible by regulation of free radical levels during the establishment of SE. © 2007 Elsevier Ireland Ltd. All rights reserved. Keywords: Vitamin E; Catalase; Hippocampus; Seizures; Status epilepticus; Pilocarpine The acute administration of a high dose of pilocarpine, mus- carinic cholinergic agonist, induces behavioural changes and seizures which progress within 1–2 h to long-lasting sta- tus epilepticus (SE) [21]. Pilocarpine-induced epilepsy rodent models, have provided information regarding behavioural and neurochemical characteristics associated with seizures activity that are similar to human temporal lobe epilepsy. Other studies suggest permanent changes in neurochemical systems different such as cholinergic system that might is altered after seizures and SE induced by pilocarpine [9,20]. Therefore, we deemed it important to study the antioxidant activity of the vitamin E related to cholinergic system during seizures and SE. ∗ Corresponding author at: Rua Frederico Severo 201, Ap 103, Bl 07, Messe- jana, Fortaleza 60830-310, Brazil. Tel.: +55 88 3412 2201; fax: +55 88 3412 2201. E-mail address: rivmendes@bol.com.br (R.M. Freitas). The pilocarpine model is an useful animal model to inves- tigate the development of neuropathology of temporal lobe epilepsy [4]. Despite numerous studies that clearly indicate the importance of enzymes activities in the epileptic phenomenon, the mechanisms by which these enzymes such as catalase influ- ence seizures and SE are not completely understood [19]. Catalase has a crucial role in antioxidant enzymatic activ- ity, hydrolyzing the H 2 O 2 to no able the free radical production [6,13]. The free radical such as O 2 - amd OH· have also been demonstrated in the development, differentiation and neural death [17]. The increased free radical levels can alter dramati- cally the neuronal function and an over release and/or synthesis of this oxidant agents has been related to SE [8]. In particular, the has been suggested that O 2 - , acting via oxidative stress, may be involved in adult neuronal plasticity [18] and the excessive content of reactive species derivate of oxygen (ROS) can induce SE and damage neuronal in young and adult rats [9,10]. Neurochemical as well as functional studies suggest that pilocarpine alters free radical metabolism in rat brain. ROS 0304-3940/$ – see front matter © 2007 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.neulet.2007.01.057