Striatal monoamines levels during status epilepticus

The purpose of the present work to investigate the striatal neurotransmissors level in adult rats after status epilepticus induced by pilocarpine. Wistar rats were treated with a single dose of pilocarpine (400 mg/kg; s.c.; P400) and the controls received saline. Adult animals were closed observed for behavioural changes during 1h. In this period, the animals that developed status epilepticus and survive this acute phase of seizures had the brains removed and striatal neurotransmissors level determiden by HPLC. The concentration of dopamine, serotonine, dihydroxyphenylacetic acid was reduced and an concentration increase in 5-hydroxyindolacetic acid. Didn't observed alteration in 4-hydroxy-3-methoxy-phenylacetic acid. These results suggest that cholinergic activation can interage with dopaminergic and serotonergic systems in acute phase of the convulsive process in rat mature striatum.O objetivo desse estudo foi verificar os níveis dos neurotransmissores estriatais de ratas adultas durante o estado epiléptico induzido pela pilocarpina. Ratas wistar foram tratadas com uma única dose de pilocarpina (400 mg/kg por via subcutânea (S.C.); P400) e os controles receberam salina. A concentração dos neurotransmissores foi determinada através do HPLC eletroquímico, no corpo estriado de ratas que no período de observação de 1 hora desencadearam estado epiléptico e que sobreviveram à fase aguda do quadro convulsivo. Foi observada redução nos níveis de dopamina, serotonina, ácido diidroxifenilacético e aumento na concentração do ácido 5-hidroxiindolacético. Nenhuma alteração foi observada no 4-hidroxi-3-metoxi-fenilacético. Os resultados sugerem que a ativação do sistema colinérgico pode interagir com os sistemas dopaminérgico e serotonérgico nos mecanismos referentes à fase aguda do processo convulsivo no corpo estriado de ratos desenvolvidos

Êxtase (MDMA): efeitos farmacológicos e tóxicos, mecanismo de ação e abordagem clínica

BACKGROUND: The consumption of the amphetamine derivative 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) by young people increased in the past years. OBJECTIVES: To conduct a literature review on the pharmacology of MDMA and particularly with respect to the putative mechanism of action implicated in the acute and long-term toxicity and neurotoxic effects. METHODS: A literature review using the key words: 3,4-methylenedioxymethamphetamine, ecstasy, neurotoxicity, intoxication, abuse drugs was performed in the databases MEDLINE and LILACS. The search covered all articles published between 1985 and 2007. RESULTS: There were still many unanswered questions regarding the pharmacology of ecstasy and the pathophysiology of its toxic effects. The fundamental mechanism of action is insufficient to explain all effects induced by the drug. The exact mechanism responsible for mediating the toxic effects of MDMA on 5-HT neurons remain to be elucidated. DISCUSSION: There is limited information in published literature about the underlying pharmacology and mechanism of action that could account for the neurotoxic and other phathophysiological effect of MDMA.CONTEXTO: O 3,4-metilenodioximetanfetamina (MDMA, êxtase) é um derivado da anfetamina, cujo consumo por jovens tem aumentado. OBJETIVOS: Conduzir uma revisão de literatura sobre os aspectos farmacológicos e fisiopatológicos do MDMA, incluindo o mecanismo de ação que possa explicar os efeitos neurotóxicos e a toxicidade aguda e a longo prazo. MÉTODOS: Revisão da literatura usando as palavras-chave: 3,4-methylenedioxymethamphetamine, ecstasy, neurotoxicity, intoxication, drug abuse, por intermédio do MEDLINE e LILACS. A busca incluiu todos os artigos publicados no período entre 1985 e 2007. RESULTADOS: Ainda existem muitas questões sem respostas sobre a farmacologia do êxtase e a fisiopatologia dos efeitos tóxicos dessa substância. A simples descrição do mecanismo de ação é insuficiente para explicar todos os efeitos induzidos pelo êxtase. O mecanismo exato responsável por mediar os efeitos tóxicos do MDMA sobre os neurônios da serotonina precisa ser elucidado. CONCLUSÕES: Existem poucas informações na literatura sobre a farmacologia e o mecanismo de ação do MDMA que possam explicar os efeitos neurotóxicos e outros efeitos fisiopatológicos. São necessários mais estudos para que o profissional de saúde possa obter informações e conhecimentos a fim de combater os efeitos terríveis do êxtase na população jovem vulnerável

Effects of hecogenin and its possible mechanism of action on experimental models of gastric ulcer in mice

This study investigates the gastroprotective effects of hecogenin, a steroid saponin isolated from Agave sisalana, on experimental models of gastric ulcer. Male Swiss mice were used in the models of ethanol-and indometacin-induced gastric ulcer. To clarify the hecogenin mechanism of action, the roles of nitric oxide (NO), sulfhydryls (GSH), K-ATP(+) channels and prostaglandins were also investigated, and measurements of lipid peroxidation (TBARS assay) and nitrite levels in the stomach of hecogenin-treated and untreated animals were performed. Furthermore, the effects of hecogenin on myeloperoxidase (MPO) release from human neutrophils were assessed in vitro. Our results showed that hecogenin (3.1, 7.5, 15, 30, 60 and 90 mg/kg, p.o.) acutely administered, before ethanol or indomethacin, exhibited a potent gastroprotective effect. Although the pretreatments with L-NAME, an iNOS inhibitor, and capsazepine, a TRPV1 receptor agonist, were not able to reverse the hecogenin effect, this was reversed by glibenclamide, a K-ATP(+) blocker, and indomethacin in the model of ethanol-induced gastric lesions. the hecogenin pretreatment normalized GSH levels and significantly reduced lipid peroxidation and nitrite levels in the stomach, as evaluated by the ethanol-induced gastric lesion model. the drug alone increased COX-2 expression and this effect was further enhanced in the presence of ethanol. It also decreased MPO release and significantly protected the gastric mucosa. in conclusion, we showed that hecogenin presents a significant gastroprotective effect that seems to be mediated by K-ATP(+) channels opening and the COX-2/PG pathway. in addition, its antioxidant and anti-inflammatory properties may play a role in the gastroprotective drug effect. (C) 2012 Elsevier B. V. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Univ Fed Ceara, Dept Physiol & Pharmacol, BR-60431270 Fortaleza, Ceara, BrazilUniv Fed Ceara, Dept Pharm, BR-60431270 Fortaleza, Ceara, BrazilUniv Fed Paraiba, Dept Pharmaceut Sci, BR-58100000 Joao Pessoa, Paraiba, BrazilUniv Fed Ceara, Dept Morphol, BR-60431270 Fortaleza, Ceara, BrazilUniversidade Federal de São Paulo, Dept Pharmacol, BR-04044020 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Pharmacol, BR-04044020 São Paulo, BrazilWeb of Scienc

Omega-3 fatty acids: possible neuroprotective mechanisms in the model of global ischemia in rats

Background. Omega-3 (omega 3) administration was shown to protect against hypoxic-ischemic injury. The objectives were to study the neuroprotective effects of omega 3, in a model of global ischemia. Methods. Male Wistar rats were subjected to carotid occlusion (30 min), followed by reperfusion. The groups were SO, untreated ischemic and ischemic treated rats with omega 3 (5 and 10 mg/kg, 7 days). The SO and untreated ischemic animals were orally treated with 1% cremophor and, 1 h after the last administration, they were behaviorally tested and euthanized for neurochemical (DA, DOPAC, and NE determinations), histological (Fluoro jade staining), and immunohistochemical (TNF-alpha, COX-2 and iNOS) evaluations. The data were analyzed by ANOVA and Newman-Keuls as the post hoc test. Results. Ischemia increased the locomotor activity and rearing behavior that were partly reversed by omega 3. Ischemia decreased striatal DA and DOPAC contents and increased NE contents, effects reversed by omega 3. This drug protected hippocampal neuron degeneration, as observed by Fluoro-Jade staining, and the increased immunostainings for TNF-alpha, COX-2, and iNOS were partly or totally blocked by omega 3. Conclusion. This study showed a neuroprotective effect of omega 3, in great part due to its anti-inflammatory properties, stimulating translational studies focusing on its use in clinic for stroke managing.Faculty of Medicine, Estácio of Juazeiro do Norte (FMJ), Rua Tenente Raimundo Rocha 515, 63040-360 Juazeiro do Norte, CE, BrazilFederal University of Ceará (UFC), Rua Coronel Nunes de Melo 1127, 60430-270 Fortaleza, CE, BrazilFederal University of São Paulo (UNIFESP), Rua Pedro de Toledo 669, 04039-032 São Paulo, SP, BrazilFederal University of São Paulo (UNIFESP), Rua Pedro de Toledo 669, 04039-032 São Paulo, SP, BrazilWeb of Scienc

Reações adversas causadas por fármacos que atuam no sistema nervoso: análise de registros de um centro de farmacovigilância do Brasil

BACKGROUND: The morbi-mortality by the use of medicines is a major health problem. The drug adverse reactions may result in death, increased hospitalizations and healthcare costs. OBJECTIVES: Describe and analyze reports of suspected adverse reactions caused by drugs that act on the nervous system (SN-ADR), registered in the database of the Pharmacovigilance Centre of Ceará, from January 1997 to March 2008. METHODS: All the NS-ADRs were classified according to criteria of the World Health Organization. The causality between the drug administered and the adverse reaction was established, as well as the analysis regarding to the severity of the reaction. RESULTS: The Centre recorded 176 notifications of RAM-SN. The most of the reactions occurred in the hospital. The main reporter was the pharmacist. All the RAM-SN were classified as possible (n = 110), probable (n = 37) and definite (n = 17). With regard to severity, the NS-ADRs were considered: light (n = 21), moderate (n = 127), serious (n = 15) and fatal (n = 1). The fatal case was reported by physician, and involved anesthetic drugs. In general the adverse reactions observed were caused predominantly by analgesics, anesthetics and antiepileptics. DISCUSSION: The data demonstrate the potential values of accessing to a local system of pharmacovigilance to report possible risks with the use of nervous system drugs.CONTEXTO: A morbimortalidade por uso de medicamentos é um grande problema de saúde. As reações adversas a medicamentos podem resultar em óbito, aumento de internações hospitalares e dos custos com a saúde. OBJETIVOS: Descrever e analisar as notificações de suspeitas de reações adversas causadas por medicamentos que atuam no sistema nervoso (RAM-SN), registradas no Centro de Farmacovigilância do Ceará, de janeiro de 1997 a março de 2008. MÉTODOS: As RAM-SN foram classificadas segundo os critérios da Organização Mundial da Saúde. Uma relação de causalidade entre o fármaco administrado e a reação adversa identificada foi realizada, bem como a análise da reação quanto à gravidade. RESULTADOS: Foram registradas 176 notificações de RAM-SN. A maioria (n = 145; 82,4%) ocorreu no ambiente hospitalar. O principal notificador foi o farmacêutico. As RAM-SN foram classificadas como: possíveis (n = 110), prováveis (n = 37) e definidas (n = 17). Quanto à gravidade, foram consideradas: leves (n = 21), moderadas (n = 127), graves (n = 15) e fatais (n = 1). O caso fatal foi notificado por médico e envolveu medicamentos anestésicos. Geralmente, as reações adversas observadas foram causadas predominantemente por analgésicos, anestésicos e antiepilépticos. DISCUSSÃO: Os dados demonstram o valor potencial de se ter acesso a sistemas de farmacovigilância local para registrar possíveis riscos com o uso de fármacos

Piperine decreases pilocarpine-induced convulsions by GABAergic mechanisms

Piperine, an alkaloid present in the Piper genus, was shown to have an anticonvulsant activity, evaluated by the pilocarpine-induced model, in mice. Pilocarpine (350 mg/kg, i.p.) was administered 30 min after piperine (2.5, 5, 10 and 20 mg/kg, i.p.) which significantly increased latencies to 1st convulsion and to death, and percentage of survivals. These parameters were also increased in the pilocarpine groups pretreated with atropine plus piperine (10 and 2.5 mg/kg, respectively), as related to the pilocarpine group. However, they were not altered in the pilocarpine groups pretreated with memantine (a NMDA-type glutamate receptors blocker, 2 mg/kg, p.o.) or nimodipine (a calcium channel blocker, 10 mg/kg, p.o.), both associated with piperine (1 or 2.5 mg/kg), as compared to the piperine plus pilocarpine group. Moreover, the pilocarpine group pretreated with diazepam (which binds to the GABA(A) receptor, 0.2 and 0.5 mg/kg, i.p.) plus piperine (1 and 2.5 mg/kg) significantly increased latency to the 1st convulsion, as related to the pilocarpine group, suggesting that the GABAergic system is involved with the piperine action. Furthermore, the piperine effect was blocked by flumazenil (2 mg/kg, i.p.), a benzodiazepine antagonist. Untreated P350 animals showed decreased striatal DA and increased DOPAC and HVA levels that were not affected in the piperine plus pilocarpine groups. Piperine increased striatal levels of GABA, glycine and taurine, and reversed pilocarpine-induced increases in nitrite contents in sera and brain. Hippocampi from the untreated pilocarpine group showed an increased number of TNF-alpha immunostained cells in all areas, as opposed to the pilocarpine group pretreated with piperine. Taken together, piperine anticonvulsant effects are the result of its anti-inflammatory and antioxidant actions, as well as TNF-alpha reduction. in addition, piperine effects on inhibitory amino acids and on the GABAergic system may certainly contribute to the drug anticonvulsant activity. (C) 2013 Elsevier Inc. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)FMJ, Fac Med Estacio Juazeiro Norte, Fortaleza, Ceara, BrazilUniversidade Federal de São Paulo, UNIFESP, São Paulo, BrazilUniv Fed Ceara, Fac Med, UFC, Fortaleza, Ceara, BrazilUniversidade Federal de São Paulo, UNIFESP, São Paulo, BrazilWeb of Scienc

Minocycline exerts a neuroprotective action against 6-OHDA-induced neurotoxicity: in vivo and in vitro studies

Background: Parkinson’s disease (PD) is a chronic neurological disorder characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta. The oxidative stress and inflammation, among other factors, are involved in the mechanisms of cell death in PD. We studied the neuroprotective properties of minocycline (Mino), focusing on its behavioral, neurochemical and immunohistochemical effects. Besides, Mino effects were also studied on an in vitro model of PD, as well as on the release of MPO in human neutrophils, and also its antioxidant activity. Methods: We used in vivo (unilateral injection of 6-OHDA into the right striatum) and in vitro (SH-SY5Y cells) models of PD. For the in vivo model, male Wistar rats were divided into the following groups: sham-operated (SO), 6-OHDA-lesioned and untreated and 6-OHDA-lesioned and treated with Mino (10 and 25 mg/kg, p.o., 7days). The animals were evaluated for behavioral, neurochemical and immunohistochemistry alterations. We also focused on Mino cytoprotective effects, as evaluated by its antioxidant and anti-inflammatory effects (nitrite determination and MPO release). Results: Mino (10 and 25 mg/kg, p.o.) significantly reversed the decrease in striatal DA and DOPAC contents, the alteration in apomorphine-induced rotational behavior and the locomotor activity observed in 6-OHDA-lesioned rats, indicative of neuroprotection. Besides, it decreased the immunoreactivity for TNF-alpha in the hippocampus. In SH-SY5Y cells, Mino increased cells viability, as evaluated by the MTT assay, and significantly decreased the high nitrite levels observed in the cells after 6-OHDA-induced cytotoxicity. Mino presented anti-inflammatory and antioxidant effects as evaluated by inhibition of MPO release (an inflammatory marker) on human neutrophils and DPPH assay. Conclusion: Minocycline exerts neuroprotective effects in vivo and in vitro, decreasing dopaminergic cell loss, through mechanisms that are a consequence of Mino anti-inflammatory and antioxidant properties, pointing out to its potential application for the treatment of neurodegenerative diseases as PD. Â