RESUMEN
Temporal lobe epilepsy (TLE) is the most frequent and medically refractory type of epilepsy in humans. In addition to seizures, patients with TLE suffer from behavioral alterations and cognitive deficits. Poststatus epilepticus model of TLE induced by pilocarpine in rodents has enhanced the understanding of the processes leading to epilepsy and thus, of potential targets for antiepileptogenic therapies. Clinical and experimental evidence suggests that inflammatory processes in the brain may critically contribute to epileptogenesis. Statins are inhibitors of cholesterol synthesis, and present pleiotropic effects that include antiinflammatory properties. We aimed the present study to test the hypothesis that atorvastatin prevents behavioral alterations and proinflammatory state in the early period after pilocarpine-induced status epilepticus. Male and female C57BL/6 mice were subjected to status epilepticus induced by pilocarpine and treated with atorvastatin (10 or 100mg/kg) for 14days. Atorvastatin slightly improved the performance of mice in the open-field and object recognition tests. In addition, atorvastatin dose-dependently decreased basal and status epilepticus-induced levels of interleukin-1ß (IL-1ß), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and interferon-γ (INF-γ) and increased interleukin-10 (IL-10) levels in the hippocampus and cerebral cortex. The antiinflammatory effects of atorvastatin were qualitatively identical in both sexes. Altogether, these findings extend the range of beneficial actions of atorvastatin and indicate that its antiinflammatory effects may be useful after an epileptogenic insult.
Asunto(s)
Atorvastatina/farmacología , Epilepsia/tratamiento farmacológico , Hipocampo/metabolismo , Pilocarpina/toxicidad , Estado Epiléptico/tratamiento farmacológico , Animales , Antiinflamatorios/farmacología , Atorvastatina/uso terapéutico , Corteza Cerebral/patología , Trastornos del Conocimiento , Convulsivantes/farmacología , Modelos Animales de Enfermedad , Femenino , Regulación de la Expresión Génica/efectos de los fármacos , Hipocampo/efectos de los fármacos , Hipocampo/patología , Humanos , Interleucina-1beta/efectos de los fármacos , Interleucina-6/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Pilocarpina/farmacología , Convulsiones/tratamiento farmacológico , Estado Epiléptico/inducido químicamenteRESUMEN
OBJECTIVES: Epilepsy is a common brain disease and a major worldwide public health problem. The seizures in a significant number of patients suffering from epilepsy remain inadequately controlled by currently available pharmacological treatments. Accordingly, there is a need for the discovery of new anticonvulsant approaches with improved efficacy and a better safety profile. In this context, natural products can be a valuable source of substances with potential anticonvulsant activity. In the present study, we tested the anticonvulsant potential of Caryocar coriaceum Wittm., a plant native from the Brazilian Cerrado biome (tropical savanna ecoregion). METHODS: Adult male C57BL/6 mice were treated with increasing doses of the fixed oil obtained from the pulp of Caryocar coriaceum Wittm. Seizure activity was induced by PTZ (60 mg/kg, i.p.), and evaluated by behavioral and electrographic methods. Potential adverse effects were investigated in the open-field, rotarod, forced swim, or object recognition tests. The antioxidant potential of the oil was evaluated by the DPPH scavenging assay. RESULTS: Administration of the oil at the dose of 100 mg/kg increased the latency for the first myoclonic jerk and the first generalized tonic-clonic seizures. The duration of generalized convulsions induced by PTZ was not altered. No significant behavioral adverse effects were detected in the open-field, rotarod, forced swim, or object recognition tests. Interestingly, a significant antioxidant activity of Caryocar coriaceum Wittm. fixed pulp oil was detected in the DPPH scavenging assay. DISCUSSION: Natural products can be a valuable source of substances with potential anticonvulsant activity and improved safety profile. Further studies are needed to evaluate the mechanisms underlying the anticonvulsant effects of Caryocar coriaceum Wittm. fixed pulp oil as well as the potential of the oil as a source of new anticonvulsant compounds.
Asunto(s)
Anticonvulsivantes/farmacología , Ericales , Aceites de Plantas/farmacología , Convulsiones , Animales , Convulsivantes/toxicidad , Electroencefalografía , Masculino , Ratones , Ratones Endogámicos C57BL , Pentilenotetrazol/toxicidad , Convulsiones/inducido químicamenteRESUMEN
Epilepsy is a chronic neurological disease characterized by spontaneous recurrent seizures (SRS). Current anticonvulsant drugs are ineffective in nearly one-third of patients and may cause significant adverse effects. Rosmarinic acid is a naturally occurring substance which displays several biological effects including antioxidant and neuroprotective activity. Since oxidative stress and excitotoxicity play a role in the pathophysiology of seizures, we aimed the present study to test the hypothesis that rosmarinic acid displays anticonvulsant and disease-modifying effects. Female C57BL/6 mice received rosmarinic acid (0, 3, 10, or 30mg/kg; p.o.) 60min before the injection of pentylenetetrazol (PTZ, 60mg/kg; i.p.) or pilocarpine (300mg/kg, i.p.). Myoclonic and generalized tonic-clonic seizure latencies and generalized seizure duration were analyzed by behavioral and electroencephalographic (EEG) methods. The effect of acute administration of rosmarinic acid on mice behavior in the open-field, object recognition, rotarod, and forced swim tests was also evaluated. In an independent set of experiments, we evaluated the effect of rosmarinic acid (3 or 30mg/kg, p.o. for 14days) on the development of SRS and behavioral comorbidities in the pilocarpine post-status epilepticus (SE) model of epilepsy. Rosmarinic acid dose-dependently (peak effect at 30mg/kg) increased the latency to myoclonic jerks and generalized seizures in the PTZ model and increased the latency to myoclonic jerks induced by pilocarpine. Rosmarinic acid (30mg/kg) increased the number of crossings, the time at the center of the open field, and the immobility time in the forced swim test. In the chronic epilepsy model, treatment with rosmarinic acid did not prevent the appearance of SRS or behavioral comorbidities. In summary, rosmarinic acid displayed acute anticonvulsant-like activity against seizures induced by PTZ or pilocarpine in mice, but further studies are needed to determine its epilepsy-modifying potential.
Asunto(s)
Anticonvulsivantes/uso terapéutico , Cinamatos/uso terapéutico , Depsidos/uso terapéutico , Convulsiones/tratamiento farmacológico , Animales , Conducta Animal/efectos de los fármacos , Cinamatos/farmacología , Depsidos/farmacología , Relación Dosis-Respuesta a Droga , Femenino , Ratones , Ratones Endogámicos C57BL , Pentilenotetrazol , Pilocarpina , Convulsiones/inducido químicamente , Ácido RosmarínicoRESUMEN
Increasing evidence suggests that plant-derived extracts and their isolated components are useful for treatment of seizures and, hence, constitute a valuable source of new antiepileptic drugs with improved efficacy and better adverse effect profile. ß-Caryophyllene is a natural bicyclic sesquiterpene that occurs in a wide range of plant species and displays a number of biological actions, including neuroprotective activity. In the present study, we tested the hypothesis that ß-caryophyllene displays anticonvulsant effects. In addition, we investigated the effect of ß-caryophyllene on behavioral parameters and on seizure-induced oxidative stress. Adult C57BL/6 mice received increasing doses of ß-caryophyllene (0, 10, 30, or 100mg/kg). After 60 min, we measured the latencies to myoclonic and generalized seizures induced by pentylenetetrazole (PTZ, 60 mg/kg). We found that ß-caryophyllene increased the latency to myoclonic jerks induced by PTZ. This result was confirmed by electroencephalographic analysis. In a separate set of experiments, we found that mice treated with an anticonvulsant dose of ß-caryophyllene (100mg/kg) displayed an improved recognition index in the object recognition test. This effect was not accompanied by behavioral changes in the open-field, rotarod, or forced swim tests. Administration of an anticonvulsant dose of ß-caryophyllene (100mg/kg) did not prevent PTZ-induced oxidative stress (i.e., increase in the levels of thiobarbituric acid-reactive substances or the decrease in nonprotein thiols content). Altogether, the present data suggest that ß-caryophyllene displays anticonvulsant activity against seizures induced by PTZ in mice. Since no adverse effects were observed in the same dose range of the anticonvulsant effect, ß-caryophyllene should be further evaluated in future development of new anticonvulsant drugs.
Asunto(s)
Anticonvulsivantes/uso terapéutico , Convulsivantes , Pentilenotetrazol , Convulsiones/inducido químicamente , Convulsiones/tratamiento farmacológico , Sesquiterpenos/uso terapéutico , Animales , Relación Dosis-Respuesta a Droga , Electroencefalografía/efectos de los fármacos , Epilepsias Mioclónicas/inducido químicamente , Epilepsias Mioclónicas/tratamiento farmacológico , Epilepsias Mioclónicas/psicología , Ratones , Ratones Endogámicos C57BL , Actividad Motora/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Sesquiterpenos Policíclicos , Equilibrio Postural/efectos de los fármacos , Reconocimiento en Psicología , Convulsiones/psicología , Natación/psicologíaRESUMEN
Together with pharmacoresistant seizures, the quality of life of temporal lobe epilepsy (TLE) patients is negatively impacted by behavioral comorbidities including but not limited to depression, anxiety and cognitive deficits. The pilocarpine model of TLE has been widely used to study characteristics of human TLE, including behavioral comorbidities. Since the outcomes of pilocarpine-induced TLE might vary depending on several experimental factors, we sought to investigate potential gender-related differences regarding selected behavioral alterations in C57BL6 mice. We found that epileptic mice, independent of gender, displayed increased anxiety-like behavior in the open-field test. In the object recognition test, epileptic mice, regardless of gender, showed a decreased recognition index at 24 (but not at 4) hours after training. On the other hand, no significant differences were found regarding mice learning and memory performance in the Barnes maze paradigm. Motor coordination and balance as assessed by the beam walk and rotarod tests were not impaired in epileptic mice of both genders. However, female mice, independent of epilepsy, performed the beam walk and rotarod tasks better than their male counterparts. We also found that only male epileptic mice displayed disturbed behavior in the forced swim test, but the mice of both genders displayed anhedonia-like behavior in the taste preference test. Lastly, we found that the extent of hilar cell loss is similar in both genders. In summary, both genders can be successfully employed to study behavioral comorbidities of TLE; however, taking the potential gender differences into account may help choose the more appropriated gender for a given task, which may be of value for the minimization of the number of animals used during the experiments.
Asunto(s)
Trastornos del Conocimiento/etiología , Trastornos Mentales/etiología , Caracteres Sexuales , Estado Epiléptico/complicaciones , Factores de Edad , Análisis de Varianza , Animales , Anticonvulsivantes/uso terapéutico , Diazepam/uso terapéutico , Modelos Animales de Enfermedad , Femenino , Preferencias Alimentarias/efectos de los fármacos , Masculino , Aprendizaje por Laberinto/efectos de los fármacos , Ratones , Ratones Endogámicos C57BL , Actividad Motora/efectos de los fármacos , Agonistas Muscarínicos/toxicidad , Pilocarpina/toxicidad , Equilibrio Postural/efectos de los fármacos , Trastornos Psicomotores/etiología , Reconocimiento en Psicología , Estado Epiléptico/inducido químicamente , Natación/psicologíaRESUMEN
Temporal lobe epilepsy (TLE) is the most common type of epilepsy with about one third of TLE patients being refractory to antiepileptic drugs. Knowledge about the mechanisms underlying seizure activity is fundamental to the discovery of new drug targets. Brain Na(+),K(+)-ATPase activity contributes to the maintenance of the electrochemical gradients underlying neuronal resting and action potentials as well as the uptake and release of neurotransmitters. In the present study we tested the hypothesis that decreased Na(+),K(+)-ATPase activity is associated with changes in the alpha subunit phosphorylation and/or redox state. Activity of Na(+),K(+)-ATPase decreased in the hippocampus of C57BL/6 mice 60 days after pilocarpine-induced status epilepticus (SE). In addition, the Michaelis-Menten constant for ATP of α2/3 isoforms increased at the same time point. Nitration of the α subunit may underlie decreased Na(+),K(+)-ATPase activity, however no changes in expression or phosphorylation state at Ser(943) were found. Further studies are necessary define the potential of nitrated Na(+),K(+)-ATPase as a new therapeutic target for seizure disorders.
Asunto(s)
Hipocampo/enzimología , ATPasa Intercambiadora de Sodio-Potasio/metabolismo , Estado Epiléptico/enzimología , Adenosina Trifosfato/metabolismo , Animales , Modelos Animales de Enfermedad , Isoenzimas , Masculino , Ratones Endogámicos C57BL , Oxidación-Reducción , Fosforilación , Pilocarpina , ATPasa Intercambiadora de Sodio-Potasio/genéticaRESUMEN
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RESUMEN
Statins are inhibitors of the enzyme 3-hydroxy-3-methylglutaryl coenzyme A reductase, the rate-limiting step in cholesterol biosynthesis. Statins effectively prevent and reduce the risk of coronary artery disease through lowering serum cholesterol, and also exert anti-thrombotic, anti-inflammatory and antioxidant effects independently of changes in cholesterol levels. On the other hand, clinical and experimental evidence suggests that abrupt cessation of statin treatment (i.e. statin withdrawal) is associated with a deleterious rebound phenomenon. In fact, statin withdrawal increases the risk of thrombotic vascular events, causes impairment of endothelium-dependent relaxation and facilitates experimental seizures. However, evidence for statin withdrawal-induced detrimental effects to the brain parenchyma is still lacking. In the present study adult male Wistar rats were treated with atorvastatin for seven days (10mg/kg/day) and neurochemical assays were performed in the cerebral cortex 30 min (atorvastatin treatment) or 24h (atorvastatin withdrawal) after the last atorvastatin administration. We found that atorvastatin withdrawal decreased levels of nitric oxide and mitochondrial superoxide dismutase activity, whereas increased NADPH oxidase activity and immunoreactivity for the protein nitration marker 3-nitrotyrosine in the cerebral cortex. Catalase, glutathione-S-transferase and xanthine oxidase activities were not altered by atorvastatin treatment or withdrawal, as well as protein carbonyl and 4-hydroxy-2-nonenal immunoreactivity. Immunoprecipitation of mitochondrial SOD followed by analysis of 3-nitrotyrosine revealed increased levels of nitrated mitochondrial SOD, suggesting the mechanism underlying the atorvastatin withdrawal-induced decrease in enzyme activity. Altogether, our results indicate the atorvastatin withdrawal elicits oxidative/nitrosative damage in the rat cerebral cortex, and that changes in NADPH oxidase activity and mitochondrial superoxide dismutase activities may underlie such harmful effects.
Asunto(s)
Corteza Cerebral/efectos de los fármacos , Corteza Cerebral/metabolismo , Ácidos Heptanoicos/efectos adversos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/efectos adversos , Pirroles/efectos adversos , Síndrome de Abstinencia a Sustancias/etiología , Síndrome de Abstinencia a Sustancias/metabolismo , Animales , Atorvastatina , Corteza Cerebral/enzimología , Ácidos Heptanoicos/administración & dosificación , Inhibidores de Hidroximetilglutaril-CoA Reductasas/administración & dosificación , Masculino , Óxido Nítrico/metabolismo , Oxidación-Reducción , Pirroles/administración & dosificación , Ratas , Ratas Wistar , Síndrome de Abstinencia a Sustancias/enzimología , Superóxido Dismutasa/metabolismo , Tirosina/análogos & derivados , Tirosina/metabolismoRESUMEN
Ciliary neurotrophic factor (CNTF) regulates the differentiation and survival of a wide spectrum of developing and adult neurons, including motor neuron loss after injury. We recently described a cell-penetrant recombinant human CNTF (rhCNTF) molecule, formed by fusion with the human immunodeficiency virus-1 transactivator of transcription (TAT) protein transduction domain (TAT-CNTF) that, upon subcutaneous administration, retains full neurotrophic activity without cytokine-like side-effects. Although the CNTF receptor is present in hypothalamic nuclei, which are involved in the control of energy, rhCNTF but not TAT-CNTF stimulates signal transducers and activators of transcription 3 phosphorylation in the rat hypothalamus after subcutaneous administration. This could be due limited TAT-CNTF distribution in the hypothalamus and/or altered intracellular signaling by the fusion protein. To explore these possibilities, we examined the effect of intracerebroventricular administration of TAT-CNTF in male adult rats. TAT-CNTF-induced weight loss, although the effect was smaller than that seen with either rhCNTF or leptin (which exerts CNTF-like effects via its receptor). In contrast to rhCNTF and leptin, TAT-CNTF neither induced morphological changes in adipose tissues nor increased uncoupling protein 1 expression in brown adipose tissue, a characteristic feature of rhCNTF and leptin. Acute intracerebroventricular administration of TAT-CNTF induced a less robust phosphorylation of signal transducers and activators of transcription 3 in the hypothalamus, compared with rhCNTF. The data show that fusion of a protein transduction domain may change rhCNTF CNS distribution, while further strengthening the utility of cell-penetrating peptide technology to neurotrophic factor biology beyond the neuroscience field.