Fluvoxamine alters the activity of energy metabolism enzymes in the brain

Objective: Several studies support the hypothesis that metabolism impairment is involved in the pathophysiology of depression and that some antidepressants act by modulating brain energy metabolism. Thus, we evaluated the activity of Krebs cycle enzymes, the mitochondrial respiratory chain, and creatine kinase in the brain of rats subjected to prolonged administration of fluvoxamine. Methods: Wistar rats received daily administration of fluvoxamine in saline (10, 30, and 60 mg/kg) for 14 days. Twelve hours after the last administration, rats were killed by decapitation and the prefrontal cortex, cerebral cortex, hippocampus, striatum, and cerebellum were rapidly isolated. Results: The activities of citrate synthase, malate dehydrogenase, and complexes I, II-III, and IV were decreased after prolonged administration of fluvoxamine in rats. However, the activities of complex II, succinate dehydrogenase, and creatine kinase were increased. Conclusions: Alterations in activity of energy metabolism enzymes were observed in most brain areas analyzed. Thus, we suggest that the decrease in citrate synthase, malate dehydrogenase, and complexes I, II-III, and IV can be related to adverse effects of pharmacotherapy, but long-term molecular adaptations cannot be ruled out. In addition, we demonstrated that these changes varied according to brain structure or biochemical analysis and were not dose-dependent. .

Prophylactic treatment with Bacopa monnieri leaf powder mitigates paraquat- induced oxidative perturbations and lethality in Drosophila melanogaster.

Environmental exposure to the oxidant-producing herbicide, paraquat (PQ) (1, 1’-dimethyl-4, 4’-bipyridinium dichloride) has long been implicated as a risk factor in Parkinson’s disease (PD). PQ-induced oxidative stress has been exploited as a model to screen putative neuroprotective compounds employing Drosophila. In the present study, we investigated the prophylactic efficacy of Bacopa monnieri (BM) against PQ-induced oxidative stress, mitochondrial dysfunctions and lethality. Exposure of adult male flies (Oregon K) to PQ alone (40 mM in 5% sucrose) resulted in 50% mortality at 48 h. Prophylaxis (7 days) with BM extract (0.1%) offered significant protection (40%) against PQ-induced mortality. Further, oxidative impairments and mitochondrial dysfunctions were monitored among Drosophila exposed to PQ (20, 40 mM) for 24 h. Significant induction of oxidative stress was observed in terms of enhanced malondialdehyde and hydroperoxide levels, and elevated activities of antioxidant enzymes (catalase and SOD). Mitochondrial dysfunctions included of significant reduction in the activities of succinate dehydrogenase (23%), complex I-III (26%), and complex II-III (30%) enzymes. Interestingly, prophylaxis with BM extract prevented the oxidative stress induction by PQ and restored the activity of ETC complexes, suggesting clearly its specific effect on the mitochondria. While the precise mechanism of action of BM needs further investigations, it may be related to its ability to enhance antioxidant defences and thus mitigate PQ-induced oxidative stress in Drosophila.

Effect of alpha-tocopherol on mitochondrial electron transport in experimental myocardial infarction in rats.

The effect of alpha-tocopherol pretreatment (6 mg/100 g body wt/day, orally for a period of 90 days) on mitochondrial electron transport in myocardial infarction induced by isoproterenol (20 mg/100 g body wt, subcutaneously for two days) was studied in rats. A significant decrease was observed in the activities of isocitrate dehydrogenase, alpha-ketoglutarate dehydrogenase, succinate dehydrogenase, malate dehydrogenase, NADH dehydrogenase and cytochrome oxidase in heart mitochondria of isoproterenol administered rats. The cytochrome content and the oxidation of succinate in state 3 and state 4 decreased significantly in the cardiac mitochondria treatment. In alpha-tocopherol pretreated rats, the activities of TCA cycle enzymes, concentration of cytochromes and the oxidation of succinate in state 3 and state 4 were retained at near normal values, following isoproterenol administration.

Monofluoroacetato de sódio (Composto 1080) / Sodium monofluoroacetate (Compound 1080)

O sal sódico do ácido monofluoroacético (FCH2-COO-Na), também conhecido como 1080, é um potente rodenticida, extremamente tóxico para todos os vertebrados, incluindo o homem e os animais domésticos. Estudos experimentais indicam tratar-se de substância de toxicidade aguda das mais pronunciadas. Em países desenvolvidos é usado com extremo controle como rodenticida, mas no Braisl a situaçäo é grave, porque há evidências de que este produto vem sendo comercializado ilegalmente e utilizado sem o menor critério, com relatos de casos de intoxicaçöes fatais tanto em humanos como em animais domésticos. Além do mais, é o princípio ativo da Palicourea marcgravii e, muito provavelmente, de outras espécies vegetais nativas, que causam "morte súbita" no gado. A ausência na literatura brasileira de informaçöes sobre o monofluoroacetato de sódio justifica esta revisäo , que aborda aspectos da toxicidade, da toxicocinética, e da toxicodinâmica deste agente, bem como sinais e sintomas, diagnóstico e possível tratamento de sua intoxicaçäo