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This study evaluated the effects of omega-3 on inflammation, oxidative stress, and energy metabolism parameters in the brain of mice subjected to high-fat diet-induced obesity model. Body weight and visceral fat weight were evaluated as well. Male Swiss mice were divided into control (purified low-fat diet) and obese (purified high-fat diet). After 6 weeks, the groups were divided into control + saline, control + omega-3, obese + saline, and obese + OMEGA-3. Fish oil (400 mg/kg/day) or saline solution was administrated orally, during 4 weeks. When the experiment completed 10 weeks, the animals were euthanized and the brain and visceral fat were removed. The brain structures (hypothalamus, hippocampus, prefrontal cortex, and striatum) were isolated. Treatment with omega-3 had no effect on body weight, but reduced the visceral fat. Obese animals showed increased inflammation, increased oxidative damage, decreased antioxidant enzymes activity and levels, changes in the Krebs cycle enzyme activities, and inhibition of mitochondrial respiratory chain complexes in the brain structures. Omega-3 treatment partially reversed the changes in the inflammatory and in the oxidative damage parameters and attenuated the alterations in the antioxidant defense and in the energy metabolism (Krebs cycle and mitochondrial respiratory chain). Omega-3 had a beneficial effect on the brain of obese animals, as it partially reversed the changes caused by the consumption of a high-fat diet and consequent obesity. Our results support studies that indicate omega-3 may contribute to obesity treatment.

Neurological dysfunction as a result of neuroinflammation has been reported in sepsis and cause high mortality. High levels of cytokines stimulate the formation of neurotoxic metabolites by kynurenine (KYN) pathway. Vitamin B6 (vit B6) has anti-inflammatory and antioxidant properties and also acts as a cofactor for enzymes of the KYN pathway. Thus, by using a relevant animal model of polymicrobial sepsis, we studied the effect of vit B6 on the KYN pathway, acute neurochemical and neuroinflammatory parameters, and cognitive dysfunction in rats. Male Wistar rats (250-300 g) were submitted to cecal ligation and perforation (CLP) and divided into sham + saline, sham + vit B6, CLP + saline, and CLP + vit B6 (600 mg/kg, s.c.) groups. Twenty-four hours later, the prefrontal cortex and hippocampus were removed for neurochemical and neuroinflammatory analyses. Animals were followed for 10 days to determine survival rate, when cognitive function was assessed by behavioral tests. Vitamin B6 interfered in the activation of kynurenine pathway, which led to an improvement in neurochemical and neuroinflammatory parameters and, consequently, in the cognitive functions of septic animals. Thus, the results indicate that vit B6 exerts neuroprotective effects in acute and late consequences after sepsis.

Studies have consistently reported the participation of oxidative stress, energetic metabolism impairment, and creatine kinase (CK) activity alterations in rat brain in early times in an animal model of sepsis and persist for up to 10 days. We have assessed the antioxidant effects of administration of Ebselen (Eb) e diphenyl diselenide (PhSe)2 two organoselenium compounds on brain oxidative stress, energetic metabolism, and CK activity 12, 24 h, and 10 days after sepsis by cecal ligation and perforation (CLP) in rats. Male Wistar rats underwent either sham operation or CLP and were treated with oral injection of Eb (50 mg/kg) or (PhSe)2 (50 mg/kg) or vehicle. 12, 24 h, and 10 days after CLP, the rats were sacrificed, and samples from brain (hippocampus, striatum, cerebellum, prefrontal cortex, and cortex) were obtained and assayed for thiobarbituric acid reactive species and protein carbonyls formation, mitochondrial respiratory chain, and CK activity. We observed in the results a reduction of oxidative damage to lipids and proteins in the different cerebral structures studied and times with the administration of (PhSe)2; however, Eb seems to exert the same effect. Such changes are reflected in the assessment of mitochondrial respiratory chain complexes by reversing the decreased activity of the complex caused by the model of CLP and CK activity. Our data provide the first experimental demonstration that (PhSe)2 was able to reduce the brain dysfunction associated with CLP-induced sepsis in rats, by decreasing oxidative stress parameters mitochondrial dysfunction and CK activity in early times and in late time.

Traumatic brain injury (TBI) induces glutamatergic excitotoxicity through N-methyl-D-aspartate (NMDA) receptors, affecting the integrity of the mitochondrial membrane. Studies have pointed to mitochondria as the master organelle in the preconditioning-triggered endogenous neuroprotective response. The present study is aimed at understanding energy metabolism in the brains of mice after preconditioning with NMDA and TBI. For this purpose, male albino CF-1 mice were pre-treated with NMDA (75 mg/kg) and subjected to brain trauma. Mitochondrial respiratory chain and creatine kinase activities were assessed at 6 or 24 h after trauma. The mice preconditioned and subjected to TBI exhibited augmented activities of complexes II and IV in the cerebral cortex and/or cerebellum. Creatine kinase activity was also augmented in the cerebral cortex after 24 h. We suggest that even though NMDA preconditioning and TBI have similar effects on enzyme activities, each manage their response via opposite mechanisms because the protective effects of preconditioning are unambiguous. In conclusion, NMDA preconditioning induces protection via an increase of enzymes in the mitochondria.

Obesity is a chronic and multifactorial disease, whose prevalence is increasing in many countries. Pharmaceutical strategies for the treatment of obesity include drugs that regulate food intake, thermogenesis, fat absorption, and fat metabolism. Fenproporex is the second most commonly consumed amphetamine-based anorectic worldwide; this drug is rapidly converted in vivo into amphetamine, which is associated with neurotoxicity. In this context, the present study evaluated DNA damage parameters in the peripheral blood of young and adult rats submitted to an acute administration and chronic administration of fenproporex. In the acute administration, both young and adult rats received a single injection of fenproporex (6.25, 12.5 or 25 mg/kg i.p.) or vehicle. In the chronic administration, both young and adult rats received one daily injection of fenproporex (6.25, 12.5, or 25 mg/kg i.p.) or Tween for 14 days. 2 h after the last injection, the rats were killed by decapitation and their peripheral blood removed for evaluation of DNA damage parameters by alkaline comet assay. Our study showed that acute administration of fenproporex in young and adult rats presented higher levels of damage index and frequency in the DNA. However, chronic administration of fenproporex in young and adult rats did not alter the levels of DNA damage in both parameters of comet assay. The present findings showed that acute administration of fenproporex promoted damage in DNA, in both young and adult rats. Our results are consistent with other reports which showed that other amphetamine-derived drugs also caused DNA damage. We suggest that the activation of an efficient DNA repair mechanism may occur after chronic exposition to fenproporex. Our results are consistent with other reports that showed some amphetamine-derived drugs also caused DNA damage.

Several studies have appointed for a role of glutamatergic system and/or mitochondrial function in major depression. In the present study, we evaluated the creatine kinase and mitochondrial respiratory chain activities after acute and chronic treatments with memantine (N-methyl-D: -aspartate receptor antagonist) and imipramine (tricyclic antidepressant) in rats. To this aim, rats were acutely or chronically treated for 14 days once a day with saline, memantine (5, 10 and 20 mg/kg) and imipramine (10, 20 and 30 mg/kg). After acute or chronic treatments, we evaluated mitochondrial respiratory chain complexes (I, II, II-III and IV) and creatine kinase activities in prefrontal cortex, hippocampus and striatum. Our results showed that both acute and chronic treatments with memantine or imipramine altered respiratory chain complexes and creatine kinase activities in rat brain; however, these alterations were different with relation to protocols (acute or chronic), complex, dose and brain area. Finally, these findings further support the hypothesis that the effects of imipramine and memantine could be involve mitochondrial function modulation.

Silver has been used for years in medicine; it has known antimicrobial properties. Additionally, silver has been used in water and air filtration to eliminate microorganisms, and, more recently, as a biocide to prevent infections in burns. In contact with the human body, nanoparticles can elicit a spectrum of tissue responses such as the generation of reactive oxygen species, decreased function of mitochondria and even cell death. Mitochondries are intracellular organelles that play a crucial role in ATP production. In the present work, we evaluate the in vitro effect of silver nanoparticles (AgN) on the activities of mitochondrial respiratory chain complexes from the brain, skeletal muscle, heart, and liver of rats. Our results demonstrated that AgN (10, 25, and 50 mg l(-1)) decreases the activity of mitochondrial respiratory chain complexes I, II, III, and IV from all tissues.

Methylphenidate (MPH) is frequently prescribed for the treatment of attention deficit/hyperactivity disorder. It was previously demonstrated that MPH altered brain metabolic activity. Most cell energy is obtained through oxidative phosphorylation, in the mitochondrial respiratory chain. However, there are still few studies about MPH effects on the brain of adult rats. Thus, in the present study we evaluated the effect of acute or chronic administration of MPH on the activities of mitochondrial respiratory chain complexes I-IV in the brain of adult rats. For acute administration, a single injection of MPH was given to 60-day-old rats. For chronic administration, MPH injections were given to 60-day-old rats once daily for 28 days. Our results showed that complexes I, II, III and IV were inhibited after acute or chronic MPH administration in the hippocampus, prefrontal cortex, striatum and cerebral cortex. On the other hand, cerebellum was not affected.

We evaluated Na(+),K(+)-ATPase activity in hippocampus of rats submitted to an animal model of mania which included the use of lithium and valproate. In the acute treatment, amphetamine or saline was administered to rats for 14 days, between day 8 and 14, rats were treated with lithium, valproate or saline. In the maintenance treatment, rats were treated with lithium, valproate or saline, between day 8 and 14, amphetamine or saline were administered. Locomotor activity was assessed by open field test and Na(+),K(+)-ATPase activity was measured. Our results showed that mood stabilizers reversed and prevented amphetamine-induced behavioral effects. Moreover, amphetamine (acute treatment) increased Na(+),K(+)-ATPase activity, and administration of lithium or valproate reversed this effect. In the maintenance treatment, amphetamine increased Na(+),K(+)-ATPase activity in saline-pretreated rats. Amphetamine administration in lithium- or valproate-pretreated animals did not alter Na(+),K(+)-ATPase activity. The findings suggest that amphetamine-induced hyperactivity may be associated with an increase in Na(+),K(+)-ATPase.

Nevirapine (NVP) and efavirenz (EFV) are antiretroviral drugs belonging to potent class of non-nucleoside reverse transcriptase inhibitors (NNRTIs) widely used for the treatment human immunodeficiency virus (HIV) infection. It has been demonstrated that NVP and EFV are able to cross the blood-brain barrier and arrive at the central nervous system (CNS), causing important adverse effects related to their presence within this tissue. Considering that the exact mechanisms responsible for CNS toxicity associated with NVP and EFV remain unknown and that creatine kinase (CK) plays an important role in cell energy homeostasis, in the present work we evaluated CK activity in brain of mice after chronic administration of these drugs. Our results demonstrated that NVP and EFV significantly inhibited CK activity in cerebellum, hippocampus, striatum and cortex of mice. Although it is difficult to extrapolate our findings to the human condition, the inhibition of brain CK activity by NVP and EFV may be associated with neurological adverse symptoms of these drugs.

Typical and atypical antipsychotic drugs have been shown to have different clinical, biochemical, and behavioral profiles. It is well described that impairment of metabolism, especially in the mitochondria, leads to oxidative stress and neuronal death and has been implicated in the pathogenesis of a number of diseases in the brain. Considering that some effects of chronic use of antipsychotic drugs are still not well known and that succinate dehydrogenase (SDH) and cytochrome oxidase (COX) are crucial enzymes of mitochondria, in this work, we evaluated the activities of these enzymes in rat brain after haloperidol, clozapine, olanzapine, or aripiprazole chronic administration. Adult male Wistar rats received daily injections of haloperidol (1.5 mg/kg), clozapine (25 mg/kg), olanzapine (2.5, 5, or 10 mg/kg), or aripiprazole (2, 10 or 20 mg/kg) for 28 days. We verified that COX was not altered by any drug tested. Moreover, our results demonstrated that the atypical antipsychotic olanzapine inhibited SDH in the cerebellum and aripiprazole increased the enzyme in the prefrontal cortex. We also observed that haloperidol inhibited SDH in the striatum and hippocampus, whereas clozapine inhibited the enzyme only in the striatum. These results showed that antipsychotic drugs altered SDH activity but not COX. In this context, haloperidol, olanzapine, and clozapine may impair energy metabolism in some brain areas.

The potential of gold nanoparticles (GNPs) for use in different biological applications has led to a strong interest in the study of their possible deleterious effects in biological systems and how these effects may be mitigated. This study was undertaken to investigate the effects of the acute and chronic administration of GNPs with mean diameters of 10 and 30 nm on deoxyribonucleic acid (DNA) damage in the blood and liver of adult rats. For the acute administration, Wistar adult rats received a single intraperitoneal injection of either GNPs or a saline solution. For the chronic administration, Wistar adult rats received a daily single injection of the same GNPs or saline solution for 28 days. Twenty-four hours after either the single (acute) or final injection (chronic), the rats were euthanised by decapitation, and the blood and liver were isolated for the evaluation of DNA damage. In this study, we demonstrated that the acute and chronic administration of GNPs 10 and 30 nm in size increased the frequency of DNA damage and the damage index in the blood and liver of adult rats. These findings suggest that the DNA damage may be caused by oxidative stress, which occurred regardless of the type of administration and GNP size.