Dual Effect of Carnosine on ROS Formation in Rat Cultured Cortical Astrocytes.

Carnosine is composed of ß-alanine and L-histidine and is considered to be an important neuroprotective agent with antioxidant, metal chelating, and antisenescence properties. However, children with serum carnosinase deficiency present increased circulating carnosine and severe neurological symptoms. We here investigated the in vitro effects of carnosine on redox and mitochondrial parameters in cultured cortical astrocytes from neonatal rats. Carnosine did not alter mitochondrial content or mitochondrial membrane potential. On the other hand, carnosine increased mitochondrial superoxide anion formation, levels of thiobarbituric acid reactive substances and oxidation of 2',7'-dichlorofluorescin diacetate (DCF-DA), indicating that carnosine per se acts as a pro-oxidant agent. Nonetheless, carnosine prevented DCF-DA oxidation induced by H2O2 in cultured cortical astrocytes. Since alterations on mitochondrial membrane potential are not likely to be involved in these effects of carnosine, the involvement of N-Methyl-D-aspartate (NMDA) receptors in the pro-oxidant actions of carnosine was investigated. MK-801, an antagonist of NMDA receptors, prevented DCF-DA oxidation induced by carnosine in cultured cortical astrocytes. Astrocyte reactivity induced by carnosine was also prevented by the coincubation with MK-801. The present study shows for the very first time the pro-oxidant effects of carnosine per se in astrocytes. The data raise awareness on the importance of a better understanding of the biological actions of carnosine, a nutraceutical otherwise widely reported as devoid of side effects.

Age-Associated Upregulation of Glutamate Transporters and Glutamine Synthetase in Senescent Astrocytes In Vitro and in the Mouse and Human Hippocampus.

Aging is marked by complex and progressive physiological changes, including in the glutamatergic system, that lead to a decline of brain function. Increased content of senescent cells in the brain, such as glial cells, has been reported to impact cognition both in animal models and human tissue during normal aging and in the context of neurodegenerative disease. Changes in the glutamatergic synaptic activity rely on the glutamate-glutamine cycle, in which astrocytes handle glutamate taken up from synapses and provide glutamine for neurons, thus maintaining excitatory neurotransmission. However, the mechanisms of glutamate homeostasis in brain aging are still poorly understood. Herein, we showed that mouse senescent astrocytes in vitro undergo upregulation of GLT-1, GLAST, and glutamine synthetase (GS), along with the increased enzymatic activity of GS and [3H]-D-aspartate uptake. Furthermore, we observed higher levels of GS and increased [3H]-D-aspartate uptake in the hippocampus of aged mice, although the activity of GS was similar between young and old mice. Analysis of a previously available RNAseq dataset of mice at different ages revealed upregulation of GLAST and GS mRNA levels in hippocampal astrocytes during aging. Corroborating these rodent data, we showed an increased number of GS + cells, and GS and GLT-1 levels/intensity in the hippocampus of elderly humans. Our data suggest that aged astrocytes undergo molecular and functional changes that control glutamate-glutamine homeostasis upon brain aging.

Patients in insulin analogues use via judicial litigation: do they use the Brazilian Public Health System (SUS)? / Pacientes em uso de análogos de insulina via ação judicial: eles utilizam o Sistema Único de Saúde (SUS)?

Abstract Background Studies show that among the drugs most commonly used in judicial litigation in Brazil, are those used to treat diabetes mellitus, especially insulin analogues. Objective Evaluate the use of the Unified Health System (SUS) by patients with type 1 diabetes mellitus (T1DM), who receive insulin analogues through judicial action, before and after this process. Method In a retrospective longitudinal observational study, secondary data was used from these patients in Minas Gerais, Brazil, in 2018. Socio-demographic information was collected and related to the follow-up of these patients in the SUS. The McNemar χ2 test was used to compare the proportions of the variables. Results Of the 89 patients analyzed, women (53.9%) were predominant. Most patients were aged between 20 and 39 years (52.8%), and more than half, 55.1%, use only a private health system. After the judicial action, there was a significant increase (p <0.05) in the number of patients who had consultations in primary health care (from 19.1% to 30.3%) and emergency medical appointments (from 1.1% to 9.0%). Conclusion It is observed that the majority of patients with T1DM via judicial action in the SUS are not monitored by this health system through examinations, consultations, and hospitalizations.

Resumo Introdução Estudos mostram que, dentre os medicamentos mais adquiridos via ação judicial, estão os utilizados para o tratamento do Diabetes Mellitus, especialmente os análogos de insulina. Objetivo Avaliar a utilização do Sistema Único de Saúde (SUS) pelos pacientes com Diabetes Mellitus tipo 1 (DM1), que recebem insulina por meio de judicialização, antes e após este processo. Método Em um estudo observacional longitudinal retrospectivo, foram utilizados dados secundários de pacientes com DM1, que adquiriram insulinas por processos judiciais em Divinópolis-MG, Brasil, em 2018. Foram coletadas informações sociodemográficas e referentes ao acompanhamento destes pacientes no SUS Realizou-se o teste χ2 de McNemar para a comparação das proporções das variáveis utilizadas para a avaliação do acompanhamento antes e após a judicialização. Resultados Dos 89 pacientes analisados, predominou-se o sexo feminino (53,9%), com idade entre 20 e 39 anos (52,8%). 55,1% destes utilizam apenas o sistema privado de saúde. Após a judicialização, houve um aumento significativo (p< 0,05) no número de pacientes que realizaram consultas na atenção primária à saúde (de 19,1% para 30,3%) e consultas médicas de emergência (de 1,1% para 9,0%). Conclusão A maioria dos pacientes com DM1 que judicializam medicamentos no SUS não são acompanhados por este sistema de saúde através de realização de exames, consultas e hospitalizações.

The Potential Use of Carnosine in Diabetes and Other Afflictions Reported in Long COVID Patients.

Carnosine is a dipeptide expressed in both the central nervous system and periphery. Several biological functions have been attributed to carnosine, including as an anti-inflammatory and antioxidant agent, and as a modulator of mitochondrial metabolism. Some of these mechanisms have been implicated in the pathophysiology of coronavirus disease-2019 (COVID-19). COVID-19 is caused by severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2). The clinical manifestation and recovery time for COVID-19 are variable. Some patients are severely affected by SARS-CoV-2 infection and may experience respiratory failure, thromboembolic disease, neurological symptoms, kidney damage, acute pancreatitis, and even death. COVID-19 patients with comorbidities, including diabetes, are at higher risk of death. Mechanisms underlying the dysfunction of the afflicted organs in COVID-19 patients have been discussed, the most common being the so-called cytokine storm. Given the biological effects attributed to carnosine, adjuvant therapy with this dipeptide could be considered as supportive treatment in patients with either COVID-19 or long COVID.

Quality of Life and a Surveillant Endocannabinoid System.

The endocannabinoid system (ECS) is an important brain modulatory network. ECS regulates brain homeostasis throughout development, from progenitor fate decision to neuro- and gliogenesis, synaptogenesis, brain plasticity and circuit repair, up to learning, memory, fear, protection, and death. It is a major player in the hypothalamic-peripheral system-adipose tissue in the regulation of food intake, energy storage, nutritional status, and adipose tissue mass, consequently affecting obesity. Loss of ECS control might affect mood disorders (anxiety, hyperactivity, psychosis, and depression), lead to drug abuse, and impact neurodegenerative (Alzheimer's, Parkinson, Huntington, Multiple, and Amyotrophic Lateral Sclerosis) and neurodevelopmental (autism spectrum) disorders. Practice of regular physical and/or mind-body mindfulness and meditative activities have been shown to modulate endocannabinoid (eCB) levels, in addition to other players as brain-derived neurotrophic factor (BDNF). ECS is involved in pain, inflammation, metabolic and cardiovascular dysfunctions, general immune responses (asthma, allergy, and arthritis) and tumor expansion, both/either in the brain and/or in the periphery. The reason for such a vast impact is the fact that arachidonic acid, a precursor of eCBs, is present in every membrane cell of the body and on demand eCBs synthesis is regulated by electrical activity and calcium shifts. Novel lipid (lipoxins and resolvins) or peptide (hemopressin) players of the ECS also operate as regulators of physiological allostasis. Indeed, the presence of cannabinoid receptors in intracellular organelles as mitochondria or lysosomes, or in nuclear targets as PPARγ might impact energy consumption, metabolism and cell death. To live a better life implies in a vigilant ECS, through healthy diet selection (based on a balanced omega-3 and -6 polyunsaturated fatty acids), weekly exercises and meditation therapy, all of which regulating eCBs levels, surrounded by a constructive social network. Cannabidiol, a diet supplement has been a major player with anti-inflammatory, anxiolytic, antidepressant, and antioxidant activities. Cognitive challenges and emotional intelligence might strengthen the ECS, which is built on a variety of synapses that modify human behavior. As therapeutically concerned, the ECS is essential for maintaining homeostasis and cannabinoids are promising tools to control innumerous targets.

Caffeine Improves GABA Transport in the Striatum of Spontaneously Hypertensive Rats (SHR).

The spontaneously hypertensive rat (SHR) is an excellent animal model that mimics the behavioral and neurochemical phenotype of attention-deficit/hyperactivity disorder (ADHD). Here, we characterized the striatal GABA transport of SHR and investigated whether caffeine, a non-selective antagonist of adenosine receptors, could influence GABAergic circuitry. For this purpose, ex vivo striatal slices of SHR and Wistar (control strain) on the 35th postnatal day were dissected and incubated with [3H]-GABA to quantify the basal levels of uptake and release. SHR exhibited a reduced [3H]-GABA uptake and release, suggesting a defective striatal GABAergic transport system. GAT-1 appears to be the primary transporter for [3H]-GABA uptake in SHR striatum, as GAT-1 selective blocker, NO-711, completely abolished it. We also verified that acute exposure of striatal slices to caffeine improved [3H]-GABA uptake and release in SHR, whereas Wistar rats were not affected. GABA-uptake increase and cAMP accumulation promoted by caffeine was reverted by A1R activation with N6-cyclohexyl adenosine (CHA). As expected, the pharmacological blockade of cAMP-PKA signaling by H-89 also prevented caffeine-mediated [3H]-GABA uptake increment. Interestingly, a single caffeine exposure did not affect GAT-1 or A1R protein density in SHR, which was not different from Wistar protein levels, suggesting that the GAT-1-dependent transport in SHR has a defective functional activity rather than lower protein expression. The current data support that caffeine regulates GAT-1 function and improves striatal GABA transport via A1R-cAMP-PKA signaling, specifically in SHR. These results reinforce that caffeine may have therapeutic use in disorders where the GABA transport system is impaired.

White matter disturbances in phenylketonuria: Possible underlying mechanisms.

White matter pathologies, as well as intellectual disability, microcephaly, and other central nervous system injuries, are clinical traits commonly ascribed to classic phenylketonuria (PKU). PKU is an inherited metabolic disease elicited by the deficiency of phenylalanine hydroxylase. Accumulation of l-phenylalanine (Phe) and its metabolites is found in tissues and body fluids in phenylketonuric patients. In order to mitigate the clinical findings, rigorous dietary Phe restriction constitutes the core of therapeutic management in PKU. Myelination is the process whereby the oligodendrocytes wrap myelin sheaths around the axons, supporting the conduction of action potentials. White matter injuries are implicated in the brain damage related to PKU, especially in untreated or poorly treated patients. The present review summarizes evidence toward putative mechanisms driving the white matter pathology in PKU patients.

Single Cocaine Exposure Inhibits GABA Uptake via Dopamine D1-Like Receptors in Adolescent Mice Frontal Cortex.

Cocaine (COC) is a psychostimulant that acts by increasing catecholaminergic neurotransmission mainly due to its effects on the dopamine transporter (DAT). However, other neurotransmitter systems may also be regulated by COC, including the GABAergic system. Since the effect of COC in modulating gamma-aminobutyric acid (GABA) reuptake is not defined, we investigated the molecular mechanisms related to the increase in GABA uptake induced by acute COC exposure and its effects on locomotor activity in adolescent mice. Behavioral experiments showed that COC increased locomotor activity and decreased immobilization time in mice. A single COC exposure reduced both GABA uptake and GAT-1 protein levels. On the other hand, cyclic adenosine monophosphate (cAMP) levels increased after a COC challenge. The major changes induced by acute COC on behavioral and neurochemical assays were avoided by previous treatment with the selective D1 receptor antagonist SCH-23390 (0.5 mg/kg). Our findings suggest that GABA uptake naturally decreases during mice development from preadolescence until adulthood and that dopamine (DA) D1-like receptors are key players in the regulation of GABA uptake levels following a single COC exposure in adolescent mice.

Pacientes com diabetes mellitus tipo 2 em uso de medicamentos via judicial: há monitorização clínica e laboratorial? / Patients with type 2 diabetes mellitus using drugs by filing lawsuits: is there clinical and laboratory monitoring? / Pacientes con diabetes mellitus tipo 2 en uso de medicamentos vía judicial: ¿hay monitoreo clínico y laboratorial?

Introdução: O aumento contínuo do número de processos de judicialização da saúde, a relevância epidemiológica do diabetes mellitus tipo 2 (DM2), a escassez de recursos utilizados para monitorar os investimentos dos processos judiciais e do seu alto custo para a saúde pública, diante disso torna-se necessário estudos que analisem o perfil da judicialização dos antidiabéticos, que é a principal classe de medicamentos alvo dos processos judiciais. Objetivo: Analisar se os pacientes com DM2 atendidos via judicial, foram acompanhados e monitorados no Sistema Único de Saúde (SUS) antes e após os processos judiciais. Além de analisar o perfil de medicamentos judicializados para tratamento da DM2. Métodos: Trata-se de um estudo longitudinal retrospectivo, que utilizou dados secundários, prontuários e arquivos de processos judiciais, de 56 pacientes com DM2 que adquiriram pelo menos um de seus medicamentos por meio da judicialização, no ano de 2019, em um município mineiro. Os dados foram analisados 12 meses antes e 12 meses após a judicialização. Resultados: Dentre as 56 ações judiciais, 39% se concentraram em apenas três unidades de saúde do município. Somente 30 pacientes (53%) antes e 29 (51%) após a judicialização tiveram consultas no SUS. Além disso, apenas 15 (26%) e 13 (23%) pacientes, respectivamente antes e após a judicialização, apresentaram algum exame laboratorial realizado pelo SUS. As insulinas Levemir Flex Pen® (13%), Novo Rapid® (11%) e Lantus® (7%) foram os medicamentos mais judicializados. Conclusão: Observou-se que apesar do SUS prover o insumo terapêutico de elevado custo por meio de uma porta de entrada não convencional, não há monitorização clínica e laboratorial para avaliação da efetividade do uso da tecnologia, conforme recomendam os protocolos clínicos e dispositivos legais brasileiros sobre acesso a medicamentos.

Introducción: El aumento continuo en el número de procesos de judicialización de la salud, la relevancia epidemiológica de la diabetes mellitus tipo 2 (DM2), la escasez de recursos utilizados para monitorear las inversiones en procesos judiciales y de su alto costo para la salud pública, se vuelven necesarios estudios que analicen el perfil de la judicialización de los antidiabéticos, que es la principal clase de medicamentos a las que se dirigen los procesos judiciales. Objetivo: Analizar si los pacientes con DM2 atendidos vía judicial, fueron acompañados y monitoreados en el Sistema Único de Salud (SUS) antes y después de los procesos judiciales. Además de analizar el perfil de las drogas legalizadas para el tratamiento de la DM2. Métodos: Se trata de un estudio retrospectivo longitudinal, que utilizó datos secundarios, registros médicos y archivos de demandas, de 56 pacientes con DM2 que adquirieron al menos uno de sus medicamentos a través de la judicialización, en el año 2019, en un municipio de Minas Gerais. Los datos fueron analizados 12 meses antes y 12 meses después de la judicialización. Resultados: Entre las 56 acciones judiciales, el 39% se concentró en solo tres unidades de salud en el municipio. Solo 30 pacientes (53%) antes y 29 (51%) después de la judicialización tuvieron consultas en el SUS. Además, solo 15 (26%) y 13 (23%) pacientes, respectivamente antes y después de la judicialización, se sometieron a pruebas de laboratorio realizadas por el SUS. Las insulinas Levemir Flex Pen® (13.0%), Novo Rapid® (11%) y Lantus® (7%) fueron los medicamentos más judicializadas. Conclusión: Se observó que a pesar de que el SUS proporciona un recurso terapéutico de alto costo a través de una puerta de entrada no convencional, no hay monitoreo clínico y laboratorial para la evaluación de la efectividad del uso de la tecnología, según lo recomendado por los protocolos clínicos y dispositivos legales brasileros sobre el acceso a medicamentos.

Introduction: The continuous increase in the number of health judicialization processes, the epidemiological relevance of type 2 diabetes mellitus (DM2), the scarcity of resources used to monitor the investments of lawsuits, and their high cost to public health, that said there is a need for studies that analyze the profile of the judicialization of antidiabetics, which is the main class of drugs targeted by lawsuits. Objective: To analyze whether patients with DM2 attended by judicial system, are followed up and monitored in Brazilian Public Health System (SUS) before and after judicial proceedings. In addition to analyzing the profile of drugs legalized for the treatment of DM2. Methods: A retrospective observational study, which secondary database, medical records and judicial files, was conducted with 56 patients with DM2 who have acquired at least one of their medicines through lawsuits, in 2019, in a city in Minas Gerais. The data were analyzed 12 months before and 12 months after judicialization process. Results: Among the 56 lawsuits, 39% were concentrated in only three health units. Only 30 patients (53%) before and 29 (51%) after judicialization had appointments in SUS. Furthermore, only 15 (26%) and 13 (23%) patients, respectively before and after judicialization, had some laboratory test performed by SUS. The insulins Levemir Flex Pen® (13%), Novo Rapid® (11%), and Lantus® (7%) were the most judicialized drugs. Conclusion: It was observed that despite the SUS providing the high-cost therapeutic input through an unconventional gateway, there is no clinical and laboratory monitoring to evaluate the effectiveness of the technology, as recommended by clinical protocols and Brazilian laws about access to medicines.

Thirteen years of medication alerts issued by the Brazilian Health Regulatory Agency (ANVISA): What is the profile?

RATIONALE, AIMS, AND OBJECTIVES: As a pharmacovigilance measure, the Brazilian Health Regulatory Agency (ANVISA) monitors the postmarketing events of medication and issues alerts on actions to be taken and information updates. The present study has the objective of analysing the profile of all the alerts on medication issued by ANVISA between 2006 and 2018. METHODS: A descriptive documentary analysis was carried out through the ANVISA website and double checked with two researchers in order to avoid discrepancies in data collection and interpretation of information. RESULTS: A total of 79 alerts available in the period were analysed, the mean being 6.07 alerts/year and standard deviation of 3.81. The medications most cited in the alerts were antivirals (9.7%), followed by antidiabetics (7.3%) and contraceptives (7.3%). The main problems identified were adverse reactions (50%) and other problems related to safety (15%). The main actions directed by ANVISA were generation of a new contraindication (37.3%) and alteration in the package insert (22.3%). CONCLUSION: Alerts are an important means of communicating new information to health professionals and to society. However, they need better standardization in order to facilitate understanding, dissemination in order to broaden access to information, and studies to corroborate the current literature and improve current pharmacovigilance.

Brain bioenergetics in rats with acute hyperphenylalaninemia.

Phenylketonuria (PKU) is a disorder of phenylalanine (Phe) metabolism caused by deficient phenylalanine hydroxylase (PAH) activity. The deficiency results in increased levels of Phe and its metabolites in fluids and tissues of patients. PKU patients present neurological signs and symptoms including hypomyelination and intellectual deficit. This study assessed brain bioenergetics at 1 h after acute Phe administration to induce hyperphenylalaninemia (HPA) in rats. Wistar rats were randomized in two groups: HPA animals received a single subcutaneous administration of Phe (5.2 µmol/g) plus p-Cl-Phe (PAH inhibitor) (0.9 µmol/g); control animals received a single injection of 0.9% NaCl. In cerebral cortex, HPA group showed lower mitochondrial mass, lower glycogen levels, as well as lower activities of complexes I-III and IV, ATP synthase and citrate synthase. Higher levels of free Pi and phospho-AMPK, and higher activities of LDH, α-ketoglutarate dehydrogenase and isocitrate dehydrogenase were also reported in cerebral cortex of HPA animals. In striatum, HPA animals had higher LDH (pyruvate to lactate) and isocitrate dehydrogenase activities, and lower activities of α-ketoglutarate dehydrogenase and complex IV, as well as lower phospho-AMPK immunocontent. In hippocampus, HPA rats had higher mRNA expression for MFN1 and higher activities of α-ketoglutarate dehydrogenase and isocitrate dehydrogenase, but decreased activities of pyruvate dehydrogenase and complexes I and IV. In conclusion, our data demonstrated impaired bioenergetics in cerebral cortex, striatum and hippocampus of HPA rats.

Pinocembrin Attenuates Mitochondrial Dysfunction in Human Neuroblastoma SH-SY5Y Cells Exposed to Methylglyoxal: Role for the Erk1/2-Nrf2 Signaling Pathway.

Pinocembrin (PB; 5,7-dihydroxyflavanone) is found in propolis and exhibits antioxidant activity in several experimental models. The antioxidant capacity of PB is associated with the activation of the nuclear factor erythroid 2-related factor 2/antioxidant response element (Nrf2/ARE) signaling pathway. The Nrf2/ARE axis mediates the expression of antioxidant and detoxifying enzymes, such as glutathione peroxidase (GPx), glutathione reductase (GR), heme oxygenase-1 (HO-1), and the catalytic (GCLC) and regulatory (GCLM) subunits of the rate-limiting enzyme in the synthesis of glutathione (GSH), γ-glutamate-cysteine ligase (γ-GCL). Nonetheless, it is not clear how PB exerts mitochondrial protection in mammalian cells. Human neuroblastoma SH-SY5Y cells were pretreated (4 h) with PB (0-25 µM) and then exposed to methylglyoxal (MG; 500 µM) for further 24 h. Mitochondria were isolated by differential centrifugation. PB (25 µM) provided mitochondrial protection (decreased lipid peroxidation, protein carbonylation, and protein nitration in mitochondrial membranes; decreased mitochondrial free radical production; enhanced the content of GSH in mitochondria; rescued mitochondrial membrane potential-MMP) and blocked MG-triggered cell death by a mechanism dependent on the activation of the extracellular-related kinase (Erk1/2) and consequent upregulation of Nrf2. PB increased the levels of GPx, GR, HO-1, and mitochondrial GSH. The PB-induced effects were suppressed by silencing of Nrf2 with siRNA. Therefore, PB activated the Erk1/2-Nrf2 signaling pathway resulting in mitochondrial protection in SH-SY5Y cells exposed to MG. Our work shows that PB is a strong candidate to figure among mitochondria-focusing agents with pharmacological potential.

Carnosic Acid Protects Mitochondria of Human Neuroblastoma SH-SY5Y Cells Exposed to Paraquat Through Activation of the Nrf2/HO-1Axis.

Carnosic acid (CA; C20H28O4), which is also called salvin, is a major phenolic diterpene found in Rosmarinus officinalis L. and exhibits antioxidant, anti-inflammatory, and antiproliferative properties. CA activates the nuclear factor erythroid 2-related factor 2 (Nrf2) transcription factor, leading to the upregulation of antioxidant and phase II detoxification enzymes, such as heme oxygenase-1 (HO-1), glutathione reductase (GR), γ-glutamate-cysteine ligase (γ-GCL), and glutathione S-transferase (GST), among others. We have previously demonstrated that CA upregulates the total and mitochondrial synthesis of glutathione (GSH), causing mitochondrial protection against paraquat (PQ) and methylglyoxal (MG). Nonetheless, the complete mechanism by which CA prevented mitochondrial dysfunction was not clear yet. Here, we examine whether HO-1 would be involved in the CA-induced mechanism of mitochondrial protection in SH-SY5Y-treated cells. SH-SY5Y cells were pretreated with CA (1 µM) for 12 h prior to a challenge with PQ at 100 µM for additional 24 h. Zinc protoporphyrin IX (ZnPP IX; a specific inhibitor of HO-1; 10 µM) was utilized prior to exposure to CA in order to investigate whether HO-1 was involved in the cytoprotective effects elicited by CA. We found that the CA-induced Nrf2-dependent HO-1 upregulation ameliorated, at least in part, the mitochondrial function in PQ-treated cells. Therefore, CA protected mitochondria of SH-SY5Y cells and exerted anti-apoptotic effects by activating the Nrf2/HO-1 axis.

Carnosic Acid Affords Mitochondrial Protection in Chlorpyrifos-Treated Sh-Sy5y Cells.

Carnosic acid (CA; C20H28O4) is a phenolic diterpene found in rosemary (Rosmarinus officinalis L.) and exhibits protective properties, e.g., antioxidant, anti-inflammatory, antitumor, and antimicrobial activities. In this context, CA has been viewed as a neuroprotective agent due to its ability in rescuing neuronal cells from pro-oxidant and pro-apoptotic challenges. In the present work, we found that CA pretreatment at 1 µM for 12 h suppressed the mitochondria-related pro-oxidant and mitochondria-dependent pro-apoptotic effects of chlorpyrifos (CPF) in human neuroblastoma SH-SY5Y cells. CA prevented mitochondrial membrane potential disruption and decreased the levels of oxidative stress markers in mitochondrial membranes obtained from cells exposed to CPF. CA also inhibited cytochrome c release and activation of the caspases-9 and -3, as well as decreased DNA fragmentation, in CPF-treated cells. CA upregulated the content of glutathione (GSH) in mitochondria by a mechanism involving the activation of the phosphoinositide-3-kinase (PI3K)/Akt/nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway, since inhibition of PI3K/Akt or silencing of Nrf2 using siRNA strategy abolished the protection exerted by CA in SH-SY5Y cells. Therefore, CA protected mitochondria of SH-SY5Y cells through the activation of the PI3K/Akt/Nrf2 axis, causing upregulation of the mitochondrial GSH content and consequent antioxidant and anti-apoptotic effects.

Protective effect of carnosic acid against paraquat-induced redox impairment and mitochondrial dysfunction in SH-SY5Y cells: Role for PI3K/Akt/Nrf2 pathway.

Carnosic acid (CA) is a phenolic diterpene isolated from Rosmarinus officinalis and exerts anti-inflammatory, antioxidant, and anticarcinogenic activities in different cell types. It has been reported that CA is able to cause protective effects on experimental models of neurodegeneration. However, the exact mechanism by which CA prevents neuronal degeneration remains to be better studied. We investigated here whether there is a role for CA as a neuroprotective agent in a paraquat (PQ) model of Parkinson's disease (PD) regarding cellular and mitochondrial-related redox parameters. SH-SY5Y cells were treated with CA for 12h and were exposed to 100 µM PQ for 24h. It was found that CA at different concentrations prevented the effects of PQ on cell viability and redox parameters. CA alleviated reactive oxygen and nitrogen species production elicited by PQ, as well as decreased the toxic effect on mitochondrial function. Inhibition of Pi3K/Akt pathway with LY294002 or silencing of Nrf2 expression partially blocked the reversal of redox impairment induced by CA. Therefore, CA activated Nrf2 through modulation of PI3K/Akt pathway resulting in increased levels of antioxidant enzymes and consequent neuroprotection. Thus, CA may be viewed as a potential neuroprotective agent to be used in cases of Parkinson's disease (PD).

Role for the PI3K/Akt/Nrf2 signaling pathway in the protective effects of carnosic acid against methylglyoxal-induced neurotoxicity in SH-SY5Y neuroblastoma cells.

Glycation, a process that occurs endogenously and generates advanced glycation end products (AGEs), presents an important role in cases of neurodegeneration, as for instance Alzheimer's disease (AD). Methylglyoxal (MG), a dicarbonyl compound, is the most potent inducer of AGEs, whose levels have been found increased in samples obtained from subjects suffering from AD. Moreover, MG induces protein cross-linking and redox impairment in vitro and in vivo. Carnosic acid (CA), a phenolic diterpene isolated from Rosmarinus officinalis, exerts protective effects in neuronal cells by increasing antioxidant defenses and detoxification systems. In the present work, we aimed to investigate whether there is a role for CA against MG-induced neurotoxicity. Data obtained here clearly demonstrate that CA pretreatment (1 µM for 12 h) caused cytoprotective effects and counteracted the damage elicited by MG in SH-SY5Y cells. CA inhibited loss of mitochondrial membrane polarity (MMP) and cytochrome c release from mitochondria, consequently blocking activation of pro-apoptotic caspase enzymes. Furthermore, CA alleviated MG-induced oxidative and nitrosative damage. CA prevented MG-dependent neurotoxicity by activating the PI3K/Akt/Nrf2 signaling pathway and the antioxidant enzymes modulated by Nrf2 transcription factor. Overall, the data presented here show the protective role of CA by its ability to counteract MG negative effects.

Phenylketonuria Pathophysiology: on the Role of Metabolic Alterations.

Phenylketonuria (PKU) is an inborn error of phenylalanine (Phe) metabolism caused by the deficiency of phenylalanine hydroxylase. This deficiency leads to the accumulation of Phe and its metabolites in tissues and body fluids of PKU patients. The main signs and symptoms are found in the brain but the pathophysiology of this disease is not well understood. In this context, metabolic alterations such as oxidative stress, mitochondrial dysfunction, and impaired protein and neurotransmitters synthesis have been described both in animal models and patients. This review aims to discuss the main metabolic disturbances reported in PKU and relate them with the pathophysiology of this disease. The elucidation of the pathophysiology of brain damage found in PKU patients will help to develop better therapeutic strategies to improve quality of life of patients affected by this condition.

Brain and muscle redox imbalance elicited by acute ethylmalonic acid administration.

Ethylmalonic acid (EMA) accumulates in tissues and biological fluids of patients affected by short-chain acyl-CoA dehydrogenase deficiency (SCADD) and ethylmalonic encephalopathy, illnesses characterized by neurological and muscular symptoms. Considering that the mechanisms responsible for the brain and skeletal muscle damage in these diseases are poorly known, in the present work we investigated the effects of acute EMA administration on redox status parameters in cerebral cortex and skeletal muscle from 30-day-old rats. Animals received three subcutaneous injections of EMA (6 µmol/g; 90 min interval between injections) and were killed 1 h after the last administration. Control animals received saline in the same volumes. EMA administration significantly increased thiobarbituric acid-reactive substances levels in cerebral cortex and skeletal muscle, indicating increased lipid peroxidation. In addition, carbonyl content was increased in EMA-treated animal skeletal muscle when compared to the saline group. EMA administration also significantly increased 2',7'-dihydrodichlorofluorescein oxidation and superoxide production (reactive species markers), and decreased glutathione peroxidase activity in cerebral cortex, while glutathione levels were decreased only in skeletal muscle. On the other hand, respiratory chain complex I-III activity was altered by acute EMA administration neither in cerebral cortex nor in skeletal muscle. The present results show that acute EMA administration elicits oxidative stress in rat brain and skeletal muscle, suggesting that oxidative damage may be involved in the pathophysiology of the brain and muscle symptoms found in patients affected by SCADD and ethylmalonic encephalopathy.

Evaluation of the In Vivo and In Vitro Effects of Fructose on Respiratory Chain Complexes in Tissues of Young Rats.

Hereditary fructose intolerance (HFI) is an autosomal-recessive disorder characterized by fructose and fructose-1-phosphate accumulation in tissues and biological fluids of patients. This disease results from a deficiency of aldolase B, which metabolizes fructose in the liver, kidney, and small intestine. We here investigated the effect of acute fructose administration on the activities of mitochondrial respiratory chain complexes, succinate dehydrogenase (SDH), and malate dehydrogenase (MDH) in cerebral cortex, liver, kidney, and skeletal muscle of male 30-day-old Wistar rats. The rats received subcutaneous injection of sodium chloride (0.9%; control group) or fructose solution (5 µmol/g; treated group). One hour later, the animals were euthanized and the cerebral cortex, liver, kidney, and skeletal muscle were isolated and homogenized for the investigations. Acute fructose administration increased complex I-III activity in liver. On the other hand, decreased complexes II and II-III activities in skeletal muscle and MDH in kidney were found. Interestingly, none of these parameters were affected in vitro. Our present data indicate that fructose administration elicits impairment of mitochondrial energy metabolism, which may contribute to the pathogenesis of the HFI patients.

Impairment of electron transfer chain induced by acute carnosine administration in skeletal muscle of young rats.

Serum carnosinase deficiency is an inherited disorder that leads to an accumulation of carnosine in the brain tissue, cerebrospinal fluid, skeletal muscle, and other tissues of affected patients. Considering that high levels of carnosine are associated with neurological dysfunction and that the pathophysiological mechanisms involved in serum carnosinase deficiency remain poorly understood, we investigated the in vivo effects of carnosine on bioenergetics parameters, namely, respiratory chain complexes (I-III, II, and II-III), malate dehydrogenase, succinate dehydrogenase, and creatine kinase activities and the expression of mitochondrial-specific transcription factors (NRF-1, PGC-1α , and TFAM) in skeletal muscle of young Wistar rats. We observed a significant decrease of complexes I-III and II activities in animals receiving carnosine acutely, as compared to control group. However, no significant alterations in respiratory chain complexes, citric acid cycle enzymes, and creatine kinase activities were found between rats receiving carnosine chronically and control group animals. As compared to control group, mRNA levels of NRF-1, PGC-1α , and TFAM were unchanged. The present findings indicate that electron transfer through the respiratory chain is impaired in skeletal muscle of rats receiving carnosine acutely. In case these findings are confirmed by further studies and ATP depletion is also observed, impairment of bioenergetics could be considered a putative mechanism responsible for the muscle damage observed in serum carnosinase-deficient patients.