Neurobehavioral And Oxidative Stress Alterations Following Methylmercury And Retinyl Palmitate Co-Administration In Pregnant And Lactating Rats And Their Offspring

Fish consumption and ubiquitous methylmercury (MeHg) exposure represent a public health problem globally. Micronutrients presented in fish affects MeHg uptake/distribution. Vitamin A (VitA), another fish micronutrient is used in nutritional supplementation, especially during pregnancy. However, there is no information about the health effects arising from their combined exposure. The present study aimed to examine the effects of both MeHg and retinyl palmitate administered to pregnant and lactating rats. Thirty Wistar female rats were orally supplemented with MeHg (0,5 mg/Kg/day) and retinyl palmitate (7500 μg RAE1/Kg/day), either individually or in combination from the gestational day 0 to weaning. In dams, maternal behavior was scored. In neonatal and infant offspring, associative learning and neurodevelopment were evaluated. Further periadolescent male and female pups were assessed for open field, habituation and object recognition using episodic-like memory paradigm. Maternal and offspring redox parameters were evaluated. Our results showed no effects of MeHg-VitA co-administration in the quality of maternal care but showed subtle alterations in the pro-oxidant response of the hippocampus. In offspring, MeHg-VitA co-exposure affected early associative learning in neonatal pups, with no further modifications in neurodevelopment, and no locomotor or exploratory alterations in later developmental stages. Habituation was altered in a sex-dependent manner, but no overall memory disturbances were encountered

Effects Of Methylmercury And Retinol Palmitate Co-Administration In Rats During Pregnancy And Breastfeeding: Metabolic And Redox Parameters In Dams And Their Offspring

Ubiquitous low-dose methylmercury (MeHg) exposure through an increased fish consumption represents a global public health problem, especially among pregnant women. A plethora of micronutrients presented in fish affects MeHg uptake/distribution, but limited data is available. Vitamin A (VitA), another fish micronutrient is used in nutritional supplementation, especially during pregnancy. However, there is no information about the health effects arising from their combined exposure. Therefore, the present study aimed to examine the effects of both MeHg and retinyl palmitate administered on pregnant and lactating rats in metabolic and redox parameters from dams and their offspring. Thirty Wistar female rats were orally supplemented with MeHg (0,5 mg/kg/day) and retinyl palmitate (7500 µg RAE/kg/day) via gavage, either individually or in combination from the gestational day 0 to weaning. For dams (150 days old) and their offspring (31 days old), glycogen accumulation (hepatic and cardiac) and retinoid contents (plasma and liver) were analyzed. Hg deposition in liver tissue was quantified. Redox parameters (liver, kidney, and heart) were evaluated for both animals. Cytogenetic damage was analyzed with micronucleus test. Our results showed no general toxic or metabolic alterations in dams and their offspring by MeHg-VitA co-administration during pregnancy and lactation. However, increased lipoperoxidation in maternal liver and a disrupted pro-oxidant response in the heart of male pups was encountered, with apparently no particular effects in the antioxidant response in female offspring. GST activity in dam kidney was altered leading to possible redox disruption of this tissue with no alterations in offspring. Finally, the genomic damage was exacerbated in both male and female pups. In conclusion, low-dose MeHg exposure and retinyl palmitate supplementation during gestation and lactation produced a potentiated pro-oxidant effect, which was tissue-specific. Although this is a pre-clinical approach, we recommend precaution for pregnant women regarding food consumption, and we encourage more epidemiological studies to assess possible modulations effects of MeHg-VitA co-administration at safe or inadvertently used doses in humans, which may be related to specific pathologies in mothers and their children

Hepatic and neurobiological effects of foetal and breastfeeding and adulthood exposure to methylmercury in Wistar rats

Methylmercury (MeHg) is an organic bioaccumulated mercury derivative that strongly affects the environment and represents a public health problem primarily to riparian communities in South America. Our objective was to investigate the hepatic and neurological effects of MeHg exposure during the phases foetal and breast-feeding and adult in Wistar rats. Wistar rats (n = 10) were divided into 3 groups. Control group received mineral oil; The simple exposure (SE) group was exposed only in adulthood (0.5 mg/kg/day); and double exposure (DE) was pre-exposed to MeHg 0.5 mg/kg/day during pregnancy and breastfeeding (±40 days) and re-exposed to MeHg for 45 days from day 100. After, we evaluated possible abnormalities. Behavioral and biochemical parameters in liver and occipital cortex (CO), markers of liver injury, redox and AKT/GSK3β/mTOR signaling pathway. Our results showed that both groups treated with MeHg presented significant alterations, such as decreased locomotion and exploration and impaired visuospatial perception. The rats exposed to MeHg showed severe liver damage and increased hepatic glycogen concentration. The MeHg groups showed significant impairment in redox balance and oxidative damage to liver macromolecules and CO. MeHg upregulated the AKT/GSK3β/mTOR pathway and the phosphorylated form of the Tau protein. In addition, we found a reduction in NeuN and GFAP immunocontent. These results represent the first approach to the hepatotoxic and neural effects of foetal and adult MeHg exposure

Efeito da suplementação crônica do extrato de Paullinia cupana Mart. em ratos Wistar senescentes

Durante o envelhecimento há um declínio acentuado na capacidade antioxidante celular principalmente no tecido cerebral, o que leva a um desbalanço na homeostase redox gerando danos oxidativos. O extrato de Paullinia cupana Mart possui efeitos metabólicos e propriedades farmacológicas bem descritas. Neste trabalho nós investigamos o efeito do extrato comercial de guaraná (ECG) na função cognitiva, parâmetros bioquímicos e modulação da senescência em ratos Wistar de meia-idade. Os animais foram divididos em três grupos de acordo com o tratamento (solução salina: 0,9%, ECG: 21 mg/kg/dia e cafeína: 0,83 mg/kg/dia). As soluções foram administradas diariamente por gavagem. Os testes comportamentais foram realizadas antes e após o tratamento. As análises bioquímicas foram realizadas no Sistema Nervoso Central bem como no rim, fígado e coração. Nossos dados em Campo Aberto demonstraram aumento na atividade exploratória e diminuição no comportamento de ansiedade nos animais que receberam cafeína, esse comportamento não foi observado no grupo ECG. As análises do hipocampo e estriado indicam que a ECG e/ou a cafeína alteraram parâmetros analisados de modo tecido específico. O tratamento crônico com guaraná elevou a atividade enzimática da Glutationa S-transferase assim como os carbonilação de proteínas no tecido cardíaco. O tratamento com Paullinia cupana alterou parâmetros hematológicos e reduziu os níveis de gordura gonadal nos animais tratados. Em contraste a administração de cafeína isolada foi capaz de aumentar o imunoconteúdo de Sirt1 em ambos os tecidos, renal e cardíaco. Nossos dados sugerem que ECG não melhora o desenvolvimento cognitivo, mas modifica a maquinaria de estresse oxidativo e vias de sinalização neurodegenerativa, inibindo moléculas relacionadas a vias de sobrevivência no hipocampo e estriado. Isto pode contribuir para o desenvolvimento de microambientes desfavoráveis no cérebro e distúrbios neurodegenerativos. Além disso, os resultados demonstram que os principais efeitos benéficos remetem a cafeína, além de demonstrar que ao contrário da crença popular, a administração crônica do guaraná não gerou melhora nos parâmetros avaliados referentes a cognição e senescência em ratos de meia idade.During aging there is a marked decline in cellular antioxidant capacity mainly in brain tissue, which leads to an imbalance in redox homeostasis generating oxidative damage. The extract of Paullinia cupana Mart has well-described metabolic effects and pharmacological properties. In this work we investigated the effect of commercial guarana extract (CGE) on cognitive function, biochemical parameters and modulation of senescence in middle-aged Wistar rats. The animals were divided into three groups according to the treatment (saline, CGE or caffeine). The solutions were administered daily by oral gavage. Behavioral tests were performed before and after treatment. Biochemical analyzes were performed in the Central Nervous System as well as in the kidney, liver and heart. Our data in Open Field showed an increase in the exploratory activity and decrease in the behavior of anxiety in the animals that received caffeine, this behavior was not observed in the CGE group. Hippocampus and striatum analyzes indicate that CGE and/or caffeine altered parameters analyzed in a tissue-specific fashion. Chronic treatment with guarana increased the enzymatic activity of Glutathione S-transferase as well as carbonylation of proteins in cardiac tissue. Treatment with Paullinia cupana altered haematological parameters and reduced levels of gonadal fat in treated animals. In contrast, administration of caffeine alone was able to increase the immunocontent of Sirt1 in both renal and cardiac tissues. Our data suggest that CGE does not improve cognitive development but modifies the machinery of oxidative stress and neurodegenerative signaling pathways by inhibiting molecules related to survival pathways in the hippocampus and striatum. This may contribute to the development of unfavorable microenvironments in the brain and neurodegenerative disorders. In addition, the results demonstrate that the main beneficial effects refer to caffeine, in addition to demonstrating that contrary to popular belief, chronic administration of guarana did not improve the parameters evaluated for cognition and senescence in middle-aged rats

Avaliação da utilização de uma vacina de DNA contendo a região codificadora de 14-3-3 de Cryptococcus gattii como estratégia profilática para criptococose

Cryptococcus gattii é um patógeno emergente que infecta principalmente indivíduos imunocompetentes, causando criptococose. Dentre os tratamentos estão anfotericina B e fluconazol, porém são insuficientes na erradicação da doença. A estimulação da resposta imune por vacinas de DNA em diversos modelos fúngicos vem sendo relatados. Dentre as proteínas fúngicas candidatas no desenvolvimento de vacinas estão às proteínas 14-3-3, as quais foram identificadas como proteínas imudominantes em estudos de proteômica de Cryptococcus neoformans e C. gattii e em soro de pacientes com criptococose. O objetivo deste estudo foi realizar a construção do vetor recombinante contendo a região codificante do gene 14-3-3, seguido da análise preliminar da resposta imune em camundongos imunizados. A região codificante do 14-3-3 foi clonada em vetor de expressão eucariótico pcDNA3.1(+) e a funcionalidade do vetor recombinante foi confirmada a nível transcricional por RT-PCR a partir de células A549 transfectadas com a vacina de DNA e a nível traducional por imunobloting. A proteína 14-3-3 foi ainda localizada na parede celular da levedura, revelado por metodologias de microscopia por imunofluorescência. A porção codificante do gene 14-3-3 de C. gattii foi clonada em vetor de expressão pET23-d e a proteína recombinante foi expressa em células de E. coli BL21 e purificada por cromatografia de afinidade a níquel. A resposta imune humoral foi determinada por dosagem de imunoglobulinas, porém não ocorreu diferença estatística na indução de imunoglobulinas totais em camundongos inoculados com a vacina. Assim esse trabalho contribuiu para o estudo imunogenicidade da proteína 14-3-3 em C. gattii permitindo possíveis estudos em outros modelos animais usando a mesma estratégia profilática.Cryptococcus gattii is an emerging pathogen that mainly infects immunocompetent individuals, causing cryptococcosis. Among the treatments are amphotericin B and fluconazole, but they have proven insufficient in eradicating this disease. The immune responses stimulation by DNA vaccines in several fungal models has been reported. Among fungal candidate proteins in vaccine development are the 14-3-3 proteins, which were identified as immunodominant sera proteins in Cryptococcus neoformans and Cryptococcus gattii proteomics and in serum of patients with cryptococcosis. The study aimed to construct a recombinant vector containing the 14-3-3 coding region, followed by the immune response preliminary analysis of immunized mice. The 14-3-3 gene was cloned into a eukaryotic expression vector pcDNA3.1(+) vector and RT-PCR confirmed the recombinant transcriptional level functionality from A549 transfected with DNA vaccine cells and translational level by immunoblotting. The 14-3-3 protein was localized associated with the yeast cell wall, as revealed by immunofluorescence microscopy. The coding portion of the 14-3-3 C. gattii gene was cloned into pET23-d expression vector and the recombinant protein was expressed in E. coli BL21 and purified by nickel affinity chromatography. The humoral immune response was determined by serum total immunoglobulin measurements, but no statistical differences were observed in total immunoglobulins from vaccine-inoculated mice. Thus, this research contributed to 14-3-3 C. gattii protein immunogenicity study, allowing possible researches in other animal models applying the same prophylactic strategy

Exposición crónica a acroleína en ratas wistar: los efectos de los extractos de guaraná

Previous studies have reported that acrolein, may exert harmful effects on the brain. However, information regarding the neuroprotective properties of guarana against acrolein is not available. Due to the lack of research, we initiated the current study to investigate the effects of guarana extracts on acrolein-induced toxicity in the liver and the central nervous system of Wistar Rats. Twelve groups of 60 days old Wistar rats treated with guarana extracts (150, 250, and 350 mg/kg/day) for 8 weeks, were challenged with acrolein (2.5 mg/kg/day). Several parameters associated with oxidative damage to the brain and hepatic function, as well as behavior were evaluated. All tested concentrations of guarana extracts exerted protective effects against acrolein induced damage. No hepatic and oxidative damages or behavioral changes were observed in guarana control groups. To the best of our knowledge, this is the first study of its kind and therefore a milestone in this field.Estudios anteriores han informado que la acroleína puede ejercer efectos nocivos en el cerebro. Sin embargo, no se dispone de información sobre las propiedades neuroprotectoras del guaraná contra la acroleína. Debido a la falta de investigación, iniciamos el estudio actual para investigar los efectos de los extractos de guaraná sobre la toxicidad inducida por acroleína en el hígado y el sistema nervioso central de las ratas Wistar. Doce grupos de ratas Wistar de 60 días de edad tratadas con extractos de guaraná (150, 250 y 350 mg / kg / día) durante 8 semanas, fueron desafiados con acroleína (2.5 mg / kg / día). Se evaluaron varios parámetros asociados con el daño oxidativo del cerebro y la función hepática, así como el comportamiento. Todas las concentraciones probadas de extractos de guaraná ejercieron efectos protectores contra el daño inducido por acroleína. No se observaron daños hepáticos y oxidativos o cambios de comportamiento en los grupos de control de guaraná. Hasta donde sabemos, este es el primer estudio de este tipo y, por lo tanto, un hito en este campo