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This study evaluated the sociodemographic characteristics and behavior of the oral mucosa epithelium exposured to the herbicide glyphosate of family farmers in Cerro Largo, RS, Brazil. 120 individuals were selected for social data collection through interviews. According to the results, most of the interviewees uses glyphosate between 5-10 years, being exposed between 30 minutes to one hour each application and applying the herbicide 1-2 times a year. After the interview, we selected the subjects to the Micronucleus (MN) test. For this test, oral smears were performed in three distinct regions (cheek, mouth floor and tongue edges) of 10 test subjects (exposed to glyphosate, non-smoker and non-alcoholic) and 10 control subjects. Results showed that glyphosate exposure increased the frequency of MN in the test group (p = 0.0002), as well as the frequency of other cellular alterations, such as brokenegg (p = 0.001), binucleation (p = 0.0001) and karyolysis (p = 0.0004). Based on these findings, the extent use of glyphosate may be causing damage to the oral mucosa epithelium and this might respond adaptively through cellular modifications.

This manuscript portrays the CuI-catalyzed Csp-chalcogen bond formation through cross-coupling reactions of propynyl esters and diorganyl dichalcogenides by using DMSO as solvent, at room temperature, under base-free and open-to-air atmosphere conditions. Generally, the reactions have proceeded very smoothly, being tolerant to a range of substituents present in both substrates, affording the novel 3-(organochalcogenyl)prop-2-yn-1-yl esters in moderate to good yields. Noteworthy, the 3-(butylselanyl)prop-2-yn-1-yl benzoate proved to be useful as synthetic precursor in palladium-catalyzed Suzuki and Sonogashira­ type cross-coupling reactions by replacing the carbon–chalcogen bond by new carbon–carbon bond. Moreover, the 3-(phenyl­selanyl)prop-2-yn-1-yl benzoate has shown promising in vitro activity against glioblastoma cancer cells.

O Glifosato (GLY) foi sintetizado no ano de 1950, inicialmente com propriedades fitotóxicas e com capacidade herbicida reconhecida somente em 1970. O GLY é um organofosfato, formado por apenas uma molécula de glicina e uma de fosfonometila, denominado N-(fosfonometil) glicina, usado em todo o mundo para diminuir perdas de produtividade agrícola. O Round-up® é o herbicida a base de GLY mais conhecido no mercado. Muitos estudos demonstram a citotoxicidade de GLY e Round-up® em células de câncer. Os Glioblastomas (GBMs) são os tumores primários mais comuns no Sistema Nervoso Central (SNC), que correspondem a 16 % de todos os tumores cerebrais primários e neoplasias do SNC. GBMs são mais frequentes na população adulta, geralmente a partir dos 60 anos de idade, apresentando os piores diagnósticos, resultando em uma sobrevida muito baixa. Os principais tratamentos para esta neoplasia são ressecção cirúrgica, radioterapia e quimioterapia com Temozolamida. Mesmo utilizando estas estratégias terapêuticas, pacientes com GBM tem alta taxa de recorrência deste tumor e uma sobrevida muito baixa após 5 anos de tratamento. Dessa forma, a busca por estratégias que possam ser mais eficientes em aumentar a sobrevida ou mesmo curar este tumor são necessárias. Nesse estudo, foi avaliada a citotoxicidade do tratamento agudo (24, 48 e 72 horas) e crônico (5 dias de tratamento mais 23 dias de intervalo) do GLY e do Round-up® em linhagens de GBMs humano e de rato bem como a indução de senescência celular. Demonstramos pela primeira vez que o GLY e o Round-up® (nas concentrações de 0,0025 %, 0,005% e 0,001%) apresentaram efeitos citotóxicos em linhagens de GBMs, diminuindo a viabilidade celular, o número de células, a formação de colônias e a duplicação populacional. Não foi observado indução de senescência celular. Os resultados também apontaram que os efeitos citotóxicos foram mais pronunciados ao realizar o tratamento com Round-up® do que com o GLY. Dessa forma, este estudo indica pela primeira vez um potencial citotóxico do GLY e do Round-up, que precisa ser melhor compreendido a fim de se buscar um potencial mecanismo de ação e segurança para futuramente incluir como possível estratégia terapêutica.

We have previously demonstrated that quercetin (Quer), a polyphenol widely found in vegetables, decreased glioma cell growth in vitro. Here, we asked whether this compound could affect glioma growth in an in vivo rat glioma model. We found that daily intraperitoneal Quer (50 mg/kg) injections lead to a concentration of 0.15 μg of Quer per gram of brain tissue, which increased the tumor volume in a time dependent manner. We observed a small reduction in lymphocytic infiltration, a marker of good prognosis in gliomas that was accompanied by a small reduction in cell viability of peripheral T-cells. Moreover, after Quer treatment neither body weight alteration nor liver pathology markers were detected. Although in vitro studies and massive literature reports point to the antitumoral properties of Quer, the present results indicate that great caution has to be taken in the design of clinical trials and the indiscriminate use of this polyphenol as dietary supplement.

Here we investigated the neuroprotective effect of resveratrol in an in vitro model of ischemia. We used organotypic hippocampal cultures exposed to oxygen-glucose deprivation (OGD). In OGD-vehicle exposed cultures, about 46% of the hippocampus was labeled with PI, indicating a robust percentage of cell death. When cultures were treated with resveratrol 10, 25 and 50 microM, the cell death was reduced to 22, 20 and 13% respectively. To elucidate a possible mechanism by which resveratrol exerts its neuroprotective effect, we investigated the phosphoinositide3-kinase (PI3-k) pathway using LY294002 (5 microM) and mitogen-activated protein kinase (MAPK) using PD98059 (20 microM). The resveratrol (50 microM) neuroprotection was prevented by LY294002 but was not by PD98059. Immunoblotting revealed that resveratrol 50 microM induced the phosphorylation/activation of Akt and extracellular signal-regulated kinase-1 and -2 (ERK1/2) and the phosphorylation/inactivation of glycogen synthase kinase-3beta (GSK-3beta). Our results suggest that PI3-k/Akt pathway are involved in the neuroprotective effect of resveratrol.

Recent epidemiological and dietary intervention studies in animals and humans have suggested that diet-derived flavonoids, in particular quercetin, may play a beneficial role by preventing or inhibiting tumorigenesis. The aim of this study was to evaluate whether quercetin may act differently on cancer and normal neuronal tissue. In order to investigate this, the U138MG human glioma cell line and hippocampal organotypic cultures were used. The study showed that quercetin induced in glioma cell cultures results in (a) a decrease in cell proliferation and viability, (b) necrotic and apoptotic cell death, (c) arrest in the G2 checkpoint of the cell cycle, and (d) a decrease of the mitotic index. Furthermore, we demonstrated that while quercetin promotes cancer regression it was able to protect the hippocampal organotypic cultures from ischemic damage. To sum up, our results suggest that quercetin induced growth inhibition and cell death in the U138MG human glioma cell line, while exerting a cytoprotective effect in normal cell cultures.

In the present study we evaluate the effects of homocysteine on cellular damage using hippocampal slices from Wistar rats exposed to oxygen and glucose deprivation (OGD, followed by reoxygenation), an in vitro model of hypoxic–ischemic events. For chronic treatment, we induced elevated levels of homocysteine in blood (500 mM), comparable to those of human homocystinuria, and in brain (60 nmol/g wet tissue) of young rats by subcutaneous injections of homocysteine (0.3–0.6 mmol/g of body weight), twice a day with 8 h intervals, from the 6th to the 28th postpartum day and controls received saline. Rats were sacrificed 1, 3 or 12 h after the last injection. For acute treatment, 29-day-old rats received one single injection of homocysteine (0.6 mmol homocysteine/g body weight) or saline and were sacrificed 1 h later. In another set of experiments rats were pretreated with Vitamins E (40 mg/kg) and C (100 mg/kg) or folic acid (5 mg/kg) during 1 week; 12 h after the last administration they received a single injection of homocysteine or saline and were sacrificed 1 h later. Results showed that both chronic (1 h after homocysteine administration) and acute hyperhomocysteinemia increased the cellular damage measured by LDH released to de incubation medium, suggesting an increase of tissue damage caused by OGD. Pretreatment with folic acid completely prevented the damage caused by acute hyperhomocysteinemia, whereas Vitamin E just partially prevented such effect. These findings may be relevant to explain, at least in part, the higher susceptibility of hyperhomocysteinemic patients to be susceptible to ischemic events and point to a possible preventive treatment. # 2006 ISDN. Published by Elsevier Ltd. All rights reserved.

Here we investigated the effects of estradiol replacement in ovariectomized female rats using hippocampal slices exposed to oxygen-glucose deprivation (OGD). OGD induced lactate dehydrogenase (LDH) release to the incubation medium, what was assumed as a parameter of cellular death. In the estradiol-treated group the LDH release was markedly decreased by 23% as compared to the vehicle-treated group. In attempt to study a possible mechanism by which estradiol acts, we investigated some parameters of oxidative stress. In both vehicle-treated and estradiol-treated groups, OGD significantly increased the free radical production by 34% and 16%, respectively, although no significant differences on total antioxidant capacity were observed. Interestingly, estradiol replacement prevented the significant reduction in tryptophan and tyrosine contents caused by OGD observed in vehicle-treated animals. Our results show that estradiol replacement in ovariectomized female rats decreases cellular susceptibility to an ischemic-like injury and suggest a role for the hormone on protein damage prevention.

Here we investigated the neuroprotective effect of 17beta-estradiol in an in vitro model of ischemia. We used organotypic hippocampal slice cultures, acute or chronically treated with 17beta-estradiol (10 nM), and exposed to oxygen and glucose deprivation (OGD). Cellular death was quantified by measuring uptake of propidium iodide (PI), a marker of dead cells. In OGD exposed cultures, treated only with vehicle, about 70% of the CA1 area of hippocampus was labeled with PI, indicating a great percentage of cellular death. When cultures were treated with 17beta-estradiol (acute or chronically), this cellular death was reduced to 15%. This effect was prevented by LY294002 but was not by PD98059. Immunoblotting revealed that both, chronic and acute, treatments with 17beta-estradiol induced the phosphorylation/activation of Akt and the phosphorylation/inactivation of GSK-3beta. Our results show a clear neuroprotective effect of 17beta-estradiol and suggest that this effect could involve PI3-K pathway.

Introdução: a incidência de doenças neurodegenerativas tem aumentado nos últimos anos, passando a constituir um problema de saúde pública. Frente a isso se faz necessário o desenvolvimento de novas modalidades terapêuticas visando evitar, recuperar ou impedir as alterações celulares que possam levar à morte neuronal. Objetivo: realizar uma revisão bibliográfica acerca do potencial neuroprotetor, antioxidante e anti-inflamatório do Canabidiol (CBD) investigando sua ação sobre processos neurodegenerativos associados à doença de Alzheimer, Parkinson e Huntington. Metodologia: foi realizado um estudo descritivo e qualitativo desenvolvido na forma de revisão bibliográfica onde foram utilizados artigos disponíveis nos bancos de dados PubMed, Scielo e Scopus com o período de referência compreendido entre os anos de 1998 e 2016. Resultados: foram selecionados 10 artigos que tratavam do tema e todos eles mostraram que o CBD induziu neuroproteção e possuiu propriedades antioxidantes e anti-inflamatórios em diferentes modelos de citotoxicidade, estresse oxidativo e neurodegeneração. Conclusão: o CBD pode ser um importante agente terapêutico no tratamento, na prevenção e na reversão de lesões oriundas de doenças neurodegenerativas. Entretanto, há necessidade de reforçar estudos e ensaios em modelos animais antes de transpor o uso do CBD para humanos.

Introdução: o câncer de pele não melanoma é o câncer mais comum no mundo, raramente gera metástases e em geral possui bom prognóstico. No entanto, o câncer de pele tipo melanoma, apesar do desenvolvimento de novos medicamentos, possui alta taxa de mortalidade. O Resveratrol (3, 5, 4´-trihidroxiestilbeno), um composto de origem vegetal, tem surgido como uma molécula antitumoral bastante promissora. Objetivo: fazer uma revisão bibliográfica sobre o potencial do Resveratrol como quimioterápico para o câncer de pele. Metodologia: foram utilizados artigos científicos disponíveis no site PubMed, Scielo e Scopus com o período de referência compreendido entre os anos 2000 e 2017. As principais palavras chaves utilizadas foram: Resveratrol e câncer de pele; Resveratrol e melanoma. Resultados: foram encontrados vários estudos mostrando o potencial quimioterápico do Resveratrol em modelos in vivo e in vitro de câncer de pele, com efeito em diversos parâmetros celulares, tais como indução de apoptose, necrose e parada no ciclo celular e moleculares, tais como a modulação da via da Akt, MEK/ERK, caspases e p53. O Resveratrol mostrou-se promissor como agente sensibilizador de melanomas radioresistentes. Trabalhos utilizando modelos animais demonstraram que o tratamento com Resveratrol foi capaz de reduzir o crescimento tumoral e aumentar a longevidade. No entanto, alguns estudos comprovaram ausência de efeito ou efeito negativo deste composto. Conclusão: embora a revisão tenha mostrado o potencial antitumoral do Resveratrol, alguns estudos mostraram o efeito inverso, indicando que um maior cuidado deve ser tomado ao utilizar este composto em seres humanos.

Brain ischemia results in cellular degeneration and loss of brain function. Oxcarbazepine (OXC), one of the newer antiepileptic drugs, has been demonstrating its efficacy on wide spectrum neurological disorders. In this paper, we investigated the neuroprotective profile of OXC in an in vitro model of ischemia, which consists in the exposure of organotypic hippocampal slice cultures to oxygen and glucose deprivation.OXC (30 microM) was added to the medium before and/or during and/or after the oxygen and glucose deprivation induction. Cell death was quantified by propidium iodide uptake measurement. Immunoblotting was used to detect the phosphorylation of Akt.Our results showed a decrease in propidium iodide incorporation when OXC was added before oxygen and glucose deprivation, suggesting a neuroprotective effect. This effect was prevented when cultures were previously treated with LY294002, an inhibitor of phosphoinositide-3-kinase (PI3K) pathway. We also analysed the effect of OXC on Akt phosphorylation. Immunoblotting revealed that OXC did not induce any change in phosphorylation/activation of Akt.Our results reinforce the neuroprotective effect of OXC and add some evidence that its mechanism may involve the PI3K pathway, suggesting that such effect could be upstream Akt. This indicates that with respect to OXC neuroprotective, Akt may not play a crucial role in determining cell survival.

In the present study we investigated the toxicity induced by exposing organotypic slice culture to beta-amyloid peptide 25-35 (25microM) for 1, 3, 6, 12, 24 and 48h. To elucidate a mechanism involved in its toxicity, we studied the PI3-K cell signaling pathway, particularly Akt/PKB, GSK-3beta, and PTEN proteins. Cell death was quantified by propidium iodide uptake and proteins were analyzed by immunoblotting. Our results showed a significant cell death after 48h of beta-amyloid 25-35 peptide exposition. The exposition of cultures to beta-amyloid peptide resulted in an increase in the phosphorylation state of Akt and GSK-3beta proteins after 6h, followed by a decrease of the phosphorylation state of these proteins after 12h of exposition. However, after 24h of peptide treatment, the phosphorylation of GSK-3beta presented a new increase while the phosphorylation of Akt remained down. The immunocontent of the PTEN protein, an indirect Akt phosphatase, increased after 24 and 48h of beta-amyloid exposition. These results suggest an involvement of Akt dephosphorylation/inactivation in the toxicity induced by the beta-amyloid 25-35 peptide in organotypic slice hippocampal culture, probably induced by increasing PTEN immunocontent. Taken together, our results provide more information about the molecular mechanisms involved on beta-amyloid peptide toxicity.

Homocystinuria is an inherited metabolic disorder caused by severe deficiency of cystationine beta-synthase activity, resulting in the tissue accumulation of homocysteine (Hcy). Affected patients usually present many signs and symptoms such as seizures, mental retardation, atherosclerosis and stroke. The aim of this study is to evaluate in vivo and in vitro effects of Hcy using hippocampal slices from Wistar rats exposed to oxygen and glucose deprivation (OGD), followed by reoxygenation, an in vitro model of hypoxic-ischemic events. Neural cell injury was quantified by the measurement of lactate dehydrogenase (LDH) released from damaged cells into the extracellular fluid. The results showed that both in vivo and in vitro Hcy increased the LDH released to de incubation medium, suggesting an increase of tissue damage caused by OGD. This fact can be related with the high incidence of stroke in homocystinuric patients.

The molecular basis of estrogen-mediated neuroprotection against brain ischemia remains unclear. In the present study, we investigated changes in expression of estrogen receptors (ERs) alpha and beta and excitatory amino acid transporters (EAAT) 1 and 2 in rat organotypic hippocampal slice cultures treated with estradiol and subsequently exposed to oxygen--glucose deprivation (OGD). Pretreatment with 17beta-estradiol (10 nM) for 7 days protected the CA1 area of hippocampus against OGD (60 min), reducing cellular injury by 46% compared to the vehicle control group. Levels of ERalpha protein were significantly reduced by 20% after OGD in both vehicle- and estradiol-treated cultures, whereas ERbeta was significantly up-regulated by 25% in the estradiol-treated cultures. In contrast, EAAT1 and EAAT2 levels were unchanged in response to estradiol treatment in this model of OGD. These findings suggest that estrogen-induced neuroprotection against ischemia might involve regulation of ERbeta and, consequently, of the genes influenced by this receptor.

Background Temozolomide (TMZ) is the most widely used drug to treat glioblastoma (GBM), which is the most common and aggressive primary tumor of the Central Nervous System and one of the hardest challenges in oncotherapy. TMZ is an alkylating agent that induces autophagy, apoptosis and senescence in GBM cells. However, therapy with TMZ increases survival after diagnosis only from 12 to 14.4 months, making the development of combined therapies to treat GBM fundamental. One candidate for GBM therapy is Resveratrol (Rsv), which has additive toxicity with TMZ in several glioma cells in vitro and in vivo. However, the mechanism of Rsv and TMZ additive toxicity, which is the aim of the present work, is not clear, especially concerning cell cycle dynamics and long term effects. Methods Glioma cell lines were treated with Rsv and TMZ, alone or in combinations, and the induction and the role of autophagy, apoptosis, cell cycle dynamics, protein expression and phosphorylation status were measured. We further evaluated the long term senescence induction and clonogenic capacity. Results As expected, temozolomide caused a G2 cell cycle arrest and extensive DNA damage response. Rsv did not reduced this response, even increasing pATM, pChk2 and gammaH2Ax levels, but abrogated the temozolomide-induced G2 arrest, increasing levels of cyclin B and pRb(S807/811) and reducing levels of pWee1(S642) and pCdk1(Y15). This suggests a cellular state of forced passage through G2 checkpoint despite large DNA damage, a scenario that may produce mitotic catastrophe. Indeed, the proportion of cells with high nuclear irregularity increased from 6 to 26% in 48 h after cotreatment. At a long term, a reduction in clonogenic capacity was observed, accompanied by a large induction of senescence. Conclusion The presence of Rsv forces cells treated with TMZ through mitosis leading to mitotic catastrophe and senescence, reducing the clonogenic capacity of glioma cells and increasing the chronic effects of temozolomide.