The Phytochemical Agathisflavone Modulates miR146a and miR155 in Activated Microglia Involving STAT3 Signaling.

MicroRNAs (miRs) act as important post-transcriptional regulators of gene expression in glial cells and have been shown to be involved in the pathogenesis of neurodegenerative diseases, including Alzheimer's disease (AD). Here, we investigated the effects of agathisflavone, a biflavonoid purified from the leaves of Cenostigma pyramidale (Tul.), on modulating the expression of miRs and inflammatory mediators in activated microglia. C20 human microglia were exposed to oligomers of the ß-amyloid peptide (Aß, 500 nM) for 4 h or to lipopolysaccharide (LPS, 1 µg/mL) for 24 h and then treated or not with agathisflavone (1 µM) for 24 h. We observed that ß-amyloid and LPS activated microglia to an inflammatory state, with increased expression of miR-146a, miR-155, IL1-ß, IL-6, and NOS2. Treatment with agathisflavone resulted in a significant reduction in miR146a and miR-155 induced by LPS or Aß, as well as inflammatory cytokines IL1-ß, IL-6, and NOS2. In cells stimulated with Aß, there was an increase in p-STAT3 expression that was reduced by agathisflavone treatment. These data identify a role for miRs in the anti-inflammatory effect of agathisflavone on microglia in models of neuroinflammation and AD.

Effect of the Flavonoid Rutin on the Modulation of the Myenteric Plexuses in an Experimental Model of Parkinson's Disease.

Recent discoveries have shown that enteric glial cells play an important role in different neurodegenerative disorders, such as Parkinson's disease (PD), which is characterized by motor dysfunctions caused by the progressive loss of dopaminergic neurons in the substance nigra pars compacta and non-motor symptoms including gastrointestinal dysfunction. In this study, we investigated the modulatory effects of the flavonoid rutin on the behavior and myenteric plexuses in a PD animal model and the response of enteric glia. Adult male Wistar rats were submitted to stereotaxic injection with 6-hydroxydopamine or saline, and they were untreated or treated with rutin (10 mg/kg) for 14 days. The ileum was collected to analyze tissue reactivity and immunohistochemistry for neurons (HuC/HuD) and enteric glial cells (S100ß) in the myenteric plexuses. Behavioral tests demonstrated that treatment with rutin improved the motor capacity of parkinsonian animals and improved intestinal transit without interfering with the cell population; rutin treatment modulated the reactivity of the ileal musculature through muscarinic activation, reducing relaxation through the signaling pathway of nitric oxide donors, and increased the longitudinal contractility of the colon musculature in parkinsonian animals. Rutin revealed modulatory activities on the myenteric plexus, bringing relevant answers regarding the effect of the flavonoid in this system and the potential application of PD adjuvant treatment.

Activation of the Kynurenine Pathway and Production of Inflammatory Cytokines by Astrocytes and Microglia Infected With Neospora caninum.

In the central nervous system, astrocytes and microglia contribute to homeostasis, regulating the immune response to infectious agents. Neospora caninum is an obligate intracellular protozoan that infects different animal species and it is encysted in their nervous tissue while triggering an immune response modulated by glia. This study aimed to evaluate the infection of primary cultures of rat glial cells by N. caninum through the catabolites of tryptophan, the expression of inflammatory mediators and the integrity of neural tissue. Infection with this coccidium resulted in morphological and functional changes, particularly astrogliosis and microgliosis, and increased the expression of the inflammatory mediators TNF, IL1ß, IL-10, and arginase, as well as mRNA for CCL5 and CCL2, molecules involved in the CNS chemotaxis. The infection with N. caninum in glial cells also triggered the activation of the tryptophan pathway, characterized by increased kynurenine 2,3 monooxygenase (KMO) mRNA expression, and by the production of the excitotoxin quinolinic acid (QUIN). Moreover, glia-neuron co-cultures, when exposed to the secretome derived from N. caninum infected glial cells, presented greater neurons distribution and formation of neurite extensions, associated to morphological changes in astrocytes compatible with neuro-preservation. Considering that the tryptophan catabolism is associated to immune response, these findings suggest that glial activation in N. caninum infection should be responsible for modulating the inflammatory status in an attempt to restore the nervous system homeostasis, since excessive inflammatory response can cause irreversible damage to tissue preservation.

Neuroimmunomodulatory Properties of Flavonoids and Derivates: A Potential Action as Adjuvants for the Treatment of Glioblastoma.

Glioblastomas (GBMs) are tumors that have a high ability to migrate, invade and proliferate in the healthy tissue, what greatly impairs their treatment. These characteristics are associated with the complex microenvironment, formed by the perivascular niche, which is also composed of several stromal cells including astrocytes, microglia, fibroblasts, pericytes and endothelial cells, supporting tumor progression. Further microglia and macrophages associated with GBMs infiltrate the tumor. These innate immune cells are meant to participate in tumor surveillance and eradication, but they become compromised by GBM cells and exploited in the process. In this review we discuss the context of the GBM microenvironment together with the actions of flavonoids, which have attracted scientific attention due to their pharmacological properties as possible anti-tumor agents. Flavonoids act on a variety of signaling pathways, counteracting the invasion process. Luteolin and rutin inhibit NFκB activation, reducing IL-6 production. Fisetin promotes tumor apoptosis, while inhibiting ADAM expression, reducing invasion. Naringenin reduces tumor invasion by down-regulating metalloproteinases expression. Apigenin and rutin induce apoptosis in C6 cells increasing TNFα, while decreasing IL-10 production, denoting a shift from the immunosuppressive Th2 to the Th1 profile. Overall, flavonoids should be further exploited for glioma therapy.

Neurological Infection, Kynurenine Pathway, and Parasitic Infection by Neospora caninum.

Neuroinflammation is one of the most frequently studied topics of neurosciences as it is a common feature in almost all neurological disorders. Although the primary function of neuroinflammation is to protect the nervous system from an insult, the complex and sequential response of activated glial cells can lead to neurological damage. Depending on the type of insults and the time post-insult, the inflammatory response can be neuroprotective, neurotoxic, or, depending on the glial cell types, both. There are multiple pathways activated and many bioactive intermediates are released during neuroinflammation. One of the most common one is the kynurenine pathway, catabolizing tryptophan, which is involved in immune regulation, neuroprotection, and neurotoxicity. Different models have been used to study the kynurenine pathway metabolites to understand their involvements in the development and maintenance of the inflammatory processes triggered by infections. Among them, the parasitic infection Neospora caninum could be used as a relevant model to study the role of the kynurenine pathway in the neuroinflammatory response and the subset of cells involved.

Neuroimmunomodulatory and Neuroprotective Effects of the Flavonoid Apigenin in in vitro Models of Neuroinflammation Associated With Alzheimer's Disease.

Neurodegenerative disorders (ND) are characterized by the progressive and irreversible loss of neurons. Alzheimer's Disease (AD) is the most incident age-related ND, in which the presence of a chronic inflammatory compound seems to be related to its pathogenesis. Different stimuli in the central nervous system (CNS) can induce activation, proliferation, and changes in phenotype and glial function, which can be modulated by anti-inflammatory agents. Apigenin (4,5,7-trihydroxyflavone) is a flavonoid found in abundance in many fruits and vegetables, that has shown important effects upon controlling the inflammatory response. This study evaluated the neuroprotective and neuroimmunomodulatory potential of apigenin using in vitro models of neuroinflammation associated with AD. Co-cultures of neurons and glial cells were obtained from the cortex of newborn and embryonic Wistar rats. After 26 days in vitro, cultures were exposed to lipopolysaccharide (LPS; 1 µg/ml), or IL-1ß (10 ng/ml) for 24 h, or to Aß oligomers (500 nM) for 4 h, and then treated with apigenin (1 µM) for further 24 h. It was observed that the treatment with apigenin preserved neurons and astrocytes integrity, determined by Rosenfeld's staining and immunocytochemistry for ß-tubulin III and GFAP, respectively. Moreover, it was observed by Fluoro-Jade-B and caspase-3 immunostaining that apigenin was not neurotoxic and has a neuroprotective effect against inflammatory damage. Additionally, apigenin reduced microglial activation, characterized by inhibition of proliferation (BrdU+ cells) and modulation of microglia morphology (Iba-1 + cells), and decreased the expression of the M1 inflammatory marker CD68. Moreover, as determined by RT-qPCR, inflammatory stimuli induced by IL-1ß increased the mRNA expression of IL-6, IL-1ß, and CCL5, and decreased the mRNA expression of IL-10. Contrary, after treatment with apigenin in inflammatory stimuli (IL-1ß or LPS) there was a modulation of the mRNA expression of inflammatory cytokines, and reduced expression of OX42, IL-6 and gp130. Moreover, apigenin alone and after an inflammatory stimulus with IL-1ß also induced the increase in the expression of brain-derived neurotrophic factor (BDNF), an effect that may be associated with anti-inflammatory and neuroprotective effects. Together these data demonstrate that apigenin presents neuroprotective and anti-inflammatory effects in vitro and might represent an important neuroimmunomodulatory agent for the treatment of neurodegenerative conditions.

Phytoestrogen Agathisflavone Ameliorates Neuroinflammation-Induced by LPS and IL-1ß and Protects Neurons in Cocultures of Glia/Neurons.

Inflammation and oxidative stress are common aspects of most neurodegenerative diseases in the central nervous system. In this context, microglia and astrocytes are central to mediating the balance between neuroprotective and neurodestructive mechanisms. Flavonoids have potent anti-inflammatory and antioxidant properties. Here, we have examined the anti-inflammatory and neuroprotective potential of the flavonoid agathisflavone (FAB), which is derived from the Brazilian plant Poincianella pyramidalis, in in vitro models of neuroinflammation. Cocultures of neurons/glial cells were exposed to lipopolysaccharide (LPS, 1 µg/mL) or interleukin (IL)-1ß (10 ng/mL) for 24 h and treated with FAB (0.1 and 1 µM, 24 h). FAB displayed a significant neuroprotective effect, as measured by nitric oxide (NO) production, Fluoro-Jade B (FJ-B) staining, and immunocytochemistry (ICC) for the neuronal marker ß-tubulin and the cell death marker caspase-3, preserving neuronal soma and increasing neurite outgrowth. FAB significantly decreased the LPS-induced microglial proliferation, identified by ICC for Iba-1/bromodeoxyuridine (BrdU) and CD68 (microglia M1 profile marker). In contrast, FAB had no apparent effect on astrocytes, as determined by ICC for glial fibrillary acidic protein (GFAP). Furthermore, FAB protected against the cytodestructive and proinflammatory effects of IL-1ß, a key cytokine that is released by activated microglia and astrocytes, and ICC showed that combined treatment of FAB with α and ß estrogen receptor antagonists did not affect NF-κB expression. In addition, qPCR analysis demonstrated that FAB decreased the expression of proinflammatory molecules TNF-α, IL-1ß, and connexins CCL5 and CCL2, as well as increased the expression of the regulatory molecule IL-10. Together, these findings indicate that FAB has a significant neuroprotective and anti-inflammatory effect in vitro, which may be considered as an adjuvant for the treatment of neurodegenerative diseases.

Blood typing in positive DEA 1 dogs: comparative analysis between immunochromatography, hemagglutination and flow cytometry / Tipificação sanguínea em cães AEC 1 positivo: análise comparativa entre a imunocromatografia, hemoaglutinação e citometria de fluxo

Blood typing techniques have been improved to ensure greater safety for transfusion procedures. Typification for the DEA 1 antigen through flow cytometry should offer more reliability to routine immunohematology in donor and recipient dogs. Currently, the DEA 1 group is starting to be an autosomal dominant allelic system with the DEA 1 negative type and its variations of positivity. The present study investigated the DEA 1 antigen using the techniques of immunochromatography, hemagglutination and flow cytometry. Among the positive animals for the DEA 1 group, typified by flow cytometry, medium intensities of fluorescence were found, which are indicative of weak, moderate and strong antigenicity. This enabled the division of the DEA 1 group into weak positive, moderate positive and strong positive. The blood typing techniques for the DEA 1 group by flow cytometry, agglutination and immunochromatography had positive (Spearman r=0.70) and statistically significant (p>0.0001) correlations.(AU)

As técnicas de tipificação sanguínea vêm sendo aperfeiçoadas para garantir maior segurança aos procedimentos transfusionais. A tipificação para o antígeno AEC 1 com o emprego da citometria de fluxo poderá oferecer mais confiabilidade à rotina da imunohematologia em cães doadores e receptores. Na atualidade, o grupo AEC 1 passou a ser denominado como um sistema alélico autossômico dominante com o tipo AEC 1 negativo e suas variações de positividade. O presente trabalho comparou os resultados de três técnicas utilizadas para a pesquisa do antígeno AEC 1: cromatografia; hemoaglutinação e citometria de fluxo. Dentro dos indivíduos positivos para o grupo AEC 1, tipificados pela citometria de fluxo, foram encontradas intensidades médias de fluorescência indicadoras de antigenicidade fraca, moderada e forte, podendo-se dividir o grupo AEC 1 em positivo fraco, positivo moderado e positivo forte. As técnicas de tipificação sanguínea para o grupo AEC 1 por cromatografia, hemoaglutinação e citometria de fluxo apresentaram correlação positiva (Spearman r=0,70) e estatisticamente significativa (p<0,0001).(AU)

Screening on prenatal infections in the South and Southwest macro-regions in the State of Bahia, Brazil: detected on paper filter / Triagem pré-natal de infecções nas macrorregiões sul e sudoeste do estado da Bahia, Brasil: detectadas em papel de filtro

Abstract Objectives: to estimate the detection rate on prenatal screening pathologies on paper filter in the South and Southwest in the State of Bahia, as well as to delineate the epidemiological profile of these pregnant women, calculate and estimate the rate of adherence and the coverage of the Program. Methods: a descriptive study was carried out from August 2013 to August 2015, and the data were obtained from the Labimuno/ICS/UFBA. Results: 64,743 pregnant women were included; the mean ages were 25 years for the Southwest macro-region and 23 for the South. The results on the screening tests showed positivity of 0.13% and 0.29% for HBsAg, 0.17% and 0.22% for cytomegalovirus, 0.07% and 0.09% for HCV, 0.13% and 0.38% for HTLV, 0.04% and 0.19% for HIV, 1.2% and 2.84% for syphilis, and 0.54% and 0.73% for toxoplasmosis in the Southwest and South macro-regions, respectively. The estimates on coverage were considered satisfactory. Sickle cell anemia showed positivity of 0.02% and of 0.04% and 5% and 6.3% presented sickle cell trait in the Southwest and South macro-regions, respectively. Conclusions: the frequencies of infections in maternal-fetal health were considered low, highlighting on syphilis and the presence for sickle cell trait.

Resumo Objetivos: estimar a taxa de detecção de patologias da TPN em papel de filtro nas regiões Sul e Sudoeste do Estado da Bahia, bem como delinear o perfil epidemiológico dessas gestantes, calcular e estimar a taxa de adesão e abrangência de cobertura do Programa. Métodos: estudo descritivo, de agosto 2013 a agosto de 2015, de dados obtidos do Labimuno/ICS/UFBA. Resultados: foram incluídas 64.743 gestantes; as médias das idades foram de 25 anos para a macrorregião Sudoeste e 23 para Sul. Os resultados de exames de triagem mostraram positividade de 0,13% e 0,29% para AgHBs, 0,17% e 0,22% para citomegalovírus, 0,07% e 0,09% para VHC, 0,13% e 0,38% para HTLV, 0,04% e 0,19% para HIV, 1,2% e 2,84% para sífilis, e 0,54% e 0,73% para toxoplasmose, para a macrorregião Sudoeste e Sul, respectivamente. As estimativas de cobertura foram consideradas satisfatórias. A anemia falciforme mostrou positividade de 0,02% e de 0,04% e 5% e 6,3% apresentaram o traço falcêmico, macrorregião Sudoeste e Sul, respectivamente. Conclusões: as frequências das infecções na saúde materno-fetal foram consideradas baixas, com destaque para sífilis e para a presença do traço falcêmico.

Frequency of dog erythrocyte antigen 1 blood group and risk of incompatible transfusion in dogs of different breeds and mongrels from the city of Salvador - BA, Brazil / Frequência do antígeno eritrocitário canino 1 e risco de transfusão incompatível em cães de diferentes raças e mestiços da cidade de Salvador-BA, Brasil

The dog erythrocyte antigen 1 (DEA 1) is the most immunogenic blood group in dogs, and blood transfusions may trigger some undesirable effects in veterinary patients, which are directly associated with incompatible transfusions. The present study aimed to investigate the frequency of positive DEA 1 blood group in blood donor dogs from a blood bank in Salvador, Bahia, Brazil, and also to calculate the risk of managing incompatible blood in both first and second transfusion. A number of 203 dogs of different breeds, aged between 1 and 8 years, weighing 28 kg, with no degree of kinship and of both sexes in Salvador - BA, Brazil were evaluated to investigate the blood type DEA 1 frequency, by means of chromatography and flow cytometry tests for blood typing. The risk of incompatible blood transfusion in either a first or a second transfusion was also calculated. The frequency of the DEA 1 group ranged from 0% to 100% in various breeds, but with a mean positivity of 62.07% (126/203). And the lowest risk of an DEA 1 negative animal receiving DEA 1 positive blood within the group of animals evaluated was 0.92% at a first transfusion; and the risk of the same animal receiving incompatible blood for the DEA group 1 in the second transfusion was 0.008%. The highest risk of an DEA 1 negative animal receiving DEA 1 positive blood from these animals was 69.12%; and the risk of receiving incompatible blood for DEA 1 was 47.77%. In conclusion, the frequency of the DEA 1 group varied between the studied breeds and the risk of incompatible blood transfusions varies according to donor and recipiente breeds, but this can be overridden if blood typing tests are performed along with the cross-reaction test for compatibility.

O antígeno eritrocitário canino 1 (AEC 1) é o grupo sanguíneo mais imunogênico em cães, podendo as transfusões sanguíneas desencadearem alguns efeitos indesejáveis nos pacientes veterinários. Estes estão diretamente associados à transfusões incompatíveis. O presente trabalho teve como objetivo estudar a frequência do grupo sanguíneo AEC 1 em cães doadores de sangue de um banco de sangue de Salvador-BA, Brasil, e calcular o risco de administrar sangue incompatível tanto em uma primeira quanto em uma segunda transfusão. Foram avaliados 203 cães de diversas raças, de ambos os sexos, com idade entre 1 e 8 anos, peso a partir de 28 kg, sem nenhum grau de parentesco originários de Salvador ­ BA, Brasil, para pesquisa da frequência do tipo sanguíneo AEC 1, por meio de testes de imunocromatografia e citometria de fluxo para tipagem sanguínea. E calculado o risco de transfusão sanguínea incompatível tanto em uma primeira como em uma segunda transfusão. A frequência do grupo AEC 1 variou entre as raças estudadas de 0% a 100%, porém com uma positividade média de 62,07% (126/203). O menor risco de um animal AEC 1 negativo receber sangue AEC 1 positivo, dentro do grupo dos animais avaliados foi de 0,92% em uma primeira transfusão e o risco do mesmo animal receber sangue incompatível para o gruo AEC 1 na segunda transfusão foi de 0,008%. Quanto ao maior risco de um animal AEC 1 negativo receber sangue AEC 1 positivo destes animais foi de 69,12% e o risco do mesmo receber sangue incompatível para o AEC 1 foi de 47,77%. A frequência do grupo AEC 1 variou entre as raças estudadas e o risco de transfusões incompatíveis variou de acordo com as raças doadoras e receptoras, mas esse risco pode ser anulado se sempre forem realizados os testes para tipagem sanguínea junto com a prova de reação cruzada para compatibilidade.

Detection of canine anti-DEA 1 antibodies using flow cytometry in dogs following DEA 1-positive blood transfusion / Detecção de anticorpos caninos anti-AEC 1 por citometria de fluxo em cães pós-transfundidos com sangue AEC 1 positivo

The shortage of dog blood donors in veterinary emergencies can lead to blood transfusions between animals whose blood type has not been identified. The antibody profile serves as a warning sign for animals that require a second blood transfusion, which is only advisable from compatible donor dogs. This article focuses on determination of anti-DEA 1 antibodies using the flow cytometry technique in dogs that have undergone a transfusion using DEA 1-positive blood, compared to results obtained from crossmatching. Blood from 18 DEA 1-positive donors ranked according to the chromatographic technique was used to transfuse thirty-three animals with unknown blood types and which demonstrated negative crossmatching to donors. On post-transfusion days 7, 14, 21 and 28, 45% and 27% of the animals tested positive for the anti-DEA 1 antibody, through crossmatching and flow cytometry, respectively. Detecting antibodies using the flow cytometric technique has high specificity and sensitivity, while crossmatching methods are highly sensitive but manifest low specificity. Following blood transfusion, animals that did not present as positive through crossmatching or flow cytometry were considered different from all other DEA 1-positive blood groups.(AU)

A escassez de cães doadores de sangue em situações de emergência na Medicina Veterinária pode levar a realização de transfusões de sangue entre animais que não tiveram seu tipo sanguíneo previamente determinado. O padrão de anticorpos serve como um sinal de alerta para animais que serão submetidos a uma segunda transfusão sanguínea, sendo essa somente recomendável a partir de cães doadores compatíveis. Este artigo aborda a pesquisa de anticorpos anti-AEC 1 pela técnica de citometria de fluxo em cães que receberam uma transfusão utilizando sangue do grupo AEC 1 positivo, comparando os resultados com aqueles obtidos a partir de reação cruzada. Foi utilizado sangue de 18 animais doadores do tipo AEC 1 positivo classificados por técnica cromatográfica para transfundir trinta e três animais com tipos sanguíneos desconhecidos, os quais mostraram reação cruzada negativa aos doadores. Nos dias 7, 14, 21 e 28 pós-transfusão, 45% e 27% dos animais mostraram-se positivos para os anticorpos anti-AEC 1, respectivamente, pela reação cruzada e através de citometria de fluxo. A pesquisa de anticorpos com o emprego da técnica de citometria de fluxo tem alta especificidade e sensibilidade, enquanto a reação cruzada, altamente sensível, tem baixa especificidade. Animais que não apresentaram positividade após a transfusão de sangue na reação cruzada e na citometria de fluxo concomitantemente foram considerados de qualquer outro grupo sanguíneo diferente do grupo sanguíneo AEC 1 positivo.(AU)

Flavonoids from the Brazilian plant Croton betulaster inhibit the growth of human glioblastoma cells and induce apoptosis

Abstract This study investigated the effects of the flavonoids 5-hydroxy-7,4′-dimethoxyflavone, casticin, and penduletin, isolated from Croton betulaster Müll Arg., Euphorbiaceae, a plant utilized in popular medicine in Brazil, on the growth and viability of the human glioblastoma cell line GL-15. We observed that 5-hydroxy-7,4′-dimethoxyflavone and casticin were not toxic to GL-15 cells after 24 h of exposure. However, casticin and penduletin inhibited the metabolic activity of glioblastoma cells significantly at a concentration of 10 µM (p ≤ 0.05). Flavonoids casticin and penduletin also induced a significant and dose-dependent growth inhibition beginning at 24 h of exposure, and the most potent flavonoid was penduletin. It was also observed that penduletin and casticin induced an enlargement of the cell body and a reduction of cellular processes, accompanied by changes in the pattern of expression of the cytoskeletal protein vimentin. Signs of apoptosis, such as the externalization of membrane phosphatidyl serine residues, nuclear condensation, and fragmentation, were also detected in cells treated with 50–100 µM flavonoids. Our results indicate that flavonoids extracted from C. betulaster present antitumoral activity to glioblastoma cells, with penduletin proving to be the most potent of the tested flavonoids. Our results also suggest that these molecules may be promising supplementary drugs for glioblastoma treatment.

Flavonoids modulate the proliferation of Neospora caninum in glial cell primary cultures.

Neospora caninum (Apicomplexa; Sarcocystidae) is a protozoan that causes abortion in cattle, horses, sheep, and dogs as well as neurological and dermatological diseases in dogs. In the central nervous system of dogs infected with N. caninum, cysts were detected that exhibited gliosis and meningitis. Flavonoids are polyphenolic compounds that exhibit antibacterial, antiparasitic, antifungal, and antiviral properties. In this study, we investigated the effects of flavonoids in a well-established in vitro model of N. caninum infection in glial cell cultures. Glial cells were treated individually with 10 different flavonoids, and a subset of cultures was also infected with the NC-1 strain of N. caninum. All of the flavonoids tested induced an increase in the metabolism of glial cells and many of them increased nitrite levels in cultures infected with NC-1 compared to controls and uninfected cultures. Among the flavonoids tested, 3',4'-dihydroxyflavone, 3',4',5,7-tetrahydroxyflavone (luteolin), and 3,3',4',5,6-pentahydroxyflavone (quercetin), also inhibited parasitophorous vacuole formation. Taken together, our findings show that flavonoids modulate glial cell responses, increase NO secretion, and interfere with N. caninum infection and proliferation.

The flavonoid rutin but not the alkaloid arborinine induces apoptosis in a B-cell hybridoma cell line.

The effects of arborinine, an alkaloid extracted from Erthela bahiensis and of rutin, a flavonoid obtained from Dimorphandra mollis (Benth.), Brazilian medicinal plants, on the viability and function of a murine B-cell hybridoma as a tumor model were investigated. The flavonoid rutin at 50 microM induced an increase in the number of apoptotic cells of one- to fivefold and reductions in cellular proliferation and monoclonal antibody production. Less but still significant necrosis was also induced by rutin under the same experimental conditions. On the other hand, the alkaloid arborinine exerted no significant effects on the studied parameters.

Investigation of toxic factors affecting cells of rat brains exposed to 3-methylcatechol

The aim of this work was to study the effects of 3MC on the peroxidation of biomolecules in nuclear fractions and nonsynaptic mitochondrial respiration in organelles obtained from rat brains. The cytotoxicity towards rat primary astrocytes in vitro was also tested. 3MC at 1mM oxidized consuming oxygen at a rate of 1.98 ± 0.19 µM.min-1 and formed reactive quinones. At the same concentration, 3MC induced peroxidation of biomolecules in nuclear fractions obtained from rat brain homogenates and inhibited state 2 FADH2-linked respiration in nonsynaptic mitochondria. Furthermore, 3MC oxidized in the culture medium, leading to the formation of quinones. This toluene metabolite was cytotoxic to rat primary astrocytes. The concentration that killed 50 percent of cells after 72 h was 107 mM. The results of the study indicated a direct relationship between cytotoxicity and 3MC oxidation.

O 3-metilcatecol (3MC) é um metabólito do tolueno. Para esclarecer se o 3MC seria tóxico para o sistema nervoso central, examinou-se seus efeitos sobre a peroxidação de biomoléculas em frações nucleares e a respiração mitocondrial em organelas obtidas de cérebros de ratos. Também se testou a citotoxicidade para astrócitos primários de ratos. O 3MC a 1mM oxida-se consumindo oxigênio a uma taxa de 1,98 ± 0,19 mM.min-1, formando quinonas reativas. Nessa mesma concentração o 3MC peroxidou biomoléculas nas frações nucleares. Esse composto também inibiu o estado 2 da respiração mitocondrial associada ao FADH2. Além disso, o 3MC também se oxida em meio de cultura levando à formação de quinonas. Esse metabólito do tolueno foi citotóxico para astrócitos de ratos. A concentração que matou 50 por cento das células após 72 horas foi 107 mM. Os resultados desse estudo indicam uma relação direta entre a citotoxicidade e a oxidação do 3MC.

Cytotoxicity effect of alkaloidal extract from Prosopis juliflora Sw. D.C. (Algaroba) pods on glial cells

Prosopis juliflora is largely used for feeding cattle and humans. Neurological signals have been reported in cattle due to intoxication with this plant. In this study, an alkaloidal fraction (AF) obtained from P. juliflora pods was tested on astrocyte primary cultures. Astrocytes display physiological functions essential to development, homeostasis and detoxification in the central nervous system (CNS). These cells are known for their role on energetic support and immune response in the CNS. Concentrations between 0.03 to 30 µg/ml AF were assayed for 24 - 72 h. The mitochondrial activity, assayed by MTT test, showed cytotoxicity at 30 µg/ml AF after 24 h. At concentrations ranging between 0.3 - 3 µg/ ml, the AF induced an increase on mitochondrial activity, indicating cell reactivity. lmmunocytochemistry assay for GFAP cytoskeletal protein, revealed alterations on cell morphology after treatment with 0.3 - 3 µg/ ml AF for 72 h. This result corroborates with western blot analysis when ceUs treated with 0.3 - 3 I-µg/ml AF for 72 h showed GFAP upregulation. The vimentin expression was not significantly altered in all tested concentrations. These results suggest that alkaloids induce astrocyte reactivity and might be involved in the neurotoxic effects induced by P. juliflora consumption.

A Prosopis juliflora é amplamente utilizada na alimentação humana e de várias espécies animais, especialmente bovinos. Quadros de intoxicação por esta planta, nesta espécie, têm sido relatados, principalmente quando a mesma é oferecida como única fonte alimentar, desencadeando uma doença de sintomatologia nervosa. Neste estudo, objetivou-se avaliar os efeitos in vitro da fração de alcalóides totais (F A) extraída das vagens da Prosopis juliflora utilizando cultura primária de astrócitos obtidos do córtex cerebral de ratos como modelo de estudo. A avaliação da atividade mitocondrial pelo teste do MTT demonstrou a citotoxicidade em 30 µg/ ml da FA após 24 h. As concentrações de 0,3 e 3 µg/ ml da FA induziram um aumento da atividade mitocondrial, indicando reatividade celular. Testes imunocitoquimicos para a GFAP, principal proteína de citoesqueleto de astrócitos, revelaram alterações morfológicas nas células após tratamento com 0,3 e 3 µg/ml da FA por 72 h. Tais resultados são consoantes à análise desta proteína por westernblot, quando as culturas foram tratadas com 0,3 e 3 µg/ml da FA por 72 h, demonstrando interferências na regulação da expressão da GFAP. A expressão de vimentina não foi significativamente alterada em nenhuma das concentrações testadas. Estes resultados sugerem que os alcalóides da P.juliflora induzem a reatividade astrocitária, o que pode estar envolvido nos efeitos neurotóxicos providos pelo consumo desta planta.

Cytotoxicity of catechol towards human glioblastoma cells via superoxide and reactive quinones generation

It is known that the exposure to benzene in the petroleum industry causes lympho-haematopoietic cancer among workers. However, there is little data concerning the toxicity of benzene to the central nervous system. Benzene easily penetrates the brain where it is metabolized to catechol. Since catechol autoxidizes in physiological phosphate buffer, we hypothesized that it could be toxic towards glial cells due to the generation of reactive oxygen species and quinones. In this work we studied the cytotoxic properties of catechol towards human glioblastoma cells. We found that catechol was toxic towards these cells after 72 hours and this toxicity was related to the formation of quinones. Catechol at 230µM killed 50% of cells. The catechol-induced cytotoxicity was prevented by the addition of 100U superoxide dismutase, which also inhibited the formation of quinones. These data suggest that catechol induces cytotoxicity via the extracellular generation of superoxide and quinones.

Sabe-se que a exposição de trabalhadores ao benzeno na indústria petrolífera é uma causa de câncer do sistema linfo-hematopoiético. Pouco se sabe, contudo, a respeito da toxicidade do benzeno no sistema nervoso central. O benzeno penetra facilmente no cérebro, onde é metabolizado a catecol. Como o catecol se auto-oxida em tampão fosfato no pH fisiológico, supôs-se que esse composto poderia ser tóxico para células gliais por gerar espécies reativas do oxigênio e quinonas. Nesse trabalho estudou-se a citotoxicidade do catecol para células de glioblastoma humano. O catecol foi tóxico após 72 horas e essa toxicidade relacionou-se com a formação de quinonas. O catecol a 230mM matou metade das células em cultura. A toxicidade do catecol e a produção de quinonas foram inibidas por 100U de superóxido dismutase. Esses dados sugerem que a toxicidade induzida pelo catecol deve-se à produção extracelular de superóxido e quinonas reativas.

Produção de sonda de DNA diretamente biotinilada com N-hidroxisuccinimida biotina ester (BNHS) / Labeling DNA probes directly coupled with biotinyl-N -hydroxysuccinimide ester (BNHS)

A utilização de sondas de DNA para análise genômica em fase sólida tem se expandido e ultrapassado as áreas da pesquisa, estendendo-se ao terreno do diagnóstico de rotina nas áreas de medicina humana e animal, bem como nas ciências forenses. Estas sondas têm sido utilizadas desde o surgimento da primeira técnica de hibridização descrita com o southern blotting, que envolve a imobilização, em filtros de papel, de fragmentos de DNA separados eletroforeticamente. Outra técnica descrita como o dot-hibridização é menos complexa do que o southern convencional por não requerer o passo prévio de eletroforese e por ser menos exigente quanto à qualidade do DNA, já que dispensa a digestão com enzima de restrição. A marcação mais comum para estas sondas é o fósforo radioisótopo (32P), que, apesar de sua alta sensibilidade, apresenta os inconvenientes de risco físico, necessidade de autorização para manipulação de radioisótopos, alto custo e uma vida média muito curta. Uma série de alternativas para o 32P têm sido utilizadas, com marcas diretas ou secundárias, entre elas a biotina, que tem mostrado grandes vantagens e tem sido usada também em laboratórios especializados e bem equipados. Este trabalho descreve uma modificação do método clássico descrito para sondas de DNA acopladas por biotina hidrazida. Utilizamos a N-hidroxisuccinimida biotina (BNHS) em dimetilformamida, para marcar resíduos de citosina disponíveis em segmentos de fita simples de DNA extraído de Corynebacterium pseudotuberculosis. A variação da proporção de biotina e de DNA, bem como sua especificidade e sensibilidade, foram cuidadosamente testadas e criteriosamente analisadas através de ensaios de hibridização, adsorvendo-se DNA cromossômico do C. pseudotuberculosis e outros DNAs em papel de nitrocelulose, seguindo-se a incubação com as sondas biotiniladas descritas,avidina-peroxidase e revelação com 4-cloro-1-naftol. Os resultados mostraram que a sonda de DNA produzida tem as características favoráveis...

Bioquímica da esquistossomose mansônica: VI - Alteraçöes do compartimento lisossômico hepático relacionadas ao tempo de infecçäo / Biochemistry of Schistosomiasis mansoni: VI - Alterations of hepatic lysosomes behavior relative to the infection period

O Schistosoma mansoni e/ou seus ovos causam uma hepatopatia muito importante e com aspectos anátomo-clínicos bam característicos. Uma vez carregados pela corrente circulatória, os vermes podem ocluir ramos dicotômicos de maior calibre do sistema portal e, quando mortos produzem lesöes às vezes extensas, primeiro necróticas, depois inflamatórias e, posteriormente cicatriciais, sempre circunscritas e näo sistematizadas. Os ovos, além de penetrarem nos ramúsculos näo dicotômicos da rede periductal alcançam os ramos de distribuiçäo ou até mesmo as vênulas aferentes, ocluindo muitas delas e, como conseqüência, formam os granulomas intravasculares que podem levar a uma interrupçäo da corrente sangüínea portal a esse nível e alteraçöes da circulaçäo intralobular. A diminuiçäo da taxa de oxigênio disponível e conseqüêntemente o decréscimo do pH intra e extracelular säo potentes labilizadores das membranas dos diversos componentes do compartimento lisossônico. A saída de hidrolases ácidas, proteínas catiônicas e hidrolases neutras, a partir desses orgânulos, acarreta agressöes tissulares muito importantes, com o desencadeamento e/ou manutençäo dos processos inflamatórios típicos desta parasitose. Neste trabalho estudou-se as atividades lisossômicas ligadas às diversas fases da esquistossomose mansônica hepática. Os resultados indicaram que a integridade funcional dos complexos membranosos do compartimento lisossômico foi significativamente alterada, já a partir do segundo mês da infecçäo e que parece haver um estreito relacionamento entre o agravamento das lesöes inflamatórias hepáticas com uma maior labilidade lisossômica