Atividades Biológicas De Xilana De Sabugo De Milho

The corn cob is an agricultural by-product still little used, this in part due to the low knowledge of the biotechnological potential of their molecules. Xylan from corn cobs (XSM) is a polysaccharide present in greater quantity in the structure of plant and its biotechnology potential is little known. This study aimed to the extraction, chemical characterization and evaluation of biological activities of xylan from corn cobs. To this end, corncobs were cleaned, cut, dried and crushed, resulting in flour. This was subjected to a methodology that combines the use of alkaline conditions with waves of ultrasound. After methanol precipitation, centrifugation and drying was obtained a yield of 40% (g/g flour). Chemical analysis indicated a high percentage of polysaccharides in the sample (60%) and low contamination by protein (0.4%) and phenolic compounds (> 0.01%). Analysis of monosaccharide composition indicated the presence of xylose:glucose:arabinose:galactose:mannose:glucuronic acid in a molar ratio 50:20:15:10:2.5:2.5. The presence of xylan in the sample was confirmed by nuclear magnetic resonance (¹H and ¹³C) and infrared spectroscopy (IR). Tests were conducted to evaluate the antioxidant potential of XSM. This showed a total antioxidant capacity of 48.45 EAA/g sample. However, did not show scavenging activity of superoxide and hydroxyl radical and also reducing power. But, showing a high capacity chelating iron ions with 70% with about 2 mg/mL. The ability to XSM to influence cell proliferation in culture was also evaluated. This polymer did not influence the proliferation of normal fibroblast cells (3T3), however, decreased the rate of proliferation of tumor cells (HeLa) in a dose-dependent, reaching an inhibition of about 50% with a concentration around 2 mg/mL. Analyzing proteins related to cell death, by immunoblotting, XSM increases the amount of Bax, Bcl-2 decrease, increase cytochrome c and AIF, and reduce pro-caspase-3, indicating the induction of cell death induced apoptosis dependent and independent of caspase. XSM did not show anticoagulant activity in the PT test. However, the test of activated partial thromboplastin time (aPTT), XSM increased clotting time at about 5 times with 600 μg of sample compared with the negative control. The presence of sulfate on the XSM was discarded by agarose gel electrophoresis and IR. After carboxyl-reduction of XSM the anticoagulant activity decreased dramatically. The data of this study demonstrate that XSM has potential as antioxidant, antiproliferative and anticoagulant compound. Future studies to characterize these activities of XSM will help to increase knowledge about this molecule extracted from corn and allow their use in functional foods, pharmaceuticals and chemical industries.

Avaliação das atividades antioxidante, anticoagulante e antiproliferativa de extratos aquosos de marsdenia megalantha

The species of the genus Marsdenia, Apocynaceae, are widely used in folk medicine of several countries. In Brazil is found several species belonging to this genus. The in vitro antioxidant, anticoagulant and antiproliferative activities were evaluated to aqueous extracts of stalk, leaf and root of Marsdenia megalantha. In the total antioxidant capacity assay (expressed as ascorbic acid equivalents) the stalk extract showed 76.0 mg/g, while leaf and root extracts 141.3 mg/g and 57.0 mg/g, respectively. The stalk and leaf extracts showed chelating activity around 40% at 1.5 mg/mL, while root extract, at the same concentration showed, 17%. Only the leaf extract showed a significant ability in superoxide scavenging (80% at 0.8 mg/mL). Any extract was able in scavenge hydroxyl, as well anticoagulant activity. The antiproliferative activity of the extracts was evaluated against HeLa tumor cell line. The extracts inhibited in a dose-dependent manner the cell growth. However, the leaf extract showed 80% of inhibition at 1.0 mg/mL, while stalk and root extracts inhibited 63% and 30%, respectively. To assess the mechanism of cell death caused by the leaf extract in HeLa, was performed flow cytometry and western blot. The results show that leaf extract induces cell death by apoptosis through an activation caspase-independent pathway. These data indicate that stalk and leaf extracts obtained have potential to be used as antioxidants and anticancer drugs

Análise do efeito de polimorfismos não-sinônimos em genes de reparo de DNA da via BER na resposta inflamatória da meningite

In vitro and in animal models, APE1, OGG1, and PARP-1 have been proposed as being involved with inflammatory response. In this work, we have investigated if the SNPs APE1 Asn148Glu, OGG1 Ser326Cys, and PARP-1 Val762Ala are associated to meningitis and also developed a system to enable the functional analysis of polymorphic proteins. Patients with bacterial meningitis (BM), aseptic meningitis (AM) and controls (non-infected) genotypes were investigated by PIRA-PCR or PCR-RFLP. DNA damages were detected in genomic DNA by Fpg treatment. IgG and IgA were measured from plasma and the cytokines and chemokines were measured from cerebrospinal fluid samples using Bio-Plex assays. The levels of NF-κB and c-Jun were measured in CSF by dot blot assays. A significant (P<0.05) increase in the frequency of APE1 148Glu allele in BM and AM patients was observed. A significant increase in the genotypes Asn/Asn in control group and Asn/Glu in BM group was also found. For the SNP OGG1 Ser326Cys, the genotype Cys/Cys was more frequent (P<0.05) in BM group. The frequency of PARP-1 Val/Val genotype was higher in control group (P<0.05). The occurrence of combined SNPs increased significantly in BM patients, indicating that these SNPs may be associated to the disease. Increasing in sensitive sites to Fpg was observed in carriers of APE1 148Glu allele or OGG1 326Cys allele, suggesting that SNPs affect DNA repair activity. Alterations in IgG production were observed in the presence of SNPs APE1Asn148Glu, OGG1Ser326Cys or PARP-1Val762Ala. Reductions in the levels ofIL-6, IL-1Ra, MCP-1/CCL2and IL-8/CXCL8 were observed in the presence of APE1148Glu allele in BM patients, however no differences were observed in the levels of NF-κB and c-Jun considering genotypes and analyzed groups. Using APE1 as model, a system to enable the analysis of cellular effects and functional characterization of polymorphic proteins was developed using strategies of cloning APE1 cDNA in pIRES2-EGFP vector, cellular transfection of the construction obtained, siRNA for endogenous APE1 and cellular cultures genotyping. In conclusion, we obtained evidences of an effect of SNPs in DNA repair genes on the regulation of immune response. This is a pioneering work in the field that shows association of BER variant enzymes with an infectious disease in human patients, suggesting that the SNPs analyzed may affect immune response and damage by oxidative stress level during brain infection. Considering these data, new approaches of functional characterization must be developed to better analysis and interactions of polymorphic proteins in response to this context

Iga total e específica para bactérias enteropatogênicas no colostro e leite de mães da zona rural da Paraíba

Trata-se de um coorte prospectivo com amostras de leite de 28 mães da zona rural da Paraíba, durante diferentes dias de amamentação exclusiva, com objetivo de avaliar através do ensaio imunoenzimático a presença de imunoglobulina A secretora (sIgA) total e específica contra antígenos de Escherichia coli enteropatogênica (EPEC) e Shigella flexneri. A reatividade dos anticorpos foi analisada pelo Western blot . Os resultados mostram presença da sIgA em todas as amostras, com medianas no colostro de 8,092 g/L(4,546-17,252) e leite de 0,695g/L (0,020-2,830). As medianas nos títulos de colostro de IgA anti-EPEC foi 41 (1-659) e anti-Shigella flexneri de 18 (1-4727) enquanto no leite anti-EPEC foi de 8 (1-288) e anti-Shigella flexneri de 6 (1-450). Houve grandes variações entre as mães e entre os dias de amamentação. No Western blot os anticorpos sIgA reagiram com proteínas de EPEC e Shigella flexneri, destacando-se a fração antigênica de 94kDa, correspondente a intimina. Os resultados mostram que a presença de sIgA total e de anticorpos IgA contra EPEC e Shigella flexneri no colostro e leite de mães residentes em zona rural, com precárias condições sócioeconômica e sanitárias, não diferem de estudos realizados com populações de área urbana e reforçam a importância do leite materno na defesa contra infecções entéricas. Apesar da ausência na literatura de estudos avaliando o perfil de anticorpos sIgA no leite de mães residentes em zona rural do Brasil, os resultados demonstraram que a presença de sIgA total e de anticorpos IgA contra EPEC e Shigella flexneri no colostro e leite de mães residentes em zona rural, com precárias condições sócio-econômica e sanitárias, não diferem de estudos realizados com populações de área urbana e reforçam a importância do leite materno na defesa contra infecções entéricas

Soroepidemiologia da infecção pelo Trypanosoma cruzi na zona rural do semiárido do estado do Rio Grande do Norte, Brasil

Conselho Nacional de Desenvolvimento Científico e Tecnológico

Estudo da detecção do DNA do papiloma vírus humano (HPV) e da expressão imuno-histoquímica de proteína do ciclo celular no carcinoma epidermóide oral

Oral squamous cell carcinoma (OSCC) is the most common malignancy in oral cavity and human papillomavirus (HPV) may have an important role in its development. The aim of this experiment was to investigate the HPV DNA and viral types in 90 cases of OSCC. Moreover, a comparative analysis between the cases of OSSC with and without HPV DNA was performed by using cell cycle markers p21 and pRb in order to detect a possible correlation of these proteins and HPV infection. DNA was extracted from paraffin embedded tissue and amplified by PCR (polymerase chain reaction) with primers PCO3+ e PCO4+ for a fragment of human β-globin gene. After this procedure, PCR for HPV DNA detection was realized using a pair of generic primers GP5+ e GP6+. Immunohistochemical study was performed by streptoavidin-biotin technique and antibodies against p21 and pRb proteins were employed. Eighty-eight cases were positive for human β-globin gene and HPV DNA was found in 26 (29.5%) of then. It could not be detected significant correlation between HPV and age, sex and anatomical sites of the lesion. The most prevalent viral type was HPV 18 (80.8%). Regarding the immunohistochemical analysis, it was detected significant association between HPV presence and pRb immunoexpression (p=0,044), nevertheless, the same was not observed in relation to p21 protein (p =0,416). It can be concluded that the low detection of HPV DNA in OSCC by the present experiment suggests a possible role of the virus in the development and progression in just a subset of this disease

Expressão de zif268 no cérebro do lagarto Tropidurus Hispidus após exploração de um ambiente enriquecido.

In the present work, we investigated behavioral changes associated with the increase in Zif268 protein expression within telencephalic areas of the tropical lizard Tropidurus hispidus that correspond to the mammalian hippocampus (HC). We used 13 male individuals of this species, collected at the Federal Agrotechnical School of Rio Grande do Norte, under SISBIO license number 19561-1. Four animals had their brains removed and were submitted to a Western blot with antibodies for the Zif268 protein. The remaining animals were separated in two different groups: a control group (n=4) and an exploration group (n=5). Animals from the exploration group were exposed to an enriched environment with many sensory cues novel to them. Control group animals stayed in the environment they were already habituated to. After 90 min from the onset of exposure to the new environment, animals from both groups were submitted to intracardiac perfusion with fixative, and the brains were removed, cryoprotected and frozen. After that, brains were sectioned at 20 μm and the sections were subjected to immunohistochemistry for the Zif268 protein. We verified that the Zif268 protein is likely conserved in the brain of T. hispidus, which showed antigenicity for the antibody anti-Zif268 made in mammals. In animals from the exploration group, we detected an increase of the Zif268 protein in the Septum, Striatum, Dorsoventricular Area and in cortical areas corresponding to the HC. This increase was proportional to the amount of environmental exploration, with maximum positive correlation in the hippocampal subareas Medial Cortex (R = 0.94 and p = 0.004) and Dorsomedial Cortex (R = 0.92 and p = 0.006). The data corroborate the notion that the reptilian hippocampus, as well as the mammalian HC, plays an important role in spatial exploration.