237 resultados para Anti-bacterial activity


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Bacillus thuringiensis (Bt), is an environmental Gram-positive spore-forming bacterium that produces crystalline parasporal protein (Cry) during sporulation. The inclusions often exhibit strong and specific insecticidal activity, making Bt an agent for agricultural controlling insects pest, mites, protozoa and nematodes. Recent studies reported that some of these Crys do not show cytotoxicity against insects but they are capable to kill some human and animal cancer cells. These proteins were denominated parasporins (PS). However, antitumor activity of Bt parasporin on the development of murine colorectal cancer (CT-26), are not well studies and these are no reports on the in vivo effect of these proteins. Thus, the present study evaluated the in vitro and in vivo anti-tumoral activity of Bt parasporin against the murine colorectal cancer line CT-26. Therefore, Balb/c mice were s.c. inoculated with CT-26 cells and weekly treated with parasporin (i.p.) pre-activated by enzymatic digestion with trypsin or proteinase K. Our results have shown, for the first time, that despite the anti-tumor activity in vitro, parasporin crystals couldn’t combat tumor growth in vivo. Instead, this protein was highly toxic, affecting the liver and spleen, with possible effect on other organs, decreasing the survival of treated animals. The results indicate the need for studies to better detoxification or manipulation of parasporin for therapeutic use and new studies for analysis of toxicological effects of repetitive exposure of farmers to this toxin

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Natural rubber latex from Hevea brasiliensis has interesting characteristics related to this work such as: it is easy to manipulate, low cost, can stimulate the natural angiogenesis, is a biocompatible material and presents high mechanical resistance. The aim of this study was to develop a novel sustained delivery system for Stryphnodendron sp. based on Natural Rubber Latex (NRL) membranes and to study the Stryphnodendron sp. delivery system behavior. Stryphnodendron sp., commonly known as barbatimao is extensively used in folk medicine for the treatment of diarrhoea, gynaecological problems and for healing wounds. The stem bark of this species is mentioned in the Brazilian Pharmacopeia with a content of at least 20% of tannins. Previous studies showed significant cicatrizant properties, anti-inflammatory activity and gastric anti-ulcerogenic effects for the stem bark crude extract. One possible way to accelerate the tissue repair process, it was incorporated the Stryphnodendron sp. extract in NRL membranes. Stryphnodendron sp extract was incorporated into the NRL, by mixing it in solution for in vitro protein delivery experiments. Results show that the NRL membrane can release Stryphnodendron sp. for up to 49.89% of its Stryphnodendron sp. content for up 400 h. The kinetics of the extract release could be fitted with double exponential function, with two characteristic times of 0.78 and 133.22 h. In this study, we demonstrated that the induced angiogenesis provided by NRL membranes combined with a controlled release of extract is relevant for biomedical applications.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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This study evaluated the occurrence of enteric bacteria and pseudomonads resistant to tetracycline and beta-lactams in the oral cavity of patients exhibiting gingivitis (n=89); periodontitis (n=79), periodontally healthy (n=50) and wearing complete dentures (n=41). Microbial identification and presence of resistance markers associated with the production of beta-lactamases and tetracycline resistance were performed by using biochemical tests and PCR. Susceptibility tests were carried out in 201 isolates of enteric cocci and rods. Resistance to ampicillin, amoxicillin/clavulanic acid, imipenem, meropenem and tetracycline was detected in 57.4%, 34.6%, 2.4%, 1.9% and 36.5% of the isolates, respectively. beta-lactamase production was observed in 41.2% of tested microorganisms, while the most commonly found beta-lactamase genetic determinant was gene bla(TEM). Tetracycline resistance was disseminated and a wide scope of tet genes were detected in all studied microbial genus.

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1. The development of genital organs of rats chronically treated with cimetidine showed that the drug may present anti-androgenic activity. 2. This treatment did not alter the sensitivity of vas deferens to noradrenaline, but increased their sensitivity to BaCl2. 3. In the male reproductive system, cimetidine must have peripheral actions apart from the central ones observed after chronic treatment.

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Infections caused by the genus Staphylococcus are of great importance for human health. Staphylococcus species are divided into coagulase-positive staphylococci, represented by S. aureus, a pathogen that can cause infections of the skin and other organs in immunocompetent patients, and coagulase-negative staphylococci (CNS) which comprise different species normally involved in infectious processes in immunocompromised patients or patients using catheters. Oxacillin has been one of the main drugs used for the treatment of staphylococcal infections; however, a large number of S. aureus and CNS isolates of nosocomial origin are resistant to this drug. Methicillin resistance is encoded by the mecA gene which is inserted in the SCCmec cassette. This cassette is a mobile genetic element consisting of five different types and several subtypes. Oxacillin-resistant strains are detected by phenotypic and genotypic methods. Epidemiologically, methicillin-resistant S. aureus strains can be divided into five large pandemic clones, called Brazilian, Hungarian, Iberian, New York/Japan and Pediatric. The objective of the present review was to discuss aspects of resistance, epidemiology, genetics and detection of oxacillin resistance in Staphylococcus spp., since these microorganisms are increasingly more frequent in Brazil.

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Propolis has been used in folk medicine in different regions of the world including Latin America. Propolis is a resinous mixture of substances collected by honey bees from several botanical sources, and its composition contains a rich chemical variety, depending on the geographical area and plant sources. Our aim was to compare the modulatory effect of propolis samples from three different countries of Latin America (Brazil, Cuba and Mexico) on pro- and anti-inflammatory cytokine production (tumor necrosis factor (TNF)-α and interleukin (IL)-10, respectively) by human monocytes. Cells were incubated with propolis for 18 h at 37°C. Cell viability was assessed by 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide method, and cytokine production was determined by ELISA. All samples did not affect monocyte viability. Brazilian propolis stimulated both TNF-α and IL-10 production by monocytes. Cuban propolis stimulated TNF-α and inhibited IL-10 production, while Mexican sample exerted the opposite effect, inhibiting TNF-α and stimulating IL-10 production. The major compounds found in Brazilian, Cuban and Mexican propolis samples were artepillin C, isoflavonoids and pinocembrin, respectively. Brazilian, Cuban and Mexican propolis contained different components that may exert pro- and anti-inflammatory activity depending on concentration, what may provide a novel approach to the development of immunomodulatory drugs containing propolis.

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Equisetum giganteum L. (E. giganteum), Equisetaceae, commonly called giant horsetail, is an endemic plant of Central and South America and is used in traditional medicine as diuretic and hemostatic in urinary disorders and in inflammatory conditions among other applications. The chemical composition of the extract EtOH 70% of E. giganteum has shown a clear presence of phenolic compounds derived from caffeic and ferulic acids and flavonoid heterosides derived from quercitin and kaempferol, in addition to styrylpyrones. E. giganteum, mainly at the highest concentrations, showed antimicrobial activity against the relevant microorganisms tested: Escherichia coli, Staphylococcus aureus, and Candida albicans. It also demonstrated antiadherent activity on C. albicans biofilms in an experimental model that is similar to dentures. Moreover, all concentrations tested showed anti-inflammatory activity. The extract did not show cytotoxicity in contact with human cells. These properties might qualify E. giganteum extract to be a promising alternative for the topic treatment and prevention of oral candidiasis and denture stomatitis.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)