145 resultados para immunomodulatory


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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Objective: Periodontitis is a well-appreciated example of leukocyte-mediated bone loss and inflammation with pathogenic features similar to those observed in other inflammatory diseases, such as arthritis. Since Tacrolimus, is an immunomodulatory drug used for the treatment of some cases of arthritis, we hypothesized that it may modulate periodontal disease.Design: Using a murine model of ligature-induced periodontal disease, we assessed the effects of daily administrations of Tacrolimus (1 mg/kg body weight) on bone loss, enzymatic (myeloperoxidase) analysis, differential white blood cells counts, airpouch exudate and cytokine expression for 5-30 days.Results: Radiographic, enzymatic (myeloperoxidase) and histological analysis revealed that Tacrolimus reduced the severity of periodontitis. More specifically, Tacrolimus suppressed the expression of serum interleukin (IL-1 beta), tumour necrosis factor (TNF-alpha), IL-6, airpouch exudate PGE(2) and leukocytosis usually observed after the induction of periodontitis. Tacrolimus treatment in periodontitis-induced rats conferred protection against the inflammation-induced tissue and bone loss associated with periodontitis, through a mechanism involving IL-1 beta, TNF-alpha and IL-6.Conclusions: the effects of Tacrolimus on periodontal disease pathogenesis may provide clues to a novel approach to host modulation therapy in destructive periodontal disease. (C) 2007 Elsevier Ltd. All rights reserved.

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Agaricus blazei Murrill, is an edible and medicinal mushroom which is popularly consumed due to its antitumoral properties. The immunomodulatory effects of methanol (METH), dichloromethane (DM) and n-hexane (HEX) extracts of this mushroom were evaluated in Ehrlich tumor-bearing mice. Subcutaneous inoculation of Ehrlich tumor cells inhibited the natural killer (NK) activity of spleen cells (specific lysis = 6.18 +/- 2.56%) compared with normal mice (17.59 +/- 7.77%). Treatment of tumor-bearing mice with the extracts for 10 days restored the natural killer activity against Yac-1 target cells and the best results were observed by treatment with the HEX extract (21.48 +/- 15.26%). Treatment of the animals with the HEX extract for 10 days was also able to stimulate the mitogen-induced lymphoproliferative activity of spleen cells. Thirty days after the treatment, all groups presented low proliferative activity. Specific antibody production was observed to be higher in the groups treated with the DM or METH extract 30 days after the treatment. Analysis of the 3 extracts by gas chromatography mass spectrum (GCMS) and magnetic nuclear resonance (MNR) showed that the HEX extract contains mainly sugar and fatty acids and that the METH extract also contains sugar and possibly amino acids. (C) 2004 Elsevier Ltd. All rights reserved.

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Crotoxin, the main toxin of South American rattlesnake (Crotalus durissus terrificus) venom, was the first snake venom protein to be purified and crystallized. Crotoxin is a heterodimeric beta-neurotoxin that consists of a weakly toxic basic phospholipase A(2) and a nonenzymatic, non-toxic acidic component (crotapotin). The classic biological activities normally attributed to crotoxin include neurotoxicity, myotoxicity, nephrotoxicity and cardiotoxicity. However, numerous studies in recent years have shown that crotoxin also has immunomodulatory, anti-inflammatory, anti-microbial, anti-tumor and analgesic actions. In this review, we describe the historical background to the discovery of crotoxin and its main toxic activities and then discuss recent structure-function studies and investigations that have led to the identification of novel pharmacological activities for the toxin. (C) 2010 Elsevier Ltd. All rights reserved.

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We evaluated propolis influence on polyclonal activation of lymphocytes by concanavalin A (Con A). The in vitro experiments showed that propolis decreases splenocyte proliferation both in the absence or presence of Con A. The supression in mitogen-induced splenocyte proliferation also occurred when mice were treated intraperitoneally with propolis for 3 days. An increased of IFN-gamma production in the culture supernatants of the same cells was, observed. A dual action of propolis on lymphocyte activation was proposed: it decreases splenocyte proliferation in the presence or absence of Con A and stimulates IFN-gamma production by spleen cells. These results are important to understand the immunomodulatory action of propolis on the host's specific and non-specific immunity. (C) 2003 Elsevier B.V. Ireland Ltd. All rights reserved.

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Propolis has been used in folk medicine since ancient times due to its, many biological properties: such as antimicrobial. antinflammatory, antioxidant, immunomodulatory activities, among others. 'Macrophages play an important role in the early phase of Salmonella infection. In this work, macrophages were prestimated with Brazilian or Bulgarian propolis and subsequently challenged with Salmonella Typhimurium at different macrophage/bacteria ratio. After 60 min of incubation. cells were harvested with Triton-X to lyse the macrophages. To assess the bactericidal activity. The number of colony-forming units (CFU) of S. typhimurium was determined by plating 0.1 mL in 'Mueller Hinton agar. After 24 h. CFU were counted. and the percentage of bactericidal activity was obtained. Propolis from Brazil and Bulgaria enhanced the bactericidal activity of macrophages, depending on its concentration. Brazilian propolis seemed to be more efficient than that from Bulgaria. because of their different chemical composition. In Bulgaria, bees collect the material mainly from the bud exudate of poplar tree, while in Brazil, Baccharis dracunculifolia DC. was shown to be the main propolis source. Our data also showed that the increased bactericidal activity of macrophages involved the participation of oxygen (H2O2) and nitrogen (NO) intermediate metabolites. (C) 2004 Elsevier B.V. All rights reserved.

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Propolis is a beehive product with a very complex chemical composition, widely used in folk medicine because of its several therapeutic activities. Its biological properties and chemical composition may vary according to the geographic location and to the different plant sources. The possible mechanism of action of propolis as well as of its active compounds has been the subject of researchers in recent years. In this work, first we reported the results of our study on the seasonal effect of the immunomodulatory action of propolis on antibody production in bovine serum albumin (BSA)-immunized rats. Then, we compared the effect of Brazilian and Bulgarian propolis, some isolated compounds and Baccharis extract on anti-BSA antibody levels. Based on the results, we conclude that propolis stimulates antibody production, independently of the season and geographic origin. Caffeic acid, quercetin and Baccharis extract had no effect on antibody production, although the importance of isolated compounds is well reported in other biological assays. Propolis action is a consequence of plant-derived products with synergic effects. while isolated compounds or extracts from its plant sources had no effect in this assay. (c) 2005 Elsevier B.V.. All rights reserved.

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Baccharis dracunculifolia D.C. (Asteraceae), a shrub which grows wild in Brazil, is the main botanical source of Brazilian green propolis. Since Brazilian propolis shows an immunomodulatory activity, the goal of this work was to evaluate the action of B. dracunculifolia extracts and some of its isolated compounds on reactive oxygen intermediate (H2O2) production by macrophages obtained from male BALB/c mice. The results showed that the leaf (Bd-L) (25, 50, and 100 mu g mL(-1)), leaf rinse (Bd-LR) (25 mu g mL(-1)), and the root (Bd-R) (25 mu g mL(-1)) extracts enhanced H2O2 release by macrophages. A phytochemical study of the root and leaves of B. dracunculifolia was carried out. The chromatographic fractionation of Bd-R, using several techniques, afforded the isolation of baccharis oxide (1), friedelanol (2), viscidone (11), 11-hydroxy-10,11-dihydro-euparin (12), and 6-hydroxy-tremetona (13), while Bd-LR gave the following isolated compounds: baccharis oxide (1), friedelanol (2), isosakuranetin (3), aromadendrin-4'-methyl ether (4), dihydrocumaric acid (5), baccharin (6), hautriwaic acid lactone (7), hautriwaic acid acetate (8), drupanin (9), and cumaric acid (10). Among the isolated compounds, baccharis oxide (1) and friedelanol (2) increased H2O2 production at a concentration of 1001,M. This is the first time that the presence of compounds 7, 8, 12, and 13 in B. dracunculifolia has been reported. Based on these results it is suggested that the crude extracts and some isolated compounds from B. dracunculifolia display an immunomodulatory action.

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Propolis has been used empirically for centuries and it was always mentioned as an immunomodulatory agent. In recent years, in vitro and in vivo assays provided new information concerning its mechanisms of action, thus a review dealing with propolis and the immune system became imperative. This review compiles data from our laboratory as well as from other researchers, focusing on its chemical composition and botanical sources, the seasonal effect on its composition and biological properties, its immunomodulatory and antitumor properties, considering its effects on antibody production and on different cells of the immune system, involving the innate and adaptive immune response. In vitro and in vivo assays demonstrated the modulatory action of propolis on murine peritoneal macrophages, increasing their microbicidal activity. Its stimulant action on the lytic activity of natural killer cells against tumor cells, and on antibody production was demonstrated. Propolis inhibitory effects on lymphoproliferation may be associated to its anti-inflammatory property. In immunological assays, the best results were observed when propolis was administered over a short-term to animals. Propolis antitumor property and its anticarcinogenic and antimutagenic potential are discussed. Since humans have used propolis for different purposes and propolis-containing products have been marketed, the knowledge of its properties with scientific basis is not only of academic interest but also of those who use propolis as well. This review opens a new perspective on the investigation of propolis biological properties, mainly with respect to the immune system. (c) 2007 Elsevier B.V.. All rights reserved.

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Propolis is a resinous substance produced by honeybees that possesses many biological activities, such as antitumor, antioxidant, antimicrobial, anti-inflammatory, and immunomodulatory, among others. The purpose of the present study was to investigate the biochemical profile of propolis-treated rats to observe whether propolis might lead to side effects after administration. Three different treatments were analyzed: (1) rats were treated with different concentrations of propolis (1, 3 and 6 mg/kg/day) during 30 days; (2) rats were treated with I mg/kg/day of ethanolic or water extracts of propolis (EEP, WEP) during 30 days; (3) rats were treated with I mg/kg/day of ethanolic extract of propolis during 90 and 150 days. Our results demonstrated no alterations in the seric levels of cholesterol, HDL-cholesterol, total lipids, triglycerides and in the specific activity of aminotransferases (AST) and lactic dehydrogenase (LDH) of propolis-treated groups when compared to controls. on the basis of our findings, since propolis does not induce any significant change in seric parameters, it is claimed that long-term administration of propolis might not have any cardiac injury. (c) 2005 Elsevier B.V.. All rights reserved.

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