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Previous issue date: 2016-01-21 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / Glucanas s?o polissacar?deos com diversas atividades farmacol?gicas e biol?gicas descritas. Contudo, h? pouco relatos sobre as atividades das dextranas com figura??o do tipo ? (alfa). Nesse contexto, dextranas (?-D-glucanas) extra?das da bact?ria Leuconostoc mesenteroides, com massas moleculares de 10 (D10), 40 (D40) e 147 (D147) kDa e seus derivados fosforilados P10, P40 e P147 foram avaliados quanto ao seu potencial antioxidante, anticoagulante e imunomodulador pela primeira vez, com o intuito de elucidar compostos com atividades potentes e pouco t?xicas. An?lises de espectroscopia de infravermelho, composi??o monossacar?dica e dosagens qu?micas comprovaram que estas dextranas s?o o mesmo polissacar?deo, mas com massas moleculares diferentes, al?m de confirmar o sucesso da fosforila??o. Nenhuma das dextranas tem atividade anticoagulante. No teste do poder redutor verificou-se que D147 e P147 foram duas vezes mais potentes que as outras dextranas. Por outro lado, as seis amostras tiveram atividade semelhante (50%) em sequestrar o radical OH. Frente ao sequestro do ?on super?xido, apenas D10 teve uma atividade pronunciada (50%). D40 foi a ?nica dextrana nativa com a??o imunomodulat?ria, pois estimulou em dobro a prolifera??o de macr?fagos mur?nicos (RAW 264.7) e dobrou a libera??o de NO por essas c?lulas, tanto na aus?ncia como na presen?a de LPS. Al?m disso D40 teve maior atividade sequestradora (50%) de per?xido de hidrog?nio, o que fez com que ela tamb?m fosse a dextrana mais potente em inibir peroxida??o lip?dica (70%). J? P147 apresentou maior atividade quelante de ?ons ferro e cobre (~85%), al?m de aumentar o triplo a libera??o de NO na aus?ncia e na presen?a de LPS. P10 provou ser o composto mais efetivo sobre a prolifera??o de macr?fagos. Os dados indicam que dextranas com massa aproximada de 40 kDa s?o as ideais para serem utilizadas como antioxidantes e imunomoduladores, podendo ter suas atividades potencializadas com o processo de fosforila??o. Contudo, estudos futuros com D40 e outras dextranas de massa semelhante confirmar?o esta hip?tese. / Glucans are polysaccharides with different pharmacological and biological activities described. However, there are some reports about the activities of the glucan type ? (alpha). In this context, a group of ?-D-glucans called dextrans extracted from Leuconostoc mesenteroides bacteria, with molecular weights of 10 (D10), 40 (D40) and 147 (D147) kDa and their phosphorylated derivatives P10, P40 and P147, were evaluated as for their antioxidant, anticoagulant and immunomodulatory potential for the first time, in order to elucidate compounds with potent activities and low toxicity. Infrared spectroscopy analysis, monosaccharide composition and chemical dosages showed that these dextrans are the same polysaccharide, but with different molecular weights, besides confirming the success of phosphorylation. None presented with anticoagulant features. The reducing power test showed that D147 was twice as potent as other dextrans. On the other hand, all six samples showed similar activity (50%) when it came to scavenging the OH radical. To the superoxide ion scavenging, only D10 had a pronounced activity (50%). D40 was the single native dextran that presented with immunomodulatory features since it double stimulated the proliferation of murine macrophages (RAW 264.7) and double the release of nitric oxide by the cells, both in the absence and presence of lipopolysaccharides (LPS). In addition, D40 showed a greater scavenging activity (50%) for the hydrogen peroxide, which caused it to also be the more potent dextran when it came to inhibiting lipid peroxidation (70%). On other hand, P147 showed the highest iron and copper ion chelation activity (~85%). P10 proved be the most effective compound to macrophage proliferation. The results point toward dextrans with a 40 kDa weight as being ideal for antioxidant and immunomodulatory use, could be supplemented with phosphorylated derivatives. However, future studies with the D40 and other similarly dextrans are to confirm this hypothesis.
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/20735 |
| Date | 21 January 2016 |
| Creators | Soeiro, Vin?cius Campelo |
| Contributors | 04647720446, http://lattes.cnpq.br/4991977240761750, Albuquerque, Ivan Rui Lopes de, 91237386420, http://lattes.cnpq.br/2266021166245706, C?mara, Rafael Barros Gomes da, 06156497420, http://lattes.cnpq.br/9200036511632745, Rocha, Hugo Alexandre de Oliveira, Costa, Leandro Silva |
| Publisher | Universidade Federal do Rio Grande do Norte, PROGRAMA DE P?S-GRADUA??O EM BIOQU?MICA, UFRN, Brasil |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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