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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Avalia??o das propriedades farmacol?gicas de polissacar?deos do fungo Scleroderma nitidum

Nascimento, Mar?lia da Silva 23 February 2010 (has links)
Made available in DSpace on 2014-12-17T14:03:31Z (GMT). No. of bitstreams: 1 MariliaSN.pdf: 1926704 bytes, checksum: da3259de4a29785c64e3b5736af19e2f (MD5) Previous issue date: 2010-02-23 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Several pharmacological properties have been attributed to isolated compounds from mushroom. Recently, have these compounds, especially the polysaccharides derived from mushrooms, modulate the immune system, and its antitumor, antiviral, antibiotic and antiinflammatory activities. This study assesses the possible pharmacological properties of the polysaccharides from Scleroderma nitidum mushroom. The centesimal composition of the tissue showed that this fungus is composed mainly of fibers (35.61%), ash (33.69%) and carbohydrates (25.31%). The chemical analysis of the polysaccharide fraction showed high levels of carbohydrates (94.71%) and low content of protein (5.29%). These polysaccharides are composed of glucose, galactose, mannose and fucose in the following molar ratios 0.156, 0.044, 0.025, 0.066 and the infrared analysis showed a possible polysaccharide-protein complex. The polysaccharides from Scleroderma nitidum showed antioxidant potential with concentration-dependent antioxidant activity compared to ascorbic acid. The analysis scavenging of superoxide radical and inhibition of lipid peroxidation showed that the polysaccharides from S. nitidum have an IC50 of 12.70 mg/ml and EC50 10.4 μg/ml, respectively. The antioxidant activity was confirmed by the presence of reducing potential of these polysaccharides. The effect of these polymers on the inflammatory process was tested using the carrageenan or histamine-induced paw edema model and the sodium thioglycolate or zymosan-induced model. The polysaccharides were effective in reducing edema (73% at 50 mg/kg) and cell infiltrate (37% at 10 mg/kg) in both inflammation models tested. Nitric oxide, a mediator in the inflammatory process, showed a reduction of around 26% at 10 mg/kg of body weight. Analysis of pro- and anti-inflammatory cytokines showed that in the groups treated with polysaccharides from S. nitidum there was an increase in cytokines such as IL-1ra, IL-10, and MIP-1β concomitant with the decrease in INF-γ (75%) and IL-2 (22%). We observed the influence of polysaccharides on the modulation of the expression of nuclear factor κB. Thus, polysaccharides from S. nitidum reduced the expression of NF-κB by up to 64%. The results obtained suggest that NF-κB modulation is one of the possible mechanisms that explain the anti-inflammatory effect of polysaccharides from the fungus S. nitidum. / Diversas propriedades farmacol?gicas t?m sido atribu?das aos compostos isolados de fungos. Recentemente, t?m-se referido quanto ? capacidade desses compostos, principalmente os polissacar?deos derivados de cogumelos, de modular o sistema imunol?gico, al?m de suas a??es antitumoral, antiviral, antibi?tica e antiinflamat?ria. Este estudo avalia a capacidade dos polissacar?deos do fungo Scleroderma nitidum quanto ?s suas poss?veis propriedades farmacol?gicas. A composi??o centesimal do tecido deste fungo demonstrou que este ? composto principalmente por fibras (35,61%), cinzas (33,69%) e carboidratos (25,31%). As an?lises qu?micas da fra??o polissacar?dica revelaram alto teor de carboidratos (94,71%) e baixo teor de prote?nas (5,29%). Esses polissacar?deos s?o constitu?dos por glicose, galactose, manose e fucose nas seguintes propor??es molares 0,156; 0,044; 0,025; 0,066, respectivamente e a an?lise de infravermelho demonstrou um poss?vel complexo polissacar?deo-prote?na. Os polissacar?deos de S. nitidum demonstraram potencial antioxidante com atividade relativa ao ?cido asc?rbico massa-dependente. As an?lises sobre a varredura de radicais super?xido e inibi??o da peroxida??o lip?dica demonstraram que os polissacar?deos de S. nitidum apresentam um IC50 estimado em 12,70 mg/ml e EC50 10,4 μg/ml, respectivamente. A atividade antioxidante foi confirmada pela presen?a de potencial redutor dos polissacar?deos. Este estudo tamb?m avaliou a capacidade dos polissacar?deos do fungo S. nitidum como agente antiinflamat?rio. O efeito destes pol?meros no processo inflamat?rio foi testado usando-se os modelos de edema de pata induzido por carragenana ou histamina e o modelo de peritonite induzida por tioglicolato de s?dio ou zymosan. Os polissacar?deos foram efetivos na redu??o do edema (73% a 50 mg/kg) e infiltrado celular (37% a 10 mg/kg) nos dois modelos de inflama??o testados. ?xido n?trico, um mediador do processo inflamat?rio, mostrou uma redu??o de cerca de 26% nos grupos tratados com a dose 10 mg/kg dos polissacar?deos. A an?lise de citocinas pr? e antiinflamat?rias mostrou que nos grupos tratados com os polissacar?deos de S. nitidum houve aumento de citocinas como IL-1ra (2x), IL-10 (3x) e concomitante a diminui??o de INF-γ (75%), MIP-1β (29%) e IL-2 (22%). Al?m disso, nos grupos tratados com os polissacar?deos tamb?m foi verificada uma inibi??o de cerca de 64% na express?o do NF-κB. Os resultados obtidos sugerem que a modula??o do NF-κB ? um dos poss?veis mecanismos que esclarece os efeitos anti-inflamat?rios dos polissacar?deos do fungo S. nitidum.

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