Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 3 de 3
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
1.
Carbohydr Polym ; 254: 117251, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33357847

RESUMO

The research described here presents data on the effect of galactans of red algae, carrageenans (λ/µ/ν-, κ-, κ/ß-, and ι/κ-types), and agar on complement system activation in normal human serum. The experiments were based on well surfaces coated with triggering agents for binding initiating complement components -C3 and C4. The sulfated galactans inhibited C3 binding to lipopolysaccharide with direct dependence on the sulfation degree of polysaccharides. Sulfation degree was also important in carrageenans' capacity to reduce C4 binding to mannan. However, C4 binding to antibodies was considerably activated by carrageenans, especially with 3,6-anhydrogalactose. The gelling carrageenans were able to block antigen binding centers of total serum IgM and with more intensity than non-gelling. No structural characteristics mattered in ameliorating C5 cleavage by plasmin in extrinsic protease complement activation, but λ/µ/ν- and κ/ß-carrageenans almost completely inhibited C5 cleavage. Thus, galactans participated in cell surface biology by imitating surface glycans in inhibition of C3 binding and mannose binding lectin, but as to the tthe heclassical pathway these substances stimulated complement, probably due to their structure based on carrabiose.


Assuntos
Ativação do Complemento/efeitos dos fármacos , Galactanos/química , Galactanos/farmacologia , Alga Marinha/química , Anticorpos/sangue , Configuração de Carboidratos , Sequência de Carboidratos , Carragenina/química , Carragenina/farmacologia , Via Alternativa do Complemento/efeitos dos fármacos , Via Clássica do Complemento/efeitos dos fármacos , Galactanos/sangue , Humanos , Técnicas In Vitro , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Polissacarídeos/química , Polissacarídeos/farmacologia , Rodófitas/química , Espectroscopia de Infravermelho com Transformada de Fourier , Sulfatos/química
2.
Carbohydr Polym ; 230: 115629, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31887898

RESUMO

The research described here focused on the effect of sulfated red algal polysaccharides (κ-, κ/ß-, ι/κ-carrageenan) individually and in combination with lipopolysaccharide (LPS) on the synthesis of prostaglandin E2 (PGE2) and cytokines (interleukin [IL]-1ß and IL-6) in whole blood model in vitro. The results demonstrated that, at high concentrations, carrageenans have substantial ability to modulate PGE2 synthesis and stimulate IL-1ß and IL-6 synthesis. A low degree of sulfate and high molecular weight were a prerequisite for the ability of carrageenans to modulate PGE2 synthesis. Further, we investigated the ability of the carrageenans alone and in combination with casein to affect bile salt permeability through an artificial membrane imitating the gastrointestinal barrier. The least sulfated κ/ß-carrageenan could retain bile salt permeation the most but less efficiently than cholestyramine. The polysaccharides did not affect pancreatic lipase activity. Our data confirm a possible mechanism of the cholesterol-reducing properties of carrageenan.


Assuntos
Carragenina/farmacologia , Dinoprostona/biossíntese , Lipase/metabolismo , Ácidos e Sais Biliares/metabolismo , Células Sanguíneas/efeitos dos fármacos , Células Sanguíneas/metabolismo , Carragenina/química , Permeabilidade da Membrana Celular , Células Cultivadas , Humanos , Interleucina-1beta/biossíntese , Interleucina-6/biossíntese , Metabolismo dos Lipídeos
3.
J Biomed Mater Res A ; 105(5): 1549-1557, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28130856

RESUMO

The in vivo effect of κ/ß-carrageenan isolated from the red alga Tichocarpus crinitus on cytokine synthesis and cellular activity of murine peritoneal macrophages and also the protective effect of polysaccharides in LPS-induced endotoxemia in mice was studied. It was established that κ/ß-carrageenan given orally at a dose of 100 mg/kg stimulates the induction of anti-inflammatory cytokines (IL-10) in mouse blood cells by more than 2.5-fold compared with control, with no effect on pro-inflammatory cytokine (TNF-α) production. Pretreating mice with carrageenan once a day before injecting LPS increased the levels of IL-10 by 2.5-fold and reduced TNF-α production by 2-fold compared with control. So, κ/ß-carrageenan alone and in combination with LPS enhanced the cellular activity and mobility of peritoneal macrophages by increasing cell adhesion and migration compared with control. LPS activated cells intensively, sometimes resulting in their destruction by necrosis; carrageenan pretreatment reduced the excessive inflammatory cell activation caused by LPS. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1549-1557, 2017.


Assuntos
Carragenina , Endotoxemia/metabolismo , Interleucina-10/metabolismo , Lipopolissacarídeos/toxicidade , Macrófagos Peritoneais/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Animais , Carragenina/química , Carragenina/farmacologia , Modelos Animais de Doenças , Endotoxemia/induzido quimicamente , Endotoxemia/patologia , Feminino , Macrófagos Peritoneais/patologia , Camundongos , Camundongos Endogâmicos CBA
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA