ABSTRACT
Metabolites isolated from Gelidiella species (Rhodophyta) have been few studied. We evaluated a sulfated polysaccharidic fraction from G. acerosa collected from two Brazilian beaches on the northwestern coast of Brazil (Flecheiras-F and Pedra Rachada-PR) on coagulation proteases and thrombosis. Their toxicity in vivo was also assessed. Enzymatic extractions yielded 1.40%, and similar chromatographic profiles (DEAE-cellulose) were obtained, with fractions (Ga-IâV) containing differences among the relative proportions of sulfate (5-42%), and revealing charge density patterns by electrophoresis. Ga-IV-PR had a discrete effect (3.01 IU mg-1) on normal human coagulation compared with heparin (193 IU mg-1) and was tested on coagulation proteases (thrombin and factor Xa) in the presence of antithrombin and in a model of venous thrombosis in rats using thromboplastin as the thrombogenic stimulus. The systems were inhibited; but at higher doses (>1.0 mg kg-1), this fraction reverted the antithrombotic effect. Regarding the toxicological study, consecutive Ga-IV (9 mg kg-1) for 14 days did not cause mortality in mice, but some biochemical and hematological parameters were discretely altered. Histopathological analysis revealed that increased liver and spleen sizes had no toxicological significance. Therefore, G. acerosa does not biochemically change its matrix polysaccharide composition and proved to be safe antithrombotic agent.
Poucos estudos mostram metabólitos isolados de rodofíceas de espécies Gelidiella. Avaliou-se uma fração polissacarídica sulfatada de G. acerosa coletada a partir de duas praias brasileiras do Nordeste do Brasil (Flecheiras-F e Pedra Rachada-PR) sobre proteases da coagulação e trombose, e em ensaio de toxicidade in vivo. Extrações enzimáticas renderam 1,40% e foram obtidos perfis cromatográficos semelhantes (DEAE-celulose), apresentando frações (Ga-IâV), contendo diferenças entre as proporções relativas de sulfato (5-42%), além de a eletroforese revelar diferenças na densidade de carga. A Ga-IV-PR apresentou discreto efeito (3,01 UI mg-1) sobre a coagulação humana normal comparada à heparina (193 UI mg-1) e foi testada sobre proteases da coagulação (trombina e fator Xa) na presença de antitrombina e em um modelo de trombose venosa em ratos usando tromboplastina com estímulo trombogênico, sendo inibidos esses sistemas. Entretanto, em elevadas doses (>1,0 mg kg-1) o efeito antitrombótico foi revertido. No estudo toxicológico, Ga-IV (9 mg kg-1) consecutiva durante 14 dias não causou mortalidade em camundongos, mas alterou discretamente alguns parâmetros bioquímicos e hematológicos. O aumento nos tamanhos do fígado e baço não apresentou significância toxicológica, segunda análise histopatológica. Portanto, G. acerosa não muda bioquimicamente a composição de polissacarídeo de sua matriz e detém agente antitrombótico seguro.
Subject(s)
Fibrinolytic Agents , Rhodophyta , ToxicityABSTRACT
The aim of this study was to determine the yield, chemical composition, specific rotation (SR), infrared (IR) spectroscopy and the effect on bacterial growth of a crude sulfated polysaccharide (SP) from the red marine alga G. ornata (Go). Go-1 (25°C), Go-2 (80°C), and Go-3 (80°C) were sequentially extracted and yielded 9.2%. The contents of sulfate (5.88-10.3%) and proteins (0.1-3.7%) were small. The values of SR were [µ]D20°f -19.0, -51.0, and -56.5, respectively. IR spectrums showed the presence of galactose-4 sulfate and absence of 3,6-anydrogalactose-2 sulfate, galactose-6 sulfate and galactose-2 sulfate. SR and IR techniques confirmed SPs. Go-3 was tested on the growth of bacteria (Bacillus subtilis, Staphylococcus aureus, Enterobacter aerogens, Escherichia coli, Pseudomonas aeruginosa, Salmonela choleraesuis and Salmonela typhi), but only E. coli was inhibited.
ABSTRACT
Alternative sources of anticoagulants have arisen as a result of the increasing demand for safer anticoagulant clinical therapy, and the sulfated polysaccharides of seaweeds have gained attention in biomedicine. In this study, crude sulfated polysaccharide fractions (denominated Hf1, Hf2 and Hf3) were obtained from the red marine alga Halymenia floresia and the anticoagulant properties of a soluble crude polysaccharide fraction (Hf2s) were assayed. The three differential extractions yielded 38.6%. The polysaccharides are composed mainly of galactose, with small amounts of xylose and glucose. The anticoagulant properties of Hf2s containing 53.8% sulfate and 3% protein was also compared to those of heparin (193.0 IU mg-1) by assays of activated partial thromboplastin time (APTT) and thrombin time (TT) using normal human plasma. Hf2s showed a higher anticoagulant activity (68.4 IU mg-1) than those of Hf1s and Hf3s, whose activities were 37.6 and 36.6 IU mg-1, respectively. The compound was less active than heparin, but its anticoagulant mechanism suggested that it is dependent on cofactor heparin II to inhibit thrombin activity, but not on cofactors VIII and IX. Therefore, the polysaccharide from H. floresia interfered on coagulation cascade.
O aumento da demanda por anticoagulantes para a terapia clínica tem motivado a busca por fontes alternativas de anticoagulantes mais seguros e os polissacarídeos sulfatados de algas marinhas têm ganhado atenção na biomedicina. Objetivou-se obter frações de polissacarídeos sulfatados brutos (denominadas Hf1; Hf2 e Hf3) da alga marinha vermelha Halymenia floresia e para avaliar as propriedades anticoagulantes de uma fração polissacarídica bruta solúvel anticoagulante (Hf2s). As três extrações diferenciais renderam 38,60%. Os polissacarídeos são principalmente compostos de galactose com pequenas quantidades de xilose e glucose. As propriedades anticoagulantes da Hf2s, contendo 53,80% de sulfato e 3% de proteínas, foram também comparadas com a heparina (193,00 UI mg-1) pelo ensaio do tempo de tromboplastina parcial ativada (TTPA) e tempo de trombina (TT), usando plasma humano normal. A Hf2s apresentou maior atividade anticoagulante (68,40 UI mg-1) que Hf1s a Hf3s, cujas atividades foram 37,60 e 36,60 UI mg-1, respectivamente. O composto foi menos ativo que a heparina, mas sugere-se que o mecanismo anticoagulante seja dependente do cofator II da heparina para inibição da atividade da trombina, exceto pelos cofatores VIII a IX. Portanto, o polissacarídeo de H. floresia interferiu na cascata de coagulação.
Subject(s)
Polysaccharides , Seaweed , Galactans , AnticoagulantsABSTRACT
Alternative sources of anticoagulants have arisen as a result of the increasing demand for safer anticoagulant clinical therapy, and the sulfated polysaccharides of seaweeds have gained attention in biomedicine. In this study, crude sulfated polysaccharide fractions (denominated Hf1, Hf2 and Hf3) were obtained from the red marine alga Halymenia floresia and the anticoagulant properties of a soluble crude polysaccharide fraction (Hf2s) were assayed. The three differential extractions yielded 38.6%. The polysaccharides are composed mainly of galactose, with small amounts of xylose and glucose. The anticoagulant properties of Hf2s containing 53.8% sulfate and 3% protein was also compared to those of heparin (193.0 IU mg-1) by assays of activated partial thromboplastin time (APTT) and thrombin time (TT) using normal human plasma. Hf2s showed a higher anticoagulant activity (68.4 IU mg-1) than those of Hf1s and Hf3s, whose activities were 37.6 and 36.6 IU mg-1, respectively. The compound was less active than heparin, but its anticoagulant mechanism suggested that it is dependent on cofactor heparin II to inhibit thrombin activity, but not on cofactors VIII and IX. Therefore, the polysaccharide from H. floresia interfered on coagulation cascade.
Alternative sources of anticoagulants have arisen as a result of the increasing demand for safer anticoagulant clinical therapy, and the sulfated polysaccharides of seaweeds have gained attention in biomedicine. In this study, crude sulfated polysaccharide fractions (denominated Hf1, Hf2 and Hf3) were obtained from the red marine alga Halymenia floresia and the anticoagulant properties of a soluble crude polysaccharide fraction (Hf2s) were assayed. The three differential extractions yielded 38.6%. The polysaccharides are composed mainly of galactose, with small amounts of xylose and glucose. The anticoagulant properties of Hf2s containing 53.8% sulfate and 3% protein was also compared to those of heparin (193.0 IU mg-1) by assays of activated partial thromboplastin time (APTT) and thrombin time (TT) using normal human plasma. Hf2s showed a higher anticoagulant activity (68.4 IU mg-1) than those of Hf1s and Hf3s, whose activities were 37.6 and 36.6 IU mg-1, respectively. The compound was less active than heparin, but its anticoagulant mechanism suggested that it is dependent on cofactor heparin II to inhibit thrombin activity, but not on cofactors VIII and IX. Therefore, the polysaccharide from H. floresia interfered on coagulation cascade.
ABSTRACT
Researchers see algae as a promising tool to discover both efficient and safe agents for pain therapy. We evaluated the antinociceptive and anti-inflammatory activities of lectin from the marine alga Pterocladiella capillacea lectin (PcL). PcL was purified and tested in classical models of nociception and inflammation. Male Swiss mice received PcL 30 min prior to receiving 0.8% acetic acid (10 microl/10 g, i.p.), 1% formalin (20 microl/intraplantar) or the hot plate test, and were compared to untreated animals or animals pretreated with indomethacin or morphine. PcL (0.9, 8.1 or 72.9 mg/kg, i.v.) significantly reduced the number of writhes (30%, 39%, and 52%, respectively). PcL (72.9 mg/kg, i.v.) also reduced (p<0.05) both the first and second phases of the formalin test by 58% and 87%, respectively. However, PcL (72.9 mg/kg) did not present significant antinociceptive effects in the hot plate test when compared to morphine, suggesting that its antinociceptive action occurs via peripheral rather than a central-acting mechanism. It was also observed that leukocyte migration was induced by carrageenan (500 microg/cavity) in male Wistar rats and that PcL (8.1 mg/kg, i.v.) significantly reduced neutrophil migration by 84%, as compared to untreated animals, suggesting inhibition of inflammatory mediators. The data indicated that PcL has peripheral actions with both anti-inflammatory and antinociceptive properties.
