Anticoagulant properties of a crude sulfated polysaccharide from the red marine alga Halymenia floresia (Clemente) C. Agardh
Acta Scientiarum : Biological Sciences
Anticoagulant properties of a crude sulfated polysaccharide from the red marine alga Halymenia floresia (Clemente) C. Agardh Acta Scientiarum. 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
... rine 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. Keywords: halymeniales, Halymenia floresia, sulfated galactans, anticoagulant activity. 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. Palavras-chave: halymeniales, Halymenia floresia, galactanas sulfatadas, atividade anticoagulante.