The active sulfated polysaccharide from seaweed possesses important pharmaceutical and biomedical potential. In the study, Monostroma sulfated polysaccharide (MSP) was obtained from Monostroma angicava, and the low-molecular-weight fragments of MSP (MSP-Fs: MSP-F1⁻MSP-F6) were prepared by controlled acid degradation. The molecular weights of MSP and MSP-F1⁻MSP-F6 were 335 kDa, 240 kDa, 90 kDa, 40 kDa, 24 kDa, 12 kDa, and 6.8 kDa, respectively. The polysaccharides were sulfated rhamnans that consisted of →3)-α-l-Rhap-(1→ and →2)-α-l-Rhap-(1→ units with partial sulfation at C-2 of →3)-α-l-Rhap-(1→ and C-3 of →2)-α-l-Rhap-(1→. Anticoagulant properties in vitro of MSP and MSP-F1⁻MSP-F6 were evaluated by studying the activated partial thromboplastin time, thrombin time, and prothrombin time. Anticoagulant activities in vivo of MSP and MSP-F4 were further evaluated; their fibrin(ogen)olytic activities in vivo and thrombolytic properties in vitro were also assessed by D-dimer, fibrin degradation products, plasminogen activator inhibitior-1, and clot lytic rate assays. The results showed that MSP and MSP-F1⁻MSP-F4 with molecular weights of 24⁻240 kDa had strong anticoagulant activities. A decrease in the molecular weight of MSP-Fs was accompanied by a decrease in the anticoagulant activity, and higher anticoagulant activity requires a molecular weight of over 12 kDa. MSP and MSP-F4 possessed strong anticoagulant activities in vivo, as well as high fibrin(ogen)olytic and thrombolytic activities. MSP and MSP-F4 have potential as drug or helpful food supplements for human health.
Keywords: anticoagulant activity; depolymerization; fibrin(ogen)olytic activity; low-molecular-weight fractions; sulfated polysaccharide; thrombolytic activity.