Fucosylated Chondroitin Sulfate 9–18 Oligomers Exhibit Molecular Size-Independent Antithrombotic Activity while Circulating in the Blood

Abstract

Fucosylated chondroitin sulfate (FCS) oligosaccharides extracted from sea cucumber and depolymerized exhibit potent anticoagulant activity. Knowledge of the antithrombotic activity of different size oligosaccharides and their fucose (Fuc) branch sulfation pattern should promote their development for clinical applications. We prepared highly purified FCS trisaccharide repeating units from hexasaccharide (6-mer) to octadecasaccharide (18-mer), including those with 2,4-disulfated and 3,4-disulfated Fuc branches. All 10 oligosaccharides were identified by their nuclear magnetic resonance structures and ESI-FTMS spectroscopy. In vitro anticoagulant activities and surface plasmon resonance binding tests indicated those of larger molecular sizes and 2,4-disulfated Fuc branches showed stronger anticoagulant effects with respect to anti-FXase activity, as well as stronger binding to FIXa among various clotting proteins. However, both types of FCS 9-mer to 18-mer exhibited molecular size-independent potent antithrombotic activity in vivo at the same dose. In addition, both types of the FCS 6-mer exhibited favorable antithrombotic activity in vivo, although they showed weak anticoagulant activity in vitro. Combining absorption and metabolism studies, we conclude that FCS 9–18 oligomers could remain in the circulation to interact with various clotting proteins to prevent thrombus formation, and appreciable quantities of these oligomers could be excreted through the kidneys. All FCS 9–18 oligomers also resulted in no bleeding, hypotension, or platelet aggregation risk during blood circulation. Thus, FCS 9–18 oligomers with 2,4-disulfated or 3,4-disulfated Fuc branches exhibit potent and safe antithrombotic activity needed for clinical applications.

Marine Natural Products and Coronary Artery Disease

“…One experiment indicated that even if the patterns of sulfation differed, chondroitin sulfate obtained similar antithrombotic activity; thus, the influence of the chondroitin sulfation pattern could be less than the molecular weight with regard to the antithrombosis and anticoagulation activities ( 72 ). In regard to recent studies, we confirmed that FCS9-18 oligomers have antithrombotic activity without any adverse reaction because they might react with several blood coagulating proteins, and then, a majority of them could be discharged from the kidneys to protect against thrombosis; meanwhile, their total had nothing to do with hemorrhage, hypotension, and thrombocyte gathering through blood circulation ( 73 ).…”

The Toxicology of Native Fucosylated Glycosaminoglycans and the Safety of Their Depolymerized Products as Anticoagulants

“…It is reported that high-molecular-weight FG can potently activate the plasma contact system and cause hypotension in rats, similar to OSCS [ 13 , 14 , 16 ]. Herein, the in vivo effect of TaFG, HfFG, and their depolymerized products were studied.…”

“…For instance, a natural FG from Thelenota ananas (TaFG) exhibited weaker in vivo antithrombotic activity than its depolymerized product in a stasis-induced venous thrombosis rat model [ 7 ]. Native FGs from Ludwigothurea grisea , Isostichopus badionotus , and Pearsonothuria graeffei could cause obvious hypotension and reduced heart rate in rats after intravenous injection [ 13 , 14 ]. However, the underlying mechanism is not clear, and how the undesired activities of FG are related to its in vivo toxicology remains to be studied.…”