An Antithrombotic Fucoidan, Unlike Heparin, Does Not Prolong Bleeding Time in a Murine Arterial Thrombosis Model: A Comparative Study of Undaria pinnatifida sporophylls and Fucus vesiculosus

The antithrombotic activities and bleeding effects of selected fucoidans (source from either Undaria pinnatifida sporophylls or from Fucus vesiculosus) have been compared with heparin in the ferric chloride-induced arterial thrombus mouse model. Thrombosis was induced by applying 5% ferric chloride for 3?min on the carotid artery region of Balb/c mouse. Five minutes prior to thrombus induction, mice were infused through the tail vein with either saline (control) or polysaccharides. Either fucoidan or heparin was dosed at 0.1, 1.25, 2.5, 5.0, 10, 25, or 50?mg/kg intravenously (i.v.) The carotid blood flow was monitored until more than 60?min post-thrombus induction. Mouse tail transection bleeding time was measured up to 60?min after making a cut in the mouse tail. Both antithrombotic and bleeding effects were observed in a dose-dependent manner for both fucoidans and heparin. Thrombus formation was totally (reflected by Doppler flow meter) inhibited at either 5 or 50?mg/kg of unfractionated Undaria fucoidan or a low-molecular-weight Undaria fucoidan fraction, respectively, without prolonging the time-to-stop bleeding compared with the control (p?