Dysfunction of vascular endothelial cells causes the risk of
thrombosis. Aim of this study is to evaluate the antithrombotic effect of Okinawa mozuku (brown seaweed, Cladosiphon okamuranus) extract by using cultured vascular endothelial cells and rat carotid arterial
thrombosis model induced by
ferric chloride (FeCl3). The cell line (TKM-33) established from human umbilical vein endothelial cells were cultured with or without Okinawa mozuku extract. After incubation for 24 h, the
conditioned medium was collected to evaluate
urokinase-type plasminogen activator (
u-PA) activity. Next, rats were fed with water or water containing 5% of Okinawa mozuku extract for 8 wk. After 8 wk of treatments, the rats were provided for the carotid arterial
thrombosis model, and fibrinolytic factor and
coagulation factor in blood were measured. Okinawa mozuku extract significantly augmented
u-PA activity in the
conditioned medium. The decrease of carotid artery blood flow induced by 40% FeCl3 injury in rats fed with Okinawa mozuku extract was less than that in control rats. Thus,
oral administration of Okinawa mozuku extract prevented
thrombus formation in this model.
Oral administration of Okinawa mozuku extract significantly increased
u-PA activity in
euglobulin fraction, compared with control group. On the other hand, platelet aggregation activity, activated partial thromboplastin time, and active
PAI-1 level in plasma exhibited no significant differences between control and Okinawa mozuku groups. These results indicate that
oral administration of Okinawa mozuku enhances fibrinolytic activity in plasma and prevents
thrombus formation which is induced by injury of vascular endothelial cells.