ABSTRACT
OBJECTIVE: To study the protective action on endotheliocytes of fucoidan with different molecular weight from Laminaria japonica, and to explore its mechanism. METHODS: In vivo, endotheliocytes injury model in rats was used to examine the protective action on endotheliocytes of fucoidan with different molecular weight from Laminaria japonica; aortal endothelium section by HE stain under optical microscope was observed, and the the content of von willebrand factor (vWF) in plasma was determined by ELISA. In vitro, endothelial cell culture was used to determine the effect of fucoidan on content of vWF and endothelial microparticles (EMPs). RESULTS: In vivo, aortal endothelium section by HE stain under optical microscope showed low molecular weight (LMW) fucoidan had a remarkable protective effect, and the protection effect of LMWF fucoidans are stronger than middle molecular weight (MMW) fu-coidans. Administration of LMW fucoidan significantly decreased the vWF content. Administration of MMW fucoidan didn't change vWF content. In vitro, Administration of LMW fucoidan significantly decreased the vWF content and EMPs numbers. Administration of MMW fucoidan didn't change the vWF content and EMPs numbers. CONCLUSION: The LMW fucoidan fractions have good protective action on endothelial cells. The protective effect of LMW fucoidans is significantly stronger than MMW fucoidans. The protective action on endotheliocytes of LMW fucoidans relies on decreasing the concentration of EMPs and vWF, and thus inhibiting platelet activation indirectly.
ABSTRACT
OBJECTIVE: To study the antithrombotic activity of fucoidan with different molecular weight from Laminaria japonica, and to explore its mechanism by observing antiplatelet activities and fibrinolysis. METHODS: FeCl3-induced arterial thrombosis in rats were used to examine the antithrombotic activity of four fucoidan fractions with different molecular weight; the TXB2, 6-keto-PGF1α, PLG, t-PA and PAI-1 in plasma were determined by ELISA to evaluate the inhibitory effects of the drugs on platelet aggregation and fibrinolytic system. RESULTS: Four fucoidan fractions with different molecular weight could significantly decreased the weight of the thrombus, and Middle molecular weight (MMW) fucoidan fractions exhibited better antithrombotic activity than low molecular weight fucoidan (LMW). Administration of LMW fucoidan significantly decreased the TXB2 content and promoted 6-keto-PGF1α content. Administration of MMW fucoidan only decreased the TXB2 content and didn't change 6-keto-PGF1α content. In four fucoidan fractions group, the activity of t-PA were increased, the activity of PAI-1 were decreased, the ratio of t-PA/PAI-1 was increased, and the activity of PLG had no change. CONCLUSION: Four fucoidan fractions with different molecular weight have strong anti-thrombosis effect, the action mechanism may have correlation with the increase in the activities of anti-platelet aggregation and fibrinolysis system. Copyright 2012 by the Chinese Pharmaceutical Association.