Kelp Fucoidans Facilitate Vascular Recanalization via Inhibiting Excessive Activation of Platelet in Deep Venous Thrombosis Model of Mouse

This study was carried out explore the mechanism underlying the inhibition of platelet activation by kelp fucoidans in deep venous thrombosis(DVT)mouse.In the control and sham mice,the walls of deep vein were regular and smooth with intact intima,myometrium and adventitia.The blood vessel was wrapped with the tissue and there was no thrombosis in the lumen.In the DVT model,the wall was uneven with thicken intima,myometrium and adventitia.After treated with fucoidans LF1 and LF2,the thrombus was dissolved and the blood vessel was recanalized.Compared with the control group,the ROS content,ET-1 and VWF content and the expression of PKC-βand NF-κB in the model were significantly higher(P<0.05);these levels were significantly reduced following treatments with LF2 and LF1.Compared with H_(2)O_(2)treated-HUVECs,combined LF1 and LF2 treatment resulted in significant decrease in the expression of PKC-β,NF-κB,VWF and TM protein(P<0.05).It is clear that LF1 and LF2 reduces DVT-induced ET-1,VWF and TM expressions and production of ROS,thus inhibiting the activation of PKC-β/NF-κB signal pathway and the activation of coagulation system and ultimately reducing the formation of venous thrombus.

小球藻多糖的结构与生物活性研究进展

小球藻中存在多种组成和结构复杂的多糖,其主要由半乳糖、鼠李糖、葡萄糖、阿拉伯糖、甘露糖、木糖和葡萄糖醛酸等多种单糖组成。多糖中存在多样的连接方式,比如α-1,6-葡萄糖、β-1,3-半乳糖、α-1,6-半乳糖、α-1,3-鼠李糖、α-1,2-鼠李糖、α-1,5-阿拉伯糖、α-1,6-甘露糖和β-1,4-木糖等,部分多糖上存在甲基化、硫酸根和乙酰化修饰。同时众多研究表明,小球藻多糖具有免疫调节、抗炎、抗氧化、抗肿瘤、抗菌和调节肠道菌群等活性功能。目前主要采用单糖组成分析、甲基化结合气相色谱-质谱联用法和二维核磁共振法研究小球藻多糖的结构,解析多种小球藻多糖的单糖组成、糖苷键类型、支链取代位置和支链类型等结构特点。本文通过对不同小球藻多糖的化学组成、结构及其分析技术和生物活性进行分析总结,以期为小球藻多糖的精细结构分析和构效关系研究提供参考和依据。

两宋温州书院与永嘉学派的关系探析

北宋中后期,温州涌现出大批本土知名学者,作为温州地区书院的开创者和永嘉学派的先行者,他们开启了温州的书院教育,并以书院为阵地著书游学、藏书传世,促进了两宋温州书院文化的繁荣。随着书院文化的发展,良好的书院学风奠定了稳定的师承关系,培养了众多温州士子,造就了他们在南宋科场的盛况,逐渐形成了以研究事功之学为主要内容的永嘉学派。可以说永嘉学派发源于书院,书院作为永嘉学派的重要阵地,对传承和发扬永嘉学派发挥了重要的作用。

近代中国商民运动的滞后性探析

商民运动是1924年到1930年开展的一项以商民协会为依托、以商民为主体的民众运动。但是,商民运动无论是在普及范围还是在影响力方面都不及其他民众运动,这就使商民运动呈现出滞后性的特点。其滞后的原因也是多方面的,主要体现在历史上对商人及其组织的误解,商会与商民协会的斗争,商人的自身局限性以及那一时期政局的动荡。在论述商民运动的滞后性时应该从多个方面入手,以当时的政治环境为背景,以当时中国民众运动的发展为线索,以商人为研究对象去探讨。

Studies on Antiviral and Immuno-Regulation Activity of Low Molecular Weight Fucoidan from Laminaria japonica

The antiviral activity in vitro and in vivo and the effect of the immune system of two fucoidan fractions with low molecular weight and different sulfate content from Laminaria japonica(LMW fucoidans) were investigated in order to examine the possible mechanism. In vitro, I-type influenza virus, adenovirus and Parainfluenza virus I were used to infect Hep-2, Hela and MDCK cells, respectively. And 50% tissue culture infective dose was calculated to detect the antiviral activity of two LMW fucoidans. The results indicated that compared with the control group, 2 kinds of LMW fucoidans had remarkable antiviral activity in vitro in middle and high doses, while at low doses, the antiviral activity of 2 kinds of LMW fucoidans was not statistically different from that in the blank control group. And there was no statistically difference between two LMW fucoidans in antiviral activity. In vivo, LMW fucoidans could prolong the survival time of virus-infected mice, and could improve the lung index of virus-infected mice significantly, which have statistical differences with the control group significantly(p < 0.01). However, the survival time of the two LMW fucoidans was not statistically significant(p > 0.05). In this study, it was shown that both of two LMW fucoidans(LF1, LF2) could increase the thymus index, spleen index, phagocytic index, phagocytosis coefficient and half hemolysin value in middle and high doses, which suggested that LMW fucoidans could play an antiviral role by improving the quality of immune organs, improving immune cell phagocytosis and humoral immunity.

Study on Antithrombotic and Antiplatelet Activities of Low Molecular Weight Fucoidan from Laminaria japonica

The antithrombotic and antiplatelet effects of two fucoidan fractions with low molecular weight and different sulfate content from Laminaria japonica were compared in order to examine the influence of chemical character on their antithrombotic activity and the possible mechanism. Both LMW fucoidan fractions exhibited favorable antithrombotic activity in an Fecl3-induced arterial thrombosis. The antithrombotic activity of LMW fucoidan was related with decrease of TXB2 and whole blood viscosity and hematocrit. LMW fucoidan showed a correlation between anticoagulant, antiaggregant and antithrombotic effects in vivo. For LMW fucoidan, antithrombotic activity required high dose of 5-10 nmol kg-1, concomitantly with increase in anticoagulant activity and inhibition of platelet aggregation. Administration of LMW fucoidan significantly promoted the 6-keto-PGF1α content and decreased the TXB2 content, indicating its inhibition of tissue factor pathway and regulation of metabolism of arachidonic acid. By comparison, highly sulfated fucoidan LF2 with Mw 3900 seemed to be a more suitable choice for antithrombotic drug for its antithrombotic activity accompanied with specific inhibitory activity on platelet aggregation, low anticoagulant activity and low hemorrhagic risk in vivo.

Mechanism Study of Endothelial Protection and Inhibits Platelet Activation of Low Molecular Weight Fucoidan from Laminaria japonica

Several studies have indicated that fucoidan fractions with low molecular weight and different sulfate content from Laminaria japonica could inhibit the activation of platelets directly by reducing the platelet aggregation. To explore the direct effect of LMW fucoidan on the platelet system furthermore and examine the possible mechanism, the endothelial protection and inhibits platelet activation effects of two LMW fucoidan were investigated. In the present study, Endothelial injury model of rats was made by injection of adrenaline(0.4 mg kg-1) and human umbilical vein endothelial cells were cultured. v WF level was be investigated in vivo and in vitro as an important index of endothelial injury. LMW fucoidan could significantly reduce v WF level in vascular endothelial injury rats and also significantly reduce v WF level in vitro. The number of EMPs was be detected as another important index of endothelial injury. The results showed that LMW fucoidan reduced EMPs stimulated by tumor necrosis factor. In this study, it was found that by inhibiting platelet adhesion, LMW fucoidan played a role in anti-thrombosis and the specific mechanism of action is to inhibit the flow of extracellular Ca2+. All in a word, LMW fucoidan could inhibit the activation of platelets indirectly by reducing the concentration of EMPs and v WF, at the same time; LMW fucoidan inhibited the activation of platelets directly by inhibiting the flow of extracellular Ca2+.