褐藻糖胶抗血栓研究进展

褐藻糖胶是一种酸性硫酸化多糖，有多种生物活性和药理作用，其抗血栓活性尤为明显。褐藻糖胶能够抑制凝血酶的产生及活性，提高组织型纤溶酶原活化剂对纤溶酶原的激活作用，从而具有抗血栓形成和溶栓功能。     

褐藻多糖硫酸酯的药理活性及作用机制研究进展

目的介绍关于褐藻多糖硫酸酯的最新药理活性的研究状况及可能的机制,为进一步研究其各种生物学功能提供参考。方法对近几年来有代表性的中英文文献进行分析、归纳。结果褐藻多糖硫酸酯拥有许多有前景的药理活性。结论加强对褐藻多糖硫酸酯的药理活性和作用机制的进一步研究,对于有目的的进行应用开发方面的研究有重要指导意义。     

从海带中提取褐藻糖胶工艺的研究

目的以海带为原料研究褐藻糖胶的提取工艺。方法通过单因素和正交试验,摸索海带粒度、提取温度、提取溶剂、提取时间、料液比和醇沉体积分数对提取纯化褐藻糖胶的影响。结果提取纯化褐藻糖胶的最佳条件为:在20目的海带粉中加入15倍pH2的15g·L-1CaCl2溶液,在60℃下提取1.5h,提取液浓缩后加乙醇至体积分数为65%,使褐藻糖胶沉淀、离心、洗涤并干燥。结论采用该工艺从海带中提取纯化褐藻糖胶,成本低且效果较好。     

不同提取方法对褐藻糖胶理化性质的影响

目的 比较不同提取方法对褐藻糖胶理化性质的影响。方法 分别采用稀盐酸法和氯化钙从6种褐藻粗多糖中获得 12 种褐藻糖胶(Fucoidan),并进一步对其理化性质进行分析和比较。采用高效液相色谱法(HPLC)测定其单糖组成,离子色谱法(IC)测定其硫酸基含量,Folin-酚法测定其粗蛋白含量,高效凝胶渗透色谱与多角度激光散射仪联用法(HPGPC-MALLS)测定其绝对分子量。结果 稀盐酸法提取褐藻糖胶的得率显著高于氯化钙法,但所得褐藻糖胶的硫酸基含量和绝对分子量都明显降低。结论 稀盐酸法提取褐藻糖胶造成糖链断裂及硫酸基脱落,破坏褐藻糖胶的结构,因此采用氯化钙法更适合褐藻糖胶的提取。     

褐藻糖胶的药理作用及机制的研究进展

褐藻糖胶是一种硫酸多糖,近年来因其具有多种生物活性而倍受关注。本文就褐藻糖胶的抗血栓、抗肿瘤、抗氧化、调节血脂、抗病毒、抗辐射和抑制补体激活等药理作用及其作用机制进行综述。     

褐藻糖胶通过抑制Wnt/β-catenin通路诱导多发性骨髓瘤细胞PRMI8226凋亡

目的探讨褐藻糖胶诱导多发性骨髓瘤细胞PRMI8226凋亡时Wnt/β-catenin通路的变化。方法褐藻糖胶不同浓度(25、50、100、200、400μg·mL-1)分别作用于PRMI8226细胞24、48、72 h,采用MTT法检测PRMI8226细胞增殖情况并求得半数抑制浓度(IC50);以1/2 IC50浓度的褐藻糖胶作用于PRMI8226细胞72 h后,采用流式细胞术检测细胞凋亡率。将细胞分为空白对照组、Wnt通路抑制剂(DKK-1)组(100 ng·mL-1)及褐藻糖胶(25μg·mL-1)组,采用Western blot检测β-catenin、c-myc、bax及caspase 3蛋白表达水平。结果褐藻糖胶对PRMI8226细胞增殖抑制作用呈时间-剂量依赖性增强。PRMI8226细胞经褐藻糖胶25μg·mL-1处理72 h后,其凋亡率(12.22%)明显高于对照组(4.82%)(P<0.05)。Western blot结果显示,与空白对照组比较,两组β-catenin和c-myc表达水平均有显著差异(P<0.05),褐藻糖胶组β-catenin和c-myc表达水平与DKK-1组比较无显著差异(P>0.05);褐藻糖胶组caspase3和bax蛋白表达水平较DKK-1组增加(P<0.05),两组与空白对照组比较表达亦增加,均有显著差异(P<0.05)。结论褐藻糖胶通过抑制Wnt/β-catenin通路的活化,能诱导多发性骨髓瘤PRMI8226细胞凋亡。     

选育羊栖菜与野生羊栖菜中褐藻胶与褐藻糖胶组成分析

目的比较选育羊栖菜(H.fusiformis)与野生羊栖菜中褐藻胶与褐藻糖胶的组成差异。方法采用高效凝胶渗透色谱法(HPGPC)分析多糖相对分子量,用核磁共振氢谱法测定褐藻胶中G/M比,并用高效离子色谱(HPIC)法分析褐藻糖胶中单糖组成。结果选育羊栖菜和野生羊栖菜中褐藻胶和褐藻糖胶含量分别为29.23%,1.89%和32.18%,2.40%;褐藻胶中G/M比分别为2.62和1.05;褐藻糖胶均含有8种单糖,分别为岩藻糖,半乳糖,甘露糖,葡萄糖醛酸,葡萄糖,木糖,葡萄糖胺和甘露糖醛酸,其摩尔比分别为34.62,18.55,14.17,12.72,10.60,5.79,2.42,1.13及34.76,19.26,10.21,12.70,5.49,10.22,0.70,6.66。结论选育羊栖菜褐藻胶中古罗糖醛酸含量以及褐藻糖胶中葡萄糖,甘露糖和氨基葡萄糖含量均明显高于野生羊栖菜。     

昆布多糖药理作用的研究进展

昆布中富含多种功能性物质。其中具有重要生物活性的物质主要为多糖，主要包括褐藻胶、褐藻糖胶、褐藻淀粉3种。在调节免疫、抗肿瘤、抗凝血、调血脂、降血糖、抗辐射、抗氧化等方面具有独特的功能。     

褐藻糖胶的抗肿瘤作用及构效关系研究进展

作为1种天然来源的海洋硫酸多糖,褐藻糖胶因其复杂的化学结构和独特的生物学功能,引起众多科学工作者的高度关注,近年来已成为海洋天然药物研究的热点。本文就褐藻糖胶的抗肿瘤作用及其相关机制进行综述。     

褐藻多糖生物活性的研究进展

海藻类的生物活性引起了人们的广泛关注,尤其是对褐藻多糖的研究。海藻多糖是海洋中最重要的药理活性物质之一,而且资源丰富,容易获取。对褐藻多糖以及生物活性的研究,已有较多的报道,并取得较大的进展。褐藻多糖虽在组成和化学结构上存在差异,但在生物活性方面有很多的相似性,如大多具有抗肿瘤、抗氧化、抗菌、调节免疫和抗炎活性、保湿等作用。     

岩藻多糖的药理作用研究进展

岩藻多糖是从褐藻细胞壁和细胞间质中分离得到的一类天然硫酸化杂多糖。岩藻多糖具有多样的生物活性，如抗炎、抗肿瘤、神经保护、抗凝、调节肠道菌群、调节血脂、抗病毒作用。对岩藻多糖的药理作用进行了总结，以期为进一步开发利用岩藻多糖提供参考。     

A 4-week repeated oral dose toxicity study of fucoidan from the Sporophyll of Undaria pinnatifida in Sprague–Dawley rats

Fucoidan is extracted from brown seaweeds, which can have anti-coagulant, antithrombotic, antitumor, and antiviral activities. However, detailed studies on the toxicology of fucoidan have not been performed. Here we tested the toxicity of fucoidan in Sprague–Dawley rats. Fucoidan (1350 mg/kg bw/day for 4 weeks) did not induce statistically significant differences in groups matched by gender with respect to body weight, ophthalmoscopy, urinalysis, hematology, and histopathology. Fucoidan did not change prothrombin time or activated partial thromboplastin time, indicating an inability to change blood clotting. This study demonstrated that fucoidan is not toxic under this administration paradigm.     

Effects of fucoidan on chronic renal failure in rats

The effects of fucoidan on chronic renal failure (CRF) were investigated in vivo in a subtotal nephrectomy CRF model and a cryoinjury induced CRF model in rats. Fucoidan showed renoprotective effects in both models. Fucoidan (100 or 200 mg/kg, orally) significantly decreased elevated serum creatinine and urea nitrogen levels. Histopathological changes of renal tubules and interstitium were markedly alleviated by fucoidan and the mesangial areas were also greatly reduced. The activities of fucoidan were dose-dependent.     

岩藻聚糖硫酸酯药理学活性研究进展

岩藻聚糖硫酸酯是一类来源于褐藻且结构复杂的海洋硫酸多糖,主要由硫酸化岩藻糖、半乳糖、甘露糖、葡萄糖醛酸及少量葡萄糖和木糖组成。研究表明,岩藻聚糖硫酸酯具有抗凝血与促凝血、抗炎、抗肿瘤、抗氧化、抗病毒、抗菌、免疫调节、降血脂、降血糖、抗补体及促进肠道益生菌生长等多种药理学活性。本文对岩藻聚糖硫酸酯的上述活性进行了综述,并对其应用前景进行展望,为其深度开发利用提供有用参考。     

Protective effect of fucoidan against acetaminophen-induced liver injury

Fucoidan, a sulfated polysaccharide extracted from various brown seaweeds, possesses a wide range of pharmacological properties. In this study, we investigated the protective effect of fucoidan on acetaminophen-induced acute liver injury in rats. Liver injury was induced by administration of acetaminophen (800 mg/kg, i.p.) and fucoidan was administered (100 mg kg, p.o.) 2 h before and after acetaminophen administration. After 24 h, co-treatment of fucoidan ameliorated liver damage and cell death induced by acetaminophen. Acetaminophen induced the overexpression of CYP2E1, one of the metabolizing enzymes of acetaminophen, but cotreatment with fucoidan suppressed its increased expression of CYP2E1. Fucoidan also reduced the hepatic apoptosis induced by acetaminophen exposure as shown in the protein expression of Bax, Bcl-2, and cleaved caspase-3. The anti-oxidative effect of fucoidan was observed from the increase of the production and expression of glutathione, superoxide dismutase, and glutathione peroxidase, both of which were decreased by acetaminophen. Also, fucoidan decreased the expression of inflammatory mediators, including tumor necrosis factoralpha, interleukin 1 beta, and inducible nitric oxide synthase. Taken together, the data demonstrate the hepato-protective effects of fucoidan against acetaminophen-induced liver injury via anti-oxidant, anti-inflammatory, and anti-apoptotic mechanisms.     

Fucoidan stimulation induces a functional maturation of human monocyte-derived dendritic cells

Fucoidan is a complex sulfated polysaccharide with a wide variety of biological activities for modulating immune cell functions. However, the effects of fucoidan on maturation process and activation of human monocyte-derived dendritic cells (DCs) remain to be elucidated. The present study demonstrated that the level of special marks and polarization phenotype of DCs was altered by fucoidan. Human monocytes were cultured with GM-CSF and IL-4 for 5 days followed by another 2 days in the presence of fucoidan or LPS. Then DCs were harvested on day 7 and were examined using functional assays. We demonstrated that fucoidan up-regulated the expression of HLA-DR and co-stimulatory molecules of DCs. However the endocytic activity was impaired markedly. Fucoidan induces their Th1-promoting tumor necrosis factor alpha (TNF-alpha) and interleukin-12 (IL-12) secretion, and enhances their allostimulatory capacity. In an allogeneic MLR assay, DCs treated with fucoidan were potent in the secretion of IL-12p70, TNF-alpha and IFN-gamma. Naive T cells stimulated by fucoidan-treated DCs differentiated towards a helper T cell type 1 (Th1) response depending on IL-12 secretion. These results suggest that fucoidan may induce immature DCs maturation and drive their differentiation towards a Th1-polarizing phenotype. Moreover, our data suggest that DCs appear to be a potential target for the immunomodulatory capacity of fucoidan and fucoidan may be used on DC-based vaccines for cancer immunotherapy.     

Fucoidan partly prevents CCl4-induced liver fibrosis

Fucoidan, a sulfated polysaccharide extracted from brown algae, has a wide range of biological activities, including anti-inflammatory, anti-viral, and anti-tumor activities. In the present study, we investigated the effects of fucoidan on CCl₄-induced liver fibrosis. Administration of fucoidan reduced CCl₄-induced acute and chronic liver failure. Hepatic fibrosis induced by CCl₄ was also attenuated by injection of fucoidan. Damage to hepatocytes and activation of hepatic stellate cells are key events in liver fibrosis, and, interestingly, treatment of hepatocytes with fucoidan prevented CCl₄-induced cell death and inhibited the proliferation hepatic stellate cells. These results indicate that fucoidan might be a promising anti-fibrotic agent possessing dual functions, namely, protection of hepatocytes and inhibition of hepatic stellate cell proliferation.     

Induction of hepatocyte growth factor by fucoidan and fucoidan-derived oligosaccharides

Fucoidan, which is extracted from brown seaweed, is a complex sulphated polysaccharide that is mostly composed of L-fucose and sulphated ester groups. The structural and anionic characteristics of fucoidan are similar to those of heparin. Heparin stimulates production of hepatocyte growth factor (HGF), which has key roles in tissue regeneration. We have shown that fucoidan and fucoidan-derived oligosaccharides have similar ability to stimulate production of HGF as heparin and heparin-derived oligosaccharides. This induction of HGF by heparin or fucoidan and their oligosaccharide derivates occurs primarily at the level of translation, probably via the same mechanism. Fucoidan may thus be useful to protect tissues and organs from various injuries and diseases, via mechanisms involving HGF.