小有刺参硫酸软骨素和岩藻聚糖硫酸酯抗血小板聚集活性的比较

目的 从小有刺参中制备纯化硫酸软骨素和岩藻聚糖硫酸酯及其低分子量组分,并比较不同结构硫酸多糖的抗血小板聚集活性,揭示海参硫酸多糖抗血小板聚集活性的构效关系。方法 利用离子交换色谱和自由基降解技术,从小有刺参中制备硫酸软骨素和岩藻聚糖硫酸酯及各自的低分子量组分。采用体外凝血酶诱导血小板聚集模型,比较不同结构的硫酸软骨素和岩藻聚糖硫酸酯对血小板聚集率的影响。结果 4～60 μg/mL硫酸软骨素和低分子量硫酸软骨素具有显著的抑制血小板聚集的活性,在浓度为20 μg/mL时对血小板聚集的抑制率高达94.6%和95.3%,且分子量的降低对其活性无影响。比较不同来源的岩藻聚糖硫酸酯的活性发现,在4～60 μg/mL浓度范围内,海参与海带来源的岩藻聚糖硫酸酯都显著抑制血小板聚集,且活性没有显著差异,但经过自由基降解后,海参和海带来源的岩藻聚糖硫酸酯的抗血小板聚集活性都显著降低。结论 海参硫酸软骨素的抗血小板聚集活性显著高于岩藻聚糖硫酸酯,海参硫酸多糖可以应用于新型抗血小板聚集药物的研究开发。     

岩藻聚糖硫酸酯F2靶向SGLT2的抗糖尿病肾病活性研究

目的 旨在从细胞水平上探讨岩藻聚糖硫酸酯F2对SGLT2的抑制作用及抗糖尿病肾病(DN)活性,并阐述其抗DN机制.方法 通过Q-Sepharose Fast Flow强阴离子交换层析法对墨角藻来源岩藻聚糖硫酸酯(FvF)进行分离纯化,并采用高效液相、离子色谱等方法测定其分子量、单糖组成、硫酸根含量等基本理化性质,利用流...     

海带岩藻聚糖硫酸酯对栓塞性脑缺血损伤的保护及作用机制的研究D

目的 对不同分子量海带岩藻聚糖硫酸酯对大鼠栓塞性脑缺血损伤的保护活性及其作用机制进行研究比较。方法 以海带高分子量和低分子量岩藻聚糖硫酸酯为研究对象,采用电刺激造栓法建立大鼠动脉栓塞性脑缺血损伤模型,观察岩藻聚糖硫酸酯对神经行为学评分、脑梗死体积、大脑皮层形态学、血液中花生四烯酸代谢产物（TXB2和6-kelo-PGF1α）、磷脂代谢产物（PA和LPA）和纤溶系统（t-PA和u-PA）的影响。结果 静脉注射高分子量和低分子量岩藻聚糖硫酸酯对大鼠栓塞性脑缺血损伤具有很好的保护作用,显著降低神经行为学评分、脑梗死体积和脑皮层神经细胞的损伤,低分子量岩藻聚糖硫酸酯的保护活性是高分子量组分的1/10。岩藻聚糖硫酸酯预防栓塞性脑缺血损伤的作用机理为：抑制TXB2生成,提高6-kelo-PGF1α的水平,抑制LPA的释放,从而抑制血栓的进一步发展;促进t-PA和u-PA的生成从而激活纤溶系统。结论：岩藻聚糖硫酸酯在预防栓塞性脑缺血损伤方面具有很好的应用潜质。     

分子量对海参岩藻聚糖硫酸酯在体内吸收的影响

目的 利用高温高压降解法制备两种不同分子量的岩藻聚糖硫酸酯,探究口服不同分子量的海参岩藻聚糖硫酸酯的吸收特性。方法 采用分子排阻凝胶色谱法、离子高效液相色谱法,检测海参硫酸多糖高温高压降解前后分子量、硫酸根含量的变化,并利用PMP柱前衍生-高效液相色谱法测定岩藻聚糖硫酸酯的单糖组成,以及大鼠血清中单糖的变化。结果 口服低分子量海参岩藻聚糖硫酸酯后,大鼠血清中岩藻糖和半乳糖的吸收速度和最大浓度明显高于中分子量岩藻聚糖组,血清中甘露糖、氨基葡萄糖的含量也显著上升,血清中氨基半乳糖的含量略有上升。而口服中、低分子量岩藻聚糖硫酸酯都能够降低血清中葡萄糖的含量。结论 分子量低于10 kDa的低分子量岩藻聚糖具有很好的体内的吸收率,适合于开发口服岩藻聚糖功能产品。     

不同性质海洋硫酸多糖的制备及其改善大鼠脂肪肝作用的比较研究

目的 探索了不同来源、不同分子量的海洋硫酸多糖对脂肪肝大鼠脂肪代谢的调节作用.方法 SD大鼠随机分为7组,正常对照组、脂肪肝模型对照组、0.1%低分子量海参岩藻聚糖硫酸酯组、0.1%海参岩藻聚糖硫酸酯组、0.2%海参岩藻聚糖硫酸酯组、0.2%海藻岩藻聚糖硫酸酯组、0.2%海参硫酸软骨素组,每组6只.饲料中添加1%乳清酸...     

相对低分子质量海带岩藻聚糖硫酸酯的制备及其对纤溶系统的影响

目的 研究自由基氧化降解得到的相对低分子质量岩藻聚糖硫酸酯化学性质以及对新西兰大白兔体內纤溶系统的影响.方法 采用H2O2-Cu2+自由基氧化结合分步超滤法,制备了重均分子量为7.68 kD和3.89 kD的两个相对低分子质量岩藻聚糖硫酸酯组分.采用静脉注射的方式研究两个相对低分子质量岩藻聚糖硫酸酯组分对新西兰大白兔的...     

五种海藻多糖体外抗血小板聚集作用观察

本文主要对海带（Laminaria japenioa Aresch)、鼠尾藻[Sargassum thunbergil(Mert)o‘Kuntge]、萱藻[Scytosiphon Lomentarius(Lyngb)J.Ag]、石莼[Ulva.lactucal]、刚毛[Cladophora kutzing]5种海藻多糖的硫酸基含量以及体外抗血小板聚集作用进行了观察。结果发现,萱藻多糖的硫酸基含量及抗血小板聚集作用显著高于其他海藻多糖,其他依次为鼠尾藻、海带、石莼。刚毛多糖的抗血小板聚集的作用不显著。5种海藻多糖的抗凝血活性与其硫酸基含量呈显著正相关。     

褐藻多糖硫酸酯抗PAF作用研究

目的：对从褐藻多糖硫酸酯分离的各组分进行抗PAF作用测定和化学分析，探讨其构效关系。方法：用碱提醇沉法获取褐藻中褐藻多糖硫酸酯的不同组分。用兔血小板聚集试验检测其抗PAF作用。用硫酸-咔唑法测定其葡萄糖醛酸含量，用氯化钡沉淀法测定其硫酸根含量，用硫酸-半胱氨酸法测定其岩藻糖含量。结果：研究结果表明，各组分均呈现出一定的抗PAF活性；各组分中岩藻糖含量变化不大，而SO4^2-和葡萄糖醛酸含量变化较大。葡萄糖醛酸含量愈低、硫酸根含量愈高，其抗PAF作用愈强。结论：褐藻多糖硫酸酯各组分均有一定的抗PAF活性，其作用随葡萄糖醛酸含量降低、硫酸根含量升高而增强。     

海带硫酸多糖的降解、分离纯化及理化性质分析

文章采用自由基方法降解海带硫酸多糖，然后通过琼脂糖凝胶电泳、凝胶色谱等方法进行分离纯化；分别利用硫酸酚法和明胶比浊法，测定糖的含量和硫酸根的含量；MN-纤维素膜层析和气相色谱测定单糖组成；利用超滤和凝胶过滤测定降解多糖的分子质量等。海带硫酸多糖可以被自由基有效地降解，降解之后海带硫酸多糖的多糖含量、硫酸根含量及单糖组成基本没有变化，分子质量可被降解到10000-15000左右。     

绿藻硫酸多糖SHW及其低分子量片段的结构及抗凝活性研究*

目的 对绿藻多糖SHW及其低分子量片段的结构及抗凝活性进行研究。方法 通过热水提取、强阴离子交换色谱和凝胶渗透色谱,从绿藻硬毛藻中提取分离得到硫酸多糖SHW;通过可控酸解方法制备SHW低分子量片段;采用高效凝胶渗透色谱、高效液相色谱、红外光谱及甲基化方法对多糖结构进行表征;通过活化部分凝血活酶时间、凝血酶时间、凝血酶原时间研究多糖SHW及其低分子量片段体外抗凝血活性。结果 多糖SHW及其低分子量片段主要由阿拉伯糖组成,含有少量半乳糖和氨基葡萄糖;糖链中阿拉伯糖主要以→4)-Arap-(1→和→3,4)Arap-(1→的形式存在,半乳糖以→4)-Galp-(1→存在形式,硫酸根主要位于→4)-Arap-(1→的C-3位。SHW及其低分子量片段A1～A6的分子量分别为492 kDa、200 kDa、170kDa、100kDa、26kDa、14kDa 和10 kDa。SHW 具有较高的抗凝血活性,且其抗凝活性随着其分子量的减少而降低。结论 海藻多糖SHW是一种具有抗凝活性的新颖硫酸多糖,其抗凝活性与分子量密切相关。     

海带多糖结构解析以及生物活性研究进展

海带多糖是一种来源于褐藻的硫酸化多糖,由于其独特的硫酸化结构,并且富含海藻糖岩藻糖,因而具有许多生物活性,包括抗凝血、抗氧化、抗炎、抗病毒和抗肿瘤活性。海带多糖的生物活性不仅与海带种类、地理位置、收获季节有关,而且与多糖本身的化学组成、分子量、单糖组成、硫酸盐含量和硫酸酯基团位置密切相关,另外,不同提取分离纯化手段也是重要的影响因素。本文综述了海带多糖的提取分离纯化和结构解析,同时详细介绍了近些年有关海带多糖的生物活性研究进展,并对未来研究的重点方向进行了总结和展望。     

Fucoidan is the active component of fucus vesiculosus that promotes contraction of fibroblast-populated collagen gels

The fibroblast-populated collagen gel culture method has been evaluated as a dermal model of wound contraction and granulation in tissues during the wound healing process and as an in vitro model of dermal tissue. We previously reported that an extract of Fucus vesiculosus promoted fibroblast-populated collagen gel contraction and that the promotion of the gel contraction was due to the increased expression of integrin alpha2beta1 on the surface of the fibroblasts. In this study, we investigated the active component of the extract of this alga using extraction and fractionation techniques. Water extraction of the alga was followed by precipitation with excess ethanol and then gel filtration with the boundary molecular weight of 30,000. The high molecular weight fraction obtained from gel filtration was fractionated by ion exchange chromatography on diethylaminoethyl cellulose column to give active fractions that have more polar properties. These polar, high molecular weight fractions which contained molecules with fucose and sulfate groups showed significant gel contraction-promoting activity and integrin expression-enhancing activity, and were estimated to be the sulfated-polysaccharide fucoidan. Commercially available fucoidan showed similar activities to the above-described fraction of this alga. Although it remains necessary to precisely identify the specific active component, the above results indicate that fucoidan is the active component which promotes collagen gel contraction, and also indicate the possibility that it dose so by enhancing the integrin alpha2beta1 expression.     

Toxicological evaluation of fucoidan extracted from Laminaria japonica in Wistar rats.

Fucoidans, the sulfated polysacchrides extracted from brown algae, have been extensively studied for their diverse biological activities. However, there is no detailed report investigating the toxicity of fucoidan. In this study, the acute and subchronic (6 months) toxicity of varying levels of fucoidan extracted from Laminaria japonica was investigated in Wistar rats after oral administration. The results showed that no significant toxicological changes were observed when 300 mg/kg body weight per day fucoidan was administered to rats. But when the dose was increased to 900 and 2500 mg/kg body weight per day, the clotting time was significantly prolonged. Besides this, no other signs of toxicity were observed. Based on these results, it can be concluded that the no adverse effect level of fucoidan from L. japonica is 300 mg/kg body weight per day.     

相对低分子质量岩藻聚糖硫酸酯治疗慢性乙酸胃溃疡的临床研究

目的：观察慢性乙酸胃溃疡在低分子质量的岩藻聚糖硫酸酯作用下的疗效。方法：用灌胃方法对患有乙酸胃溃疡的白鼠灌输分子质量较低的岩藻聚糖硫酸酯,设为试验组;单纯乙酸胃溃疡白鼠设为对照组。观察胃溃疡白鼠在岩藻聚糖硫酸酯作用下胃部溃疡的情况、受氧程度、一氧化氮产生情况以及对过氧化物酶活性的影响。结果：胃溃疡白鼠接受低分子质量岩藻聚糖硫酸酯灌输后,胃黏膜损伤得到一定修复,与对照组白鼠相比,溃疡面积有所减少,同时,在岩藻聚糖硫酸酯的作用下,胃部抗氧化酶得到了很好的保护,过氧化物酶得到了明显抑制。相比对照组白鼠,试验组白鼠胃中一氧化氮含量明显上升,过氧化物活性大幅度下降。结论：抗氧化物的活性影响了岩藻聚糖硫酸酯对辅助治疗的效果,同时,岩藻聚糖硫酸酯对白鼠慢性乙酸胃溃疡有辅助治疗的效果。乙酸慢性胃溃疡在一氧化氮的产生以及炎症细胞辅助下得到了很好的修复,溃疡也得到了愈合的效果。     

海带硫酸多糖的提取、纯化及其理化分析

目的研究海带硫酸多糖 (LPS)的提取制备及其组分的纯化和理化性质。方法采用酶解法从海带提取制备LPS,海带浆加入纤维素酶、半纤维素酶、果胶酶和蛋白酶 ,50℃水解 4h。取滤液加入氯化钙 ,离心去除海藻酸钙。取上清液加入十六烷基三甲基溴化铵 (CTAB)与LPS结合沉淀 ,离心收集CTAB LPS沉淀物。加入氯化钙溶液进行盐解 ,将LPS游离释放出来 ,加入乙醇使LPS析出。离子交换色谱和凝胶过滤色谱法分离纯化其多糖组分。结果酶解提取法的收率为 5‰ ,色谱法分离得到 4个主要多糖组分 ,测定其分子量分别为 2 1 0、1 2 0、40 0和 1 4 0kD。酶解法的提取收率高于水煮法。结论LPS的开发具有广阔的前景     

岩藻聚糖硫酸酯降血糖作用机制的研究进展

糖尿病是以高血糖和胰岛素抵抗为特征的内分泌和代谢系统疾病,已成为世界范围内一种普遍疾病。岩藻多糖基于其特定的化学结构,如单糖组成和糖苷键,具有良好的降糖作用和理想的糖尿病治疗潜力。岩藻聚糖硫酸酯具有多种生物活性,但其结构复杂、高分子量和高粘性的特性限制了其应用,而低分子量岩藻多糖粘度低、溶解度好,且研究表明低分子量岩藻多糖具有更好的降血糖作用,因此其低分子量产物的研究具有重大意义。本文讨论了岩藻多糖的结构特征,包括主干结构、糖苷键位置、单糖类型、硫酸盐含量,着重介绍了多糖分子量和降血糖活性的关联,继而引申出低分子量降血糖作用及其作用机理,以期为明晰岩藻多糖的构效关系及进一步的应用提供理论基础。     

Purification and Structural Characterization of Sulfated Polysaccharide from Sargassum myriocystum and its Efficacy in Scavenging Free Radicals

Sulfated polysaccharides from marine algae are one of the commercially beneficial compounds with a range of pharmaceutical and biomedical applications. They are testified to be effective against free radicals and related health complications. This study aims to determine the antioxidant potential of the sulfated polysaccharide from Sargassum myriocystum, followed by its purification and structural characterization. Amount of extract obtained was 5% from 10 g of plant material. The carbohydrate and sulfate content were found to be 31 and 0.34 mg/10 g of plant material, respectively. Total sulfated polysaccharide extract showed a good radical scavenging activity at lower concentrations. The active principle from the total sulfated polysaccharide was fractionated in anion exchange and gel filtration columns followed by structural characterization using Fourier transform infrared and nuclear magnetic resonance spectroscopy. Fraction 12 closely matched with the Fourier transform infrared and nuclear magnetic resonance spectra of fucoidan. Based on the results obtained, we conclude that sulfated polysaccharide from Sargassum myriocystum is identified as Fucoidan with potential radical scavenging activity compared to butylated hydroxyl toluene.     

Hydroxychavicol, a novel betel leaf component, inhibits platelet aggregation by suppression of cyclooxygenase, thromboxane production and calcium mobilization

BACKGROUND AND PURPOSE: Platelet hyperactivity is important in the pathogenesis of cardiovascular diseases. Betel leaf (PBL) is consumed by 200-600 million betel quid chewers in the world. Hydroxychavicol (HC), a betel leaf component, was tested for its antiplatelet effect. EXPERIMENTAL APPROACH: We tested the effect of HC on platelet aggregation, thromboxane B(2) (TXB(2)) and reactive oxygen species (ROS) production, cyclooxygenase (COX) activity, ex vivo platelet aggregation and mouse bleeding time and platelet plug formation in vivo. The pharmacokinetics of HC in rats was also assessed. KEY RESULTS: HC inhibited arachidonic acid (AA) and collagen-induced platelet aggregation and TXB(2) production. HC inhibited the thrombin-induced TXB(2) production, but not platelet aggregation. SQ29548, suppressed collagen- and thrombin-induced TXB(2) production, but not thrombin-induced platelet aggregation. HC also suppressed COX-1/COX-2 enzyme activity and the AA-induced ROS production and Ca(2+) mobilization. HC further inhibited the ex vivo platelet aggregation of platelet-rich plasma (>100 nmole/mouse) and prolonged platelet plug formation (>300 nmole/mouse) in mesenteric microvessels, but showed little effect on bleeding time in mouse tail. Moreover, pharmacokinetics analysis found that more than 99% of HC was metabolized within 3 min of administration in Sprague-Dawley rats in vivo. CONCLUSIONS AND IMPLICATIONS: HC is a potent COX-1/COX-2 inhibitor, ROS scavenger and inhibits platelet calcium signaling, TXB(2) production and aggregation. HC could be a potential therapeutic agent for prevention and treatment of atherosclerosis and other cardiovascular diseases through its anti-inflammatory and antiplatelet effects, without effects on haemostatic functions.