海洋小球藻多糖的制备及其体外抑制肿瘤血管生成活性的研究

目的 研究海洋小球藻多糖的制备工艺及其抑制肿瘤血管生成的作用。 方法 比较多种提取方法提取多糖,确定最适提取工艺,经乙醇沉淀,并结合DEAE- Cellulose 52 柱色谱分离纯化;采用创伤愈合法测定小球藻多糖对肿瘤细胞培养液诱导的内皮细胞迁移的抑制作用。结果 选择闪式萃取结合酶法最适宜提取小球藻多糖,其最佳提取条件为胰蛋白酶酶用量为1.5%、酶解pH值为6.5、酶解温度为40℃、酶解时间为1.5h,经柱色谱分离得到的小球藻多糖在浓度50、100ug/mL时可抑制肿瘤细胞培养液诱导的内皮细胞迁移。结论 采用闪式萃取-酶解结合柱色谱可获得小球藻多糖,其具有一定的抑制肿瘤血管生成活性。     

Isolation,characterisation and complement fixation activity of acidic polysaccharides from Argemone mexicana used as antimalarials in Mali

ContextGlobal studies on Argemone mexicana L. (Papaveraceae) traditionally used against malaria in Mali are limited to its low-mass compounds activities, and little information on its bioactive polysaccharides is available.ObjectiveThis study determines the structure and the immunomodulatory activity of polysaccharides from aerial parts of A. mexicana.Materials and methodsAcidic polysaccharides from this plant material named HMAmA1 and HMAmA2 were isolated from water extracts. Their monosaccharide composition was determined by gas chromatography. Glycosidic linkages were determined using GC-MS. NMR was also applied. The polymers were tested for effects on the human complement system in vitro at different doses.ResultsThe monosaccharide composition showed that the two polysaccharides contained in different amounts the following monomers: arabinose, rhamnose, galactose, and galacturonic acid. Overall structural analysis showed the presence of a low ratio of 1,2-linked rhamnose compared to 1,4-linked galacturonic acid with arabinogalactans substituted on position 4 of rhamnose. NMR data showed the presence of galacturonans alternated by rhamnogalacturonans bearing arabinose and galactose units. α-Linkages were found for l-arabinose, l-rhamnose and d-galacturonic acid, while β-linkages were found for d-galactose. The two polysaccharides exhibited strong complement fixation activities, with HMAmA1 being the highest potent fraction. ICH₅₀ value of HMAmA1 was 5 µg/mL, compared to the control BPII being 15.9 µg/mL.Discussion and conclusionsPolysaccharides form A. mexicana presented a complement fixation effect. The complement system is an important part of the immune defense, and compounds acting on the cascade are of interest. Therefore, these polymers may be useful as immunodulatory agents.     

多糖抗2型糖尿病作用机制研究进展及分析

多糖是由10个以上单糖分子通过糖苷键连接形成的大分子化合物.多糖来源广泛、安全低毒,且具有抗肿瘤、抗病毒、免疫调节、降血糖、降血脂等多种生物活性,受到研究学者的广泛关注.2型糖尿病(type 2 diabetes mellitus,T2DM)是一种以高血糖、胰岛素抵抗、低度炎症为特征的慢性代谢紊乱疾病.近年来,多糖对T...     

健脾类中药多糖对脾虚相关病症肠道菌群影响研究现状

中医认为,脾乃后天之本,气血生化之源,若脾失健运,运化失司,则出现腹胀、肠鸣、泄泻等症状,与现代医学胃肠、免疫、代谢等疾病密切相关。肠道菌群作为与机体长期共生的微生物系统,在抵御病原入侵、保护胃肠、恢复免疫等一系列病理生理过程中发挥重要作用。近年研究表明,肠道菌群紊乱可看作中医"脾失健运"病理体现,健脾类中药及其组分可通过调节肠道菌群改善其相关病理,尤其多糖是发挥功能的主要活性成分。本文对健脾类中药多糖组分调节肠道菌群的相关作用及可能机制进行综述,可为改善脾虚相关疾病的进一步研究及临床应用提供参考。     

Effect of the heme oxygenase gene on mycelial growth and polysaccharide synthesis in Ganoderma lucidum

The heme oxygenase gene has antioxidant and cytoprotective effects in organisms, but no related research has been conducted in Ganoderma lucidum. For the first time, we cloned the HMX1 gene in G. lucidum. The CDS is 1092 bp in length and encodes 363 amino acids. The HMX1 protein was prokaryotically expressed and purified, and the enzyme activity of the purified protein was measured. The value of K_m was 0.699 μM, and V_m was 81.9 nmol BV h⁻¹ nmol⁻¹ protein. By constructing the silencing vector pAN7-dual-HMX1i, the transformants HMX1i1 and HMX1i2 were obtained. Compared with the wild-type (WT), the average growth rate of HMX1i1 and HMX1i2 decreased by 31% and 23%, respectively, and the mycelium biomass decreased by 53% and 48%, respectively. Compared with the WT, the extracellular polysaccharide content of HMX1i1 and HMX1i2 increased by 59% and 51%, and the intracellular polysaccharide content increased by 24% and 22%, respectively. These results indicate that the HMX1 gene affects mycelial growth and polysaccharide synthesis in G. lucidum.     

黄芪多糖对2型糖尿病ZDF大鼠血糖及肝脏脂代谢影响

目的观察黄芪多糖对2型糖尿病ZDF大鼠血糖及肝脏脂代谢的影响。方法选取30只成年雄性ZDF大鼠,随机分为模型组、APS低剂量、APS中剂量组、APS高剂量组和二甲双胍组;另取6只成年雄性ZDF(fa/+)大鼠作为正常组。实验组灌胃给予相应剂量药物,模型组和正常组灌胃给予生理盐水溶液,测定各组ZDF大鼠体重、空腹血糖;肝脂代谢指标:TC、TG、LDL-C、HDL-C含量;肝损伤指标:AST、ALT活性;肝脏病理学检测,从而探讨APS对2型糖尿病ZDF大鼠血糖及肝脏脂代谢的影响。结果给药前实验组大鼠体重、空腹血糖显著增高,TC、TG、LDL-C显著增加,符合糖尿病症状,且肝损伤存在一定程度损伤;予APS后各实验组大鼠体重较模型组显著降低(P0.05),同时与给药前相比体重显著性降低(P0.05);空腹血糖较模型组显著性降低(P0.05),其中黄芪多糖大剂量降血糖作用最为显著(P0.01),与给药前相比得出同样的结论;各实验组大鼠TC、TG、LDL-C较模型组均有降低趋势,其中APS高剂量组TC、TG、LDL-C含量下降最显著(P0.05);肝损伤方面,各给药组大鼠ALT、AST较模型组均有降低趋势,且APS高剂量组最为显著(P0.05);肝脏HE结果显示模型组细胞核皱缩,胞质呈网丝状,细胞间存在明显脂滴沉积;予APS后,肝脏细胞形态趋于正常,部分细胞内存在细小脂滴,肝小叶结构正常,肝细胞索呈放射状排列。结论黄芪多糖通过降血糖和纠正肝脏脂代谢紊乱,改善肝脏脂滴沉积,对抗糖尿病引起的肝损伤,从而起到抗2型糖尿病的作用。     

基于比折光指数增量值（dn/dc）的多糖HPSEC-RID定量分析

目的 建立基于比折光指数增量值(dn/dc)的多糖高效分子排阻色谱法-示差折光检测法(high performance size exclusion chromatography-refractive index detector,HPSEC-RID)通用定量分析方法。方法 基于浓度敏感型检测器对样品响应的峰面积与浓度呈线性相关,根据已知dn/dc值的分析物如氯化钠(0.174 mL·g^-1)水溶液峰面积与浓度线性关系,计算仪器校准常数(K_RI),进而根据多糖通用dn/dc值实现不需要对照品以及多角度光散射(multi-angle laser light scattering,MALLS)检测器和第三方软件的多糖含量测定;并以枸杞多糖为例,比较所建立方法与应用第三方软件方法所得结果一致性。结果 基于氯化钠水溶液dn/dc值,离线和在线2种模式下测得仪器K_RI均为0.998;基于通用dn/dc值结合HPSEC-RID测定的不同批次枸杞子中枸杞多糖测定结果与HPSEC-MALLS-RID测定结果一致,RAD为0.45%~1.23%。结论 基于dn/dc值结合HPSEC-RID即可实现天然多糖的简单、快速、准确的定量分析,无需对照品以及MALLS检测器和第三方软件。     

Nonlinear relations between house dust mite allergen levels and mite sensitization in farm and nonfarm children

BACKGROUND: Low sensitization rates to common allergens have been observed in farm children, which might be due to high exposure to microbial agents. It is not known how microbial agents modify the association between specific allergen exposure and sensitization. OBJECTIVE: To examine the relations between house dust mite allergen exposure and mite sensitization in farm and nonfarm children and to assess the effects of microbial agents levels on this association. METHODS: Major mite allergens of Dermatophagoides pteronyssinus (Der p 1) and Dermatophagoides farinae (Der f 1), endotoxin, beta(1,3)-glucans and fungal extracellular polysaccharides were measured in mattress dust of 402 children participating in a cross-sectional study in five European countries. Mite allergen (Der p 1 + Der f 1) levels were divided into tertiles with cut-offs 1.4 and 10.4 microg/g. Sensitization was assessed by measurement of allergen-specific immunoglobulin E against house dust mite. RESULTS: Prevalence ratios of mite sensitization for medium and high when compared with low mite allergen levels were 3.1 [1.7-5.7] and 1.4 [0.7-2.8] respectively. Highest mite sensitization rates at intermediate exposure levels were consistently observed across country (except for Sweden) and in both farm and nonfarm children. The shape of the dose-response curve was similar for above and below median mattress microbial agent levels, but the 'sensitization peak' appeared to be lower for above median levels. CONCLUSIONS: Our data suggest a bell-shaped dose-response relationship between mite allergen exposure and sensitization to mite allergens. In populations with high microbial agent levels and low sensitization rates, the curve is shifted down.     

黄芪多糖调控多胺介导的Ca~(2+)-RhoA通路促进小肠上皮细胞迁移研究

目的考察黄芪多糖对小肠上皮细胞(IEC-6)迁移及迁移过程细胞内多胺水平、细胞质游离钙离子([Ca2+]cyto)的量、细胞骨架蛋白Rho A表达的影响,探讨黄芪修复胃肠黏膜损伤的疗效机制。方法黄芪药材经水提醇沉、Sevage法去蛋白后得到黄芪粗多糖,运用DEAE纤维素柱分离得到黄芪多糖I、II、III、IV,黄芪多糖I以Sephadex LH-20凝胶柱色谱得到黄芪多糖V。Tips划痕法建立IEC-6细胞损伤迁移模型,柱前衍生高效液相色谱法测定多胺的量,流式细胞仪检测[Ca2+]cyto水平,Western blotting法检测Rho A蛋白表达。考察黄芪多糖对正常IEC-6细胞[未加α-二氟甲基鸟氨酸(DFMO)]和多胺耗竭IEC-6细胞(加入DFMO)迁移、多胺水平、[Ca2+]cyto的量及Rho A蛋白表达的影响。结果黄芪粗多糖、黄芪多糖I、黄芪多糖V(50、100、200 mg/L)均能促进IEC-6细胞迁移(P0.01),并且可逆转多胺合成抑制剂DFMO所致的细胞迁移抑制效果(P0.01);在正常(未加DFMO)或多胺耗竭情况(加DFMO),黄芪多糖V均可提高迁移过程细胞内多胺的量(P0.01);黄芪多糖V可提高细胞迁移过程[Ca2+]cyto水平(P0.01),并且可逆转DFMO所致的[Ca2+]cyto水平下降(P0.01);黄芪多糖V(100、200 mg/L)可明显提高Rho A蛋白表达,同时可逆转DFMO所导致的Rho A蛋白表达抑制作用。结论黄芪多糖可加速胃肠黏膜损伤早期修复过程,其机制可能与增加黏膜上皮细胞多胺的量,提升[Ca2+]cyto,从而提高Rho A蛋白表达,进而促进胃肠黏膜上皮细胞迁移有关。     

高效液相法测定黄芪中性多糖的单糖组成

目的:采用高效液相法测定黄芪中性多糖的单糖组成。方法:正交设计优选三氟乙酸水解黄芪中性多糖的条件;水解产物直接采用高效液相-视差检测器(HPLC-RID)检测或经1-苯基-3-甲基-5-吡唑啉酮柱前衍生化后高效液相-二极管阵列检测器(HPLC-DAD)检测两种方法,以6种单糖为对照,测定水解产物中单糖的组成。结果:黄芪中性多糖的三氟乙酸完全酸水解最佳条件为采用1M TFA,水解温度100℃,水解时间5 h;两种高效液相色谱法测得水解产物中的单糖均为葡萄糖。结论:采用三氟乙酸完全酸水解条件和高效液相色谱法测定单糖的方法简便易行,可用于黄芪中性多糖的单糖组成研究。