枸杞多糖免疫调节作用机制研究进展

枸杞子是传统的名贵补益中药,具有"滋阴补血、益精明目"之功效.枸杞多糖是其中的主要生物活性成分,具有免疫调节、抗肿瘤、抗衰老等多种生物学作用.近年来,随着植物化学分离纯化技术的不断改进,枸杞多糖得到了进一步的分离和纯化,因此其免疫作用的分子机制如其作用的靶细胞、信号转导途径等研究取得了较明显进展.     

枸杞多糖对外周血单核细胞激活作用

目的:探讨枸杞多糖对外周血单核细胞是否具有激活作用。方法:贴壁法分离培养外周血单核细胞并进行鉴定。应用中性红实验检测枸杞多糖对单核细胞吞噬作用;用非特异性酯酶染色及电镜技术检测枸杞多糖诱导单核细胞内溶酶体的改变;用0.312,1.250,5.000g.L-1枸杞多糖对体外培养的外周血单核细胞进行诱导培养12h,ELISA法测定单核细胞肿瘤坏死因子-α(TNF-α)和白细胞介素-6(IL-6)的表达。结果:枸杞多糖能增强单核细胞的吞噬作用,增加单核细胞胞质内溶酶体量,显著诱导单核细胞表达TNF-α和IL-6。结论:枸杞多糖对单核细胞具有激活作用。     

枸杞多糖对肝癌Hca-F 荷瘤小鼠的抗肿瘤作用及其机制

目的研究枸杞多糖（LBP）对小鼠Hca-F肝癌的生长抑制作用及机制。方法建立小鼠Hca-F肝癌模型,腹腔注射不同浓度的枸杞多糖连续10d。称重检测枸杞多糖对肿瘤生长、脾脏和胸腺指数的影响;采用MTT法、ELISA法分析枸杞多糖对荷瘤小鼠脾巨噬细胞的吞噬活性、细胞因子分泌等免疫指标的影响。结果枸杞多糖对小鼠实体瘤生长具有抑制作用,枸杞多糖40mg·kg^-1与对照组相比有显著差异（P〈0.05）;实验组小鼠脾指数和胸腺指数均高于对照组。枸杞多糖40mg·kg^-1即可明显促进IL-2的产生,降低VEGF蛋白的表达。结论枸杞多糖对Hca-F肝癌小鼠肿瘤生长有抑制作用,可能与提高荷瘤小鼠细胞和分子免疫活性有关。     

枸杞多糖药理作用与临床应用

枸杞多糖是枸杞子的主要有效成分,临床研究表明,枸杞多糖具有免疫促进和免疫调节、保肝、抗应激作用以及辐射防护等药理作用。鉴于枸杞多糖的多重药理作用,对其进行深入的研究和发掘,使其能够更好的在临床中得到应用,合理发挥其药理作用,对造福患者具有重要的意义。本文在介绍枸杞多糖各种药理作用的基础上,对枸杞多糖目前在临床上的主要应用进行了介绍,以期为枸杞多糖的进一步研究和应用提供参考。     

枸杞的免疫功能、降血糖作用研究进展

枸杞为医食同源常用药物,民间常用代茶饮、煲汤等,以滋补强壮身体.中医认为枸杞甘平质润,为滋补肝肾之药.适用于肝肾阴虚、腰膝酸软、消渴遗精等症.现代研究表明,枸杞及其多糖具有良好地免疫促进、延缓衰老、抗辐射损伤、降低血糖、降血脂、抗氧化以及促进肿瘤细胞凋亡等作用.现将有关枸杞免疫功能、降血糖作用研究资料概述如下.     

刺糖多糖免疫活性的初步研究

目的研究刺糖多糖对免疫抑制小鼠的免疫调节作用。方法采用水提醇沉法得刺糖多糖。建立免疫抑制小鼠动物模型,小鼠灌胃刺糖多糖,利用碳粒廓清实验测定非特异性免疫功能;血清溶血素实验反映抗体生成水平;测定血清中细胞因子的生成水平来评价刺糖多糖的免疫活性。结果刺糖多糖可以增强免疫抑制小鼠的碳粒廓清能力和血清溶血素水平,能够提升由环磷酰胺造成的免疫抑制小鼠血清中IL-2、IL-10的含量。结论刺糖多糖对免疫抑制小鼠免疫功能有促进作用。     

裙带菜多糖对人外周血淋巴细胞因子分泌的影响

目的分析裙带菜多糖对人外周血淋巴细胞亚群、细胞因子分泌的影响,探讨裙带菜多糖的免疫调节机制。方法用流式细胞术检测淋巴细胞亚群的变化,用酶联免疫方法测定裙带菜多糖作用后淋巴细胞培养上清中细胞因子的浓度。结果不同浓度的裙带菜多糖可使CD+8T细胞比例明显增加(P<0.01);并可使CD+4T细胞比率增加,但与阴性对照组比较差异无统计学意义(P>0.05);裙带菜多糖对B细胞增殖反应无明显影响(P>0.05)。不同浓度的裙带菜多糖作用后,NK细胞比例明显增高(P<0.01),并呈浓度依赖性,可明显刺激外周血淋巴细胞产生白细胞介素-2(IL-2)(P<0.01),但对IL-6及IL-10的产生作用无明显影响(P>0.05)。结论裙带菜多糖可促进CD+8、NK细胞增殖,产生Th1类细胞因子发挥免疫调节作用。     

文蛤多糖与文蛤提取物对小鼠免疫调节影响的比较研究

本文对文蛤多糖与文蛤提取物在小鼠免疫调节方面进行了比较研究。结果表明，小鼠灌服文蛤多糖与文蛤提取物，都可使免疫抑制状态下小鼠脾脏重量，外周血白细胞数以及巨噬细胞的吞噬功能显著增加，明显促进特异性抗体的恢复。对受环磷酰胺抑制的迟发型超敏反应(DTH)，具有明显上调作用，对受环磷酰胺所致过高的DTH反应，具有明显下调作用。在同等剂量下，文蛤多糖比之于文蛤提取物显示出更强的药效。提示文蛤多糖是文蛤提取物免疫作用的主要成分，且可能具有双向免疫调节功能。     

具有抗肿瘤活性的多糖及其作用机理研究概况

多糖广泛存在于动植物体内 ,其生理功能除了粘附和支持作用外 ,在细胞识别、信号传导、调控机体免疫功能以及控制细胞的迁移、增殖、分化、代谢等方面都有十分重要的作用。近几年 ,从植物、动物中提取的多糖 (polysaccharide)类药物的抗肿瘤作用引起了人们广泛的注意并对其作用机理研究 :发现多糖的抗肿瘤作用主要在于其能增强机体的体液免疫和细胞免疫功能 ,有的能直接作用于肿瘤细胞。1　主要的一些具有抗肿瘤作用的多糖1.1　枸杞多糖 (lyciumbarbarumpolysaccharides,LBP)枸杞子是茄科落叶灌木植物宁夏枸杞LyciumbarbarumL .和枸杞L .…     

中药多糖的免疫调节及抗肿瘤近年研究概述

中药多糖具有肯定的调节机体免疫功能和抗肿瘤作用，其作用是多途径、多环节、多靶点的，如促进免疫细胞增殖与分化，分泌各种淋巴因子，调节神经-内分泌-免疫网络(NIM)的平衡等。在世界药物研究趋势由化学合成药物转向研究天然药物的今天，人们对中药多糖类药物的研究也正如火如荼。本文对近年来中药多糖的免疫调节作用及其抗肿瘤作用的研究进展作一概述。     

Efficacy of gut lavage,hemodialysis, and hemoperfusion in the therapy of paraquat or diquat intoxication

Clinical and in vitro investigations were carried out to test the efficacy of gut lavage, hemodialysis, and hemoperfusion in the treatment of poisoning with paraquat or diquat. In a patient suffering from diquat intoxication 130 times more diquat was removed by gut lavage 30 h after ingestion than was removed by complete aspiration of the gastric contents.Determination of in vitro clearances for paraquat and diquat by hemodialysis showed that, at serum concentrations of 1–2 ppm, such as are frequently encountered in poisoning in man, toxicologically relevant quantities of herbicide cannot be removed from the body. At a concentration of 20 ppm, on the other hand, hemodialysis proved to be effective, the clearance being 70 ml/min at a blood flow rate of 100 ml/min. The efficacy of hemoperfusion with coated activated charcoal was on the whole better. Especially at concentrations around 1–2 ppm, the clearance values for hemoperfusion were some 5–7 times higher than those for hemodialysis.In a patient suffering from paraquat poisoning, both hemodialysis as well as hemoperfusion were carried out. The in vitro results could be confirmed: At serum concentrations of paraquat less than 1 ppm no clearance could be obtained by hemodialysis while by hemoperfusion with activated charcoal quite high clearance values were measured and the serum level dropped down to zero.

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Zusammenfassung Klinische Untersuchungen und Laboratoriumsversuche wurden durchgeführt, um die Wirksamkeit von Darmspülung, Hämodialyse und Hämoperfusion bei Paraquat- und Deiquat-Vergiftungen zu prüfen.Bei einem Patienten wurde 30 Std nach Deiquat-Aufnahme durch Darmspülung 130mal mehr Deiquat entfernt als durch vollständige Aspiration des Mageninhaltes. In vitro-Versuche ergaben, daß bei Blutserumkonzentrationen von 1–2 ppm, die bei Vergiftungen oft gemessen werden, durch Hämodialyse keine toxikologisch relevanten Paraquat- oder Deiquat-Mengen entfernt werden können. Dagegen erwies sich die Hämodialyse bei 20 ppm und einer Blutumlaufgeschwindigkeit von 100 ml/min mit einer Clearance von 70 ml/min als wirksam. Die Hämoperfusion mit beschicheter Aktivkohle war in diesen Versuchen aber eindeutig überlegen, denn insbesondere bei Konzentrationen um 1–2 ppm waren die Clearance-Werte 5–7mal höher als bei der Hämodialyse.Die in vitro-Ergebnisse wurden bei einem Patienten mit einer Paraquat-Vergiftung bestätigt: Bei Konzentrationen unter 1 ppm war die Hämodialyse wirkungslos, während durch Hämoperfusion relativ hohe Clearance-Werte erreicht wurden, so daß der Serumspiegel rasch unter die Nachweisgrenze abfiel.

     

In vitro studies on sterically stabilized liposomes (SL) as enzyme carriers in organophosphorus (OP) antagonism

This study describes a new approach for organophosphorous (OP) antidotal treatment by encapsulating an OP hydrolyzing enzyme, OPA anhydrolase (OPAA), within sterically stabilized liposomes. The recombinant OPAA enzyme was derived from Alteromonas strain JD6. It has broad substrate specificity to a wide range of OP compounds: DFP and the nerve agents, soman and sarin. Liposomes encapsulating OPAA (SL)* were made by mechanical dispersion method. Hydrolysis of DFP by (SL)* was measured by following an increase of fluoride ion concentration using a fluoride ion selective electrode. OPAA entrapped in the carrier liposomes rapidly hydrolyze DFP, with the rate of DFP hydrolysis directly proportional to the amount of (SL)* added to the solution. Liposomal carriers containing no enzyme did not hydrolyze DFP. The reaction was linear and the rate of hydrolysis was first order in the substrate. This enzyme carrier system serves as a biodegradable protective environment for the recombinant OP-metabolizing enzyme, OPAA, resulting in prolongation of enzymatic concentration in the body. These studies suggest that the protection of OP intoxication can be strikingly enhanced by adding OPAA encapsulated within (SL)* to pralidoxime and atropine.     

Aquatic Insects and Trace Metals: Bioavailability,Bioaccumulation, and Toxicity

Abstract

The uptake of metals from food and water sources by insects is thought to be additive. For a given metal, the proportions taken up from water and food will depend both on the bioavailable concentration of the metal associated with each source and the mechanism and rate by which the metal enters the insect. Attempts to correlate insect trace metal concentrations with the trophic level of insects should be made with a knowledge of the feeding relationships of the individual taxa concerned. Pathways for the uptake of essential metals, such as copper and zinc, exist at the cellular level, and other nonessential metals, such as cadmium, also appear to enter via these routes. Within cells, trace metals can be bound to proteins or stored in granules. The internal distribution of metals among body tissues is very heterogeneous, and distribution patterns tend to be both metal and taxon specific. Trace metals associated with insects can be both bound on the surface of their chitinous exoskeleton and incorporated into body tissues. The quantities of trace meals accumulated by an individual reflect the net balance between the rate of metal influx from both dissolved and particulate sources and the rate of metal efflux from the organism. The toxicity of metals has been demonstrated at all levels of biological organization: cell, tissue, individual, population, and community. Much of the literature pertaining to the toxic effects of metals on aquatic insects is based on laboratory observations and, as such, it is difficult to extrapolate the data to insects in nature. The few experimental studies in nature suggest that trace metal contaminants can affect both the distribution and the abundance of aquatic insects. Insects have a largely unexploited potential as biomonitors of metal contamination in nature. A better understanding of the physico-chemical and biological mechanisms mediating trace metal bioavailability and exchange will facilitate the development of general predictive models relating trace metal concentrations in insects to those in their environment. Such models will facilitate the use of insects as contaminant biomonitors.     

Alzheimer’s disease – current trends in basic and clinical research. Highlights from the 16th ECNP

Advances in the molecular biological knowledge of neuronal nicotinic acetylcholine receptors (nAChRs) have led to a growing interest by the pharmaceutical industry in the development of novel compounds that selectively modulate nAChR function. The ability of (-)-nicotine, an activator of nAChRs, to enhance attentional aspects of cognition in animals and humans, to exert neuroprotective and anxiolytic-like effects, and presumably to mediate the negative correlation between smoking and Alzheimer's (and Parkinson's) Disease, has focused interest on the potential therapeutic utility of modulators of nAChR function for treatment of some of the deficits associated with these progressive, neurodegenerative conditions. Numerous compounds are known which activate nAChRs and which might serve as lead compounds toward the development of such agents. The pharmacologic diversity of neuronal nAChR subtypes suggests the possibility of developing selective compounds which would have more favourable side-effect profiles than existing agents. This broader class of agents, collectively called cholinergic channel modulators (ChCMs), is anticipated to encompass compounds which would have more favourable side-effect profiles than existing agents, which generally exhibit low selectivity. This selectivity may be achieved by preferentially activating some subtypes of nAChRs (i.e., Cholinergic Channel Activators, ChCAs) or inhibiting the function of other subtypes (Cholinergic Channel Inhibitors, ChCIs). An overview of the biology of nAChRs and the rationale for the use of ChCMs for the treatment of dementia related to neurodegenerative diseases are presented, followed by a discussion of lead compounds and compounds under consideration for clinical evaluation.     

Steroidal sapogenin contents in some domestic plants

In order to find out the values of the steroid resources for the future use. the compositions and contents of steroidal sapogenins from 13 domestic plants have been investigated. As a result,Dioscorea nipponica, D. quinqueloba andSmilax china were found to have large amount of diosgenin. And pennogenin inTrillium kamtschaticum andParis verticillata, yuccagenin inAllium fistulosum, hecogenin inAgave americana and neochlorogenin inSolanum nigum were appeared to be major steroidal sapogenins.