女贞子中8个化合物对胰岛素抵抗HepG2细胞葡萄糖消耗的影响

目的探讨女贞子中乙酰齐墩果酸、齐墩果酸、19α-羟基-3-乙酰乌索酸、槲皮素、GI3、女贞苷、对羟基苯乙醇-O-β-D-葡萄糖苷、芹菜素-6＇＇-O-乙酰-7-O-β-D-葡萄糖苷对胰岛素抵抗HepG2细胞葡萄糖消耗的影响。方法采用高浓度胰岛素诱导培养HepG2细胞,建立胰岛素抵抗细胞模型,培养液中加入各化合物共同孵育,采用葡萄糖试剂盒检测培养液中的葡萄糖含量。探讨其对胰岛素抵抗HepG2细胞葡萄糖消耗的影响。结果齐墩果酸、19α-羟基-3-乙酰乌索酸、GI3、对羟基苯乙醇-O-β-D-葡萄糖苷、芹菜素-6＇＇-O-乙酰-7-O-β-D-葡萄糖苷在不合胰岛素条件下可使胰岛素抵抗HepG2细胞的葡萄糖消耗量增加11．62％、17．21％、10．54％、12．08％、11.85％,加入生理浓度胰岛素后,上述化合物可使细胞葡萄糖消耗量增加12．95％、13.83％、10．84％、14．26％、17．41％。槲皮素、女贞苷在不含胰岛素条件下不增加细胞的葡萄糖消耗量,加入生理浓度胰岛素后,可使细胞萄萄糖消耗量增加15．70％、17．04％,其中槲皮素促进细胞增殖。结论齐墩果酸、芹菜素-6＇＇-O-乙酰-7-O-β-D-葡萄糖苷等增加胰岛素抵抗HepG2细胞的葡萄糖消耗量呈非胰岛素依赖性,其中芹菜素-6＇＇-O-乙酰-7-O-β-D-葡萄糖苷与生理浓度胰岛素有协同增强作用;女贞苷、槲皮素增加细胞葡萄糖消耗量呈胰岛素依赖性,槲皮素能显著促进细胞增殖。     

齐墩果酸衍生物对胰岛素抵抗的改善作用及机制

目的研究齐墩果酸衍生物Bio对HepG2细胞胰岛素抵抗的改善作用,并探讨其作用机制。方法通过高浓度胰岛素诱导HepG2细胞,建立胰岛素抵抗模型。采用葡萄糖氧化酶法,检测不同浓度化合物对HepG2细胞胰岛素抵抗模型的葡萄糖消耗的影响。RT-PCR测定化合物对PPARγmRNA转录水平的影响。Western blot检测化合物对PPARγ蛋白表达的影响。结果 HepG2细胞经1.72×10-5mol·L-1的胰岛素诱导后,葡萄糖消耗量明显降低(P<0.05),胰岛素抵抗模型建立成功。10-5、10-6、10-7mol·L-1的Bio均可增加HepG2胰岛素抵抗细胞的葡萄糖消耗(P<0.05),增加率分别为135%、62%、39%。RT-PCR检测显示Bio可提高胰岛素抵抗细胞PPARγmRNA的表达。Western blot结果显示Bio可上调胰岛素抵抗细胞中PPARγ蛋白的表达。结论 Bio对HepG2细胞的胰岛素抵抗具有改善作用,其作用机制与上调PPARγ的表达相关。     

HepG2细胞胰岛素抵抗模型的建立及在筛选桑叶有效部位中的应用

目的体外建立HepG2细胞胰岛素抵抗模型,并用于筛选桑叶防治胰岛素抵抗活性的有效部位。方法采用高浓度胰岛素诱导HepG2细胞建立肝胰岛素抵抗模型,研究桑叶有效部位对胰岛素抵抗模型细胞葡萄糖消耗的影响。结果将HepG2细胞置于10 μg·mL－1胰岛素中48 h,HepG2细胞对胰岛素的抵抗作用最明显,其特性可维持48 h。桑叶水提部位能促进HepG2胰岛素抵抗模型的葡萄糖消耗。结论高胰岛素诱导培养法可以复制出稳定可靠的肝胰岛素抵抗细胞模型。桑叶水提物、多糖、黄酮均可以促进葡萄糖的吸收。     

蜕皮甾酮对胰岛素抵抗细胞模型胰岛素敏感性和糖代谢的影响

目的应用高胰岛素体外诱导培养建立的胰岛素抵抗HepG2细胞模型探讨蜕皮甾酮对其胰岛素敏感性和糖代谢的影响。方法采用3H-D-葡萄糖的参入试验评价细胞的胰岛素敏感性,在诱导胰岛素抵抗HepG2细胞模型的过程中或模型建立后,培养液中加入蜕皮甾酮及吡格列酮共同孵育,观察蜕皮甾酮及吡格列酮对HepG2细胞葡萄糖参入率,同时观察蜕皮甾酮对胰岛素抵抗细胞模型葡萄糖消耗量的影响。结果含有蜕皮甾酮(浓度为1×10-6~10-4mol·L-1)的胰岛素抵抗HepG2细胞的葡萄糖参入率与葡萄糖消耗量明显高于不含蜕皮甾酮的胰岛素抵抗HepG2细胞(对照细胞,P<0·01)。蜕皮甾酮与吡格列酮对胰岛素抵抗模型细胞的葡萄糖参入率与葡萄糖消耗量差异无显著性(P>0·05)。结论蜕皮甾酮在胰岛素抵抗细胞模型中能提高胰岛素介导的葡萄糖摄取和利用能力,即增加胰岛素的敏感性;并能明显改善糖代谢。     

番石榴果实化学成分研究

番石榴果实95%乙醇提取物的二氯甲烷和乙酸乙酯萃取部位使用硅胶柱色谱、MCI柱色谱、中压液相色谱以及制备液相色谱进行系统的分离纯化,从中分离得到1个新的番石榴苷(1),通过MS、NMR、IR等谱学技术确定了其结构,并命名为番石榴苷A (1)。同时分离得到3个已知的混源萜类化合物(2～4)和9个已知的苷类化合物(5～13),通过MS、NMR技术确定了其结构,鉴定为guajadial (2)、4,5-diepipsidial A (3)、psidial A (4)、白杨素8-C-β-D-葡萄糖苷(5)、2,6-二羟基-3,5-二甲基苯甲酮-4-O-β-D-吡喃葡萄糖苷(6)、槲皮素-3-O-β-D-吡喃葡萄糖苷(7)、槲皮素-3-O-木糖苷(8)、番石榴苷(9)、广寄生苷(10)、guavinoside E (11)、guavinoside B (12)、guajaphenone A (13)。通过CCK-8比色法测定了化合物2～4对人乳腺癌细胞(MDA-MB-231)和人神经胶质瘤细胞(U87)的抑制活性,发现化合物3对U87细胞具有抑制活性, IC₅₀值为8.37...     

吡格列酮对胰岛素抵抗HepG2细胞模型的药理学评价

目的应用高胰岛素诱导培养HepG2细胞,建立胰岛素抵抗的细胞模型。并探讨吡格列酮对该模型胰岛素敏感性和糖代谢的影响。方法将HepG2细胞置于5×10-7mol.L-1胰岛素培养液中16 h,采用3H-D-葡萄糖参入试验观察高胰岛素对HepG2细胞葡萄糖摄取率的影响。模型建立后,培养液中加入吡格列酮共同孵育,观察吡格列酮对胰岛素抵抗细胞模型葡萄糖摄取率和葡萄糖消耗量的影响。结果高胰岛素诱导培养的HepG2细胞葡萄糖参入率明显低于未用高胰岛素诱导的HepG2细胞(对照细胞)。将高胰岛素诱导培养的HepG2细胞置于不含胰岛素的培养液中60 h,其细胞葡萄糖摄取率仍明显低于对照细胞。含有吡格列酮(浓度为1×10-6~1×10-4mol.L-1)的胰岛素抵抗HepG2细胞的葡萄糖参入率与葡萄糖消耗量明显高于不含吡格列酮的胰岛素抵抗HepG2细胞(P<0.01)。结论将HepG2置于5×10-7mol.L-1胰岛素环境中16 h,该细胞对胰岛素的生物学效应产生抵抗,其胰岛素抵抗状态可维持60 h。该方法较为简便、易行、重复性好、成功率高,可广泛用于胰岛素抵抗的研究。吡格列酮能增加胰岛素抵抗模型细胞的胰岛素敏感性,并能明显改善糖代谢。     

金樱叶的化学成分及抗炎活性研究

目的 对金樱子Rosa laevigata Michx.叶的化学成分及其抗炎活性进行研究,为进一步开发其药用潜能提供科学依据。方法 用大孔树脂色谱、ODS色谱及高效液相色谱法对金樱叶乙醇提取物进行分离纯化,根据理化性质和波谱数据对所得化合物进行结构鉴定,用荧光素酶活性检测法和ELISA法对部分化合物进行体外抗炎活性检测。结果 分离得到9个化合物,分别鉴定为：isopinfaenoic acid-28-O-β-D-glucopyranoside (1);2α,3β,23-三羟基乌苏-12,19-二烯-28-O-β-D-吡喃葡萄糖苷(2);2α,3β,19α-三羟基乌苏-12-烯-28-O-β-D-吡喃葡萄糖苷(3);苦莓苷F1 (4);2α,3β,23-三羟基乌苏-12,18-二烯-28-O-β-D-吡喃葡萄糖苷(5);5,7,3′,4′-四羟基-4′′-O-甲基-3-O-β-D-葡萄糖黄酮苷(6);芦丁(7);槲皮苷(8);异落叶松脂素-9-O-β-D-吡喃葡萄糖苷(9)。用脂多糖(LPS)刺激的NF-κB-293和RAW264.7W 2种炎症细胞模型筛选出具有不同程度抗炎活性的化合物...     

倍他福林对胰岛素抵抗HepG2细胞模型的作用及其初步机制

目的:探讨倍他福林(betaphrine)对胰岛素抵抗的作用及其机制.方法:将HepG2细胞置于5×10-7mol·L-1胰岛素培养液中16 h,观察高胰岛素对HepG2细胞葡萄糖消耗量的影响.模型建立后,培养液中加入倍他福林共同孵育,观察倍他福林对胰岛素抵抗细胞模型葡萄糖消耗量以及培养液中甘油的含量.并用Western blotting法测定各组细胞内葡萄糖转运蛋白-4(GLUT-4)的表达.结果:与正常对照组相比,模型组细胞葡萄糖消耗量减少,培养液中甘油的含量增加,细胞内葡萄糖转运蛋白-4的表达减少.与模型组相比,倍他福林作用组细胞葡萄糖消耗量增加,培养液中甘油的含量减少,细胞内葡萄糖转运蛋白-4的表达增加.结论:倍他福林可改善胰岛素抵抗HepG2细胞模型初步的胰岛素抵抗性.     

体外胰岛素抵抗细胞模型的建立及在药物筛选中的应用

目的在体外建立肝胰岛素抵抗细胞模型和脂肪细胞胰岛素抵抗模型,并初步应用于中药有效成分的胰岛素抵抗活性筛选中。方法采用高胰岛素诱发HepG2细胞建立肝胰岛素抵抗模型,地塞米松诱发3T3-L1脂肪细胞建立脂肪细胞胰岛素抵抗模型,研究不同药物对胰岛素抵抗模型细胞葡萄糖消耗的影响。结果将HepG2细胞置于10-6mol·L-1的胰岛素中36h,HepG2细胞对胰岛素的抵抗作用最为明显,该特性可维持48h,但未发现细胞形态学变化;地塞米松作用3T3-L1脂肪细胞后,96h空白组与模型组葡萄糖消耗量差值最大,此时为胰岛素抵抗的最高状态;脂肪细胞胰岛素抵抗模型成立后,撤掉地塞米松,胰岛素抵抗细胞模型能够在24h内稳定。某些中药提取成分(如水苏糖、小檗碱和人参皂苷等)能促进HepG2胰岛素抵抗模型和3T3-L1脂肪细胞胰岛素抵抗模型的葡萄糖消耗。结论高胰岛素诱导培养法可以复制出稳定可靠的肝胰岛素抵抗细胞模型;地塞米松诱导3T3-L1脂肪细胞也可建立稳定的脂肪细胞胰岛素抵抗模型。     

毛杭子梢中黄酮类成分的分离鉴定及活性测定

目的研究毛杭子梢体积分数为60%的乙醇提取物的化学成分,寻找新的抗前列腺增生的活性化合物。方法运用D101大孔树脂、硅胶柱色谱、LH-20葡聚糖凝胶柱色谱、ODS反相柱、制备液相等分离手段对毛杭子梢体积分数为60%的乙醇提取物进行分离,并根据光谱数据鉴定化合物的结构;采用酶联免疫法(ELISA)评价单体化合物抑制前列腺癌细胞(LNCaP细胞)分泌前列腺特异性抗原的作用。结果从该植物中分得1个新的黄酮类化合物和6个已知的黄酮类化合物,结构分别被鉴定为2,7,4′-三羟基二氢黄酮-5-O-β-D-葡萄糖苷(2,7,4-′trihydroxyflavanone-5-O--βD-glucopyranoside,1)、7,2′-二甲氧基-5,4′-二羟基二氢异黄酮(cajanol,2)、染料木素(genistein,3)、柚皮素(naringenin,4)、二氢山柰酚(dihydrokaempferol,5)、槲皮素(quercetin,6)、山柰酚(kaempferol,7)。黄酮苷元类化合物2~7显示了不同强度的抑制前列腺癌细胞(LNCaP细胞)分泌前列腺特异性抗原活性,其半数抑制率(IC50)分别为194.6、94.4、17.2、113.5、25.8、7.2μmol.L-1,黄酮苷类化合物1则不具有活性。结论化合物1为新化合物,化合物2~7均为首次从该属中分离得到;活性测试结果表明,黄酮苷元可能为毛杭子梢中抗前列腺增生的主要活性成分。     

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.