红景天苷抗痴呆药理作用研究进展

红景天苷具有对抗缺氧、缺血、糖尿病脑病、β 淀粉样肽和老龄引起的动物痴呆作用,综述其抗痴呆作用及作用机制研究进展。其抗痴呆作用机制主要包括3 个方面;(1)通过抑制缺氧诱生因子-1α 和淀粉样前体蛋白β 位裂解酶1 的表达以及β-分泌酶活性,阻滞β 淀粉样肽生成;(2)通过抗氧化作用而阻滞β 淀粉样肽、晚期糖基化终产物、缺血、缺氧、H2O2等引起的氧化应激反应和细胞内钙超载发生,保护神经干细胞和神经细胞免遭伤害;(3)通过阻滞Notch 信号转导通路,促进BMP 信号转导通路和磷脂酰肌醇3-激酶依赖的Ca²⁺信号转导,诱导间充质干细胞和神经干细胞定向分化成神经元,从而促进神经发生。     

丁苯酞对神经干细胞向神经细胞分化的促进作用

目的 研究丁苯酞通过PI3K-AKT信号通路促进神经干细胞向神经细胞分化的作用。方法 分离培养SD大鼠胚胎脑皮质层的神经干细胞,采用分化专用完全培养基培养后,通过光镜下观察和Nestin蛋白免疫荧光法进行鉴定。设置对照组和实验组,其中实验组添加丁苯酞辅助分化,分为丁苯酞低剂量组（1 μmol·L^-1）、中剂量组（5 μmol·L^-1）和高剂量组（10 μmol·L^-1）,作用24 h后,CCK-8法检测神经干细胞的细胞活力,碱性磷酸酶染色法检测神经干细胞的分化能力,免疫荧光法检测神经细胞分化程度,RT-qPCR法检测转录因子SOX2、PAX6和NeuN的mRNA表达水平,Western-blot及RT-qPCR检测PI3K-AKT信号通路的表达。结果 丁苯酞干预后神经干细胞活力提高,分化能力提高,碱性磷酸酶试验呈强阳性,转录因子SOX2、PAX6和NeuN的mRNA表达水平增高,PI3K-AKT信号通路蛋白和mRNA表达水平均增高,且呈现剂量依赖性。结论 丁苯酞可以促进神经干细胞向神经细胞分化,其作用机制可能与PI3K-AKT的激活有关。     

杜拉鲁肽对阿尔茨海默病样神经退行性变的保护作用

目的 研究杜拉鲁肽（dulaglutide）对阿尔茨海默病（AD）样神经退行性变的保护作用及其机制。方法 应 用糖尿病治疗新药杜拉鲁肽观察和探讨其对人神经瘤母细胞SH-SY5Y细胞AD样变的影响及机制。采用MTT方法 检测各药物杜拉鲁肽、PI3K抑制剂渥曼青霉素（wortmannin）、胰高血糖素样肽-1（GLP-1）受体拮抗剂Ex9-39对细胞 活性的影响;采用蛋白免疫印迹方法检测各组细胞tau蛋白和神经丝（neurofilaments,NFs）蛋白以及PI3K/GSK-3β信 号通路中关键酶磷酸化水平。结果 杜拉鲁肽改善wortmannin诱导的细胞活性损伤,减少神经细胞内tau和NFs蛋 白的磷酸化水平,提高p-PI3K（p85）和p-GSK3β（S9）的表达水平。而Ex9-39则拮抗杜拉鲁肽的神经保护作用。结 论 杜拉鲁肽可通过PI3K /GSK-3β胰岛素信号通路来保护SH-SY5Y神经细胞的AD样退行性变。     

氧化苦参碱心脏保护作用的研究进展

氧化苦参碱对心脏具有正性肌力、负性频率和负性自律性的作用,因此具有广谱抗心律失常作用。氧化苦参碱对冠脉狭窄缺血、缺血再灌注以及异丙肾上腺素、阿霉素、感染和免疫引起的心肌损伤都有保护作用,并能阻滞心肌肥大和纤维化发生发展。氧化苦参碱心脏保护作用的基本机制是其抗氧化、抗炎和免疫抑制以及抑制盐皮质激素（醛固酮）受体的表达,产生心肌保护作用。即通过激活Nrf2/HO-1信号通路和抑制转化生长因子（TGF）-β1及I型TGF-β1受体的表达,从而抑制下游的JAK/STAT、MAPK/Smad2/3和Notch的信号通路的机制,减少心肌细胞凋亡,减轻心肌损伤和抑制胶原合成,产生抑制心肌肥大和纤维化的作用。     

厚朴及其有效成分防治阿尔茨海默病和帕金森病的药理作用及机制研究进展

动物实验证实厚朴及其有效成分（厚朴酚、和厚朴酚等）具有防治阿尔茨海默病和帕金森病的药理作用。它们最主要的作用机制是抗氧化和抗炎作用：通过直接清除自由基和提高机体的核因子红系2-相关因子-2（Nrf2）抗氧化信号通路和抗氧化酶活性间接清除自由基的方式抑制活性氧生成；通过激活去乙酰化酶（SIRT），阻滞磷脂酰肌醇-3激酶（PI3K）/蛋白激酶-B（Akt），细胞外信号调节蛋白激酶（ERK）/丝裂原活化蛋白激酶（MAPK）和Toll样受体-2（TLR2）/MAPK/核因子-κB（NF-κB）信号通路和促进线粒体自噬，抑制炎性细胞因子表达，保护脑神经（包括海马、黑质和纹状体等），表现出防治阿尔茨海默病和帕金森病的作用。     

苦参碱的心脏保护作用及其机制的研究进展

苦参碱对心脏具有正性肌力、负性频率和负性自律性的作用,因此具有广谱的抗心律失常作用。苦参碱对冠脉结扎缺血、缺血再灌注、异丙肾上腺素、高血脂、糖尿病和阿霉素引起的心肌损伤都有保护作用。苦参碱还能阻滞心肌肥大和纤维化的发生、发展。苦参碱保护心脏作用的基本机制是抗氧化、抗炎、降血糖、调血脂作用,由此抑制ROS/TLR4信号通路、PI3K/Akt信号通路和TGF-β诱导的PERK信号通路,激活Akt和STAT3信号通路和AMPKα/UCP2信号通路,上调JAK2/STAT3通路上的HSP70以及JNK、ASK1、e NOS和一氧化氮的表达,提高线粒体ATP酶活性,保护线粒体而减少心肌细胞凋亡、减轻心肌损伤和抑制胶原合成,从而抑制心肌肥大和纤维化。从抗各种心肌缺血性损伤、抗阿霉素诱导的心肌损伤、抗高糖性心肌损伤、抗心肌肥大和纤维化4个方面综述苦参碱的心脏保护作用及其机制。     

厚朴酚及和厚朴酚抗抑郁药理作用及机制的研究进展

动物实验证实厚朴酚及和厚朴酚具有防治急慢性抑郁作用,其主要机制是抗氧化和抗炎:通过直接清除自由基以及提高机体的核因子E2相关因子-2抗氧化信号通路和抗氧化酶活性间接清除自由基而抑制活性氧生成;通过阻滞磷脂酰肌醇-3蛋白激酶/蛋白激酶B,细胞外信号调节激酶/丝裂原活化蛋白激酶和把关受体/丝裂原活化蛋白激酶信号通路抑制炎性细胞因子表达和小胶质细胞、星形细胞的激活,保护脑神经。也可增强脑内5-羟色胺能神经功能,提高脑源性神经营养因子表达,促进海马神经再生,产生抗抑郁作用;还可下调抑郁时的下丘脑-垂体-肾上腺轴功能的亢进,改善抑郁样行为。     

脑缺血耐受机制及雌激素通过此机制介导的神经保护作用

目的对脑缺血耐受的分子机制新近研究及雌激素通过此机制发挥的神经保护作用进行文献综述。方法根据近年来发表的英文文献,归纳并论述脑缺血耐受发生的可能的分子机制,分析药物介导神经保护作用的潜在靶点。结果脑缺血耐受的形成涉及多种不同的信号通路,主要从HSP70、PI3K/Akt信号通路、CREB、炎症因子等方面进行了论述。在缺血预处理模型中,雌激素能够上调HSP70、CREB表达,激活PI3K/Akt信号保护通路,抑制相关炎症因子,加强脑缺血耐受,发挥神经保护作用。结论对脑缺血耐受机制及药物发挥的神经保护作用的研究,为抗脑缺血药物的开发提供新的视角和理论依据。     

苯氧茚酮类乙酰胆碱酯酶抑制剂YKY-7对β淀粉样蛋白诱导的神经细胞损伤的保护作用

目的观察苯氧茚酮类乙酰胆碱酯酶抑制剂YKY-7对β淀粉样蛋白25-35(β-amyloid peptide25-35,Aβ25-35)诱导的神经细胞损伤的保护作用及机制。方法以Aβ25-35诱导原代培养的大鼠皮层神经元和人神经母细胞瘤SK-N-SH细胞损伤模型,光学显微镜下观察细胞形态学以及MTT法检测YKY-7及多奈哌齐(donepezil)对损伤模型中神经细胞活率的影响,荧光显微镜、透射电镜、流式细胞仪检测YKY-7对Aβ25-35诱导的神经细胞病理性凋亡过程的影响,MTT法检测PI3K-Akt阻断剂LY294002对YKY-7神经细胞损伤保护作用的影响。结果 12.5μmol·L-1YKY-7可提高经Aβ25-35处理的大鼠皮层神经元和SK-N-SH细胞活率,且该保护作用强于相同浓度donepezil;12.5μmol·L-1YKY-7可减弱Aβ25-35诱导的SK-N-SH细胞凋亡损伤;LY294002可阻断YKY-7对Aβ25-35诱导的SK-N-SH细胞损伤的保护作用。结论苯氧茚酮类乙酰胆碱酯酶抑制剂YKY-7对Aβ25-35诱导的神经细胞凋亡具有一定的保护作用,该作用可能是通过PI3K-Akt信号通路调控。     

PI3K/Akt信号通路在肾小球足细胞损伤凋亡中的作用机制

[摘要]目的：初步探讨磷脂酰肌醇3-激酶/蛋白激酶B（PI3K/Akt）信号通路在肾小球足细胞损伤凋亡中的作用机制。方法：采用荧光定量PCR技术、免疫印迹（Western blot）技术及激光共聚焦技术检测肾小球足细胞凋亡相关蛋白的表达和分布情况,流氏细胞仪检测肾小球足细胞凋亡率。结果：嘌呤霉素核苷酸（PAN）损伤足细胞后CD2相关蛋白（CD2AP）分子的表达明显降低,与p85的共定位异常;给予地塞米松（DEX）干预后,CD2AP的表达及分布趋于正常,足细胞磷酸化Akt（p-Akt）及磷酸化糖原合成酶激酶-3β（p-GSK3β）的表达与PAN浓度依赖性的下降,给予DEX干预后,p-Akt及p-GSK3β的表达逐渐恢复;PAN损伤足细胞后,其凋亡率明显升高,DEX干预后凋亡率较PAN组降低（P<0.05）。结论：PI3K/Akt信号通路在肾小球足细胞凋亡中发挥了重要作用,而糖皮质激素可能通过稳定PI3K/Akt信号通路发挥保护肾小球足细胞作用。     

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.