双氢青蒿素抗炎作用机制的研究进展

目的:探讨双氢青蒿素(DHA)的抗炎作用机制,为其进一步研究和应用提供参考。方法:分析DHA对炎症介质、信号通路、免疫细胞的作用,对其抗炎机制的研究进展进行总结。结果与结论:DHA的抗炎作用机制主要是通过调节炎症介质、免疫细胞以及多种信号通路来实现的。DHA可通过调节促炎细胞因子(如肿瘤坏死因子α、白细胞介素类)发挥抗炎作用;通过调节蛋白激酶(ERK)信号通路、核因子κB(NF-κB)信号通路、腺苷酸活化蛋白激酶(AMPK)/沉默信息调节因子1(STRT1)信号通路、活性氧(ROS)-c-Jun N末端激酶1/2(JNK1/2)信号通路、哺乳动物雷帕霉素靶蛋白(mTOR)/核糖体S6激酶1(S6K1)信号通路、磷脂酰肌醇-3-激酶(PI3K)/蛋白激酶B(Akt)信号通路等,起到抗炎作用;通过调节免疫细胞(如巨噬细胞、淋巴细胞),防止炎症反应的发生。但DHA仍存在一些尚不明确的抗炎机制且缺乏相应的临床试验,应进行深入研究,推进其在临床上的应用。     

PI3K/Akt信号通路在肿瘤发展和治疗中的作用

目前发现有多条信号网络通路参与调控肿瘤生成、增殖、凋亡等分子机制,PI3K/Akt是其中比较重要的一条信号传导途径,该通路与肿瘤的发生发展密切相关。该文就PI3K/Akt信号通路的结构组成与调控肿瘤机制进行阐述,并介绍了其在临床中的应用与前景。     

双氢青蒿素通过PI3K/Akt通路逆转肺癌顺铂耐药A549/DDP细胞的分子机制

摘要：目的:研究双氢青蒿素通过磷脂酰肌醇-3-激酶/丝苏氨酸蛋白激酶（PI3K/Akt）通路逆转肺癌顺铂耐药A549/DDP细胞的分子机制。方法:体外培养人肺癌耐顺铂株（A549/DDP）,给予不同浓度双氢青蒿素(20,40,80,160,200,250,300μmol·L-1)处理48 h后,通过MTT法检测双氢青蒿素对A549/DDP细胞增殖影响,选取双氢青蒿素最佳实验浓度及在不同浓度DDP(0,20,40,60,80,100μmol·L-1)作用下观察并计算顺铂对A549/DDP细胞IC50和双氢青蒿素对A549/DDP逆转倍数;通过流式细胞术检测各组细胞凋亡率,Western blot法检测各组细胞中凋亡相关因子B淋巴细胞瘤-2基因（Bcl-2）和半胱氨酸蛋白酶3（Caspase3）及PI3K/Akt通路相关蛋白PI3K、AKT、磷酸化蛋白激酶B（p-Akt）的表达。结果:随双氢青蒿素浓度升高,细胞增殖抑制率依次升高（P<0.05）,且具有浓度依赖性,IC10（32.07±1.04）μmol·L-1是双氢青蒿素为最佳逆转耐药浓度;随DDP浓度的升高,双氢青蒿素A549/DDP细胞增殖抑制率随之升高（P<0.05）,DDP+双氢青蒿素组顺铂对A549/DDP的IC50为（26.42±1.23）μmol·L-1,顺铂组为（58.16±1.32）μmol·L-1,双氢青蒿素的逆转耐药倍数为2.21;与对照组相比,DDP组、双氢青蒿素组、DDP+双氢青蒿素组细胞凋亡率、caspase-3表达显著升高（P<0.05）,Bcl-2、PI3K、p-Akt/Akt表达显著降低（P<0.05）;与DDP组、双氢青蒿素组相比,DDP+双氢青蒿素组细胞凋亡率、caspase-3表达显著升高（P<0.05）,Bcl-2、PI3K、p-Akt/Akt表达显著降低（P<0.05）。结论:双氢青蒿素通过抑制PI3K/Akt通路促进A549/DDP细胞凋亡,在一定程度上可逆转肺癌A549/DDP细胞株对顺铂的耐药性。     

中药单体对卵巢癌信号通路的调控作用

总结近年来有关中药单体对卵巢癌信号通路调控作用的研究进展。中药单体可以调控卵巢癌的多条信号通路,按照作用机制分类,主要包括对PI3K/AKT信号通路的调控(如淫羊藿苷、千金藤素、柚皮素等)、对JAK/STAT信号通路的调控(如白藜芦醇、槲皮素、莪术醇等)、对MAPK信号通路的调控(如原薯蓣皂苷、龙胆苦苷、二氢杨梅素等)、对Wnt/β-catenin信号通路的调控(如羟基红花黄色素A、丹皮酚、芹菜素等)、对Notch信号通路的调控(如双氢青蒿素、山萘酚、姜黄素等)、对NF-κB信号通路的调控(如人参皂苷Rg1、二氢丹参酮Ⅰ、白蔹素等)、对TLR4/MyD88信号通路的调控(如莱菔子素、白术内酯Ⅰ、姜黄素等)。中药单体可通过调控上述信号通路抑制卵巢癌细胞增殖,诱导细胞凋亡,阻滞细胞周期进程,抑制细胞迁移和侵袭等,从而发挥抗肿瘤作用。     

Fstl1-TGF-β1-Smad2/3信号通路与肺纤维化的靶向治疗

肺纤维化是以上皮细胞受损、成纤维细胞增殖活化、细胞外基质聚积、肺泡不可逆破坏为特点的肺间质性疾病,其发病机制尚不十分确切,常规药物治疗疗效不显著。研究发现,转化生长因子β(TGF-β1)在肺纤维化发生发展中起到关键作用,而TGF-β1-Smad2/3通路是TGF-β1信号传导的经典通路,Fstl1-TGF-β1-Smad2/3信号通路与肺纤维化密切相关,通过某一靶点阻断其信号通路可以抑制肺纤维化的进程;而Fstl1可以通过调节TGF-β1/Smad2/3信号通路来调控成纤维细胞活化和细胞外基质合成,具有促纤维化作用。通过某一靶点阻断其信号通路可以抑制肺纤维化的进程。Fstl1-TGF-β1-Smad2/3信号的传导与调控是一个涉及多靶点的复杂过程。笔者对肺纤维化中TGF-β信号传导通路及其靶向治疗做一综述,为抗肺纤维化治疗提供参考。     

Nrf2/Keap1/ARE信号通路与难治性呼吸系统疾病研究进展

Nrf2/Keap1/ARE是重要的抗氧化信号通路,对维持体内抗氧化物与过氧化物平衡有重要作用。氧化应激发生时,Nrf2/Keap1/ARE信号通路被激活,调控下游抗氧化蛋白表达,减轻氧化应激对机体的损伤并减弱氧化应激的程度。近年来的研究发现,Nrf2/Keap1/ARE信号通路与肺纤维化、肺癌、慢性阻塞性肺病等难治性呼吸系统疾病的发生发展有密切联系,该通路可能作为治疗这类疾病的潜在靶点。该文就Nrf2/Keap1/ARE信号通路在难治性呼吸系统疾病中的作用进行综述,进一步了解其在难治性呼吸系统疾病中的作用机制,为这类疾病发病机制和治疗方案的研究提供可靠的参考。     

PI3K/AKT信号通路在肿瘤调控中的免疫作用及分子机制

磷脂酰肌醇3-激酶(phosphatidylinositol-3-kinases,PI3K)/蛋白质丝氨酸苏氨酸激酶(protein-serine-threonine kinase,AKT)信号通路是具有酶活性的细胞内信号转导通路。研究发现人类的多种肿瘤如胃癌、大肠癌、乳腺癌、肝癌、肾癌等均与PI3K/AKT信号通路密切相关,且PI3K/AKT信号通路中多种上下游分子的改变均可影响肿瘤的发生和发展。PI3K/AKT信号通路可从凋亡、炎性反应、免疫等多方面影响肿瘤的发生发展。笔者现对PI3K/AKT信号通路和其相关上下游免疫分子之间相互作用对肿瘤影响做一综述。     

PI3K/Akt信号通路与肝纤维化

PI3K/Akt信号通路为细胞内重要信号传导通路之一,在促进细胞增殖、抑制凋亡的过程中发挥重要作用。PI3K/Akt信号通路与肝纤维化的发生、发展密切相关。通过干预PI3K/Akt信号通路,研究肝纤维化的发病机制和药物治疗是有意义的途径。该文就PI3K/Akt信号通路的构成、转导途径及其在肝纤维化中的作用作一综述。     

藏药红景天的药理作用及其机制研究进展

目的:了解藏药红景天的药理作用及其机制的研究进展,为该药材的进一步开发和临床应用提供理论参考。方法:以"红景天""药理作用""机制"等的中英文为关键词,在中国知网、万方、Web of Science、PubMed、ScienceDirect等数据库中进行检索,检索时限设置为2007-2017年。结果共获得文献15 027篇,并筛选出835篇文献作为基础数据,就红景天对心脑血管系统、神经系统、呼吸系统等的药理作用及其机制进行综述。结果与结论:我国药典以大花红景天为红景天的基源植物。红景天及其活性单体(以红景天苷为主)具有改善心肌损伤、保护心肌细胞的作用;能治疗阿尔茨海默病、帕金森病、重度抑郁症、创伤性颅脑损伤及缺血性脑损伤等神经系统疾病;能治疗肺动脉高压、肺组织纤维化、慢性阻塞性肺疾病等呼吸系统疾病;还具有护肝、抗肿瘤、抗病毒等药理活性。其机制多与抗氧化应激、抗炎及抑制凋亡等有关,涉及对丝裂原活化蛋白激酶信号通路、磷酯酰肌醇3激酶/蛋白激酶B/糖原合成酶激酶3β信号通路、Wnt/β-catenin信号通路、活性氧自由基/一氧化氮相关的线粒体信号通路、应激活化蛋白激酶/Jun氮端蛋白激酶信号通路、核因子E2相关因子2抗氧化信号通路、细胞核因子κB、转化生长因子β1/Smad-2/-3通路、腺苷受体A2a相关的线粒体通路、Janus激酶2/信号传导及转录激活因子3信号通路等的调控。但目前对红景天及其活性成分的体内生物学过程及在各组织、靶器官中的分布等尚缺乏研究数据,其作用机制仍需进一步深入研究;同时,应集中关注其优势病种,尤其是缺氧诱发的心脑血管及呼吸系统疾病(高原红细胞增多症、高原脑水肿、高原肺水肿等)进行机制研究,找出红景天或其主要单体成分的关键调控靶标等,为其治疗高原缺氧引起的心脑血管疾病提供确切的分子机制。     

β-双氢青蒿素在不同溶剂中的核磁共振研究

目的研究β-双氢青蒿素在不同测试溶剂中的转化并对其核磁共振信号进行全归属。方法利用HSQC,HMBC等二维核磁共振技术,对β-双氢青蒿素进行测试,利用1H-NMR研究双氢青蒿素β-体与α-体的相互转化。结果首次利用二维核磁共振技术对β-双氢青蒿素的核磁共振信号进行了全归属,β-双氢青蒿素在DMSO中只以β-体一种构型存在。结论β-双氢青蒿素在DMSO中不存在异构体的转化,其核磁信号可以以DMSO-d6为溶剂而得到准确归属。     

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.     

Synthesis,Cytotoxicity and Antileishmanial Activity of Some N-(2-(indol-3-yl)ethyl)-7-chloroquinolin-4-amines

We report herein the condensation of 4,7-dichloroquinoline (1) with tryptamine (2) and D-tryptophan methyl ester (3) . Hydrolysis of the methyl ester adduct (5) yielded the free acid (6) . The compounds were evaluated in vitro for activity against four different species of Leishmania promastigote forms and for cytotoxic activity against Kb and Vero cells. Compound (5) showed good activity against the Leishmania species tested, while all three compounds displayed moderate activity in both Kb and Vero cells.     

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.     

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.