千金藤素在大鼠肠道内的吸收动力学

目的 考察千金藤素在大鼠肠道内的吸收动力学.方法 采用大鼠在体肠吸收方法, 用HPLC对循环液中的千金藤素进行分析.结果 千金藤素在大鼠肠道内无特定吸收部位,全肠道均有较好吸收.十二指肠、空肠、回肠、结肠的每小时吸收百分率(中浓度)分别为16.99%、17.09%、18.00%、15.4%.不同浓度千金藤素在大鼠肠道内的吸收速率常数ka经方差分析无显著性差异(P＞0.05),千金藤素吸收机理为被动扩散.结论 千金藤素在整个肠道内均有吸收,其口服制剂应以提高生物利用度为主要目标.     

盐酸千金藤素国家一级有证标准物质的研制

目的 开展盐酸千金藤素国家一级标准物质的研制,建立盐酸千金藤素纯度测量方法,并进行不确定度的评定。方法 根据我国一级标准物质研制技术规范及国际标准化组织相关导则的要求,采用差示扫描量热法与质量平衡法测定盐酸千金藤素的纯度,并对其不确定度进行评定。结果 研制的盐酸千金藤素标准物质的纯度值为99.6%,不确定度为0.4%,其中包含因子为2,置信区间为0.95。结论 研制的盐酸千金藤素被国家质量监督检验检疫总局评为国家一级标准物质,编号GBW09578。该标准物质的研制为相关药物产品的质量控制研究提供物质标准与标准方法,亦为其他天然产物标准物质的研究提供科学依据。     

千金藤素对非索非那定肠吸收的影响

目的研究千金藤素对非索非那定大鼠肠吸收的影响。方法采用大鼠肠外翻模型,以维拉帕米为阳性对照,研究千金藤素对非索非那定肠吸收的影响,并用反相高效液相色谱法测定大鼠肠黏膜内外两测的非索非那定浓度。结果非索非那定在大鼠十二指肠有吸收,千金藤素能增加非索非那定的吸收。结论千金藤素能增加非索非那定吸收,机制可能是抑制了P-糖蛋白的外排。     

不同来源千金藤中千金藤素的HPLC法测定

目的建立不同来源的千金藤植物中千金藤素的HPLC测定方法。方法采用Angela C18色谱柱(250 mm×4.6 mm,5μm);流动相:乙腈–水(52∶48,含0.5%三乙胺、0.01%磷酸);检测波长:282 nm;柱温:30℃;体积流量:1.0 m L/min;进样体积:20μL。结果千金藤素质量浓度在9~216μg/m L时与峰面积值呈良好的线性关系(r=0.999 7),平均回收率为96.0%,RSD值为2.0%(n=6)。产自湖南的千金藤(No.13)、产自广西的白药子(No.17)中千金藤素的量较高,分别为0.013 9%、0.122 1%;同一植株的不同用药部位(No.12~15)中千金藤素的量也不尽相同,湖南产千金藤中千金藤素主要分布在茎中,其质量分数为0.013 9%。结论该方法操作简便、准确、重复性好,可用于千金藤植物千金藤、地不容和白药子中千金藤素的测定。     

千金藤素对非索非那定肠吸收的影响

目的 研究千金藤素对非索非那定大鼠肠吸收的影响.方法 采用大鼠肠外翻模型,以维拉帕米为阳性对照,研究千金藤素对非索非那定肠吸收的影响,并用反相高效液相色谱法测定大鼠肠黏膜内外两测的非索非那定浓度.结果 非索非那定在大鼠十二指肠有吸收,千金藤素能增加非索非那定的吸收.结论 千金藤素能增加非索非那定吸收,机制可能是抑制了P...     

千金藤素防治白细胞减少症的作用

千金藤素(Cepharanthine)系从防已科植物千金藤(Stephania cepharantha Hayata)的根茎中分离而得一种双乌药硷型(Biscoclaurine)双苄基异喹啉类生物硷,我国赵燏黄氏于1948年亦曾获得同一生物硷。其游离硷熔点145～155℃,比旋度〔α〕_D~6+351°(氯仿)。千金藤素的生理作用是多方面的,它具有解毒,抗过敏,抗麻疯,抗结核杆菌等多种作用。在四十年代曾用千金藤素治疗结核病,并发现结核病患者,在服用千金藤素后,外周血液中有白细胞增多的现象,从而引起了千金藤素防治白细胞减少症的研究。实验研究:正常小鼠,连续七天给予千     

盐酸千金藤素逆转EAC/ADR细胞多药耐药性的作用及其机制

目的研究盐酸千金藤素对艾氏腹水癌耐药细胞株EAC/ADR多药耐药性的逆转作用及其与核因子κB(NF-κB)的关系，探讨其作用机制。方法MTT法、小鼠移植瘤模型实验观察盐酸千金藤素体外和体内逆转细胞多药耐药性的作用; Dot-ELISA法检测细胞核NF-κB水平及药物作用后的变化。结果盐酸千金藤素体外能逆转EAC/ADR细胞的耐药性，逆转倍数为13倍；体内能延长荷瘤小鼠的生存时间，生命延长率为75.37%；并能降低EAC/ADR细胞中NF-κB的持续性活性及化疗药物对其的激活。结论盐酸千金藤素具有逆转多药耐药性的作用，其机制可能与抑制NF-κB的活性有关。     

千金藤素抗病毒作用的免疫学机制研究

目的 探索千金藤素体内外的抗病毒作用,并基于抗病毒天然免疫通路探究其抗病毒作用的分子机制。方法 CCK-8 法检测千金藤素（0.062 5～64.000 0 μmol·L^-1）对 A549 细胞活力的影响;利用表达绿色荧光蛋白的水疱性口炎病毒（VSV-GFP）感染 A549 细胞模型,结合流式细胞术检测千金藤素对病毒复制的影响并探究预处理、吸附过程及吸附后加药对 VSV-GFP 病毒复制的影响;实时荧光定量 PCR（qRT-PCR）检测千金藤素对甲型流感病毒（H1N1）、脑心肌炎病毒（EMCV）和单纯疱疹病毒 I 型（HSV-1）复制的影响;构建 VSV 感染小鼠模型探究千金藤素的体内抗病毒作用;A549细胞中利用生物信息学方法探究其抗病毒机制;qRT-PCR 检测药物处理 A549 和原代胚胎成纤维细胞（MEF）后 IFNB1 及干扰素刺激基因 （ISGs） 表达变化;免疫印迹法 （Immunoblotting） 检测人源单核细胞白血病细胞（THP-1）中 TBK1 和STAT1 的磷酸化水平。结果 与模型组相比,千金藤素在 A549 细胞中显著抑制 VSV、H1N1、EMCV 和 HSV-1 复制;千金藤素不影响 VSV 的吸附过程,而预处理或吸附后给药可以显著抑制病毒复制;千金藤素提高 VSV 感染小鼠的存活率;千金藤素激活基于IFN-I通路的抗病毒天然免疫应答。结论 千金藤素通过激活基于IFN-I通路的抗病毒天然免疫发挥体内外抗病毒作用。     

HPLC-MS/MS法测定人血浆中千金藤素的浓度

目的建立人血浆中千金藤素浓度的HPLC-MS/MS测定法。方法血浆样品1.0 mL经甲基叔丁基醚萃取后,以2.5 mmol/L醋酸铵(含0.05%甲酸)-甲醇(40∶60)为流动相,采用ZORBAX Eclipse XDB-C8(150 mm×4.6 mm,5μm)柱分离,采用电喷雾电离化(ESI)方式和多反应离子监测(MRM)模式进行正离子检测。用于定量分析的离子反应分别为m/z 607.2→365.1(千金藤素)和m/z 247.2→98.0(内标甲哌卡因)。结果千金藤素血药浓度线性范围为0.10～208.40 ng/mL,定量下限为0.10 ng/mL。低、中、高3个浓度提取回收率分别为72.3%、76.8%、79.5%。结论该法操作简便、快速、灵敏,适用于千金藤素在人体内的药代动力学研究。     

千金藤素体外抗HSV-1的作用及机制初步研究

目的建立体外细胞病毒感染模型,基于细胞自噬探讨千金藤素抗HSV-1病毒感染的作用及其机制。方法用不同浓度(0.75,1.5,3 mg·L~(-1))的千金藤素作用于感染HSV-1的Vero及Hela细胞,采用空斑实验法检测细胞的病变效应;采用Western印迹法检测病毒蛋白gB、g D及自噬信号通路相关蛋白TBK1,p62,LC3的表达水平;用透射电镜检测自噬泡的形成;采用工具药氯喹体外干扰自噬的发生。结果病毒对照组空斑形成数及病毒蛋白gB、gD的表达明显高于细胞对照组,其自噬相关蛋白LC3在4～12 h表达明显升高,12～48 h表达逐渐降低。与病毒对照组相比,千金藤素能明显降低空斑的形成及g B、gD的表达,且呈剂量依赖性,其半数中毒浓度TC50为5.4 mg·L~(-1),半数抑制浓度IC50为0.835 mg·L~(-1),治疗指数TI为6.47,表明千金藤素具有体外抗HSV-1的作用;进一步实验结果显示,高、中剂量组千金藤素能持续促进自噬蛋白LC3的表达及自噬泡的形成,同时能增加TBK1及P62蛋白的磷酸化水平;氯喹阻断自噬后,千金藤素对HSV-1毒性蛋白g B、gD的抑制能力明显降低。结论千金藤素能通过激活细胞自噬发挥体外抗HSV-1病毒作用,与其TBK1的激活密切相关。     

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.