薄层扫描分析雷公藤甲素注射液质量

本文报道用单波长(218um)薄层扫描法快速分析雷公藤甲素注射液质量。雷公藤甲素在0.8～12.6μg范围内线性关系良好,回收率97.6%。本法简便、省时、准确,结果满意。     

凤尾草对雷公藤甲素的减毒作用

目的:研究凤尾草对雷公藤甲素的减毒作用以及免疫抑制和抗炎镇痛活性的影响。方法:通过比较雷公藤甲素单用及与凤尾草联用对小鼠急性毒性、肝组织形态和大鼠肝功能的影响来评价凤尾草对雷公藤甲素的减毒作用;采用噻唑兰(MTT)法测定雷公藤甲素单用及与凤尾草联用对小鼠T、B淋巴细胞增殖的影响;采用二甲苯致小鼠耳廓肿胀实验研究凤尾草对雷公藤甲素抗炎作用的影响;采用热板法和扭体法研究凤尾草对雷公藤甲素镇痛作用的影响。结果:雷公藤甲素联用凤尾草后LD50增大了约1倍,肝细胞损伤明显减轻,ALT和AST明显降低;雷公藤甲素单用及与凤尾草联用均能显著抑制小鼠T、B淋巴细胞的增殖和二甲苯致小鼠耳廓肿胀,并均有明显的镇痛作用,但两者作用效果差异无显著性。结论:联合运用凤尾草可降低雷公藤甲素毒性并基本保持其免疫抑制和抗炎镇痛活性。     

雷公藤甲素提取分离工艺研究现状

雷公藤甲素属二萜类化合物,是雷公藤中具有抗炎、抗肿瘤和免疫抑制活性的有效部位。1972年文献首次报道雷公藤甲素、雷公藤乙素和雷公藤内酯酮具有明显抑制白血病瘤株L1210,P388的效果,此后国内外形成一股雷公藤甲素药理学、毒理学研究的高潮。但雷公藤甲素在雷公藤植物中的含量不高,传统的提取工艺比较复杂,因此对雷公藤甲素进行提取、分离、富集、精制的系统研究显得很有必要。本文对近年来较新的几种制备雷公藤甲素的方法进行了介绍,包括醇提氯仿萃取法、醇提氯仿萃取法、醇提乙酸乙酯萃取法、英国专利提取法等,希望通过对这些方法的研究获得好的思路,为雷公藤甲素的工业化生产提供简单、重复性好、可靠性高的最佳提取工艺。     

雷公藤甲素脂质体制备及体内抗肿瘤实验研究

目的注入法制备雷公藤甲素脂质体,观察其形态特征和包封率,并对其体内抗H22疗效进行初步研究。方法用注入法制备雷公藤甲素脂质体,通过普通光学显微镜和动态光散色粒度分析仪测定其形态、粒径,用HPLC测定其包封率;并建立H22荷瘤模型观察其抗肿瘤活性。结果该法所得脂质体形态规则、粒度均匀,平均直径约为45.6 nm,但包封率不是很高约为46.7%;体内抗肿瘤实验结果表明,雷公藤甲素脂质体具有较强的抗H22活性,且与浓度呈正相关,而且相对“游离”雷公藤甲素毒性较小。结论雷公藤甲素脂质体具有较强的抗肿瘤活性,且不良反应较小。     

雷公藤甲素脂质体制备及体内抗肿瘤实验研究

目的注入法制备雷公藤甲素脂质体,观察其形态特征和包封率,并对其体内抗H22疗效进行初步研究。方法用注入法制备雷公藤甲素脂质体,通过普通光学显微镜和动态光散色粒度分析仪测定其形态、粒径,用HPLC测定其包封率;并建立H22荷瘤模型观察其抗肿瘤活性。结果该法所得脂质体形态规则、粒度均匀,平均直径约为45.6 nm,但包封率不是很高约为46.7%;体内抗肿瘤实验结果表明,雷公藤甲素脂质体具有较强的抗H22活性,且与浓度呈正相关,而且相对"游离"雷公藤甲素毒性较小。结论雷公藤甲素脂质体具有较强的抗肿瘤活性,且不良反应较小。     

薄层扫描法及高效液相色谱法测定雷公藤甲素含量的比较

薄层扫描法及高效液相色谱法测定雷公藤甲素含量的比较罗明珠，李进，童剀鹏（湖北省药品检验所武汉４３００６４）雷公藤片是以雷公藤醋酸乙酯提取物为原料生产的一种治疗类风湿性关节炎的药物。本文对雷公藤片中雷公藤甲素含量的薄层扫描法［１］和高效液相色谱法［２］...     

雷公藤甲素及其氨基葡萄糖结合物的表观溶解度、表观油水分配系数和解离常数的测定

目的 测定雷公藤甲素及其氨基糖结合物的表观溶解度、表观油水分配系数和解离常数(pKTa).方法 采用平衡溶解度法、摇瓶法测定雷公藤甲素及其氨基糖结合物的表观溶解度和油水分配系数;采用分光光度指示剂法测定雷公藤甲素-氨基糖结合物的解离常数.结果 雷公藤甲素的表观溶解度随pH的增加而增加,其表观油水分配系数随pH的增加而降低,但变化并不显著.雷公藤甲素-氨基葡萄糖结合物的表观油水分布系数随pH的增加而增加,在纯水中的表观溶解度为1.9325±0.1373 g,pKT =5.938 ±0.191.结论 雷公藤甲素是一个难溶性的亲脂性化合物,而雷公藤甲素-氨基葡萄糖结合物是一个弱碱性的亲水性化合物.     

正交试验优选雷公藤口服液制备工艺

目的:优选雷公藤口服液的制备工艺。方法:以正交试验法,考察雷公藤口服液制备过程的加水量、药材粉碎粒度、提取次数、时间及澄清方法;以反相高效液相色谱法测定其有效成分之一雷公藤甲素含量。结果:雷公藤甲素含量在130.6～218.8μg.100mL-1范围内线性关系良好。优选出的雷公藤口服液制备工艺为加水量12倍、药材粒度1mm、提取3次(每次分别为3、2、1h)、以ZTC1+1Ⅲ天然澄清剂澄清。结论:该法可用于雷公藤口服液的制备。     

雷公藤甲素对Caspase诱导人肝细胞L-02凋亡机制的研究

目的：研究雷公藤甲素诱导正常人肝细胞株L-02细胞凋亡的机制。方法：体外培养L-02细胞。MTT法检测雷公藤甲素的细胞毒性作用;Annexin V-FITC/PI双染法检测雷公藤甲素对L-02细胞的凋亡诱导作用;测定细胞基质中半胱天冬氨酸酶（Caspase）8、Caspase9与Caspase3活性的变化及加入Caspase抑制剂Z-DEVD-FMK后对细胞凋亡的影响。结果：雷公藤甲素能显著诱导L-02细胞的凋亡,其作用呈明显的量效关系与时间依赖性;120nmol·L-1雷公藤甲素作用L-02细胞24h使Caspase3的活性显著增强;加入Z-DEVD-FMK后,能有效抑制雷公藤甲素诱导的细胞凋亡。结论：雷公藤甲素体外诱导正常人肝细胞株L-02细胞凋亡可能与上调Caspase3、9的活性有关。     

RP-HPLC法测定雷公藤甲素缓释片的释放度

目的:采用高效液相色谱法测定雷公藤甲素缓释片的体外释放度.方法:采用桨法,以水为释放介质,转速100r·min-1;HPLC选用Lichrospher C18柱,以乙腈-水(35:65)为流动相,检测波长为210nm.结果:雷公藤甲素浓度在1.242～8.446 mg·L-1范围内与峰面积线性关系良好,r=0.999 9(n=6),平均加样回收率为101.7%,RSD为2.9%.雷公藤甲素缓释片的体外释放符合威布尔方程(r=0.997 6).结论:雷公藤甲素缓释片的Td和T50是普通片的5～7倍.     

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.