高效液相-质谱联用法(HPLC-MS)测定灯盏乙素血药浓度及其临床药代动力学研究

目的:研究灯盏花素片在中国人体内的药代动力学。方法:2 0名健康志愿者单剂量口服12 0mg灯盏花素片,用高效液相 质谱联用法测定血浆中灯盏乙素总苷元。结果:本实验建立的血药浓度测定方法,血浆中杂质不干扰样品的测定,线性范围为0 .0 12 6～3.2 4mg·L-1;日内和日间精密度均小于12 .0 %。2 0名健康受试者单剂量口服灯盏花素片(12 0mg)后,主要药代动力学参数:Tmax =7.0±2 .3h、Cmax=0 .9±0 .5mg·L-1、AUC0 -tn =5 .6±1.6mg·h·L-1、AUC0 -∞=5 .8±1.6mg·h·L-1、MRT0 -tn=8.0±1.1h、MRT0 -∞=8.6±1.4h。结论:建立的LC MS法适用于灯盏乙素人体药代动力学研究。灯盏花素片口服药代动力学特点是达峰时间较长,约占受试者总人数4 5 %的药时曲线有双峰现象。     

灯盏乙素衍生物代谢性质的快速体外评价

目的应用肝微粒体模型研究以灯盏乙素及其苷元为先导的系列化合物代谢特征,筛选代谢性质优于灯盏乙素的化合物。方法采用UPLC-MS/MS法测定大鼠肝微粒体温孵体系中不同时间点各候选化合物的含量,筛选T1/2和CLint较优的候选化合物,比较候选化合物与灯盏乙素的酶促动力学特征及其转化情况。结果与灯盏乙素及其苷元相比,候选化合物W11的半衰期较长、清除率较低;W11酶促动力学参数Vmax为(10.25±0.93)μmol·min-1·g-1,Km为(4.48±0.10)μmol·L-1,CLint为(2.29±0.23)L·min-1·g-1;灯盏乙素酶促动力学参数Vmax为(45.95±9.50)μmol·min-1·g-1,Km为(10.19±1.66)μmol·L-1,CLint为(4.48±0.20)L·min-1·g-1;W11可能代谢为M1(W11脱掉甲基后分子质量为577的化合物),并释放出灯盏乙素。结论候选化合物W11可能具有优于灯盏乙素的代谢性质并能释放活性代谢产物灯盏乙素。     

高效液相色谱法测定灯盏乙素血药浓度及其脂质体大鼠药代动力学的评价

目的研究灯盏乙素脂质体及水剂在大鼠体内的血药浓度,考察大鼠灌胃给药后体内药代动力学参数。方法通过大鼠灌胃灯盏乙素水溶液和脂质体后,用高效液相色谱法测定不同时间点的血浆药物浓度,用DAS2.0软件对血药浓度数据拟合分析,比较药动学参数。结果灯盏乙素水剂和脂质体大鼠灌胃给药后,Cmax分别是(15.35±1.37)μg/mL和(22.04±1.67)μg/mL,AUC0-∞分别为(50.03±13.45)μg/(h·mL)和(80.96±15.26)μg/(h·mL),灯盏乙素包衣脂质体大鼠口服给药后药动学呈双室模型特征,与灯盏乙素水剂相比,其脂质体的灌胃AUC0-∞显著提高(P<0.01)。结论本高效液相色谱法对大鼠血浆灯盏乙素测定,稳定性、灵敏度及专属性强,灯盏乙素脂质体可显著提高灯盏乙素的生物利用度。     

灯盏乙素苷元4'-L-氨基酸衍生物的设计、合成与抗氧化活性

为了设计合成具有较强神经细胞氧化损伤保护作用及较好理化性质的灯盏乙素苷元4'-L-氨基酸衍生物,以灯盏乙素苷元为先导化合物,根据主动转运原理在改善口服药物生物利用度应用上取得的成功经验,采用拼合设计原理在先导化合物的4'-羟基上引入L-氨基酸酯、醚结构,设计、合成灯盏乙素苷元4'-L-氨基酸衍生物。采用H2O2诱导PC12细胞氧化损伤模型对设计化合物进行了体外抗氧化活性评价,同时进行了目标化合物理化性质研究。结果发现设计的化合物均具有抗氧化活性,5个化合物抗氧化活性优于VE,灯盏乙素苷元L-氨基酸醚类化合物在缓冲液中稳定性(t1/2 9～92 h)优于酯类衍生物(t1/2 0.5 h),灯盏乙素苷元L-氨基酸酯类衍生物18、19与醚类衍生物22、24～27的水溶解度分别为1 796～4 100μg·mL-1和27.7～81.1μg·mL-1,两者水溶性分别达到灯盏乙素的120～280倍和2～6倍。以上研究提示L-氨基酸前药设计策略可适用于灯盏乙素苷元的结构修饰,以获得具有较好抗氧化活性及理化性质的灯盏乙素苷元前药。     

灯盏花素在小鼠体内药物动力学研究

目的:研究灯盏花素在小鼠体内的药物动力学和绝对生物利用度。方法:采用固相萃取 高效液相色谱(SPE HPLC)法,测定小鼠静脉注射灯盏花素5 0mg·kg-1和灌胃15 0mg·kg-1后血浆灯盏乙素浓度,3p97程序处理数据。结果:小鼠静注灯盏花素后灯盏乙素的血浓 时间变化符合三房室模型,AUC、C0 和T1 2 β分别为12 .97±3.5 5mg·L-1·h、132 .2 3±39.90mg·L-1和4 .0 4±1.2 9h。灌胃后药物吸收很快,但血浓低。采用非房室模型法计算AUC为1.97±0 .5 3mg·L-1·h ,T1 2Ke 为3.4 1±1.2 3h。绝对生物利用度为5 .0 5 %。结论:灯盏花素经静注在小鼠体内的药代动力学符合三室模型。灌胃给药吸收快,但吸收差,绝对生物利用度低,且药时曲线变化不规则。     

灯盏花素分散片在健康人体内的相对生物利用度研究

目的研究灯盏花素分散片与灯盏花素片在健康男性志愿者体内的相对生物利用度。方法采用随机双周期自身交叉对照试验设计,18名健康男性受试者分别经口给予受试制剂灯盏花素分散片和参比制剂灯盏花素片80 mg,采用LC-MS-MS法测定给药后不同时间异灯盏乙素的血药质量浓度。利用DAS软件计算药动学参数和进行统计分析,通过方差分析和双单侧t检验及90%置信区间法进行生物利用度评价。结果受试制剂与参比制剂中异灯盏乙素的ρmax为(75.81±23.24)、(62.17±17.82)μg.L-1,tmax为(6.50±1.34)、(7.78±1.52)h,AUC0→t为(454.1±194.7)、(403.9±133.3)μg.h.L-1,AUC0→∞为(460.1±199.8)、(410.3±137.1)μg.h.L-1。结论受试制剂ρmax比参比制剂大,疗效更高;受试制剂tmax比参比制剂小,起效更快;受试制剂对参比制剂的相对生物利用度(F,以AUC0-∞作为评价依据)为(116.5±43.5)%,灯盏花素分散片生物利用度较普通片高。     

野黄芩苷药动学研究进展

灯盏花素是从灯盏细辛中提取出来的黄酮类成分,主要由灯盏乙素和灯盏甲素组成,其公认的有效化学成分是灯盏乙素,又名野黄芩苷(Scutellarin),结构式为5,6,4′—三羟基黄酮-7-葡萄糖醛酸苷。目前,对灯盏花素的药理学活性研究主要是围绕其有效成分野黄芩苷进行。研究结果表明,野黄     

灯盏花素在犬体内的药动学和绝对生物利用度研究

采用 RP- HPL C法在 335 nm处测定血浆中灯盏乙素的浓度。双周期自身交叉设计 ,beagle犬随机静注 90 mg或口服 1.8g灯盏乙素 ,6 d后交叉试验。血浆中灯盏乙素的定量限为 0 .0 2 5 μg/ ml;方法回收率大于 93.2 % ,日内、日间 RSD小于 8.31% ;灯盏乙素血浆样品常温下不稳定 ;静注给药药 -时曲线符合三室模型。经剂量校正 ,口服给药的绝对生物利用度为 (0 .4 0± 0 .19) %。灯盏花素静注给药体内消除迅速 ,口服给药几乎不吸收     

灯盏花素在正常和模型大鼠中的药代动力学及代谢物研究

目的研究灯盏花素在正常和角叉菜胶致血栓形成大鼠中的药代动力学，并对其血浆样品中主要代谢物进行初步鉴定。方法RP-HPLC法测定静注36 mg·kg^-1灯盏花素后正常和模型大鼠不同时间血浆样品中灯盏乙素浓度，3P97软件拟合房室模型，计算药动学参数；HPLC-PDA(光电二极管阵列)、LC-MS/MS技术分析鉴定血浆样品中的主要色谱峰。结果血浆中灯盏乙素在0.625～80.0 μg·mL^-1(r=0.999 5)线性关系良好，最低定量浓度：0.312 μg·mL^-1；正常和角叉菜胶致血栓形成状态下，灯盏乙素药时曲线均呈现二室开放模型。血浆样品中4个主要色谱峰的可能结构分别为4′，5-二羟基黄酮-7-氧-β-D-葡糖醛酸甲酯苷(M1)、灯盏乙素(M2)、7-甲氧基-4′，5-二羟基-黄酮(M3)和7-甲氧基-4′,5,6-三羟基-黄酮(M4)。结论正常和模型大鼠体内灯盏乙素的药动学参数有显著性差异；灯盏乙素在大鼠血浆样品中的代谢主要是脱羟基和甲基化途径。     

灯盏花素β-环糊精包合物在大鼠体内的药物代谢动力学研究

目的 研究灯盏花素β-环糊精包合物在大鼠体内的吸收情况.方法 采用反相高效液相色谱法测定大鼠血浆中灯盏乙素质量浓度,比较大鼠口服灯盏花素β-环糊精包合物和灯盏花素市售片的平均药时曲线及药物代谢动力学参数.结果 灯盏花素β-环糊精包合物最高血药浓度为0.338μg/mL,普通片最高血药浓度为0.184 μg/mL,包含物的口服吸收率优于普通市售片.结论 该方法线性范围良好,准确、方便、可靠,取样量少,灵敏度可达0.025 μg/mL,尤其适用于动物体内药物代谢动力学研究.     

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.     

Pharmacological treatment of COVID-19: an opinion paper

The precocity and efficacy of the vaccines developed so far against COVID-19 has been the most significant and saving advance against the pandemic. The development of vaccines has not prevented, during the whole period of the pandemic, the constant search for therapeutic medicines, both among existing drugs with different indications and in the development of new drugs. The Scientific Committee of the COVID-19 of the Illustrious College of Physicians of Madrid wanted to offer an early, simplified and critical approach to these new drugs, to new developments in immunotherapy and to what has been learned from the immune response modulators already known and which have proven effective against the virus, in order to help understand the current situation.     

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.