灯盏花乙素苷元对大鼠血栓形成和血液流变学的影响

目的:研究灯盏花乙素苷元对大鼠血栓形成、血小板聚集和血液流变学的影响。方法:大鼠连续灌胃灯盏花乙素苷元(100,50,25 mg.kg-1)7 d。电刺激大鼠颈动脉复制动脉血栓模型,记录血栓形成时间;结扎大鼠下腔静脉复制静脉血栓模型,记录血栓湿重和干重;采用0.5×10-4mol.L-1的二磷酸腺苷(adenosine d iphosphate,ADP)诱导血小板聚集,测定最大聚集率;大鼠皮下注射肾上腺素复制血瘀模型,测定红细胞沉降率、全血表观黏度和血浆黏度。同时设灯盏花乙素(100 mg.kg-1)阳性对照。结果:灯盏花乙素苷元能够明显延缓大鼠动脉血栓形成时间,抑制静脉血栓形成,抑制ADP诱导血小板聚集,降低血瘀模型大鼠的红细胞沉降率和血黏度。结论:灯盏花乙素苷元具有抗血栓形成、抗血小板聚集、改善血液流变学指标的作用,疗效优于灯盏花乙素。     

UPLC-MS/MS联用法分析灯盏花乙素在胃肠道的代谢物

目的：研究灯盏花乙素在胃肠道的代谢物。方法：分别用盐酸、β-葡糖醛酸苷酶水解灯盏花乙素，并用健康志愿者的肠内菌对灯盏花乙素进行转化，用超高效液相．串联质谱联用法分析代谢物。结果：灯盏花乙素可被盐酸、β-葡糖醛酸苷酶水解为苷元，可被肠内菌群转化为苷元。健康受试者口服灯盏花乙素后，血浆中能检测到灯盏花乙素苷元。结论：健康受试者口服灯盏花乙素后，在吸收进入血液之前，胃肠道内灯盏花乙素与其苷元并存，而苷元更易于吸收，以总苷元为检测对象研究灯盏花乙素药代动力学是合理的。     

HPLC法测定灯盏花素片中灯盏花乙素的含量

目的:建立灯盏花素片中灯盏花乙素的含量测定方法;方法:采用高效液相色谱法,使用C18柱,流动相为甲醇-水-冰醋酸(30:70:1),检测波长335nm;结果:该制剂中灯盏花乙素在0.2～4.0μg范围内线性良好,平均回收率为100.21%,RSD为1.48%;结论:该方法简便、快速、准确,可用于灯盏花素片的含量测定和质量控制.     

灯盏乙素在兔体内药代动力学

目的建立测定灯盏乙素血浆浓度的固相萃取-高效液相色谱（SPE-HPLC）法,并研究家兔iv灯盏花素的药代动力学。方法采用甲醇-水-磷酸为流动相，Nucleosil C₁₈色谱柱为固定相,紫外检测波长335 nm,外标法定量。给家兔分别iv灯盏花素10,20和40 mg·kg^-1,SPE-HPLC法检测血浆药物浓度。结果线性范围0.02～10.0 mg·L^-1,最低检测浓度0.02 mg·L^-1,方法回收率96.15%～99.31%,日内、日间RSD值均小于10%。家兔iv灯盏花素时,灯盏乙素血浆浓度变化符合三房室模型。灯盏乙素低、中剂量组的主要药代动力学参数无显著性差异,而高剂量组与低、中剂量组比较差异显著。结论该法准确、灵敏、简便,适用于灯盏乙素血浆浓度的测定。灯盏花素经兔iv后的药代动力学符合三房室模型，剂量为10～20 mg·kg^-1时,药物的体内变化为线性动力学过程,而40 mg·kg^-1时未表现线性动力学特征。     

注射用灯盏花素对大鼠CYP2D6体内代谢活性的影响

目的:研究灯盏花素对大鼠细胞色素P4502D6(CYP2D6)体内代谢活性的影响。方法:试验分为3组,即对照(生理盐水)和灯盏花素高、低剂量(0.54、0.18mg·100g-1)组,静脉注射给药,每天1次,连续14d。各组分别于第15天注射美托洛尔溶液,于给药前和给药后不同时间点眼内眦静脉取血0.8mL,使用高效液相色谱法测定血浆中美托洛尔的浓度。结果:静脉给予大鼠注射用灯盏花素14d后,灯盏花素高剂量组美托洛尔的AUC和t1/2显著高于对照组,CL显著低于对照组(P<0.05)。灯盏花素低剂量组虽然也有相同趋势,但无显著性差异。结论:高剂量注射用灯盏花素可显著抑制大鼠CYP2D6的体内活性。     

注射用灯盏花素在比格犬与食蟹猴的体内毒性比较

目的:比较注射用灯盏花素对比格(Beagle)犬和食蟹猴的体内毒性。方法:普通级Beagle犬32只,雌雄各半,设生理氯化钠溶液(NS)对照和注射用灯盏花素40,80,120 mg·kg~(-1)剂量组。食蟹猴4只,设NS对照和注射用灯盏花素200 mg·kg~(-1)组。2种动物均静脉滴注给药13周,停药恢复4周,观察体内毒性。结果:Beagle犬80和120 mg·kg~(-1)组出现呕吐、腹泻、流涎等不良反应。120 mg·kg~(-1)组有1只动物给药11d皮肤出现斑疹、荨麻疹;给药第11周有1只动物出现呕血、便血后死亡。食蟹猴200 mg·kg~(-1)组仅发现1只动物出现间断性流涎。Bea- gle犬和食蟹猴各剂量组体重增长,进食量正常,血液、生化等其他各项检测指标未见明显异常。结论:食蟹猴和Beagle犬对注射用灯盏花素的耐受性、敏感性和毒性反应均存在种属差异。     

HPLC法测定灯盏花素片中灯盏花乙素的含量

目的建立灯盏花素片中灯盏花乙素的含量测定方法。方法采用高效液相色谱法,使用C18柱,流动相为甲醇-水-冰醋酸(30∶70∶1),检测波长335nm。结果该制剂中灯盏花乙素在0.0624～0.312μg范围内线性良好,平均回收率为99.92%,RSD为0.24%。结论该方法简便、快速、准确,可用于灯盏花素片的含量测定和质量控制。     

酶解法与LC-MS-MS相结合研究灯盏乙素在健康人体内的药代动力学

目的建立β-葡萄糖醛酸苷酶解法与LC-MS-MS法相结合测定人体血浆中灯盏乙素的苷元,研究健康男性单剂量口服灯盏花素分散片的药代动力学。方法血浆样品经β-葡萄糖醛酸苷酶水解,甲醇蛋白沉淀,色谱柱为Agilent ZORBAX SB C18(2.1 mm×150 mm,5μm),运用乙腈-甲醇-水洗脱,多反应监测(MRM)灯盏乙素苷元([M-H]-,m/z285.0/136.8)和内标槲皮素([M-H]-,m/z 301.1/120.8)。12名健康男性单剂量口服灯盏花素分散片120 mg后,采用该方法测定血浆中灯盏乙素苷元,使用DAS 1.0软件处理数据,计算药代动力学参数。结果灯盏乙素苷元在4.01~513.38μg·L-1范围内线性良好,日内日间精密度小于7.22%,提取回收率大于84.23%。12名健康男性单剂量口服灯盏花素分散片120 mg后,以灯盏乙素苷元为检测对象的主要药动学参数为:Cmax(μg·L-1):159.97±58.14;AUC(0-19)(μg·L-1·h):1151.37±279.80;AUC(0-∞)(μg·L-1·h):1194.13±264.51;Tmax(h):6.33±1.67;T1/2(h):2.83±0.60。结论建立的酶解与LC-MS-MS相结合分析方法准确灵敏,适用于灯盏乙素人体内的药代动力学研究。     

灯盏花素缓释滴丸对家兔血液流变学的影响

目的：研究灯盏花素缓释滴丸对家兔血液流变学的影响。方法：家兔16只，随机分为3组，B组灌胃给予灯盏花素缓释滴丸40 mg·kg 1·d 1，A组给予同等剂量的灯盏花素片的混悬液，对照组给予0.9%氯化钠注射液15 mL·d 1，均连续给药7 d，测定给药后的血液流变学指标。结果：B组对家兔的全血粘度、血浆粘度、血细胞比容及红细胞变形指数的作用均强于A组。结论：A、B组比较，B组具有更强的生物学效应。     

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。     

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.