UPLC-MS/MS快速鉴定乔松素在人肝微粒体中的代谢产物

目的 以超高效液相色谱质谱联用法(UPLC-MS/MS)快速鉴定乔松素在人肝微粒体中的代谢产物。 方法 以人肝微粒体体外孵育体系对乔松素进行代谢研究,以UPLC-MS/MS鉴定乔松素的体外代谢产物。 结果 建立了乔松素的体外代谢孵育体系,UPLC-MS/MS在6 min内检测到乔松素的4个代谢产物,分别鉴定为柚皮素、5,6,7-三羟基二氢黄酮、5,7,8 -三羟基二氢黄酮和乔松素-7-葡萄糖醛酸苷,这4个代谢产物均为首次发现的乔松素人肝微粒体体外代谢产物。 结论 乔松素在人肝微粒体中的主要代谢途径为羟基化和葡萄糖醛酸化,5,7,8 -三羟基二氢黄酮是其主要羟基化产物,乔松素-7-葡萄糖醛酸苷可能为乔松素的主要代谢失活形式。     

黄芩素在人及不同种属肝微粒体中的UDP-glucuronosyltransferase代谢差异（摘要）

目的：研究黄芩素在不同种属肝微粒体中的UDP-葡萄糖醛酸转移酶（UDP-glucuronosyltransferase, UDPGA）代谢差异特性。方法使用肝微粒体体外代谢孵育法、HPLC-UV分析方法,选用不同种属的肝微粒体进行黄芩素UDPGA体外代谢研究。结果黄芩素在人肝微粒体及不同种属的肝微粒中,加入UDPGA进行37℃恒温孵育,孵育结束后离心,取上清液,经HPLC-UV分离检测得到3个代谢产物,分别是：黄芩素-7-O-β-葡萄糖醛酸结合物、黄芩素-6-O-β-葡萄糖醛酸结合物和黄芩素-6-O-葡萄糖醛酸结合物-7-O-β-葡萄糖醛酸结合物;通过与标准品对照确定黄芩素的三个代谢产物都是葡萄糖醛酸化的代谢产物。同时,不同种属间UGT代谢物的活性表现出较大差异,黄芩素-7-O-β-葡萄糖醛酸结合物在人肝微粒体中的代谢活性最强,Km=1.61,Vmax=0.77（BG在人肝微粒体中的代谢活性是SD雌鼠的25.2倍）;黄芩素-6-O-β-葡萄糖醛酸结合物在比格犬肝微粒体中代谢活性最强,Km=3.05,Vmax=3.51（雄性比格犬肝微粒体的活性是雄性恒河猴肝微粒体的2.6倍）;黄芩素-6-O-葡萄糖醛酸-7-O-β-葡萄糖醛酸结合物在猪肝微粒体中代谢活性最强,Km=5.38, Vmax=0.17（猪肝微粒体的活性是人肝微粒体的13.6倍）,其他依次是犬、恒河猴、鼠和人。结论黄芩素在人及不同种属肝微粒体UGT代谢中均生成上述三种葡萄糖醛酸化代谢产物,但是不同种属间的代谢表现出酶动力学的差异。     

去氢厄弗酚在小鼠肝微粒体中代谢产物及CYP450酶亚型的鉴定

目的建立去氢厄弗酚(DHE)小鼠体外肝微粒体孵育方法,鉴定DHE在小鼠肝微粒体中的代谢产物及参与DHE代谢的CYP450酶亚型。方法采用UPLC-Q-TOF-MS/MS分析鉴定DHE在体外肝微粒体共温孵后的代谢产物,筛选7种CYP450酶亚型,并通过特异性化学抑制剂法,鉴别参与DHE代谢的主要CYP450酶亚型。结果在体外肝微粒体共温孵后,检测到4个代谢产物;所筛选的7种CYP450酶亚型中,CYP1A2、CYP2C8和CYP2D2对DHE体外肝微粒体代谢的参与度较高。结论在肝脏中,有多种代谢酶亚型参与DHE的代谢,表明DHE在临床上不易与其他药物产生相互作用。     

大鼠微粒体代谢酶对黄芩素葡萄糖醛酸化代谢物影响的实验研究

目的 观察大鼠微粒体代谢酶对黄芩素(治疗呼吸道感染中药)代谢作用的影响.方法 用体外微粒体药物代谢酶孵育法;用HPLC法测定黄芩素及其葡萄糖醛酸化代谢物的含量,在不同孵育时间和不同浓度下,观察大鼠肝肠不同微粒体对黄芩素葡萄糖醛酸化代谢产物生成速率的影响.结果 5种不同微粒体药物代谢酶对黄芩素均有代谢作用,且随孵育时间延长,代谢作用也相应增加,呈较好的时间和剂量依赖关系.在5种微粒体中,十二指肠微粒体代谢作用最强;而肝代谢作用最弱.结论 黄芩素主要代谢部位是肠道.     

芫花主要黄酮成分对肝微粒体UGTs及UGT1A1活性的体外抑制作用

目的 考察芫花主要黄酮成分芫花素和芹菜素对尿苷二磷酸葡萄糖醛酸转移酶（UGTs）及UGT1A1活性的影响。方法 采用体外肝微粒体孵育模型,以4-硝基酚（4-nitrophenol,4-NP）为底物检测UGTs活性,胆红素为底物检测UGT1A1活性;利用UV及UPLC-MS/MS测定底物或代谢产物的含量。结果 对UGTs,在大鼠肝微粒体、小鼠肝微粒体以及人肝微粒体孵育体系中,芫花素和芹菜素均能不同程度地抑制UTGs活性;抑制强弱顺序：在大鼠肝微粒体温孵体系中,芫花素>芹菜素;在小鼠肝微粒体以及人肝微粒体温孵体系中,芹菜素>芫花素。对UGT1A1,在人肝微粒体孵育体系中,芫花素和芹菜素均表现为中等强度的竞争性抑制作用,抑制强弱顺序：芹菜素（IC₅₀=12.40 μmol·L^-1）>芫花素（IC₅₀=23.21 μmol·L^-1）。结论 芫花素和芹菜素对不同肝微粒体孵育体系中UGTs及UGT1A1均可产生显著抑制作用且存在种属差异。芫花素及芹菜素可能存在基于UGT酶的药物相互作用。     

2种重组人源化葡糖醛酸化转移酶对染料木素代谢的作用研究

目的:比较研究2种重组人源化葡糖醛酸化转移酶UGT1A9和UGT1A10(分别主要存在于肝脏和肠道)对异黄酮类化合物染料木素的代谢作用,预测染料木素的主要代谢途径和机制。方法:采用体外微粒体药物代谢酶孵育法,高效液相色谱法检测染料木素在3个不同浓度(2.5、10、35μmol.L-1)下被2种代谢酶转化为葡糖醛酸结合物的代谢速率。结果:UGT1A9和UGT1A10都对染料木素有显著代谢作用,且随着浓度的增加,代谢速率加快,呈较好的浓度依赖关系,但以UGT1A9代谢速率更快。结论:UGT1A9对染料木素的代谢作用大于UGT1A10,提示染料木素的主要代谢部位在肝脏,但肠道也有部分代谢。     

水飞蓟宾非对映异构体在大鼠肝微粒体中葡萄糖醛酸化代谢的酶动力学比较研究

目的比较水飞蓟宾A(silybin A,sa)和水飞蓟宾B(silybin B,sb)在大鼠肝微粒体中葡萄糖醛酸化代谢的酶动力学特性。方法将系列浓度的水飞蓟宾(sa和sb的质量比为45∶53)加入到大鼠肝微粒体孵育液中进行孵育,采用HPLC法分别测定β-葡萄糖苷酸酶水解前和水解后孵育液中sa和sb的浓度,据此计算sa和sb的葡萄糖醛酸结合物的浓度,绘制酶动力学曲线,并计算酶动力学参数。结果 sa和sb的最大反应速率(vmax)分别为(2.80±0.14)mmol·min~(-1)·kg~(-1)和(4.21±0.31)mmol·min~(-1)·kg~(-1),米氏常数(Km)分别为(36.66±7.52)μmol·L-1和(89.78±23.08)μmol·L-1,内在清除率(Clint)分别为76.38 L·min~(-1)·kg~(-1)和46.89 L·min~(-1)·kg~(-1)。结论水飞蓟宾在大鼠肝微粒体中的葡萄糖醛酸化代谢具有立体选择性,sb的代谢速率快于sa。     

辛伐他汀对大鼠肝微粒体药物代谢酶活性的影响

目的研究辛伐他汀(simvastatin, SV)对大鼠肝脏药物代谢酶活性的影响。方法大鼠口服给予SV,qd×7,超速离心法分离肝微粒体,一氧化碳示差光谱法测定细胞色素P450(CYP)含量,以红霉素、苯胺、CDNB、利尿酸、7-羟基-4-甲基香豆素和对羟基联苯为底物分别测定肝微粒体红霉素脱甲基酶(CYP3A4)、苯胺羟化酶(CYP2E1)、谷胱甘肽-S-转移酶(glutathione S transferase, GST)及其π亚型 (πGST)、尿苷二磷酸葡萄糖醛酸转移酶(uridine diphosphoglucuronyl transferase, UGT1和UGT2)活性。结果大鼠口服给予SV可明显降低大鼠肝微粒体CYP含量及CYP3A4活性,对CYP2E1则没有显明影响。同时,SV 则可显著增高大鼠肝微粒体GST、πGST及UGT1和UGT2活性。结论SV可降低大鼠肝微粒体CYP3A4活性,而增高肝微粒体Ⅱ相代谢酶的活性。     

枸橼酸爱地那非人肝微粒体代谢产物鉴定及性别差异

目的研究枸橼酸爱地那非在不同性别来源的人肝微粒体体外代谢孵育体系中的代谢差异。方法将枸橼酸爱地那非与不同性别来源的人肝微粒体进行体外共孵育,采用超高效液相色谱-四极杆-飞行时间质谱仪,鉴定并推测爱地那非在不同性别来源的人肝微粒体中的代谢产物。色谱柱为Acquity UPLC BEH C₁₈(2.1 mm×100 mm×1.7μm),流动相为乙腈与0.4%甲酸溶液,梯度洗脱,流速0.3 mL·min^-1。采用电喷雾离子源,正离子模式检测。结果结合色谱保留时间和质谱碎片离子信息,在体外肝微粒体孵育体系中鉴定了原型分子爱地那非,以及爱地那非经Ⅰ相代谢反应产生的8种代谢产物。所有代谢产物均为水溶性分子,无明显毒性结构。不同性别肝微粒体孵育体系中检测到的代谢产物种类相同。结论建立了爱地那非的体外肝微粒体孵育体系模型,初步研究推测不同性别人群对爱地那非的肝脏微粒体代谢过程一致。     

辛伐他汀对大鼠肝微粒体药物代谢酶活性的影响

目的 研究辛伐他汀(simvastatin, SV)对大鼠肝脏药物代谢酶活性的影响。方法 大鼠口服给予SV,qd×7,超速离心法分离肝微粒体,一氧化碳示差光谱法测定细胞色素P450(CYP)含量,以红霉素、苯胺、CDNB、利尿酸、7-羟基-4-甲基香豆素和对羟基联苯为底物分别测定肝微粒体红霉素脱甲基酶(CYP3A4)、苯胺羟化酶(CYP2E1)、谷胱甘肽-S-转移酶(glutathione S transferase, GST)及其π亚型 (πGST)、尿苷二磷酸葡萄糖醛酸转移酶(uridine diphosphoglucuronyl transferase, UGT1和UGT2)活性。结果 大鼠口服给予SV可明显降低大鼠肝微粒体CYP含量及CYP3A4活性,对CYP2E1则没有显明影响。同时,SV 则可显著增高大鼠肝微粒体GST、πGST及UGT1和UGT2活性。结论 SV可降低大鼠肝微粒体CYP3A4活性,而增高肝微粒体Ⅱ相代谢酶的活性。     

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.     

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.