基于HPLC-QAMS同时测定荷叶水提物中6个成分的含量

目的:建立一测多评法(QAMS)同时测定荷叶水提取物中O-去甲荷叶碱、槲皮素-3-O-桑布双糖苷、金丝桃苷、异槲皮苷、槲皮素-3-O-葡萄糖醛酸苷、荷叶碱的含量。方法:色谱柱为Lamdo Stamsil C₁₈(250 mm×4.6mm, 5μm),流动相为0.1%磷酸水溶液-乙腈,梯度洗脱,流速为0.6 mL·min^-1,检测波长为270 nm,柱温为25℃,进样量为5μL。以O-去甲荷叶碱为内参物,计算其他5个成分的相对校正因子,并测定含量。结果:O-去甲荷叶碱、槲皮素-3-O-桑布双糖苷、金丝桃苷、异槲皮苷、槲皮素-3-O-葡萄糖醛酸苷、荷叶碱分别在各自范围内线性关系良好(r≥0.999 5),精密度、重复性、稳定性试验结果的RSD均<3.0%,平均加样回收率为94.6%～108.0%,RSD为0.95%～2.1%。QAMS法测得荷叶水提物中上述6个成分的含量分别为0.23、3.43、1.69、10.59、41.23、0.69 mg·g^-1。结论:建立的荷叶水提物中6个成分的含量测定方法可靠,可用于其质量控制...     

荷叶不同生长期荷叶碱含量比较

目的比较荷叶不同生长期荷叶碱的含量。方法采用高效液相色谱法,对不同生长期荷叶所含荷叶碱的含量进行比较。结果与结论处于不同生长期的荷叶所含荷叶碱的含量存在一定差异,随荷叶从幼叶生长荷叶碱量逐渐增加,至成熟期达最高,整个生长过程中差异不是特别大,而当荷叶开始衰老时荷叶碱含量急骤下降。为保证荷叶质量,应掌握好采收期。     

反相高效液相色谱法测定荷叶口服液中荷叶碱的含量

［摘要］目的建立高效液相色谱法测定荷叶口服液中荷叶碱含量。方法固定相：HypersilBDS C18柱 （4.6 mm×150 mm, 5 μm）;流动相：甲醇：水：三乙胺：冰醋酸（50：48：1.4：0.7）;流速：0.7mL&#8226;min 1;检测波长：270 nm;柱温：40 ℃;进样量：10 μL。结果荷叶碱在1.282～25.640 μg&#8226;mL 1范围内线性关系良好（r＝0.999 1）;3份荷叶碱的平均加样回收率分别为99.7%（RSD=1.25%）,101.0%（RSD＝0.95%）,99.5%（RSD＝1.14%）。结论该方法准确可靠,快速灵敏,可以作为荷叶口服液中荷叶碱的质量控制标准。     

荷叶碱在大鼠体内的药代动力学研究

目的：建立大鼠血浆中荷叶碱的HPLC测定方法并进行大鼠体内药代动力学研究。方法：大鼠尾静脉注射后,不同时间点眼底静脉丛取血,乙酸乙酯提取大鼠血浆样品的荷叶碱,HPLC测定大鼠血浆中荷叶碱的含量,DAS软件计算药代动力学参数。结果：荷叶碱在大鼠体内的t1／2。为（1．73±0．58）h,V为（5．03±0．24）L／kg,CL为（4．23±0．78）L·h。·kg,药时曲线下面积（AUC0。－Inf）为（2．35±O．46）mg·L叫·h;在血浆中的平均驻留时间（MRT）为（1．51±0．31）h。结论：所建立的HPLC分析方法快速、准确、简便,能够满足荷叶碱药代动力学的研究要求。按10mg／kg单剂量单次静脉给药后,荷叶碱主要在血浆中分布,消除速度较快。     

高效液相色谱法测定荷叶与荷梗中荷叶碱的含量

目的 建立一种测定荷叶与荷梗中荷叶碱含量的高效液相色谱方法.方法 采用Kromasil C18柱(4.6mm×250mm,5.0μm),以乙腈-水-三乙胺-冰醋酸(27:70.6:1.6:0.78)为流动相,流速1.0 mL·min-1,柱温25℃,检测波长270nm.结果 荷叶碱获得良好分离,在26.4～92.4μg·mL-1范围内绒性良好(r=0.9997),平均回收率为97.49%,RSD=0.55%(n=5).结论 该方法准确、重现性好,可用于荷叶与荷梗中荷叶碱含量的测定.     

高效液相色谱法测定荷叶中荷叶碱的含量

目的:建立 HPLC 测定荷叶中荷叶碱含量的方法。方法:采用 Symmetry-C_(18)柱(3.9mm×150mm,5μm),流动相为乙腈-水-三乙胺-冰醋酸(56∶44∶1∶0.15);流速:0.5mL·min~(-1);检测波长:270nm;柱温:25℃。结果:荷叶碱在3.00～15.00μg·mL~(-1)范围内具有良好的线性关系,r=0.9999,平均回收率为98.3%,RSD=2.1%(n=5)。结论:本法简便、准确,灵敏度高,重复性好,可用于荷叶成分的含量测定。     

RP—HPLC法测定Beagle犬血浆中荷叶碱的浓度及药动学研究

目的：建立Beagle犬血浆中荷叶碱的RP—HPLC含量测定方法，研究Beagle犬灌胃给予荷叶生物碱提取物后荷叶碱血浆药代动力学特征。方法：采用高效液相色谱法，Hypersil—C18色谱柱（4．6mm&#215;250mm，5μm）；0．1％三乙胺水溶液-乙腈（53：47）为流动相；检测波长270nm，柱温：35℃，流速：1．0mL&#183;min^-1。Beagle犬灌胃给予荷叶生物碱提取物后定时取血，测定血浆荷叶碱药物浓度，采用DAS软件计算药动学参数。结果：荷叶碱浓度在0．0515～2．06μg&#183;mL^-1浓度范围内线性关系良好（r=0．9933）；Beagle犬灌胃给予荷叶生物碱提取物0．10，0．15，0．20g&#183;kg^-1后符合二室开放式模型，t1／2α分别为0．22，0．23，0．26h；t1/2β分别为0．56，0．85，0．77h；荷叶碱在体内符合一级药动学过程。结论：该法专属性强、灵敏、准确，能够满足药代动力学研究需要。     

薄层扫描法测定荷叶中荷叶碱的含量

目的: 建立薄层扫描法分离测定荷叶中荷叶碱的含量.方法: 采用0.5%氢氧化钠溶液制备的硅胶GF254薄层板,以氯仿-醋酸乙酯-甲醇-水(30∶40∶20∶10)为展开剂,检测波长272 nm.结果: 荷叶碱在0.5～5 μg范围内呈现良好线性关系,平均回收率为97.4%,RSD=3.83%(n=5).结论: 该方法简便准确,稳定性高,可作为其质量控制依据.     

荷叶HPLC-UV指纹图谱研究

目的采用HPLC法建立荷叶药材的指纹图谱。方法 Ultimate XB-C18色谱柱(4.6 mm×250 mm,5μm),流动相为0.1%甲酸+0.2%三乙胺溶液(A)-乙腈(B)进行梯度洗脱,检测波长254 nm,体积流量1.0 mL.min-1,柱温35℃。结果建立了荷叶的HPLC-UV的指纹图谱,指定出11个共有指纹峰,共指认3个共有峰的结构并对不同产地和不同采收时期荷叶的相似度进行了比较。结论本方法操作简便,快速,重现性好,为荷叶的鉴别和质量控制提供有效依据。     

HPLC法测定荷叶与莲房中荷叶碱的含量

目的建立高效液相色谱法测定荷叶与莲房中荷叶碱含量的方法。方法采用Agilent Eclipse XDBC18(4.6 mm×250 mm,5μm),以乙腈-水-三乙胺-冰醋酸(27∶70.6∶1.6∶0.8)为流动相;流速:1.0 mL·min-1;柱温:25℃;检测波长:270 nm。结果荷叶碱在3.01⁴8.16μg·mL-1范围内线性良好(r=0.999 0),平均回收率为96.97%,RSD=0.99%(n=6)。结论该方法准确、简便、灵敏度高、重现性好,可用于荷叶与莲房中荷叶碱含量的测定。     

Theophylline kinetics in peripheral tissues in vivo in humans

Several biochemical and cellular effects have been described for methylxanthines under in vitro conditions. However, it is unknown, whether threshold concentrations required to exert these effects are attained in target tissues in vivo. We therefore employed the microdialysis technique for measuring theophylline concentrations in peripheral tissues under in vivo conditions.Following in vitro and in vivo calibration, microdialysis probes were inserted into the medial vastus muscle and into the periumbilical subcutaneous adipose layer of healthy volunteers. Following single oral dose administration of 300 mg or i.v. infusion of 240 mg theophylline, in vivo time courses of theophylline concentrations were monitored in tissues and plasma. Major pharmacokinetic parameters (c_max, t_max, AUC) were calculated for plasma and tissue time courses. The mean AUC_tissue /AUC_plasma-ratio was 0.56 (p.o.) and 0.55 (i.v.) for muscle and 0.55 (p.o.) and 0.72 (i.v.) for subcutaneous adipose tissue.We conclude that microdialysis provides important information on the distribution and the tissue pharmacokinetics of theophylline.Abbreviations FPIA Fluorescence polarisation immuno assay - AUC Area under the curve - t_max Time to peak concentration - c_max Peak concentration     

Interindividual variability in metabolic activation in humans in vivo

In assessing interindividual variability in metabolic activation, the toxic metabolite is often too unstable for conventional analysis. Possible alternatives include a stable product of the reactive metabolite e.g. cysteinyl derivatives of N-acetyl-4-benzoquinoneimine, the toxic metabolite of paracetamol, adducts with DNA or protein, and indirect measurement of the activity of the enzyme(s) producing the active metabolite. An example of the last approach is the use of furafylline, a highly specific inhibitor of human CYP1A2, to determine the extent of the metabolic activation of the cooked food mutagens PhIP and MeIQx. The extent of inhibition, determined from levels of unchanged amine in urine, is an indirect measure of the activity of the activation pathway. Further refinement of this approach, allied to improved measures of the biological process of interest should prove of value in evaluating interindividual variability and its role in the risk assessment process.     

休克时血中氧自由基的变化

本实验测定10名休克患者血浆和红细胞的丙二醛(MDA)、血浆总抗的氧化活性(AOA)的含量。结果表明:休克病人红细胞膜和血浆 MDA 含量(4.298±0.722;5.348±0.834)与对照组(3.235±0.682;4.356±1.081)比较明显增高(P<0.05);血浆 AOA(39.65±7.858)与对照组(48.21±10.81)比较明显降低(P<0.01)。提示:休克时,患者机体内自由基反应增强是引起组织细胞损伤的原因之一。     

Quantitative in vivo and in vitro sex differences in artemisinin metabolism in rat

1. The pharmacokinetics of the antimalarial compound artemisinin were compared in the male and female Sprague-Dawley rat after single dose i.v. (20 mg.kg) or i.p. (50 mg.kg) administration of an emulsion formulation. 2. Plasma clearance of artemisinin was 12.0 (95% confidence interval: 10.4, 13.0) l.h. kg in the male rat and 10.6 (95% CI: 7.5, 15.0) l.h. kg in the female rat suggesting high hepatic extraction in combination with erythrocyte uptake or clearance. Artemisinin half-life was 0.5 h after both routes of administration in both sexes. Values for plasma clearance and half-lives did not statistically differ between the sexes. 3. After i.p. administration artemisinin AUCs were 2-fold higher in the female compared with male rat (p 0.001). Artemisinin disappearance was 3.9-fold greater in microsomes from male compared with female livers and it was inhibited in male microsomes by goat or rabbit serum containing antibodies against CYP2C11 and CYP3A2 but not CYP2B1 or CYP2E1. 4. The unbound fraction of artemisinin in plasma was lower (p 0.001) in plasma obtained from the male (8.8 2.0%) compared with the female rat (11.7 2.2%). 5. The possibility of a marked sex difference, dependent on the route of administration, has to be taken into account in the design and interpretation of toxicological studies of artemisinin in this species.     

Polymorphisms in genes involved in neurotransmission in relation to smoking

Smoking behavior is influenced by both genetic and environmental factors. The genetic contribution to smoking behavior is at least as great as its contribution to alcoholism. Much progress has been achieved in genomic research related to cigarette-smoking within recent years. Linkage studies indicate that there are several loci linked to smoking, and candidate genes that are related to neurotransmission have been examined. Possible associated genes include cytochrome P450 subfamily polypeptide 6 (CYP2A6), dopamine D₁, D₂, and D₄ receptors, dopamine transporter, and serotonin transporter genes. There are other important candidate genes but studies evaluating the link with smoking have not been reported. These include genes encoding the dopamine D₃ and D₅ receptors, serotonin receptors, tyrosine hydroxylase, trytophan 2,3-dioxygenase, opioid receptors, and cannabinoid receptors. Since smoking-related factors are extremely complex, studies of diverse populations and of many aspects of smoking behavior including initiation, maintenance, cessation, relapse, and influence of environmental factors are needed to identify smoking-associated genes. We now review genetic polymorphisms reported to be involved in neurotransmission in relation to smoking.     

Pradigastat disposition in humans: in vivo and in vitro investigations

1.?Pradigastat is a potent and specific diacylglycerol acyltransferase-1 (DGAT1) inhibitor effective in lowering postprandial triglycerides (TG) in healthy human subjects and fasting TG in familial chylomicronemia syndrome (FCS) patients.

2.?Here we present the results of human oral absorption, metabolism and excretion (AME), intravenous pharmacokinetic (PK), and in vitro studies which together provide an overall understanding of the disposition of pradigastat in humans.

3.?In human in vitro systems, pradigastat is metabolized slowly to a stable acyl glucuronide (M18.4), catalyzed mainly by UDP-glucuronosyltransferases (UGT) 1A1, UGT1A3 and UGT2B7. M18.4 was observed at very low levels in human plasma.

4.?In the human AME study, pradigastat was recovered in the feces as parent drug, confounding the assessment of pradigastat absorption and the important routes of elimination. However, considering pradigastat exposure after oral and intravenous dosing, this data suggests that pradigastat was completely bioavailable in the radiolabeled AME study and therefore completely absorbed.

5.?Pradigastat is eliminated very slowly into the feces, presumably via the bile. Renal excretion is negligible. Oxidative metabolism is minimal. The extent to which pradigastat is eliminated via metabolism to M18.4 could not be established from these studies due to the inherent instability of glucuronides in the gastrointestinal tract.     

Changes in immunoreactive somatostatin in brain following lidocaine-induced kindling in rat

The kindling phenomenon has become a useful model for studying epileptogenesis. The present authors have previously reported increased levels of immunoreactive somatostatin (IR-SRIF) in various regions of the brain of electrically-amygdaloid kindled (EAK) rats. In this study, an examination was made of immunoreactive somatostatin in pharmacologically-kindled (PK) rats. Sixteen male Sprague-Dawley rats were injected intraperitoneally (i.p.) with a subthreshold dose of lidocaine (60 mg/kg), once daily. Once the kindling phenomenon was established, kindled rats (7), non-kindled rats (9) and controls (6) were sacrificed by microwave irradiation. Another group of 5 rats was injected with a single suprathreshold dose of lidocaine (110 mg/kg) and killed 10 min after the resultant seizure. Various brain areas were removed and assayed for immunoreactive somatostatin in kindled rats. Immunoreactive somatostatin was significantly greater than in controls in the amygdala (56%; P less than 0.02), entorhinal + piriform cortex (50%; P less than 0.05) and hypothalamus (29%; P less than 0.02). In non-kindled rats, immunoreactive somatostatin increased only in the amygdala (58%; P less than 0.02). No difference was found in the immunoreactive somatostatin content of rats injected with an suprathreshold dose of lidocaine compared to controls. The alteration of immunoreactive somatostatin, in both lidocaine-kindled and electrically-amygdaloid kindled rats suggests a possible role of this neuropeptide in kindling.     

纳米材料在止血方面的研究进展

纳米材料因其独特的微观结构优势,已被广泛应用于材料制备、微电子与计算机技术、医学与健康、环境与能源等领域。与传统止血材料相比,纳米材料在一定程度上能提高传统止血药物的生物利用度和稳定性,增强药物的缓控与靶向释放,为现代化新型止血材料的发展奠定了良好的基础。对脂质体、纳米粒、自组装纳米肽、纳米纤维等多种纳米止血材料的前沿设计和应用进展进行了综述,最后简述纳米止血材料存在的问题和发展前景。