基于灰色关联分析探索艾纳香非挥发性部位的抗炎活性谱效关系

目的:研究艾纳香非挥发性部位UPLC指纹图谱与抗炎药效之间的相关性,为明确艾纳香抗炎药效物质基础提供实验依据。方法:采用UPLC建立12批艾纳香非挥发性部位的指纹图谱,运用UPLC-Q-TOF-MS对艾纳香非挥发性部位的共有指纹峰进行指认,通过二甲苯致小鼠耳廓肿胀炎症模型获取相应的药效数据,通过灰色关联分析建立其谱效关系。结果:UPLC指纹图谱显示艾纳香非挥发性部位有14个共有峰,与抗炎药效的关联度处于0.717 1~0.550 5,各特征峰所代表的化学成分对其抗炎药效贡献的大小顺序为3号峰 9号峰 4号峰 11号峰 2号峰 1号峰 14号峰 7号峰 6号峰 5号峰 12号峰 8号峰 10号峰 13号峰,并指认了其中9个共有峰,对抗炎药效贡献较大的前2个共有峰(3号和9号)对应的化学成分分别为3-O-咖啡酰基奎宁酸和3,5-O-二咖啡酰基奎宁酸。结论:通过谱效关系研究获得了艾纳香非挥发性部位的抗炎药效物质群,其抗炎药效是多种成分共同作用的结果,明确咖啡酰基奎宁酸类化合物为艾纳香非挥发性部位发挥抗炎药效的主要物质基础。     

基于UPLC-Q-TOF-MS技术的黑骨藤血清药物化学分析

目的:对黑骨藤的血清药物化学进行研究,探讨黑骨藤提取物在大鼠体内的药效物质基础。方法:采用UPLCQ-TOF-MS技术,以及Data Analysis和Metabolite Detect等软件分析,通过比对黑骨藤提取物、含药血清、空白血清指纹图谱以及空白血清与含药血清的差异图谱,根据质谱所提供的保留时间、精确相对分子质量以及与对照品的比较,判定口服黑骨藤提取物后在大鼠体内的入血成分。结果:口服黑骨藤提取物后,从血清中检测出17个入血成分,其中10个为原型成分,7个为代谢产物。鉴定了其中7个原型吸收入血成分,依次为5-O-咖啡酰基奎宁酸,4-O-咖啡酰基奎宁酸,3-O-咖啡酰基奎宁酸,3,4-O-二咖啡酰基奎宁酸,3,5-O-二咖啡酰基奎宁酸,4,5-O-二咖啡酰基奎宁酸、杠柳毒苷。结论:这些入血成分可能是黑骨藤在体内直接作用的物质,有助于阐明其药效物质基础和作用机制。     

Slow calcium current is not reduced in malignant hyperthermic porcine myotubes

Malignant hyperthermia-susceptible (MHS) pigs express a sarcoplasmic reticulum (SR) Ca²⁺-release channel mutation that results in lower than normal contractile thresholds in skeletal muscles. In adult MHS pig muscles the L-type calcium current (I_s) is also reduced. We tested the hypothesis that there is a causal relationship between I_s and the lower contractile threshold by recording I_s from MHs and normal porcine myotubes using the whole cell patch-clamp technique. Current voltage relationships for both MHS and normal myotubes were similar, with peak I_s between +20 and +30 mV. Maximum I_s amplitudes were not different (normal: 4976 ± 566 pA; MHS: 6516 ± 1088 pA) nor was I_s specific density (normal: 9.0 ± 0.8; MHS: 8.8 ± 1.1 pA/pF). In both MHS and normal myotubes, both the dihydropyridine antagonist PN200 –110 (200 nmol/L) and holding the membrane potential at −10 mV for 5 min decreased I_s significantly (by more than 50%). There was no apparent direct relationship between the mutation in the SR Ca²⁺-release channel and lowered I_s. We concluded that reduced I_s in adult MHS pig muscles may be a secondary effect of the SR Ca²⁺-release channel mutation on muscle development. © 1996 John Wiley & Sons, Inc.     

壳聚糖及其衍生物对HaCaT细胞膜电位的影响

 目的用流式细胞仪检测壳聚糖及其衍生物对HaCaT细胞膜电位的影响。方法合成不同取代度的N-三甲基壳聚糖(TMC)和N-羧甲基壳聚糖(MCC);用纯水作对照,运用荧光分子探针DiBAC₄(3)标记HaCaT细胞膜电位,流式细胞仪检测壳聚糖及其衍生物处理之后细胞膜电位的变化情况。结果与纯水组比较,壳聚糖及其衍生物都能显著降低细胞膜电位,其中,TMC20组作用最明显,TMC40组作用最微弱。结论壳聚糖及其衍生物降低细胞膜电位,可能是其具备透皮吸收促进作用的原因之一。     

In vitro interaction of a novel neutrophil growth factor with human liver microsomal cytochromes P450 and the contribution of UDP-glucuronosyltransferases to its metabolism

1. Neutrophil growth factors (NGFs) stimulate neutrophil growth and survival. The first synthetic cytokinin-derived NGF was recently discovered and is a prospective drug owing to its potential use in anti-inflammatory therapy. The metabolism of some cytokinin-derived drugs (e.g. R-roscovitine, olomoucine II) has already been studied and it has been shown that they may give rise to drug-drug interactions.

2. In this in vitro study, the interactions of the novel neutrophil growth factor NGF1568 with two of the main classes of human drug-metabolizing enzymes, cytochromes P450 (CYPs) and UDP-glucuronosyltransferases (UGTs), were tested. Of the CYPs evaluated, NGF1568 was found to inhibit only CYP2C9, by an uncompetitive mechanism and with a K_i value of 349 μM.

3. Formation of a glucuronide of NGF1568 was detected by LC/MS/MS analysis after it was incubated with human liver microsomes and UDP-glucuronic acid. The human recombinant UGT1A9 enzyme (major liver expression) and UGT1A7, UGT1A8, UGT1A10 enzymes (expressed in gastrointestinal tract instead of liver) were found to be responsible for NGF1568 glucuronidation.

4. These results show that interaction of NGF1568 with CYPs is not as important as it is in the case of the cytokinin CDK inhibitors R-roscovitine and olomoucine II, but the conjugation enzymes (UGTs) play a major role in its metabolism. Thus, possible interference of NGF1568 with metabolism of other coadministered drugs at least on level of liver, kidney or intestinal UGTs should be thoroughly considered.

     

Novel self-assembled micelles based on palmitoyl-trimethyl-chitosan for efficient delivery of harmine to liver cancer

Backgroud: Polymeric micelles is a safe and effective delivery system, which belong to the targeted delivery system (TDS). An anticancer drug, harmine(HM) is a hydrophobic drug with much adverse effects when used for treatment of liver cancer. Chitosan (CS) is a polysaccharide and can be modified to be an amphiphilic polmer which could self-assemble into micelles and be applied for delivery of hydrophobic drugs.

Objectives: To synthesize three kinds of novel biodegradable polymers, designated as palmitoyl-trimethyl-CS (TPCS)1, TPCS2 and Lac-TPCS2, and investigate their efficiency and mechanism of delivery HM to liver tumors in vitro and in viro.

Results: The self-assembled micelles presented satisfactory particle size (～ 200 nm) and drug release characteristics in vitro. It's proved that Lac-TPCS2/HM may enter HepG2 cell through endocytosis. Antitumor experiments in vivo revealed that Lac-TPCS2/HM could significantly inhibit tumor growth and extend the lifetime of mice bearing H22 tumors after intravenous administration. Subsequently in vivo near-infrared fluorescence imaging results demonstrated a satisfactory liver tumor-targeting effect of Lac-TPCS2/HM.

Conclusion: Three novel polymers hold great potential in the development of nanomedicine for treatment of liver tumors, in particular Lac-TPCS2 exhibits the greatest antitumor potential through active target effect.     

The molecular identity of Ca channel α1-subunits expressed in rat sympathetic neurons

Much of our understanding of the mechanisms of the gating, modulation, and function of neuronal Ca channels has its origins in investigations of sympathetic neurons. In this article, we use molecular analyses to identify the three Ca channel α₁-subunits that are the likely counter-parts to the pharmacologically defined: ω-Conotoxin GVIA-sensitive N-type; dihydropyridine-sensitive L-type, and ω-Conotoxin GVIA-insensitive, dihydropyridine-insensitive Ca channel currents observed in sympathetic neurons. With a combination of degenerate and exact primers, small regions of Ca channel α₁-subunit sequences were amplified by the polymerase chain reaction (PCR). Although all five Ca channel α₁-subunit genes were expressed in rat sympathetic ganglia, α_1B ⁻, α_1D ⁻, and α_1E-derived cDNAs were the dominant species. No novel Ca channel α₁-sequences were identified in the regions selected for amplification, and we conclude that α_1B, α_1D, and α_1E likely encode, respectively, N-type, L-type, and non-N/non-L-type channel currents of rat sympathetic neurons. In addition, we show that Ca channel β₂ ⁻, β₃ ⁻, and β₄-subunit sequences are strongly represented in sympathetic ganglia. The results of this study also suggest that α_1D, and not α_1C, regulates Ca influx through dihydropyridine-sensitive Ca channel currents.