中药白花前胡提取工艺的优化

目的为合理提取白花前胡中降肺动脉高压的活性成分提供实验依据。方法采用正交试验法,考察提取溶媒、提取次数、提取时间对提取效率的影响;采用HPLC法,以8-甲氧基补骨脂素含量为指标测定提取物含量。结果白花前胡的最佳提取工艺为用质量分数80%的乙醇提取3次,提取时间分别为1.0、0.5、0.5 h,3次所用溶媒量分别为药材质量的8、6、4倍;按照筛选出的最佳工艺条件进行的3次重复性实验,测得浸膏中8-甲氧基补骨脂素含量质量分数为0.094%,折合1 g生药中含量为0.1712 mg,与预测值基本一致。结论所确定的最佳提取工艺可合理提取白花前胡中的活性成分。     

高效液相色谱法测定小儿清肺化痰口服液中白花前胡甲素的含量

<正>小儿清肺化痰口服液用于急性支气管炎,其成分中前胡的有效成分白花前胡为伞形科植物白花前胡(Peucedanum praeruptorum Dunn)的干燥根,具有散风清热,止咳化痰的功效[1]。现代研究表明,白花前胡香豆素类成分在防治心血管疾病方面具有确切的临床疗效,白花前胡甲素为其主要的     

前胡药材中香豆素类成分稳定性考察

摘要：目的:建立外标法测定前胡药材中香豆素类成分的含量,并研究其稳定性。方法:HPLC法测定前胡中白花前胡甲素、白花前胡乙素和白花前胡E素的含量,采用ACE Excel 5 C18-PFP色谱柱（250 mm×4.6 mm,5μm）,流动项为甲醇-水（73∶27）,检测波长为321 nm,柱湿为30℃,流速为1.0 ml·min-1,进样量为10μl,分别采用温度试验法和强光照射法对前胡进行稳定性试验。结果:白花前胡甲素平均回收率为97.55%,RSD为1.49%;白花前胡乙素平均回收率为99.82%,RSD为1.44%;白花前胡E素平均回收率为100.84%,RSD为1.87%（n=9）;温度试验前后白花前胡甲素、白花前胡乙素和白花前胡E素样品含量差异无统计学意义（P>0.05）; 10 d强光照射试验后样品白花前胡甲素含量由1.026 0%下降至0.952 6%,白花前胡乙素含量由0.236 3%下降至0.217 3%,白花前胡E素含量由0.170 1%下降至0.157 5%。结论:建立的前胡含量测定外标法简单可靠,可用于前胡药材的质量评价。前胡中香豆素成分在强光照射试验中不稳定,在温度试验中相对稳定,建议药材在遮光、阴凉的环境中炮制及储藏。     

高效液相一测多评法同时测定参苏片中葛根素、迷迭香酸、白花前胡甲素、白花前胡乙素、白花前胡E素的含量

摘要：目的:建立高效液相一测多评法同时测定参苏片中葛根素、迷迭香酸、白花前胡甲素、白花前胡乙素、白花前胡E素的含量。方法:采用Kromasil C18色谱柱（250 mm×4. 6 mm,5μm）;以甲醇-0. 1%甲酸溶液为流动相,梯度洗脱;流速:0. 9 ml·min-1;检测波长:250 nm（葛根素）、321 nm（迷迭香酸、白花前胡甲素、白花前胡乙素、白花前胡E素）;柱温:30℃;以迷迭香酸为内标物,计算葛根素、白花前胡甲素、白花前胡乙素、白花前胡E素的相对校正因子,测定其含有量,同时采用外标法测定这5个组分的含量。结果:5种成分在各自范围内线性关系良好（r≥0. 999 1）,平均加样回收率97. 46%～99. 83%,RSD为0. 71%～1. 67%,一测多评法计算值与外标法实测值间无明显差异。结论:利用相对校正因子对参苏片中5种成分的含量测定是可行的,所建立的高效液相一测多评法可以用于参苏片的质量评价研究。     

前胡香豆素类成分HPLC指纹图谱研究

目的 建立前胡香豆素类成分的HPLC指纹图谱，为科学评价其质量提供可靠方法。方法 采用Ecosil-C₁₈色谱柱（4.6 mm×250 mm，5 μm），以甲醇-水（68：32）为流动相，分析时间50 min，流速1.0 mL·min^-1，柱温40℃，检测波长323 nm；采用LC-MS对前胡香豆素类成分进行解析，并对特征峰进行归属；运用中药色谱指纹图谱相似度评价系统软件，对18批前胡样品和4批混淆品进行相似度评价。结果 以白花前胡甲素和白花前胡乙素为参照物，建立了以8个共有峰为指标成分的前胡药材指纹图谱，通过LC-MS定性分析结合对照品比对，推测8个共有峰为前胡香豆素D、前胡香豆素E、peucedanumarin Ⅱ、白花前胡甲素、peucedanumarin Ⅰ、白花前胡乙素、白花前胡素E及其同分异构体，并且以相似度为0.9能很好地区分前胡正品和混淆品。结论 该方法简单、重复性良好，可为前胡药材的质量评价提供有效鉴别方法。     

白花前胡挥发油成分的研究

本文用气质联用首次对白花前胡挥发油成分进行了分离鉴定，证明其主要成分为香木兰烯，β－榄香烯等倍半萜成分，抗菌实验表明白花前胡挥发油对金黄色葡萄球菌的生长有较强的抑制作用。     

浙产前胡栽培及野生药材的质量研究

目的 研究浙江省不同产地前胡栽培品和野生品的质量.方法 色谱柱为YMC-ODS-A柱(250 mm×4.6 mm,5μm);流动相为甲醇-水(78:22);流速为1.0 ml·min-1;检测波长为321 nm.以白花前胡甲素、白花前胡丁素和白花前胡素E为对照品.结果 临安、淳安一带的前胡质量较佳,同时不同产地前胡栽培品和野生品的质量相差不大.结论 文中的研究结果可为前胡的引种驯化、扩大栽培和GAP基地的建设提供依据.     

白花前胡挥发油成分的研究

本文用气质联用首次对白花前胡挥发油成分进行了分离鉴定，证明其主要成分为香木半烯，β－榄香烯等倍半萜成分，抗菌实验表明白花前胡挥发油对金黄色葡萄球菌的生长有较强的抑制作用。     

甘肃地产前胡的质量研究

对甘肃产华北前胡（Ｐｅｕｃｅｄａｎｕｍ　ｈａｒｒｙ－ｓｍｉｔｈｉｉＦｅｄｄｅ　ｅｘ　Ｗｏｌｆｆ．）和少毛北前胡（Ｐ．ｈａｒｒｙ－ｓｍｉｔｈｉｉ　ｖａｒ。ｓｕｂｇｌａｂｒｕｍ　Ｓｈａｎ　ｅｔ　ＳｈａｎｅｔＳｈｅｈ．）的根与白花前胡（Ｐ．ｐｒａｅｒｕｐｔｏｒｕｍ　Ｄｕｎｎ．）进行了药材质量对比的研究。结果表明３者主成分基本一致，甘肃产白花前胡质量稍差，醇浸出物含量偏低。     

前胡有效成分含量与土壤因子的相关性分析

目的 探讨前胡有效成分含量与土壤因子的相关性，为前胡的人工栽培种植提供依据。方法 测定不同前胡产地共9省30批次样品中的总香豆素、醇溶性浸出物、白花前胡甲素、白花前胡乙素、白花前胡素E和7-羟基香豆素含量，此外还测定7个土壤肥力指标和10个土壤微量元素指标。应用主成分分析法、聚类分析法、Pearson相关性分析法和灰色关联度分析法寻找影响前胡有效成分含量变异的关键土壤因子。结果 聚类分析表明30个不同产地的土壤可以分成2大类。Pearson相关性分析表明与6种有效成分最相关的分别为全钾、有机质、pH值、阳离子交换量和有效磷。除了锰含量与总香豆素呈负相关；其余均呈正相关。灰色关联度分析表明影响前胡有效成分的主导土壤因子是锌、铁、铜、全磷、全量钠含量，阳离子交换量以及pH值。结论 研究结果提示在前胡生产实践中可以通过适当控制土壤有机质含量，增施特定无机肥等农艺措施调控前胡香豆素类成分含量。本研究为保证前胡质量及其临床用药的有效性，提高前胡的合理利用提供理论依据。     

白花前胡中的香豆素类成分

从中药白花前胡（ＰｅｕｃｅｄａｎｕｍｐｒａｅｒｕｐｔｏｒｕｍＤｕｎｎ）根中分离得到６个化合物,经理化常数和波谱特征分别鉴定为Ｐｄ Ⅱ（Ⅰ）、顺式 ３′,４′ 二千里光酰基 ３′,４′ 二氢邪蒿内酯（Ⅱ）、ｉｓｏｂｏｃ ｃｏｎｉｎ（Ⅲ）、ａｅｇｅｌｉｎｏｌ（Ⅳ）、（－） 反式凯林内酯（Ⅴ）和伞形花内酯（Ⅵ）．化合物（Ⅲ）和（Ⅳ）为从前胡属植物首次分离得到,（Ⅱ）为从白花前胡中首次分离得到     

CAR-mediated up-regulation of CYP3A4 expression in LS174T cells by Chinese herbal compounds

The constitutive androstane receptor (CAR) is an orphan nuclear receptor which has been shown to participate in the activation of human CYP3A4, which metabolizes more than 50% of clinically used drugs. We investigated the effects of an array of compounds isolated from herbal medicines such as Rheum palmatum (Da Huang), Peucedanum praeruptorum Dunn (Qian Hu), Cortex Mori Radicis (Sang Bai Pi), Radix Asteris (Zi Wan), Salvia miltiorrhiza (Dan Shen), Polygonum cuspidatum Sieb. et Zucc (Hu Zhang), and Ginkgo biloba (Yin Xing) on the CAR-mediated transactivation of CYP3A4. The effect of herbal compounds on CYP3A4 expression was measured using a CYP3A4 luciferase reporter gene assay in transiently transfected human intestinal LS174T cells. The gene expression, protein expression, and catalytic activity of CYP3A4 in LS174T cells transfected with CAR were determined by using real-time PCR, Western blot analysis, and LC-MS/MS-based substrate assay. The study found that in CAR-transfected cells, praeruptorin A, C, and D significantly induced CYP3A4 luciferase activity, mRNA expression, and functional activity through the CAR-mediated pathway; conversely, induction was not found in untransfected cells. Our findings suggest that these herbal compounds can significantly up-regulate the CYP3A4 gene via the CAR-mediated pathway, which has important implications in herb-drug interactions.     

Interaction of hydrogen sulfide with ion channels

1. Hydrogen sulfide (H₂S) is a signalling gasotransmitter. It targets different ion channels and receptors, and fulfils its various roles in modulating the functions of different systems. However, the interaction of H₂S with different types of ion channels and underlying molecular mechanisms has not been reviewed systematically. 2. H₂S is the first identified endogenous gaseous opener of ATP‐sensitive K⁺ channels in vascular smooth muscle cells. Through the activation of ATP‐sensitive K⁺ channels, H₂S lowers blood pressure, protects the heart from ischemia and reperfusion injury, inhibits insulin secretion in pancreatic β cells, and exerts anti‐inflammatory, anti‐nociceptive and anti‐apoptotic effects. 3. H₂S inhibited L‐type Ca²⁺ channels in cardiomyocytes but stimulated the same channels in neurons, thus regulating intracellular Ca²⁺ levels. H₂S activated small and medium conductance K_Ca channels but its effect on BK_Ca channels has not been consistent. 4. H₂S‐induced hyperalgesia and pro‐nociception seems to be related to the sensitization of both T‐type Ca²⁺ channels and TRPV₁ channels. The activation of TRPV₁ and TRPA₁ by H₂S is believed to result in contraction of nonvascular smooth muscles and increased colonic mucosal Cl^? secretion. 5. The activation of Cl^? channel by H₂S has been shown as a protective mechanism for neurons from oxytosis. H₂S also potentiates N‐methyl‐d ‐aspartic acid receptor‐mediated currents that are involved in regulating synaptic plasticity for learning and memory. 6. Given the important modulatory effects of H₂S on different ion channels, many cellular functions and disease conditions related to homeostatic control of ion fluxes across cell membrane should be re‐evaluated.     

The Activation Effect of Hainantoxin-I,a Peptide Toxin from the Chinese Spider,Ornithoctonus hainana,on Intermediate-Conductance Ca2+-Activated K+ Channels

Intermediate-conductance Ca²⁺-activated K⁺ (IK) channels are calcium/calmodulin-regulated voltage-independent K⁺ channels. Activation of IK currents is important in vessel and respiratory tissues, rendering the channels potential drug targets. A variety of small organic molecules have been synthesized and found to be potent activators of IK channels. However, the poor selectivity of these molecules limits their therapeutic value. Venom-derived peptides usually block their targets with high specificity. Therefore, we searched for novel peptide activators of IK channels by testing a series of toxins from spiders. Using electrophysiological experiments, we identified hainantoxin-I (HNTX-I) as an IK-channel activator. HNTX-I has little effect on voltage-gated Na⁺ and Ca²⁺ channels from rat dorsal root ganglion neurons and on the heterologous expression of voltage-gated rapidly activating delayed rectifier K⁺ channels (human ether-à-go-go-related gene; human ERG) in HEK293T cells. Only 35.2% ± 0.4% of the currents were activated in SK channels, and there was no effect on BK channels. We demonstrated that HNTX-I was not a phrenic nerve conduction blocker or acutely toxic. This is believed to be the first report of a peptide activator effect on IK channels. Our study suggests that the activity and selectivity of HNTX-I on IK channels make HNTX-I a promising template for designing new drugs for cardiovascular diseases.     

粉防己碱对缺氧所致大鼠皮层神经元钙通道功能变化的影响

用细胞贴附式膜片钳单通道记录技术 ,研究了粉防己碱 ( Tet)对缺氧状态下大鼠大脑皮层神经元L-和 N-型钙通道变化的影响 .结果发现 ,Tet7.5,1 5和 30 μmol·L-1浓度依赖性缩短由缺氧诱导的L-和 N-型钙通道开放时间增加 ,降低开放概率 .Tet对皮层神经元 L-和 N-型钙通道的这一作用可能是其脑缺氧保护作用的机理之一 .     

阿托伐他汀抗心肌缺血再灌注损伤的作用机制研究

目的:研究阿托伐他汀(ATV)在对心肌缺血再灌注损伤(IRI)的保护效应中,两种ATP依赖的K+(KATP)通道的作用.方法:将32只实验家兔随机分为对照组、ATV组、ATV+5-HD(A1组)、ATV+HMR1883(A2组).通过结扎和放松冠状动脉左前降支,分别进行30 min的心肌缺血和再灌注.实验中持续监测左室舒张末期压(LVEDP)、左心室压最大变化速率(±dp/dtmax)的变化.结果:与对照组相比:ATV组及A2组各项心功能指标在再灌注30 min后明显改善(P＜0.05),而A1组差异无显著性(P＞0.05).结论:ATV的抗心肌IRI保护效应可能与线粒体KATP通道有关.     

Effects of KATP openers on the QT prolongation induced by HERG‐blocking drugs in guinea‐pigs

Objectives This work evaluated the potential usefulness of pharmacological activation of cardiac ATP‐sensitive potassium channels (K_ATP) in the prevention of drug‐induced QT prolongation in anaesthetised guinea‐pigs. Prolongation of cardiac repolarisation and QT interval is an adverse effect of many drugs blocking HERG potassium channels. This alteration can be dangerously arrhythmogenic and has been associated with the development of a particular form of ventricular tachyarrhythmia known as torsade de pointes. Methods The well‐known K_ATP openers aprikalim, cromakalim and pinacidil were used. Moreover, three benzothiazine derivatives, which have been reported as potent activators of K_ATP channels, were also used. Key findings Pharmacological activation of K_ATP channels caused a reduction of the QT prolongation, induced by astemizole, cisapride, quinidine and thioridazine. In contrast, the QT prolongation induced by haloperidol, sotalol and terfenadine, which are known to block HERG channels but also K_ATP channels, was not influenced by K_ATP activation. Glibenclamide and tolbutamide (non‐selective blockers of K_ATP channels expressed both in sarcolemmal and in mitochondrial membranes) antagonised the effects of K_ATP openers, whereas 5‐hydroxydecanoic acid (selective blocker of the mitochondrial K_ATP channels) failed to antagonise the effects of K_ATP openers, indicating that only the sarcolemmal K_ATP is involved in the cardioprotective activity. Conclusions The data suggest that pharmacological K_ATP activation might represent an option for treatment of patients exposed to QT‐prolonging drugs.     

Functional contribution of the endothelial component to the vasorelaxing effect of resveratrol and NS 1619, activators of the large-conductance calcium-activated potassium channels

Large-conductance calcium-activated potassium channels (BK) of smooth muscle play a role in the relevant modulation of vascular tone, due to their calcium- and voltage-dependent mechanisms of activation. A potential role of endothelial BK channels has also been suggested by approaches on endothelial cell cultures. However, no functional study, aimed at evaluating the contribution of endothelial BK channels to the effect of BK-openers, has been reported. Resveratrol and NS 1619, BK-openers, have been tested on endothelium-intact and -denuded aortic rings. Furthermore, the effects of high depolarisation of potassium channel blockers TEA (Tetraethylammonium), 4-AP ( 4-Aminopyridine) and IbTX (Iberiotoxin) and of inhibitors of NO-pathway (L-NAME and ODQ) have been evaluated. The presence of endothelium increased the vasorelaxing potency of BK-openers. This potentiation was eliminated by L-NAME and ODQ. TEA, 4-AP, IbTX and high depolarisation had modest or no antagonist influence on resveratrol in endothelium-denuded aortic rings. The effects of NS 1619 on endothelium-denuded aortic rings were not affected by IbTX, and were modestly antagonised by TEA, 4-AP and high depolarisation. In intact endothelium vessels, TEA, IbTX and 4-AP antagonised the vasorelaxing effect of the two BK-activators. A BK-mediated release of endothelial NO seems a very important factor, determining a strong influence on vasodilator profile of BK-openers. Therefore, an eventual therapy with a BK-opener could promote a series of cardiovascular impacts not confined to the only direct vasorelaxing effects, but also due to a significant contribution of endothelial NO.     

黄芩苷对羟自由基诱发心肌损伤的保护作用

目的:研究黄芩苷(baicalin,Bai)对羟自由基诱导大鼠心肌损伤的保护作用。方法:体外羟自由基发生系诱导心肌脂质过氧化,无机磷法测定心肌三磷酸腺苷(ATP)酶活性,分光光度法检测脂质过氧化物(MDA)含量、线粒体膨胀度和细胞色素氧化酶活性。结果:在羟自由基作用下心肌细胞膜中MDA含量明显升高,ATP酶活性显著降低,且ATP酶活性与MDA含量间呈显著负相关;线粒体膨胀明显,细胞色素氧化酶活性下降。Bai可降低保护羟自由基引起的心肌细胞膜MDA含量的升高和提高ATP酶活性;降低线粒体膨胀程度,恢复细胞色素氧化酶活性。结论:Bai可能通过清除氧自由基,抑制MDA的生成实现其保护心肌的功能。     

钠通道的分离纯化及其结合活性的研究

目的对大鼠脑和骨骼肌纤维膜进行钠离子通道分离和纯化,并将其应用于芋螺毒素的研究。方法3种色谱分离纯化钠通道粗组分,配体结合实验研究钠通道活性及其与桶型芋螺毒素的相互作用。结果经过纯化,大鼠脑钠通道纯化倍数达370倍,平均特异活性位点数达1.3nmol.g-1。大鼠骨骼肌钠通道被纯化2436倍,平均特异活性位点数达268nmol.g-1;用纯化的钠通道与桶型芋螺毒素进行竞争结合,发现Ⅴ8成分与钠通道作用最强。结论纯化出了较高纯度的大鼠脑钠通道和大鼠骨骼肌钠通道;桶型芋螺毒素中的Ⅴ8成分与钠通道作用强烈,与传统型μ-芋螺毒素非常相似。