人参总皂苷诱导K562细胞凋亡的实验研究

目的：研究人参总皂苷诱导白血病细胞凋亡及其机制，为进一步开发人参总皂苷提供实验依据。方法：采用细胞体外培养，图像分析技术、流式细胞术、形态学观察与免疫细胞化学等方法，研究人参总皂苷诱导K562细胞凋亡。结果：人参总皂苷对K562细胞有增殖抑制作用，并可诱导K562细胞凋亡明显增加，同时K562细胞癌基因产物C－MYC，BCL－2表达明显降低。结论：人参总皂苷能诱导K562细胞凋亡，其机制可能与调控癌基因产物的表达有关。     

中医药通过mTOR途径调节细胞凋亡与自噬的研究进展

哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)是一种进化保守的丝氨酸/苏氨酸蛋白激酶,其生物学功能主要是参与细胞的增殖、生长及分化,从而调节机体的代谢过程。诸多国内外研究表明,mTOR是细胞凋亡及自噬信号转导通路的交汇点,营养、药物及氧化应激等多种刺激均可通过mTOR介导的信号通路对细胞的凋亡和自噬起到关键性的调控作用。目前,诸多研究已经证明,mTOR信号通路的改变与多种人类疾病的发病机制密切相关,如癌症、代谢紊乱(肥胖和2型糖尿病)、心血管和神经退行性疾病、与年龄有关的疾病和卵泡发育障碍等。近年来,越来越多的医家以该通路为切入点,以细胞凋亡和自噬为研究载体,研究了中医药对细胞凋亡和自噬的调节。其中包括中药单体、中成药、中药复方以及针灸等药物及物理疗法调控凋亡及自噬的实验研究。本文从mTOR信号通路入手,探讨了mTOR与细胞凋亡及自噬的关系,综述了中医药经mTOR途径调节细胞凋亡与自噬的最新进展,为中医药在该领域的深入研究提供了思路与参考。今后,中医药领域仍可以mTOR信号通路为依托,在中医基础理论的指导下对细胞凋亡和自噬的时效关系进行探索,为中医药在机体的作用机制提供新的现代医学的理论支持和作用靶点。     

凋亡抑制因子sFas、Bcl-2与Graves病的相关性研究

Graves病（GD）是一种常见的自身免疫性甲状腺病，最近研究发现细胞凋亡及凋亡的调控异常与GD的发生密切相关，甲状腺细胞凋亡的抑制可能是GD甲状腺增生及功能亢进的潜在机制。其中Fas／FasL（Fas配体）凋亡途径及抗凋亡蛋白Bcl-2的表达异常备受关注。我们探讨血清中凋亡抑制因子sFas、Bcl-2是否与GD发病有关，为明确Graves病的发病机制提供新的依据。     

中药对原发性肝癌细胞凋亡的影响的研究进展

凋亡（apoptosis）一词由Kerr于1972年首先提出。细胞凋亡是指在特定时空发生的、受机体严密调控的细胞自杀现象，它呈现其独特的、有别于细胞坏死的形态学和生物化学特点，被普遍认为是有机体维持个体内稳态恒定的极其重要的机制之一。它与有丝分裂相反而又互补，并共同参与调控细胞群落，细胞数量的恒定，其调控机制的失常是包括肿瘤在内的一系列疾病的产生根源。因此细胞凋亡已成为当今细胞生物学尤其是肿瘤学基础与临床研究的前沿与热点。近年来，有关中药诱导肝癌细胞凋亡的研究报道逐年增多。1994年，日本的Yano等首先报道中药小柴胡汤具有诱导人肝细胞癌细胞系KIMll凋亡的作用，此后，国内也陆续开展此类研究，其中既有使用中药有效成分，也有使用中药复方诱导肝癌细胞凋亡的报道。     

凋亡相关基因Bax与消化道恶性肿瘤的关系

细胞凋亡是在生命进化过程中形成的保守的基本生命活动之一,它清除机体损伤、衰老或多余的细胞,是维持机体发育和自身组织稳定的重要生命现象,而不能维持细胞数量的适当平衡是肿瘤的一个特征.Bax是Bcl-2基因家族中的一员,Bax既可形成同聚体促进凋亡,又可与Bcl-2形成杂二聚体抑制后者的抗凋亡效应.目前Bax在细胞凋亡中对Caspase的调节作用机制已成为研究的热点之一.现就Bax与消化道肿瘤的研究进展作一概述.     

参麦注射液体外诱导骨肉瘤MG-63细胞凋亡的机制研究

目的:研究参麦注射液体外对骨肉瘤MG-63细胞生长的影响及作用机制。方法:体外培养MG-63细胞,以不同浓度的参麦注射液作用于细胞,MTT法检测肿瘤细胞生长抑制率;流式细胞术测细胞凋亡率和细胞周期;ELISA法测凋亡基因Caspase-3、Caspase-9的含量;Bradford法测SOD、MDA含量。结果:参麦注射液能显著抑制MG-63细胞的增殖,呈剂量依赖性;增加MG-63细胞的凋亡率,并诱导出现S细胞周期阻滞;作用MG-63细胞后,Caspase-3和Caspase-9蛋白表达量增加;升高细胞内SOD的活性,降低MDA的含量。结论:参麦注射液抑制人骨肉瘤MG-63细胞增殖的作用机制与诱导细胞凋亡和将细胞周期阻滞于S期有关,其诱导凋亡的机制与Caspase家族,以及增加机体的抗氧化功能有关。     

青藤碱抑制Hela细胞增殖与诱导凋亡的P13K／Akt信号转导通路研究

目的：探讨青藤碱诱导Hela细胞凋亡的可能机制。方法：MTT法检测细胞生长情况、流式细胞仪检测细胞凋亡情况、Westernblot检测COX-2、P-AKT、caspase-3的表达情况。结果：与空白对照组比较，青藤碱可显著抑制Hela胞生长、促进Hela细胞凋亡及影响CDX-2、P-AKT、caspase-3的表达。结论：青藤碱可诱导Hela细胞凋亡，其机制与其对P13K／Akt-Caspase-3信号转导通路的影响有关。     

白毛藤诱导人结肠癌SW1116细胞凋亡作用及其机制研究

目的:研究白毛藤诱导人结肠癌细胞凋亡的作用及其机制。方法:荧光显微镜观察不同浓度白毛藤诱导SW1116细胞凋亡的作用,RT-PCR检测Bcl-2、Fas基因表达量的变化。结果:白毛藤具有诱导SW1116细胞凋亡的作用,并且上调Fas基因、降低Bcl-2基因的表达。结论:白毛藤促进SW1116细胞凋亡,其机制可能与激活Fas基因、抑制Bcl-2基因表达有关。     

淋巴细胞凋亡及中药调控的临床意义

细胞凋亡 (ａｐｏｐｔｏｓｉｓ)是细胞在基因调控下有序死亡的的方式 ,是多细胞机体维持完整性和自身稳定的一种基本生理机理 ,通过细胞凋亡机体消除损伤衰老与突变的细胞以维持生理平衡[1] 。近年来的研究发现 ,免疫细胞的分化发育及正确行使功能与细胞凋亡的关系密切[2 ] 。免疫细胞的凋亡成为当今细胞凋亡研究的一个热点 ,其中Ｔ、Ｂ淋巴细胞凋亡研究最多。1　淋巴细胞的凋亡细胞凋亡研究中最常用的模型要数淋巴细胞 ,80年代的细胞凋亡实验多数是用皮质激素诱导动物胸腺细胞凋亡。这些研究揭示了细胞凋亡的形态学特征 ,表现为凋亡细胞膜…     

Caspase-3与肿瘤细胞凋亡关系的中医药研究进展

细胞凋亡是机体在生长、发育和受到外来刺激时,清除多余、衰老和受损细胞,以保持内环境平衡、维持正常生理活动的自我调节机制。研究表明,肿瘤发生与细胞凋亡不足密切相关,而凋亡蛋白Caspase-3在细胞凋亡过程中发挥重要的作用。随着中医药研究的现代化进展,抗肿瘤中药对肿瘤组织中凋亡蛋白Caspase-3影响的研究逐步深入,探索Caspase-3与肿瘤细胞凋亡关系的中医药研究有其重大意义。参考文献30篇。     

Semi-synthesis of C20 3H-resiniferatoxin

There has recently been considerable interest concerning the biochemical and pharmacological mechanisms of action of resiniferatoxin (Rx). Rx is a daphnane diterpene ester, which is part of the phorbol ester family of diterpenes. We have synthesized ³H-Rx in a three-step process from the parent alcohol, resiniferonol (Ro). The tritium label is incorporated into the resiniferonol nucleus at the C₂₀ position, before esterification of ³H-Ro to ³H-Rx. This compound will be of use in the elucidation of the binding characteristics of Rx to its biochemical receptor site(s).     

Curcumin Serves as a Human Kv1.3 Blocker to Inhibit Effector Memory T Lymphocyte Activities

Curcumin, the principal active component of turmeric, has long been used to treat various diseases in India and China. Recent studies show that curcumin can serve as a therapeutic agent for autoimmune diseases via a variety of mechanisms. Effector memory T cells (T_EM, CCR7^‐CD45RO⁺ T lymphocyte) have been demonstrated to play a crucial role in the pathogenesis of T cell‐mediated autoimmune diseases, such as multiple sclerosis (MS) or rheumatoid arthritis (RA). Kv1.3 channels are predominantly expressed in T_EM cells and control T_EM activities. In the present study, we examined the effect of curcumin on human Kv1.3 (hKv1.3) channels stably expressed in HEK‐293 cells and its ability to inhibit proliferation and cytokine secretion of T_EM cells isolated from patients with MS or RA. Curcumin exhibited a direct blockage of hKv1.3 channels in a time‐dependent and concentration‐dependent manner. Moreover, the activation curve was shifted to a more positive potential, which was consistent with an open‐channel blockade. Paralleling hKv1.3 inhibition, curcumin significantly inhibited proliferation and interferon‐γ secretion of T_EM cells. Our findings demonstrate that curcumin is able to inhibit proliferation and proinflammatory cytokine secretion of T_EM cells probably through inhibition of hKv1.3 channels, which contributes to the potency of curcumin for the treatment of autoimmune diseases. This is probably one of pharmacological mechanisms of curcumin used to treat autoimmune diseases. Copyright © 2012 John Wiley & Sons, Ltd.     

Vasodilatory effects of ethanol extract of Radix Paeoniae Rubra and its mechanism of action in the rat aorta

Ethnopharmacological relevance

Radix Paeoniae Rubra (RPR) is an important traditional Chinese medicine (TCM) commonly used in clinic for a long history in China. RPR is the radix of either Paeonia lactiflora Pall. or Paeonia veitchii Lynch. RPR has a wide variety of pharmacological actions such as anti-thrombus, anti-coagulation, and anti-atherosclerotic properties, protecting heart and liver. However, the mechanisms involved are to be defined.

Aim of the study

The aim of the present study was to define the effect of Paeonia lactiflora Pall. extracts on vascular tension and responsible mechanisms in rat thoracic aortic rings.

Materials and methods

Ethanol extract of Paeonia lactiflora Pall. (EPL) was examined for their vascular relaxant effects in isolated phenylephrine-precontracted rat thoracic aorta.

Results

EPL induced relaxation of the phenylephrine-precontracted aortic rings in a concentration-dependent manner. Vascular relaxation induced by EPL was significantly inhibited by removal of the endothelium or pretreatment of the rings with N^G-nitro-l-arginine methylester (l-NAME) or 1H-[1,2,4]-oxadiazolo-[4,3-α]-quinoxalin-1-one (ODQ). Extracellular Ca²⁺ depletion or diltiazem significantly attenuated EPL-induced vasorelaxation. Modulators of the store-operated Ca²⁺ entry (SOCE), thapsigargin, 2-aminoethyl diphenylborinate and Gd³⁺, and an inhibitor of Akt, wortmannin, markedly attenuated the EPL-induced vasorelaxation. Further, the EPL-induced vasorelaxation was significantly attenuated by pretreatment with tetraethylammonium, a non-selective K_Ca channels blocker, or glibenclamide, an ATP-sensitive K⁺ channels inhibitor, respectively. Inhibition of cyclooxygenases with indomethacin, and adrenergic and muscarinic receptors blockade had no effects on the EPL-induced vasorelaxation.

Conclusions

The present study suggests that EPL relaxes vascular smooth muscle via endothelium-dependent and Akt- and SOCE-eNOS-cGMP-mediated pathways through activation of both K_Ca and K_ATP channels and inhibition of L-type Ca²⁺ channels.     

钩藤碱对AngⅡ诱导大鼠血管平滑肌细胞增殖的抑制作用

 目的研究钩藤碱(rhynchophylline,Rhy)对血管紧张素Ⅱ(angiotensinⅡ,AngⅡ)诱导大鼠血管平滑肌细胞(vascular smooth muscle cells,VSMCs)增殖的抑制作用及机制。方法采用细胞计数法和MTT比色法检测Rhy对AngⅡ诱导大鼠VSMCs增殖的影响;测定Rhy对AngⅡ作用的VSMCs上清液一氧化氮(nitric oxide,NO)含量和一氧化氮合酶(constitutive nitric oxide synthase,cNOS)活性的影响;实时定量聚合酶链式反应(RT-PCR)检测VSMCs中c-myc、NOS和高血压相关基因-1(hypertension related gene-1,rHRG-1)mRNA的表达。结果Rhy(3×10^-6～3×10^-7mol·L^-1)呈浓度依赖性地抑制AngⅡ诱导大鼠VSMCs的增殖,升高细胞上清液中NO的含量和NOS活性,降低c-myc mRNA,升高rHRG-1和NOS mRNA的表达。结论Rhy明显抑制AngⅡ诱导大鼠VSMCs的增殖,机制可能与增加VSMCs中NOS活性并促进NO的合成和释放以及下调c-myc、上调NOS和rHRG-1 mRNA的表达有关。     

Vasorelaxant effects and mechanisms of action of Heracleum sphondylium L. (Apiaceae) in rat thoracic aorta

Ethnopharmacological relevance

Aerial parts of Heracleum sphondylium L. (HS) are used in traditional medicine to treat hypertension. To provide pharmacological basis for this use, we investigated the vasorelaxant effects of a dichloromethane extract of HS (HSDE) and the mechanisms involved.

Materials and methods

Activity of HSDE was evaluated on rat isolated thoracic aortic rings.

Results

HSDE induced vasorelaxation in phenylephrine (PE, 10⁻⁶ mol/L) and high KCl—(6×10⁻² mol/L) pre-contracted aortic rings that was independent on the presence of endothelium. HSDE markedly decreased extracellular Ca²⁺-induced contraction in high-KCl and PE pre-challenged rings. It also inhibited the intracellular Ca²⁺ release sensitive to PE (10⁻⁶ M). The relaxant effect of HSDE were blunted by 4-amino-pyridine (4-AP, 10⁻³ mol/L), an inhibitor of voltage-dependent K⁺ channels.

Conclusion

Our results provide the first evidence that a dichloromethane extract of Heracleum sphondylium L. exhibits vasorelaxant properties through endothelium-independent mechanisms involving the inhibition of Ca²⁺ mobilization and changes in Kv channel conductances. These data argue for its use as antihypertensive therapy in traditional medicine.     

Ellagic Acid‐Induced Endothelium‐Dependent and Endothelium‐Independent Vasorelaxation in Rat Thoracic Aortic Rings and the Underlying Mechanism

The present study first investigated the mechanisms of vasorelaxation induced by ellagic acid (EA), which is one of the major compounds extracted from the pomegranate in the rat thoracic aorta. Male Wistar rats aged 10 to12 weeks weighing 250–350 g were used for the present study. The animals were killed by decapitation, and thoracic aortas were immediately excised and placed in Krebs solutions, cleaned, and freed from surrounding connective tissue. The isolated arteries were cut into rings (4‐ to 5‐mm long) and placed in 20‐mL tissue chambers filled with Krebs solution. Initially, the aortic rings were equilibrated for 60 min until a resting tension of 1.0 gr. After the equilibration period, aortic rings were firstly contracted with phenylephrine to increase tone. Once a stable contraction was achieved, EA (10^?8 to 10^?4 M) was added cumulatively on aortic rings with or without endothelium into organ bath. To characterize the mechanisms involved in EA‐induced vasorelaxant effect, the aortic rings were incubated with each inhibitor added to the bath for 30 min before phenylephrine was added to increase tone. The results of the present study have demonstrated in the rat thoracic aorta that EA causes vasorelaxations, which are partly modulated via endothelium‐dependent mechanisms and through inhibition of calcium influx. Copyright © 2012 John Wiley & Sons, Ltd.     

卡铂碳包铁纳米笼壳聚糖纳米球的制备和特征

 目的制备双重物理机制载药的卡铂碳包铁纳米笼壳聚糖纳米球,优选制备工艺,观测其特征。方法碳包铁纳米磁粉经稀盐酸处理后制得碳包铁纳米笼。以此纳米笼为磁性内核,壳聚糖为基质,采用反相微乳法制备卡铂碳包铁纳米笼壳聚糖纳米球。该纳米球通过基质包裹和碳包铁纳米笼吸附双重物理机制载药。利用正交实验设计优选纳米球制备工艺,观测纳米球的形貌、粒径、载药量、磁响应性和体外释药性能。结果碳包铁纳米笼与其前体相比,比表面积由20.98 m2·g^-1增至40.38 m²·g^-1,孔容由70 mm³·g^-1增至110mm³·g^-1,对卡铂的吸附量为9.6%。卡铂碳包铁纳米笼壳聚糖纳米球球形圆整,磁响应性强,平均粒径(207±21)nm,载药量为(11.40±1.31)%。纳米球的体外释药持续5 d,累计释药量依次为51%,68%,80%,87%,91%。结论良好的磁性内核和双重物理载药机制的有机结合能够优化纳米球的性能,制备出理想的磁靶向纳米药物载体。     

大黄素增强吉西他滨对裸鼠SW1990细胞移植瘤的抑瘤作用

目的:探讨大黄素增强吉西他滨对裸鼠SW1990细胞移植瘤的抑瘤作用及其机制。方法:在裸鼠SW1990细胞移植瘤的动物模型上,分为生理盐水组(N组),大黄素组(E组,40 mg.kg-1),吉西他滨组(G组,125 mg.kg-1),联合用药组(E+G组,大黄素40 mg.kg-1+吉西他滨80 mg.kg-1)。各组均采取腹腔注射药物,3 d 1次,前后共11次。观察各组用药过程中肿瘤体积、瘤重、体重的变化。末次用药后1周处死裸鼠取肿瘤组织。采用Tunel法检测各组肿瘤组织凋亡情况。采用免疫组织化学染色法和Western blot法检测肿瘤组织凋亡相关蛋白Bax,Bcl-2和Cytochrome C的表达变化。结果:末次用药后1周E+G组肿瘤体积和瘤重明显小于其他各组;Tunel法显示E+G组肿瘤细胞凋亡比其余各组显著增多;免疫组织化学染色和Western blot法显示E+G组的Bax,Cytochrome C的表达比其他各组显著增多,而Bcl-2的表达比其余各组明显降低,经计算Bcl-2/Bax显著下降。结论:大黄素能显著增强吉西他滨对裸鼠体内人胰腺癌SW1990细胞移植瘤的抑瘤效果,其机制可能是大黄素通过促进胰腺癌SW1990细胞中Bax的表达和抑制Bcl-2的表达,降低Bcl-2/Bax,继而促进线粒体Cytochrome C释放,从而增强吉西他滨对胰腺癌SW1990细胞移植瘤的促凋亡作用,达到增强吉西他滨在体内的抑瘤效果。     

Hypotensive effect of Aspidosperma subincanum Mart. in rats and its mechanism of vasorelaxation in isolated arteries

Ethnopharmacological relevance

Aspidosperma subincanum is a medicinal herb that is known to be useful for the treatment of cardiovascular-related illnesses. However, its effects and pharmacological mechanisms of action have not been studied. The aim of the present study was to determine the effect of an ethanol extract of Aspidosperma subincanum (EEAS) on blood pressure (in vivo) and vascular tension (in vitro) in the rat thoracic aorta.

Materials and methods

Catheters were inserted into the right femoral vein and artery of anesthetized rats for EEAS infusion and the measurement of blood pressure, heart rate and aortic blood flow (flow probes were placed around the aorta). Moreover, the vasodilator effect of EEAS in isolated pre-contracted rat aortas was examined.

Results

Intravenous infusion of EEAS resulted in significant and dose-dependent hypotension, bradycardia and increased aortic blood flow. In isolated arteries, EEAS (0–27 μg/mL) induced a concentration-dependent relaxation of pre-contracted aortic rings; endothelial denudation potentiated this effect. Pre-treatment of the aortic rings with ODQ, an inhibitor of soluble guanylyl cyclase (sGC); MDL-12,330A, an inhibitor of adenylyl cyclase (AC); or CPA, a SERCA inhibitor, reduced EEAS-induced vasorelaxation. Treatment with an EEAS impaired contractions induced by phenylephrine (an adrenergic agonist) and Bay K 8644 (an L-type Ca²⁺ channel activator). The blockade of K⁺ channels with tetraethylammonium, clotrimazole, glibenclamide or 4-aminopyridine reduced the relaxation stimulated by EEAS.

Conclusions

These findings suggest that EEAS induces hypotension associated with bradycardia. EEAS induces endothelium-independent vascular relaxation. The sGC/cGMP and AC/cAMP pathways, SERCA activation and Ca²⁺ and K⁺ flux across the sarcolemma, are likely involved in this relaxation.