丹参酮类化合物对NB4细胞的增殖抑制与构效关系探讨

目的比较丹参酮类化合物对人急性早幼粒细胞白血病NB4细胞的体外增殖抑制作用,并探讨其分子结构与细胞毒性之间的关系。方法采用改良MTT法测定不同浓度的丹参酮类化合物与细胞共培养一定时间后对NB4细胞的增殖抑制作用;采用倒置显微镜观察其细胞形态。结果供试丹参酮类化合物均能有效抑制NB4细胞的增殖,其抑制作用呈明显的时间和剂量依赖性。与NB4细胞共培养24 h后,二氢丹参酮Ⅰ与丹参酮Ⅰ的IC50值分别为1.86、3.62μg·mL-1,丹参酮ⅡA和隐丹参酮的IC50值均大于10μg·mL-1;共培养48 h后二氢丹参酮Ⅰ、丹参酮Ⅰ、丹参酮ⅡA、隐丹参酮的IC50值分别为0.65、1.41、1.83、5.41μg·mL-1;72 h后的IC50值分别为0.28、0.33、0.45、2.59μg·mL-1。结论 4种丹参酮类化合物对NB4细胞均具有增殖抑制作用,作用强度大小依次为二氢丹参酮Ⅰ、丹参酮Ⅰ、丹参酮ⅡA、隐丹参酮,提示丹参酮类化合物的A环为芳环时可增强细胞毒性,C环的呋喃环结构可能影响其细胞毒性。     

叶黄素对SGC-7901细胞增殖抑制及凋亡诱导作用

叶黄素(Lutein)是广泛存在于蔬菜、花卉和水果中的一种类胡萝卜素,绿色叶菜和万寿菊中含量最为丰富[1].近年来大量流行病学证据表明[2],叶黄素在预防视黄斑退化、心血管疾病,阻断肿瘤发生与发展及增强机体免疫力等方面都有着广泛的生物学活性.     

Effects of arsenic trioxide, all-trans-retinoic acid and dexamethasone on NB4 cell line

Background and the purpose of the study

Experimental and preclinical observations have indicated that combination therapy with all-trans-retinoic acid (ATRA) and arsenic trioxide (ATO) may strongly enhance their therapeutic effects in the treatment of acute promyelocytic leukemia (APL). Whilst dexamethasone (Dex) is routinely used for the control of APL- differentiation syndrome, its effect on the pharmacodynamics of ATO is not clear. Therefore, in this study, effects of therapeutic concentrations of ATO, ATRA and Dex and their sequential usages on the proliferation, differentiation and apoptosis in t(15;17)-positive NB4 cells was investigated.

Methods

Cells were treated with therapeutic concentrations of ATO, ATRA and Dex either as single or in combination and cell proliferation was assessed by XTT assay. Expression of CD11b as an indicator of cell differentiation and the percentage of 7-AAD positive cells as a marker of apoptosis were determined by flow cytometry.

Results

ATO, but not ATRA and Dex, decreased proliferation of the cells dose-dependently. Pre-treatment of the cells with any of the drugs did not alter the effects of other drugs on the proliferation. Pre-treatments with Dex blocked the apoptotic effect of ATO (1 µM).

Conclusion

No improvement or antagonistic effects was observed with the pretreatment/ combination of the ATO and ATRA on the differentiation and apoptosis of the cells. It is possible that concomitant usage of Dex with apoptotic doses of ATO in APL patients counteract therapeutic effects of ATO.     

虫草素体外抑制NB4细胞增殖与诱导细胞凋亡作用研究

目的观察虫草素体外对急性早幼粒细胞性白血病细胞（NB4细胞）的抑制增殖和诱导凋亡作用。方法将0.5,1.0,1.5,2.0 mg•mL 1虫草素在体外与NB4细胞共同培养,采用细胞计数、噻唑蓝（MTT）法检测不同浓度虫草素在24,48,72 h对NB4细胞增殖的抑制作用;用细胞瑞氏染色法、Hoechst33258荧光染色法、DNA亚二倍体检测法和线粒体膜蛋白检测法观察虫草素诱导NB4细胞凋亡的作用。结果与对照组比较,不同浓度虫草素均能显著抑制NB4细胞增殖,并呈剂量和时间依赖的量效关系;不同浓度虫草素作用24 h后均能显著促进NB4细胞凋亡。结论虫草素在体外能明显抑制NB4细胞增殖,并诱导细胞凋亡。     

姜黄素对NB4细胞的增殖抑制作用及其作用机制

目的: 探讨姜黄素对急性早幼粒细胞白血病细胞株NB4细胞的增殖抑制作用及其作用机制。方法:以 0, 5, 10, 20, 30μmol·L-1浓度的姜黄素作用于体外培养的NB4细胞,分别于培养后 12, 24,36, 48, 60, 72h用四氮唑蓝比色法检测细胞生长抑制率,应用流式细胞仪及Hoechst33258荧光染色法观察细胞凋亡,采用聚合酶链反应 酶标记免疫吸附法检测细胞凋亡前后的端粒酶活性。结果: 10 ~30mol·L-1浓度的姜黄素作用 24 ~72h可显著降低NB4细胞端粒酶活性,抑制细胞的生长,诱导细胞发生凋亡。姜黄素对细胞的增殖抑制作用呈现出一定的剂量 效应与时间 效应关系, 细胞凋亡率在药物作用 60h左右达高峰。结论:姜黄素具有显著的体外抗白血病作用,降低细胞端粒酶活性可能是其重要作用机制之一。     

Genotoxic effects of tanshinones from Hyptis martiusii in V79 cell line.

The genotoxic effect of two tanshinones isolated from roots of Hyptis martiussi Benth (Labiatae) was studied using V79 (Chinese hamster lung) cells by the alkaline comet assay and micronucleus test. Tanshinones were incubated with the cells at concentrations of 1, 3, 6 and 12 microg/mL for 3 h. Tanshinones were shown to be quite strongly genotoxic against V79 cells at all tested concentrations. The data obtained provide support to the view that tanshinones has DNA damaging activity in cultured V79 cells under the conditions of the assays.     

Macrocyclic inhibitors of HCV NS3-4A protease: design and structure activity relationship

HCV NS3, a serine protease, that when bound to NS-4A cofactor facilitates development of mature virons by catalyzing cleavage of a single polyprotein to form functional and structural proteins of HCV. X-ray structure of the enzyme reveal a very shallow binding pocket at the catalytic site which makes development of inhibitors a daunting task. Various novel approaches have been used to design, preorganized, depeptidized macrocyclic inhibitors linking the P(2)-P(4) residues and P(1)-P(3) groups. The design and structure activity relationship of these macrocyclic inhibitors are reviewed in the following article. X-ray structure of inhibitor bound to the active site of the enzyme is also discussed. Macrocyclization proved to be an effective tool for depeptidization of peptidic inhibitors, imparting enhanced metabolic stability and improved pharmacokinetic properties in the resultant molecules.     

Three-dimensional quantitative structure activity relationship analysis of anilinoquinazolines for c-Src kinase inhibition

Three-dimensional quantitative structure activity relationship (3D-QSAR) models was developed using molecular field analysis (MFA) for 36 anilinoquinazoline derivatives, inhibiting c-Src kinase. The QSAR model was developed using 29 compounds and its predictive ability was assessed using a test set of seven compounds. The predictive 3D-QSAR model has conventional r ² values of 0.961 while the cross-validated coefficient q ² and bootstrap correlation coefficient r _BS² values of 0.910 and 0.957, respectively. The developed model provides a powerful tool to design potent c-Src inhibitors as novel antitumor agents. Six new inhibitors were designed and their pIC₅₀ were predicted.     

Analgesic and antioxidant activity of mangiferin and its derivatives: the structure activity relationship

Mangiferin, 2-beta-D-glucopyranosyl-1,3,6,7-tetrahydroxy-9H-xanthen-9-one, obtained directly from methanolic extracts of Bombax ceiba leaves in substantial amounts demonstrated strong antioxidant activity (EC(50) 5.8+/-0.96 mug/ml or 13.74 muM) using DPPH assay comparable to rutin, commonly used as antioxidant for medical purposes. The acetyl and cinnamoyl derivatives were found to be less active than mangiferin whereas, methyl and 3,6,7-trimethylether tetraacetate derivatives were inactive implying that for antioxidant activity, free hydroxyl groups and catechol moiety are essential. Moreover, mangiferin showed hepatoprotective activity against carbon tetrachloride induced liver injury further supporting the free radical scavenging property in the in vivo system. Additionally, plant extracts and mangiferin failed to exhibit acute anti-inflammatory activity whereas, it displayed significant analgesic effect in acetic acid-induced writhing and hot plate tests in mice. Using naloxone, it was revealed that plant extracts induced analgesia was independent of opioid receptor, whereas, mangiferin demonstrated significant interaction with it at peripheral site with a slight contribution at the neuronal level.     

新头孢菌素衍生物的定量构效关系研究

目的　研究一类新合成的抗流感嗜血杆菌头孢菌素衍生物的定量构效关系。方法　应用半经验量子化学方法和误差反向传播人工神经网络的方法。结果　系统计算了4 8个头孢菌素类化合物的1 8个分子描述符,从中筛选出7个描述符。随机挑选4 3个化合物作为训练样本集,5个化合物作为测试样本集,检验结果表明模型具有较高的精度(检验样本最大相对误差小于5 %)。结论　头孢菌素化合物的LUMO能量、疏水性、C8原子及C3 位取代基的净电荷是影响其抗菌活性的主要因素,所建立的定量构效关系模型能够有效地进行体外抗流感嗜血杆菌活性与头孢菌素类化合物分子描述符的相关性分析。     

曲格列酮对白血病NB4细胞的增殖抑制作用及其作用机制

目的:探讨过氧化物酶体增殖物激活受体γ(PPARγ)激动剂曲格列酮(troglitazone,TGZ)对白血病NB4细胞的增殖抑制作用及其作用机制。方法:以不同浓度的TGZ(0～80μmol/L)作用于体外培养的NB4细胞0、24、48、72h,应用MTT法检测细胞生长抑制率,Hoechst33258染色法检测细胞凋亡,琼脂糖凝胶电泳观察细胞凋亡时的DNA梯状条带。用免疫印迹法(Western Blot)检测Caspase-3及其裂解底物多聚(ADP-核糖)聚合酶PARP[(poly(ADP-ribose)polymerase)]表达水平的变化,并对凋亡调节蛋白Bax及Bcl-2的表达水平进行检测。结果:20μmol/L以上的TGZ可显著抑制细胞的生长,在Hoechst染色后可见典型的细胞凋亡现象,并呈现出明显的量-效与时-效关系,药物作用72h后在琼脂糖凝胶电泳上可见明显的DNA梯状条带。WesternBlot检测结果表明,Caspase-3被活化出现20000的亚单位,同时PARP被裂解出现89000的亚单位片段。药物作用48h后凋亡抑制蛋白Bcl-2的表达水平明显降低,而促凋亡蛋白Bax的表达水平显著升...     

茉莉素对人神经母细胞瘤细胞株SH-SY5Y的生长抑制作用及其机制研究

目的探讨茉莉素对人神经母细胞瘤细胞株SH-SY5Y的生长抑制作用及其机制。方法0·5~2·5mmol·L-1茉莉酸甲酯、顺式茉莉酮、茉莉酸分别处理SH-SY5Y细胞6~24h后,MTT法检测瘤细胞生长活性;PI单染流式细胞术检测细胞周期;Hoechst 33258荧光染色法、AnnexinⅤ-FITC/PI双染流式细胞术检测细胞凋亡;RT-PCR检测PCNA、cyclin D1、N-myc基因表达。结果各浓度茉莉素作用后,SH-SY5Y细胞呈时间、浓度依赖性生长抑制,其中茉莉酸甲酯作用最强;0·5~2·5mmol·L-1茉莉酸甲酯作用24h后,细胞生长抑制率为5·75%~88·7%(P<0·01),IC50为1·47mmol·L-1;2·5mmol·L-1茉莉酸甲酯、顺式茉莉酮、茉莉酸作用后,G2/M期细胞比率增高,部分瘤细胞发生典型的凋亡形态学改变,细胞凋亡率分别为78·9%(P<0·01)、37·46%(P<0·01)、8·32%(P<0·01);0·5~2·5mmol·L-1茉莉酸甲酯作用24h后,PCNA、N-myc基因表达分别下调33·1%~61·8%(P<0·01)、15·3%~50·6%(P<0·01),而cyclinD1基因表达无变化(P>0·05)。结论茉莉素能通过诱导细胞周期阻滞和凋亡抑制人神经母细胞瘤细胞株的生长活性,下调PCNA、N-myc基因表达可能是其作用机制之一。     

褪黑素诱导NB4细胞凋亡及机制的研究

目的探讨褪黑素对NB4细胞凋亡的增殖抑制和凋亡诱导作用。方法将0、10~(-8)、10~(-6)、10~(-4)mol/L褪黑素在体外与NB4细胞共同培养,应用噻唑蓝(MTT)比色法测定细胞活性,Hoechst荧光染色检测细胞凋亡,流式细胞技术检测凋亡细胞比例,分光光度计检测上清液中Caspase-3及Caspase-9含量。结果褪黑素能显著抑制NB4细胞增殖,促进细胞凋亡,增加凋亡因子的表达。结论褪黑素促进NB4细胞凋亡的机制可能与增加Caspase-3及Caspase-9表达有关。     

Quantitative structure activity relationship studies on the flavonoid mediated inhibition of multidrug resistance proteins 1 and 2

In the present study, the effects of a large series of flavonoids on multidrug resistance proteins (MRPs) were studied in MRP1 and MRP2 transfected MDCKII cells. The results were used to define the structural requirements of flavonoids necessary for potent inhibition of MRP1- and MRP2-mediated calcein transport in a cellular model. Several of the methoxylated flavonoids are among the best MRP1 inhibitors (IC(50) values, ranging between 2.7 and 14.3 microM) followed by robinetin, myricetin and quercetin (IC(50) values ranging between 13.6 and 21.8 microM). Regarding inhibition of MRP2 activity especially robinetin and myricetin appeared to be good inhibitors (IC(50) values of 15.0 and 22.2 microM, respectively). Kinetic characterization revealed that the two transporters differ marginally in the apparent K(m) for the substrate calcein. For one flavonoid, robinetin, the kinetics of inhibition were studied in more detail and revealed competitive inhibition with respect to calcein, with apparent inhibition constants of 5.0 microM for MRP1 and 8.5 microM for MRP2. For inhibition of MRP1, a quantitative structure activity relationship (QSAR) was obtained that indicates three structural characteristics to be of major importance for MRP1 inhibition by flavonoids: the total number of methoxylated moieties, the total number of hydroxyl groups and the dihedral angle between the B- and C-ring. Regarding MRP2 mediated calcein efflux inhibition, only the presence of a flavonol B-ring pyrogallol group seems to be an important structural characteristic. Overall, this study provides insight in the structural characteristics involved in MRP inhibition and explores the differences between inhibitors of these two transporters, MRP1 and MRP2. Ultimately, MRP2 displays higher selectivity for flavonoid type inhibition than MRP1.     

Use-dependent inhibition of hHCN4 by ivabradine and relationship with reduction in pacemaker activity

BACKGROUND AND PURPOSE: Ivabradine, a specific and use-dependent I(f) inhibitor, exerts anti-ischaemic activity purely by reducing heart rate. The aim of this work was to characterize its effect on the predominant HCN channel isoform expressed in human sino-atrial nodes (hSAN), to determine its kinetics in HCN channels from multicellular preparations and rate-dependency of its action. EXPERIMENTAL APPROACH: RT-PCR analysis of the four HCN channel isoforms was carried out on RNAs from hSAN. Patch-clamp and intracellular recordings were obtained from CHO cells stably expressing hHCN4 and isolated SAN, respectively. Beating rate of rat isolated atria was followed using a transducer. KEY RESULTS: hHCN4 mRNAs were predominant in hSAN. Ivabradine induced a time-dependent inhibition of hHCN4 with an IC(50) of 0.5 microM. In rabbit SAN, ivabradine progressively reduced the frequency of action potentials: by 10% after 3 h at 0.1 microM, by 14% after 2 h at 0.3 microM and by 17% after 1.5 h at 1 microM. After 3h, ivabradine reduced the beating rate of rat right atria with an IC(30) of 0.2 microM. The onset of action of ivabradine was use-dependent rather than time-dependent with slower effects than caesium, an extracellular I (f) blocker. Ivabradine 3 microM decreased the frequency of action potentials in SAN from guinea-pig, rabbit and pig by 33%, 21% and 15% at 40 min, respectively. CONCLUSIONS AND IMPLICATIONS: The use-dependent inhibition of hHCN4 current by ivabradine probably contributes to its slow developing effect in isolated SAN and right atria and to its increased effectiveness in species with rapid SAN activity.     

Synthesis, anti-inflammatory, and structure antioxidant activity relationship of novel 4-quinazoline

The practice of medicinal chemistry is devoted to the discovery and development of new agents for treating disease. A new derivative of methyl 2-((E)-3-(3,4-dihydroxyphenyl)acrylamido)benzoate 2 was synthesized by reacting the amino group of methyl anthranilate 1 with caffeic acid in the presence of PCl₃. Cyclcondensation of 2 with hydrazine hydrate afforded the corresponding 2,3-dihydro-2-(3,4-dihydroxyphenyl) pyrazolo[5,1-b]quinazolin-9(1H)-one 3. The median lethal doses (LD_50s) of compounds 2 and 3 in mice were 1,135 and 495 mg/kg b.w., respectively. The anti-inflammatory, reducing power, chelating activity on Fe²⁺, free radical-scavenging, and total antioxidant activities were more pronounced in compound 2 compared to compound 3. On the other hand, antipyretic activity was more pronounced in compound 3 compared to compound 2. Antioxidant activity of compounds 2 and 3 increased with increased concentrations. Total antioxidant activity of compounds 2, 3 and both standards decreased in the order of α-tocopherol > compound 2 > trolox > BHA > BHT > compound 3. Administration of compounds 2 and 3 orally to the rats at dose of 50, 100, and 150 mg/kg b.w., for 10 days showed non-significant changes in serum level of GOT, GPT, ALP, γ-GT, and LDH as compared with the control group. In addition, oral administration of the compound 2 at a concentration of 100 and 150 mg/kg b.w. and compound 3 at a concentration of 150 mg/kg b.w. daily to normal rats for 10 days showed a significant increase in liver GSH, GPx, GR, and GST activities and significant decrease in TBARS level. But, administration of diclofenac sodium (30 mg/kg b.w.) orally to the rats daily for 10 days to rats showed significant increase in serum SGOT, SGPT, ALP, γ-GT, and LDH and significant decrease in liver GSH, GPx, GR, and GST activities. These findings suggest that compounds 2 and 3 exhibited good antioxidant and anti-inflammatory activity and also showed effects on liver enzymes.     

Growth-inhibitory and apoptosis-inducing effects of tanshinones on hematological malignancy cells and their structure-activity relationship

This study has investigated the growth-inhibitory and apoptosis-inducing effects of dihydrotanshinone, tanshinone I, tanshinone IIA, and cryptotanshinone on hematological malignancy cell lines, aiming to explore their structure-activity relationship. The growth-inhibitory effects of the tanshinones on K562 and Raji cells were assessed using a modified MTT assay; the apoptosis-inducing effects were assessed by fluorescence microscopy and flow cytometry analysis. The changes in cellular morphology were observed using an inverted phase-contrast microscope. MTT results revealed that these tanshinones inhibited cell proliferation in a concentration-dependent and time-dependent manner. The IC50 values of dihydrotanshinone, tanshinone I, tanshinone IIA, and cryptotanshinone for K562 cells were 3.50, 13.52, 19.32, and 47.52 μmol/l at 24 h; 1.36, 4.70, 5.67, and 22.72 μmol/l at 48 h; and 1.15, 1.59, 2.82, and 19.53 μmol/l at 72 h, and the values for Raji cells were 3.30, 4.37, 12.92, and 52.36 μmol/l at 24 h; 1.55, 1.71, 6.54, and 25.45 μmol/l at 48 h; and 1.07, 1.38, 1.89, and 18.47 μmol/l at 72 h. The flow cytometry analysis demonstrated that these tanshinones induced apoptosis of K562 cells in a concentration-dependent manner, and dihydrotanshinone as well as tanshinone I were more potent than tanshinone IIA and cryptotanshinone. Some noticeable apoptotic morphologies could be observed by fluorescence microscopy on tanshinones-treated Raji cells. Collectively, these tanshinones caused growth inhibition and apoptosis in hematological malignancy cell lines, with dihydrotanshinone being the most potent, followed by tanshinone I, tanshinone IIA, and cryptotanshinone. These results suggested that the structure of aromatic ring A enhanced the cytotoxicity and the structure of ring C may have contributed to the cytotoxicity, but the mechanisms need to be further investigated.     

柠檬醛抑制NB4细胞生长并诱导凋亡机制的研究

目的研究柠檬醛（Citral）对急性早幼粒细胞白血病NB4细胞株生长抑制和诱导凋亡作用;研究柠檬醛诱导NB4细胞凋亡可能的机制。方法采用台盼蓝拒染法测定细胞活力;采用CCK-8比色法检测柠檬醛对细胞增殖的影响;形态学观察和流式细胞仪检测细胞凋亡;流式细胞仪检测线粒体膜电位（MMP）改变情况。结果 2～20 mg·L^-1柠檬醛具有时间和剂量依赖方式抑制NB4细胞增殖,诱导细胞凋亡,明显降低细胞线粒体膜电位。结论柠檬醛诱导NB4细胞内线粒体膜电位崩溃可能是引起细胞凋亡的机制之一。     

拓扑替康对宫颈癌HeLa细胞的抑制及放疗增敏作用

目的研究拓扑替康(TPT)对宫颈癌HeLa细胞的抑制和放疗增敏作用。方法噻唑蓝法(MTT)和流式细胞仪法(FCM)检测不同浓度TPT在不同作用时间下对HeLa细胞的抑制作用;细胞克隆形成法进一步检测TPT作用24h和48h后对HeLa细胞抑制及放疗增敏作用,应用单击多靶模型拟合细胞存活曲线并计算放疗增敏比。结果TPT对宫颈癌HeLa细胞的抑制作用呈时间剂量依赖性,作用浓度越大、作用时间越长,对肿瘤细胞的抑制程度越大(P<0.05)。TPT作用24h时的半数致死浓度(IC50)为8μg/mL,显著低于作用48h和72h时IC50(P<0.05)。FCM检测TPT联合放射线辐射对HeLa细胞的抑制率为68.2%,明显高于单化疗组(45.7%)和单放射线辐射组(14.4%)(P<0.05)。细胞克隆形成法表明TPT作用24h和48h后联合不同剂量放射线,对HeLa细胞的杀伤作用明显增强,提示TPT具有放疗增敏作用。应用单击多靶模型拟合生存曲线得到24h和48h放疗增敏比为1.167和1.344。结论TPT对宫颈癌HeLa细胞具有抑制和放疗增敏作用,呈时间剂量依赖性,其机制可能与细胞放射线损伤修复功能抑制有关。