光甘草定-富勒醇联合应用对抑制酪氨酸酶活性和清除DPPH·的协同作用

目的:探索富勒醇与光甘草定联合应用对酪氨酸酶活性的影响及对DPPH·的清除效果。方法:采用比色法测定光甘草定、富勒醇单独及联合应用对酪氨酸酶活性的抑制及对DPPH·的清除作用。结果:光甘草定对酪氨酸酶的活性有抑制作用,IC50为20.38μmol·L-1;富勒醇对酪氨酸酶仅有很微弱的活性抑制作用且无IC50值;光甘草定、富勒醇清除DPPH·的IC50分别为14.31,47.66 mg·L-1。低浓度光甘草定与富勒醇联合应用,体系对酪氨酸酶的抑制活性明显增强;清除DPPH·的效能也同样增强,合并指数为0.72。结论:低浓度光甘草定与富勒醇联合对酪氨酸酶的抑制作用明显增强;同时,对DPPH·的清除效率呈现协同作用。     

海带硫酸多糖对胶质瘤细胞增殖的抑制作用

目的探讨海带硫酸多糖(LPS)对大鼠胶质瘤细胞(C6)的体外生长及细胞周期的影响。方法以不同浓度的LPS处理C6细胞,用细胞计数法测定细胞增殖情况,流式细胞仪记录细胞周期的改变,用比色法测定谷胱甘肽-S-转移酶(GSTs)的含量变化。结果随着LPS浓度的增加与作用时间的延长,LPS使细胞增殖能力下降,细胞周期阻滞在G0/G1期,且LPS可以降低GSTs的活性。结论 LPS可明显抑制C6细胞的增殖,并通过阻滞细胞周期促进C6细胞凋亡;LPS还可抑制GSTs活性。     

槲皮素单硫酸酯钠对 HL-60细胞生长的影响(英文)

通过观察槲皮素单硫酸酯钠 (SQMS)对 HL-60细胞毒作用 ,细胞周期变化 ,胞内 Ca2 +浓度([Ca2 +]i)变化及蛋白激酶 CK2活性的变化研究SQMS对 HL- 60细胞生长的影响 .发现 SQMS(2 0- 1 2 0μmol· L-1)可浓度依赖性抑制 HL- 60细胞的生长 ,阻断 HL- 60细胞于 G0 /G1期 ;SQMS(1 0 0μmol· L-1)可使 [Ca2 +]i 由 (1 0 5± 9) nmol·L-1上升到 (2 0 1± 1 3) nmol· L-1;低浓度 SQMS(0 .55-8.8μmol· L-1)可显著抑制从 HL- 60细胞中纯化的蛋白激酶 CK2的活性 .结果提示 ,SQMS可抑制HL- 60细胞生长 ,其机理可能与抑制 HL- 60细胞中蛋白激酶 CK2的活性 ,提高细胞 [Ca2 +]i 及促进细胞分化有关 .     

20(S)-原人参二醇对SMMC-7721细胞体内外作用的研究

目的观察不同剂量的20(S)-原人参二醇(Protopanaxadiol,PPD)在体内外对人肝癌细胞株SMMC-7721抗肿瘤作用。方法建立人肝癌裸鼠皮下移植瘤模型,观察20(S)-原人参二醇的肿瘤抑制作用。MTT比色法检测20(S)-原人参二醇对SMMC-7721细胞的增殖抑制作用,Ho-echst33342核染色观察细胞凋亡形态学改变,采用FITC-An-nexinⅤ/PI双染流式细胞术分析凋亡情况,同时检测Caspase-3活性。结果在体内,PPD可抑制SMMC-7721细胞裸鼠异种移植瘤生长;在体外,PPD对SMMC-7721细胞的增殖具有明显的抑制及诱导其凋亡作用,呈时间和剂量依赖性,Hoechst33342核染色可见凋亡小体,同时伴有Caspase-3活性的增加。结论20(S)-原人参二醇在体内外均可抑制SMMC-7721细胞增殖,并诱导其凋亡,其机制可能通过活化Caspase-3诱导细胞凋亡而发挥抗肿瘤作用。     

雷公藤内酯醇体内外对HL-60细胞作用的研究

目的探讨雷公藤内酯醇(triptolide,TPL)在体内外对人髓系白血病细胞株HL-60的作用。方法运用MTT比色法检测TPL对HL-60细胞的增殖抑制作用,采用TdT酶介导的缺口末端标记法(TUNEL)检测TPL对HL-60细胞的诱导凋亡作用;建立HL-60裸鼠异种移植瘤模型,观察经TPL治疗后的肿瘤抑制率。结果在体外,TPL对HL-60细胞的增殖具有明显的抑制及诱导凋亡作用,呈时间和剂量依赖性;在体内,TPL可抑制HL-60细胞裸鼠异种移植瘤生长,抑制率最高可达53.5%。结论TPL在体内外均可抑制HL-60细胞增殖,并诱导其凋亡。     

二氨基肉豆蔻酸活化胱天蛋白酶依赖的线粒体途径诱导HL-60细胞凋亡

目的探讨二氨基肉豆蔻酸(D-82)诱导HL-60细胞凋亡的作用及与线粒体途径活化的关系。方法 D-821.5,3和6mg·L-1处理HL-60细胞6h,或D-826mg·L-1处理细胞6,12及24h后,锥虫蓝染色法检测细胞存活率;AO-EB染色分析凋亡率;琼脂糖凝胶电泳检测DNA损伤;罗丹明123染色流式细胞术检测线粒体膜电位变化;比色法测定胱天蛋白酶3和胱天蛋白酶9活性;Western印迹法检测胞浆和线粒体细胞色素c(Cytc)及细胞中Bcl-2和Bax蛋白表达。结果 D-82的浓度和作用时间与HL-60细胞存活率密切相关,相关系数分别为0.938(P<0.01)和0.809(P<0.05)。D-821.5,3和6mg·L-1处理HL-60细胞6h,细胞存活率分别为(81±11)%,(70±9)%和(56±11)%;D-826mg·L-1作用HL-60细胞12和24h,存活率降至(36±7)%和(24±9)%。D-821.5,3和6mg·L-1诱导HL-60细胞出现凋亡形态学改变及DNA阶梯状条带,凋亡率从正常对照组的(2±2)%上升至(18±4)%,(40±11)%和(75±11)%(n=3,P<0.05)。D-823和6mg·L-1组,罗丹明平均荧光强度由正常对照组的24±5降至20±5及12±4(n=3,P<0.05),说明线粒体膜电位降低;D-823和6mg·L-1组胱天蛋白酶3活性分别增加39%和125%,胱天蛋白酶9活性分别增加61%和145%(P<0.05,P<0.01)。与正常对照组比,D-823和6mg·L-1组线粒体Cytc表达分别降低22%和38%(P<0.05,P<0.01),胞浆中Cytc表达分别升高22%和65%(P<0.05);Bax表达分别增加45%和116%(P<0.05,P<0.01),Bcl-2表达分别减少27%和40%(P<0.01)。结论 D-82通过活化胱天蛋白酶依赖的线粒体途径诱导HL-60细胞凋亡。     

原发性高血压患者外周血单个核细胞中MMP-9和TIMP-1的表达及意义

目的探讨原发性高血压(EH)患者外周血单个核细胞中基质金属蛋白酶9(MMP-9)和基质金属蛋白酶组织抑制因子1(TIMP-1)的表达及意义。方法 EH患者94例(EH组)分为单纯EH(A组,20例)和合并颈动脉粥样硬化(B组,74例),另选健康人60例为对照(C组),采用实时荧光定量PCR检测外周血单个核细胞中MMP-9 mRNA、TIMP-1 mRNA水平。结果EH组MMP-9mRNA水平和MMP-9mRNA/TIMP-1mRNA比值为1.264±0.135和2.313±0.335,B组MMP-9mRNA水平和MMP-9mRNA/TIMP-1mRNA比值为1.353±0.159和2.549±0.413,均高于C组的0.796±0.078和1.132±0.180(P<0.05)。A组的上述指标与C组无明显差异(P>0.05)。结论 EH患者外周血单个核细胞中MMP-9mRNA和TIMP-1mRNA可作为EH相关血管活性异常的间接标志物。     

维康醇诱导小鼠B16F0细胞凋亡的研究

目的本研究探讨维康醇诱导小鼠黑色素瘤B16F0细胞凋亡的机制。方法噻唑蓝(MTT)法检测维康醇对小鼠B16F0细胞增殖的影响;台盼蓝拒染法检测细胞致死率;吖啶橙/溴乙啶(AO/EB)荧光染色法观察细胞凋亡形态;Hoechst 33258染色观察药物处理后细胞形态的变化;流式细胞仪Annexin V-FITC/PI检测细胞凋亡率;Caspase-9/3试剂盒检测半胱氨酸蛋白酶-9(Caspase-9)和半胱氨酸蛋白酶-3(Caspase-3)的活性;实时荧光定量(Real-Time PCR)法检测Bax、Bcl-2基因表达水平。结果维康醇能抑制B16F0细胞的恶性增殖,并呈剂量依赖性(P<0.05或P<0.01);细胞致死率也不断上升(P<0.05或P<0.01);在荧光显微镜下发现维康醇作用于B16F0细胞后出现明显的凋亡形态;随着维康醇浓度的增加,细胞凋亡率呈剂量依赖性增长(P<0.05或P<0.01);Caspase-3、Caspase-9活性逐渐升高(P<0.05或P<0.01);Bax/Bcl-2表达的比率上调(P<0.01)。结论维康醇能够通过抑制B16F0细胞的恶性增殖,最终诱导细胞的凋亡。其机制是通过上调Bax/Bcl-2表达的比率,活化Caspase-9并进一步激活Caspase-3诱导B16F0细胞凋亡。推测维康醇诱导B16F0细胞凋亡是通过线粒体调控的内源通路介导的。     

基质金属蛋白酶与胃癌侵袭转移研究进展

基质金属蛋白酶(MMPs)是能降解基质的蛋白水解酶(丝氨酸蛋白酶、半胱氨酸蛋白酶、天门冬氨酸蛋白酶、基质金属蛋白酶)中较重要的—类。其活性被体内天然存在的基质金属氨酸蛋白酶组织抑制剂(Tissue inhibitors of metalloproteinases TIMPs)所抑制。二者平衡参与细胞外基质(Extracellular matrix，ECM)的合成与降解，使基质处于不断更新、降解、重塑的动态平衡，维持正常组织机构与功能及细胞的生长分化。二者的平衡也影响肿瘤侵袭转移的生物学行为。MMPs与TIMPs在胃癌的侵袭转移中的作用研究，取得了很多进展，现加以综述。     

MPP+和6-羟基多巴胺对C6胶质瘤细胞摄取谷氨酸的影响

目的：研究1-甲基4-苯基-吡啶离子(MPP^ )和6-羟基多巴胺(6-OHDA)对C6胶质瘤细胞摄取谷氨酸(Glu)的影响。方法：应用放射免疫法测定C6胶质瘤细胞对培养液中[^3H]-D，L-谷氨酸的摄取；应用四氮唑(MTY)比色法检测胶质瘤细胞的活性。结果：6-OHDA和MPP^ 均不同程度地抑制C6胶质瘤细胞摄取Glu；6-OHDA显抑制C6胶质瘤细胞活性，而MPP^ 却不影响细胞活性；蛋白激酶C(PKC)激动剂TPA显增强C6细胞对Glu的摄取，并拮抗：MPP^ 对C6细胞摄取Glu的抑制。结论：6-OHDA抑制C6胶质瘤细胞对Glu的摄取，可能与其抑制细胞活性有关，而MPP^ 的抑制作用可能与直接影响转运体的摄取功能有关，并可能由PKC途径介导。     

Interactions of HIV protease inhibitors with a human organic cation transporter in a mammalian expression system.

Recently, we cloned a human organic cation transporter, hOCT1, which is expressed primarily in the liver. hOCT1 plays an important role in the cellular uptake and elimination of various xenobiotics including therapeutically important drugs. HIV protease inhibitors are a new class of therapeutic agents. The purpose of this study was to elucidate the interactions of HIV protease inhibitors with hOCT1 and to determine whether hOCT1 is involved in the elimination of these compounds. We studied the interactions of HIV protease inhibitors with hOCT1 in a transiently transfected human cell line, HeLa. Uptake studies were carried out 40 h post-transfection using the radiolabeled model organic cation, [(14)C]tetraethylammonium (TEA), under different experimental conditions. In cis-inhibition studies, all of the HIV protease inhibitors tested, i.e., indinavir (IC(50) of 62 microM), nelfinavir (IC(50) of 22 microM), ritonavir (IC(50) of 5.2 microM), and saquinavir (IC(50) of 8.3 microM) inhibited TEA uptake in HeLa cells expressing hOCT1. However, none of the HIV protease inhibitors trans-stimulated [(14)C]TEA uptake, suggesting that they are poorly translocated by hOCT1. Nelfinavir, ritonavir, and saquinavir demonstrated an apparent "trans-inhibition" effect. No enhanced uptake of [(14)C]saquinavir was observed in hOCT1 DNA-transfected cells versus empty vector-transfected cells. These data suggest that HIV protease inhibitors are potent inhibitors, but poor substrates, of hOCT1. Some HIV protease inhibitors may potently inhibit the uptake and elimination of cationic drugs that are substrates for hOCT1, leading to potential drug-drug interactions. Other transporters, e.g., MDR1 and MRP1, in HIV-targeted cells may control the intracellular concentrations of HIV protease inhibitors.     

Biosynthesis,protease optimization and purification of alkaline serine from Shewanella algae and its potential application as silver recovery

The current study proposes an substitute method to recover silver from trash X-ray film as opposed to conventional methods that are costly and hazardous to the environment. The isolated bacterium was taxonomically identified as Shewanella algae through 16S rRNA gene sequence analysis. The significant factors for protease production (Gelatin, Beef extract, pH and Temperature) were optimized by Box-Benhen factorial design. The predicted and actual values of protease activity were recorded as 162% and 152%, respectively, through RSM. The purified 45 KDa bacterial enzyme unveiled stability in a extensive range of pH (7.0–10.0) and temperature (40-60 °C) with protease activity at pH 9.0 and 50 °C. The purified proteolytic enzyme withstand in the existence of solvents, surfactants and metal ions. Further, the purified protease was inhibitor of (PMSF) can inhibit the Shewanella algae alkaline protease. In this study, protease of 150 U/ml and could effectively hydrolyze the gelatin layer within 60 min.     

Interaction between saquinavir soft-gel and rifabutin in patients infected with HIV

AIMS: To evaluate the potential pharmacokinetic interaction between the HIV protease inhibitor saquinavir and rifabutin. METHODS: Fourteen HIV-infected patients provided full steady-state pharmacokinetic profiles following administration of rifabutin alone (300 mg once daily) or saquinavir soft-gel formulation (1200 mg three times daily) plus rifabutin (300 mg once daily) in this open label, partially randomized study. RESULTS: Coadministration of saquinavir and rifabutin resulted in a reduction in saquinavir AUC(0,8 h) and C(max)(0,8 h) of 47% (95% CI 30, 60%) and 39% (95% CI 11, 59%), respectively. Rifabutin AUC(0,24 h) and C(max)(0,24 h) was increased by an average of 44% (95% CI 17, 78%) and 45% (95% CI 14, 85%), respectively. Saquinavir in combination with rifabutin was well tolerated. Gastrointestinal intolerance and asymptomatic increases in liver enzymes were the only adverse events of note. CONCLUSIONS: Administration of rifabutin with saquinavir may decrease the efficacy of this HIV protease inhibitor.     

七氟烷对大鼠缺血再灌注后肺组织氧自由基的影响

目的通过建立在体大鼠肺缺血再灌注损伤模型,观察七氟烷对缺血再灌注后肺组织氧自由基(OFRs)表达的影响,探讨缺血再灌注后肺损伤和七氟烷肺保护的可能机制。方法选择96只雄性wistar大鼠,参照改良的Eppinger方法建立在体大鼠肺缺血再灌注损伤模型。共分4组,每组24只大鼠。C组:开胸游离左肺门,未行肺门阻断;IR组:阻断肺门45min后开放再灌注;Sev-C组:吸入1MAC七氟烷30min,游离肺门不阻断;Sev-IR组:吸入七氟烷30min后阻断左肺门45min,然后开放再灌注。每组包括3个时点:缺血阻断45min、再灌注60min、再灌注120min,每时点6只大鼠,另外再灌注120min时,各组另取6只大鼠行支气管灌洗。记录各时点MAP、SpO2,测定W/D、肺通透指数(LPI),生化法检测肺组织MDA、SOD和MPO含量。结果与C组和Sev-C组比较,IR组和Sev-IR组再灌注后W/D、LPI均上升(P<0.05),Sev-IR组W/D、LPI升高的程度低于IR组(P<0.05);IR组再灌注60min、120min肺组织MDA、MPO含量增加(P<0.05),SOD含量减少(P<0.05)。Sev-IR组MDA、MPO增加、SOD减少的程度都低于IR组(P<0.05)。结论肺缺血再灌注后血管通透性增加,再灌注后肺损伤的机制与OFRs产生过多有关,七氟烷预处理能抑制OFRs的生成,对再灌注后肺组织具有一定的保护作用。     

Synthesis, stability, antiviral activity, and protease-bound structures of substrate-mimicking constrained macrocyclic inhibitors of HIV-1 protease

Three new peptidomimetics (1-3) have been developed with highly stable and conformationally constrained macrocyclic components that replace tripeptide segments of protease substrates. Each compound inhibits both HIV-1 protease and viral replication (HIV-1, HIV-2) at nanomolar concentrations without cytotoxicity to uninfected cells below 10 microM. Their activities against HIV-1 protease (K(i) 1.7 nM (1), 0.6 nM (2), 0.3 nM (3)) are 1-2 orders of magnitude greater than their antiviral potencies against HIV-1-infected primary peripheral blood mononuclear cells (IC(50) 45 nM (1), 56 nM (2), 95 nM (3)) or HIV-1-infected MT2 cells (IC(50) 90 nM (1), 60 nM (2)), suggesting suboptimal cellular uptake. However their antiviral potencies are similar to those of indinavir and amprenavir under identical conditions. There were significant differences in their capacities to inhibit the replication of HIV-1 and HIV-2 in infected MT2 cells, 1 being ineffective against HIV-2 while 2 was equally effective against both virus types. Evidence is presented that 1 and 2 inhibit cleavage of the HIV-1 structural protein precursor Pr55(gag) to p24 in virions derived from chronically infected cells, consistent with inhibition of the viral protease in cells. Crystal structures refined to 1.75 A (1) and 1.85 A (2) for two of the macrocyclic inhibitors bound to HIV-1 protease establish structural mimicry of the tripeptides that the cycles were designed to imitate. Structural comparisons between protease-bound macrocyclic inhibitors, VX478 (amprenavir), and L-735,524 (indinavir) show that their common acyclic components share the same space in the active site of the enzyme and make identical interactions with enzyme residues. This substrate-mimicking minimalist approach to drug design could have benefits in the context of viral resistance, since mutations which induce inhibitor resistance may also be those which prevent substrate processing.     

HIV protease inhibitor ritonavir: a more potent inhibitor of P-glycoprotein than the cyclosporine analog SDZ PSC 833

The effect of P-glycoprotein inhibition on the uptake of the HIV type 1 protease inhibitor saquinavir into brain capillary endothelial cells was studied using porcine primary brain capillary endothelial cell monolayers as an in vitro test system. As confirmed by polymerase chain reaction and Western blot analysis, this system functionally expressed class I P-glycoprotein (pgp1A). P-Glycoprotein isoforms pgp1B or pgp1D could not be detected. The uptake of saquinavir into endothelial cells could be described as the result of a diffusional term of uptake and an oppositely directed saturable extrusion process. Net uptake of saquinavir into cultured brain endothelial cells could be increased significantly up to 2-fold by SDZ PSC 833 in a dose-dependent manner, with an IC(50) of 1.13 microM. In addition, the HIV protease inhibitor ritonavir inhibited p-glycoprotein-mediated extrusion of saquinavir with an IC(50) of 0.2 microM, indicating a high affinity of ritonavir for p-glycoprotein. In conclusion, we showed that the HIV protease inhibitor ritonavir is a more potent inhibitor of P-glycoprotein than the multidrug resistance (MDR)-reversing agent SDZ PSC 833. The inclusion of this drug in combination regimens may greatly facilitate brain uptake of HIV protease inhibitors, which is especially important in patients suffering from AIDS dementia complex.     

Dual Role of Photosensitizer and Carrier Material of Fullerene in Micelles for Chemo–Photodynamic Therapy of Cancer

Derivatives of fullerene (C60) as photosensitizers have rarely been studied as delivery carrier materials. The focus of this study was to explore the potential advantages of diadduct malonic acid‐fullerene (DMA‐C60) as delivery carrier materials and combination of chemo–phototherapy of some tumors. In this study, DMA‐C60 and docetaxel (DTX) were coentrapped in micelles (MCs) (DMA‐C60/DTX‐MC). The addition of DMA‐C60 could obviously improve static stability and decrease critical MC concentration of DTX‐MC without hemolysis. The sustained release of DTX and DMA‐C60 could be achieved, following Higuichi and first‐order model, respectively. DMA‐C60 could still produce reactive oxygen species efficiently in HeLa cells after encapsulation in MC. The addition of DMA‐C60 under irradiation caused DTX‐MC more stronger cytotoxicity, cell cycle changes, and more early apoptotic cells in vitro. More importantly, after intravenous injection, the addition of DMA‐C60 in DTX‐MC could result in 2.25‐fold and 4.57‐fold longer mean residence time compared with DTX‐MC and Duopafei®, increase drug intratumoral distribution and decrease drug distribution in heart and kidney, and enhance antitumor effect under irradiation without body weight loss. These results suggested tremendous promise of DMA‐C60 as carrier materials of MC and significant advantages in combination of chemo–phototherapy of some tumors.     

Ritonavir and Saquinavir directly stimulate anterior pituitary prolactin secretion,in vitro

An association between human immunodeficiency virus type I (HIV-1) protease inhibitors (PIs) and galactorrhoea/hyperprolactinemia adverse effect has recently been reported in four HIV-1-infected women treated with PIs (indinavir, nelfinavir, ritonavir or saquinavir). This could be explained by a direct effect of ritonavir and saquinavir on anterior pituitary prolactin (PRL) release, and/or an indirect effect of PIs on the secretion of hypothalamic dopamine, which is the main PRL inhibitory factor. Anterior pituitaries were explanted from adult male Wistar rats, the cells were trypsin dispersed, plated into multiwell cultures and incubated for 1 h with either ritonavir or saquinavir (0.01 nM-1μM). PRL release into the incubation medium was evaluated by radioimmunoassay. Hypothalamic neuronal endings (synaptosomes) were prepared by tissue homogenization, incubated with ³H-dopamine, substituting for the endogenous dopamine pool, and perfused with ritonavir or saquinavir, both basally and during depolarization (K⁺ 15 mM)-induced dopamine release. Beta-emission from 2 min perfusate fractions, corresponding to ³H-dopamine release, was detected by liquid scintillation scanning. We found that both ritonavir and saquinavir are able to significantly stimulate PRL secretion, with saquinavir slightly more effective than ritonavir. On the contrary, both protease inhibitors do not modify either basal or depolarization-induced dopamine release. We can speculate that HIV PIs despite a high affinity for the catalytic site of HIV protease, could also bind to and inhibit homologous mammalian proteins in the anterior pituitary that are involved in PRL secretion.