丹酚酸B体外抑制淀粉样β蛋白的纤维形成及其细胞毒作用(英文)

目的:观察丹酚酸B对淀粉样β蛋白的纤维形成及其细胞毒作用的影响。方法:将不同浓度丹酚酸B与淀粉样β蛋白(1-40)在25℃共同孵育,于不同时间取样品电镜观察纤维形成。用MTT法观察此不同时间点淀粉样β蛋白(1-40)对PC12细胞的毒性作用。另将淀粉样β蛋白(25-35)预先老化7d,用MTT法观察此老化蛋白对PC12细胞的毒性及丹酚酸B的作用。结果:丹酚酸B10—100nmol/L可以完全抑制淀粉样β蛋白(1-40)25℃放置30h的纤维形成,对淀粉样β蛋白(1-40)25℃放置48及100h的纤维形成也有明显抑制作用。MTT法显示,经与丹酚酸B共同孵育的淀粉样β蛋白(1-40)明显较未与丹酚酸B孵育的淀粉样β蛋白对PC12细胞的毒性小。丹酚酸B1μmol/L可明显抑制预先老化的淀粉样β蛋白(25-35)对PC12细胞的毒性作用。结论:丹酚酸B可抑制淀粉样β蛋白的老化及纤维形成,同时可直接抑制老化淀粉样β蛋白对PC12细胞的毒性作用。 (责任编辑 吴民淑)     

地昔帕明对皮质酮诱导培养的PC12细胞凋亡的拮抗作用

AIM: To study possible action mechanism of a tricyclic antidepressant, desipramine (DIM). METHODS: Cultured PC12 cells were exposed to corticosterone in the absence or presence of DIM for 5 d. Agarose gel electrophoresis, flow cytometry, and electron microscopy were used to detect the apoptosis of PC12 cells. RESULTS: Corticosterone 10 micromol/L treatment for 5 d elicited typical apoptotic biochemical and morphological changes including condensed chromatin shaped like crescent moon, nuclear fragmentation, and DNA degradation. The highest percentage of apoptotic cells accumulated to 28 % +/- 9 %. Agarose gel electrophoresis showed typical DNA ladders pattern. While in the presence of DIM 1 or 5 micromol/L, apoptosis percentage was markedly decreased with lightened DNA ladder and ultrastructure of the cells was improved. CONCLUSION: DIM could antagonize the apoptosis in PC12 cells induced by corticosterone, which may be one of the cellular mechanisms of its antidepressant effect.     

阿魏酸钠对H_2O_2诱导的PC12细胞凋亡的保护作用的探讨

目的　探讨阿魏酸钠 (sodiumferulate ,SF)对H2 O2 引起的PC12细胞凋亡保护作用的可能机制。方法　在H2 O2诱导PC12细胞凋亡模型的基础上 ,采用MTT比色分析测细胞存活率 ,RT PCR检测 par 4和caspase 3基因mRNA表达 ,Westernblot检测Par 4蛋白表达和Caspase 3P2 0活性片段 ,用比色法检测Caspase 3相对活性。 结果　不同剂量SF预处理 1h可提高PC12细胞的存活率 ,降低 par 4和cas pase 3的mRNA表达以及Par 4的蛋白表达 ,Caspase 3P2 0活性片段和Caspase 3相对活性减少 ,但变化不明显。结论　SF可剂量依赖性地对抗H2 O2 的神经毒性作用 ,其机制可能与凋亡基因 par 4表达有关 ,与Caspase 3的关系尚需进一步探讨     

Inhibition of serum deprivation-induced PC12 cell apoptosis by tanshinone II A.

AIM: To study the effect of tanshinone II A (Tan II A) on PC12 cell apoptosis induced by serum deprivation. METHODS: PC12 cell survival was measured by MTT assay. The DNA content and percentage of apoptosis were monitored by flow cytometry and DNA fragmentation was analyzed by agarose gel electrophoresis. RESULTS: Serum-free (12 h) medium induced apoptosis in PC12 cells. When the cells had been treated with Tan II A (0.1 and 1 micromol . L-1) for 12 h, the percentage of PC12 cell apoptosis was greatly decreased to 25.71 % and 4.89 % from 96.07 % in serum deprivation alone group, and DNA fragmentation was prevented. Tan II A (0.01 - 10 micromol . L-1) attenuated the cytotoxic effect of sodium cyanide (20 mmol . L-1), glutamate (0.5 mmol . L-1), and sodium nitroprusside (0.5 mmol . L-1). CONCLUSION: Tan II A prevented PC12 cells from apoptosis induced by serum-free medium.     

人参皂甙Rg1对抗多巴胺诱导的PC12细胞凋亡

目的:探讨外源性多巴胺诱导PC12细胞凋亡以及人参皂甙Rg1保护作用的分子机制。方法:流式细胞仪定量测定PC12细胞的凋亡和Bcl-2、Bax蛋白的表达;电子显微镜观察PC12细胞的形态;凝胶电泳评价DNA的断裂;荧光分光光度计法测定caspase-3的活力;半定量RT-PCR分析bcl-2和bax mRNA的表达。结果:多巴胺(浓度为0.15、0.30、0.45和0.60mmol/L)诱导PC12细胞凋亡,各剂量组细胞凋亡率分别从对照组1.1％±0.4％增加到41％±3％,46.4％±2.7％,53％±3％和64.5％±2.7％;人参皂甙Rg1 10μmol/L预处理24h后,较多巴胺0.45mmol/L单独处理时,PC12细胞的凋亡率和caspase-3的活力分别从53％±3％和683±8(平均荧光强度)下降到1.9％±0.6％和325±5,Bcl-2蛋白阳性率从14.3％±1.1％增加到25.9％±1.6％,Bax蛋白阳性率从48％±3％下降到35％±3％。结论:人参皂甙Rg1通过抑制cas-pase-3的激活并调节Bcl-2和Bax两者间蛋白的比值对抗多巴胺对PC12细胞凋亡的诱导作用。     

新合成腺苷结构类似物B2对无血清培养PC12细胞损伤的保护作用

研究新合成腺苷结构类似物B2对无血清培养所致PC12细胞损伤的保护作用,并对其机制进行初步探讨。采用放射性配基3H-MSX-2与腺苷A2A受体竞争结合法检测B2与大鼠纹状体腺苷A2A受体的亲和力;MTT法检测B2对无血清培养PC12细胞存活率的影响;用荧光探针DCFDA检测细胞内活性氧(ROS)含量变化。放射性配基受体竞争结合实验求得B2与大鼠脑纹状体A2A受体结合的Ki值为0.37μmol.L 1。B2(0.1、1、10和100μmol.L 1)可使去血清培养24 h的PC12细胞存活率由模型组的49.6%分别上升至63.3%、74.9%、86.3%、88.1%。合并使用0.1μmol.L 1 SCH 58261使B2(0.1～10μmol.L 1)的作用分别下降16.1%,24.0%和19.8%。去血清培养24 h使PC12细胞内ROS含量升高为对照组的3.5倍,B2(1～100μmol.L 1)可使胞内荧光强度分别降低为对照组的3.1倍、2.4倍和1.5倍。B2对无血清培养所致PC12细胞损伤有明显的保护作用,该作用与腺苷A2A受体相关,同时可显著降低去血清培养时细胞内活性氧自由基的过度生成,可能是其产...     

Effect of curcumin on multidrug resistance in resistant human gastric carcinoma cell line SGC7901/VCR

AIM: To investigate the reversal effects of curcumin on multidrug resistance (MDR) in a resistant human gastric carcinoma cell line. METHODS: The cytotoxic effect of vincristine (VCR) was evaluated by MTT assay. The cell apoptosis induced by VCR was determined by propidium iodide (PI)-stained flow cytometry (FCM) and a morphological assay using acridine orange (AO)/ethidium bromide (EB) dual staining. P-glycoprotein (P-gp) function was demonstrated by the accumulation and efflux of rhodamine123 (Rh123) using FCM. The expression of P-gp and the activation of caspase-3 were measured by FCM using fluorescein isothiocyanate (FITC)-conjugated anti-P-gp and anti-cleaved caspase-3 antibodies, respectively. RESULTS: Curcumin, at concentrations of 5 micromol/L, 10 micromol/L, or 20 micromol/L, had no cytotoxic effect on a parent human gastric carcinoma cell line (SGC7901) or its VCR-resistant variant cell line (SGC7901/VCR). The VCR-IC50 value of the SGC7901/VCR cells was 45 times more than that of the SGC7901cells and the SGC7901/VCR cells showed apoptotic resistance to VCR. SGC7901/VCR cells treated with 5 micromol/L, 10 micromol/L, or 20 micromol/L curcumin decreased the IC50 value of VCR and promoted VCR-mediated apoptosis in a dose-dependent manner. Curcumin (10 micromol/L) increased Rh123 accumulation and inhibited the efflux of Rh123 in SGC7901/VCR cells, but did not change the accumulation and efflux of Rh123 in SGC7901 cells. P-gp was overexpressed in SGC7901/VCR cells, whereas it was downregulated after a 24-h treatment with curcumin (10 micromol/L). Resistant cells treated with 1 mumol/L VCR alone showed 77% lower levels of caspase-3 activation relative to SGC7901 cells, but the activation of caspase-3 in the resistant cell line increased by 44% when cells were treated with VCR in combination with curcumin. CONCLUSION: Curcumin can reverse the MDR of the human gastric carcinoma SGC7901/VCR cell line. This might be associated with decreased P-gp function and expression, and the promotion of caspase-3 activation in MDR cells.     

Huperzine A derivative M3 protects PC12 cells against sodium nitroprusside-induced apoptosis

Aim:

To investigate the effects of M3, a derivative of huperzine A, on the apoptosis induced by sodium nitroprusside (SNP) in PC12 cells.

Methods:

Cell viability was detected using MTT method. Apoptosis was examined with annexin V/prodium iodide (PI) stain. The levels of reactive oxygen species (ROS) were measured using fluorophotometric quantitation. The amount of malonaldehyde (MDA) was determined with MDA detection kits. The expression of caspase-3 and Hsp70 were analyzed using Western blotting.

Results:

Exposure of PC12 cells to SNP (200 μmol/L) for 24 h decreased the cell viability to 69.0% of that in the control group. Pretreatment with M3 (10 μmol/L) or huperzine A (10 μmol/L) significantly protected the cells against SNP-induced injury and apoptosis; the ratio of apoptotic bodies in PC12 cells was decreased from 27.3% to 15.0%. Pretreatment with M3 (10 μmol/L) significantly decreased ROS and MDA levels, and increased the expression of Hsp70 in the cells. Quercetin (10 μmol/L) blocked the protective effect of M3, while did not influence on that of huperzine A.

Conclusion:

M3 protects PC12 cells against SNP-induced apoptosis, possible due to ROS scavenging and Hsp70 induction.     

As2S2诱导K562细胞凋亡及其机制

目的:探索As_2S_2对K562细胞的作用及其机制.方法:As_2S_2对K562细胞的生长抑制作用用细胞计数法;细胞凋亡的检测用流式细胞分析、基因组DNA电泳、细胞形态学观察等方法;Western-blot方法用于蛋白表达的检测;基因表达的变化用半定量RT-PCR方法.结果:As_2S_2浓度在1-5μmol/L作用24-72 h即可抑制K562细胞生长,大于3μmol/L时可诱导K562细胞凋亡.As_2S_2能降低K562细胞中Bcr-Abl蛋白水平及 c-abl和 Bcr-Abl PTK活性,但不调变bcr-abl基因表达水平.As_2S_2也能诱导慢性粒细胞性白血病(CML)患者单个核细胞凋亡,且Ph~ 单个核细胞比Ph~- 单个核细胞对As_2S_2诱导的凋亡更敏感.结论:As_2S_2可通过降低Bcr-Abl蛋白含量而诱导CML细胞凋亡.As_2S_2可能为治疗CML的有效药物.     

细胞保护作用是抗抑郁剂作用的共同通路之一

目的：探讨抗抑郁剂可能的共同作用机制。方法：以MTT比色法检测细胞活性状态;以Fura 2-AM荧光标记法测定胞内Ca^2 浓度：以RT-PCR法检测神经生长因子(NGF)mRNA水平。结果：以高浓度皮质酮0．2mmol/L处理PC12细胞48h以模拟抑郁症脑神经细胞损伤状态,发现目前三类经典抗抑郁剂,包括三环抗抑郁剂地昔帕明(DIM)0．625—10μmol／L,5-HT重摄取抑制剂氟西丁(FLU)0．625—10μmol／L,单胺氧化酶A抑制剂马氯贝胺(MOC)2．5—40μmol／L对皮质酮损伤的PC12细胞具有显著的保护作用,而抗精神病药氯丙嗪和抗焦虑药地西泮无此作用、DIM1,5μmol/L或FLU1,5μmol/L几显著减弱皮质酮0．1mmol／L处理PC12细胞48h诱导的胞内Ca^2 超载,进一步研究发现,DIM或FLU 10μmol／L处理PC12细胞48h显著提高NGF mRNA的表达水平。结论：尽管各类抗抑郁剂结构迥异,但细胞保护作用可能是其共同作用通路,而减弱胞内Ca^2 超载和提高NGF等神经营养因子的表达是抗抑郁药的细胞保护作用机制之一。     

5-Hydroxytryptamine-induced proliferation of pulmonary artery smooth muscle cells are extracellular signal-regulated kinase pathway dependent

AIM: To investigate the effect of 5-hydroxytryptamine transporter (5-HTT) inhibitor fluoxetine and antisense oligodeoxynucleotide (ODN) to extracelluar signal-regulated kinases (ERKs) on pulmonary arterial smooth muscle cells (PASMCs) proliferation induced by 5-HT. METHODS: Liposomal transfection was used to introduce ODNs to ERK1/2 into cultured rat PASMCs and the transfection efficiency was measured by observing the uptake of the fluorecein isothiocynate (FITC)-labeled antisense ODN in PASMCs. The effects of 5-HTT selective inhibitor fluoxetine and ODNs on the proliferation of PASMCs were evaluated by cell number counting and cell cycle analysis, and measured by microculture tetrazolium (MTT) assay and flow cytometry (FCM), respectively. RESULTS: Liposomes mediated the transfection of ODNs into PASMCs with high efficiency. MTT assay showed fluoxetine (10 micromol/L, 1 micromol/L, and 100 nmol/L) concentration dependently inhibited the proliferation of PASMCs induced by 5-HT (1 micromol/L) in vitro. The proliferation rate of PASMCs by 5-HT was significantly inhibited by pretreatment with ERK1/2 antisense ODN (0.2 micromol/L) from 251%+/-18% to 86%+/-5% (P<0.01). Flow cytometric analysis of cell cycle distribution showed that the increase of 5-HT induced S phase fraction (SPF) and proliferation index (PI) were significantly inhibited by fluoxetine (1 micromol/L) or antisense ODN with SPF from 36%+/-4% to 26%+/-3% and 24%+/-4%, and PI from 34%+/-2% to 29%+/-2% and 24%+/-2%, respectively. CONCLUSION: 5-HTT mediates the mitogenic effect of 5-HT on PASMCs and the proliferation of PASMCs induced by 5-HT is dependent on ERKs signal pathway.     

Anticancer effect of two diterpenoid compounds isolated from Annona glabra Linn

INTRODUCTION Traditional Chinese medicine afforded a valuableapproach in the searching for new anticancer drugs.Studies on the pharmacological mechanism and search-ing for new chemical structures from herbal extractfor new anticancer drugs caught great interest[1]. Taxol,isolated from the stem bark of Taxus brevifolia, pro-vided a typical example in this respect. Taxol was rankedas “the most important new drug we have had in can-cer for 15 years”[2]. Annonaceous acetogenius were …     

Investigation of ouabain-induced anticancer effect in human androgen-independent prostate cancer PC-3 cells

To determine the therapeutic potential of cardiac glycosides in androgen-independent prostate cancer, we examined ouabain-induced cytotoxic effect as well as the signaling pathways in PC-3 cells. Ouabain induced a time- and concentration-dependent cytotoxicity using mitochondrial MTT reduction assays, and the effective threshold concentration was in nanomolar level. At the concentrations less than 10 nM, ouabain induced a decrease of mitochondrial activity until a 7-hr exposure was performed, while it induced a rapid drop of mitochondrial function as early as a 2-hr treatment of cells with high concentrations of ouabain suggesting the involvement of two distinct mechanisms to ouabain action. After functional examinations, the data showed that both low and high concentrations of ouabain induced an inhibition of Na+-K+ ATPase and a subsequent 45Ca2+ influx into PC-3 cells. High concentrations of ouabain induced a significant and time-dependent loss of mitochondrial membrane potential (Deltapsim), a sustained production of reactive oxygen species (ROS), and severe apoptotic reaction. Ouabain also induced an increase of Par-4 (prostate apoptosis response 4) expression. Furthermore, an antisense, but not nonsense, oligomer against Par-4 expression significantly inhibited the cytotoxicity induced by low concentrations of ouabain. It is suggested that ouabain induces two modes of cytotoxic effect in human hormone-independent prostate cancer PC-3 cells. Low concentrations of ouabain induce the increase of Par-4 expression and sensitize the cytotoxicity; while high concentrations of ouabain induce a loss of Deltapsim, a sustained ROS production and a severe apoptosis in PC-3 cells.     

银杏叶提取物对1—甲基—4—苯基—1，2，3，6—四氢吡啶所致帕金森症的保护作用及机制

目的:观察银杏叶提取物(EGb)对1-甲基-4-苯基-1,2,3,6-四氢吡啶(MPTP)及其离子1-甲基-4-苯基吡啶(MPP~ )诱导的帕金森症(PD)模型的保护作用。方法:用脑立体定位仪向黑质(AP-5.4mm,-2.2mm,H8.3mm)内注射MPTP诱导大鼠旋转。在注射MPTP 24h后将大鼠处死,硫代巴比妥法测定黑质中丙二醛(MDA),羟胺法(即改进的黄嘌呤氧化酶法)测定黑质中超氧化物歧化酶(SOD),荧光分光光度法(激发波长310nm,发射波长390nm)测定纹状体中多巴胺(DA)的含量。MPP~ 诱导PC12细胞凋亡,HE染色,光镜下观察凋亡细胞;吖啶橙/溴乙锭(AO/EB)染色,荧光显微镜记数凋亡细胞,观察不同浓度EGb(25,50,100mg/L)在6h,12h,24h对细胞凋亡率的影响。结果:EGb 100mg/kg组可减少模型鼠的旋转次数及旋转持续时间(n=10,P<0.05);与MPTP组比较,EGb 50mg/kg和100mg/kg组MDA相对降低,SOD及DA相对增高(n=10,P<0.05和P<0.01)。MPP~ 10μmol/L可诱导PC12细胞凋亡,EGb 50和100mg/L组在6h,12h,24h可降低细胞凋亡率(P<0.05和P<0.01,n=3)。结论:EGb对MPTP诱导的PD动物模型及其离子MPP~ 诱导的PD细胞模型均有保护作用,其保护机制与清除自由基及抑制神经元凋亡有关。     

Resveratrol as a novel agent for treatment of multiple myeloma with matrix metalloproteinase inhibitory activity

AIM: To examine the in vitro antitumor activity of resveratrol against multiple myeloma (MM) cell lines (RPMI 8226, U266, and KM3), and the mechanisms involved. METHODS: The growth inhibition of resveratrol was determined by 3-(4, 5-dimethyl-2-thiazyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. The effect of resveratrol on the apoptosis was investigated by combined annexin V-propidium iodide staining. The effect of resveratrol on the invasion through Matrigel matrix was detected by transwell invasion analyses. The activity of matrix metalloproteinase (MMP)-2 and -9 proteins were determined by gelatin zymography analysis. The expression of MMP-2, MMP-9, Bcl-2, Bcl-x(L), XIAP and Bax protein were detected using Western blotting analysis. RESULTS: Resveratrol inhibited proliferation of MM cells in a dose- and time-dependent manner. Incubation of MM cells with resveratrol resulted in apoptotic cell death. Resveratrol down-regulated the expression of the antiapoptotic proteins Bcl-2, Bcl-x(L) and XIAP and up-regulated the expression of the proapoptotic protein Bax. Furthermore, resveratrol inhibited invasion of RPMI 8226, U266, and KM3 cells with IC50 values of 64+/-8 micromol/L, 93+/-11 micromol/L, and 153+/-11 micromol/L, respectively.Resveratrol inhibited the constitutive expression of MMP-2 and -9 proteins of MM cells and suppressed its gelatinolytic activity. CONCLUSION: Resveratrol inhibits the proliferation of MM cells by inducing apoptotic cell death. Resveratrol also inhibits MM cell invasion. The inhibition of invasion may be associated with the attenuation of the enzymatic activities of MMP-2 and -9.     

Chemoprevention of Pancreatic Cancer: Characterization of Par-4 and its Modulation by 3,3′ Diindolylmethane (DIM)

PURPOSE: Cancer chemoprevention is defined as the use of natural, synthetic, or biological agents to suppress, reverse or prevent the carcinogenic process from turning into aggressive cancer. Prostate apoptosis response-4 (Par-4) is a unique pro-apoptotic protein that selectively induces apoptosis in prostate cancer cells. However, its role in other malignancies has not been fully explored. This study tries to identify the functional significance of Par-4 in pancreatic cancer. METHODS: Multiple molecular techniques such as Western blot analysis, trypan blue assay for cell viability, MTT assay for cell growth inhibition and Histone/DNA ELISA for apoptosis were used. RESULTS: Western blot analysis revealed that 3,3'-diindolylmethane (DIM) a chemopreventive agent, specifically its more bioavailable formulation, B-DIM, at low doses (20 mumol/L) induces Par-4, in L3.6pl and Colo-357 pancreatic cancer cells. At similar doses, DIM reduced cell viability and caused cell growth inhibition and apoptosis. Moreover, DIM pre-treatment sensitized the cells to cytotoxic action of chemotherapeutic drug gemcitabine through up-regulation of Par-4. CONCLUSION: The induction of Par-4 is indirectly related to increased sensitivity and cell death through apoptosis. To our knowledge the results reported here showed, for the first time, the induction of Par-4 by chemopreventive agents, in general, and DIM, in particular, in pancreatic cancer cells in vitro.     

PC-407 inhibited proliferation and induced apoptosis in human colon cancer SW-1116 cells

AIM: To study whether PC-407 [4-[5-naphthyl-3- (trifluoromethyl)-1H-pyrazol-1-yl] benzenesulfonamide] inhibits cell viability and induces apoptosis in human colon cancer SW-1116 cells. METHODS: Inhibition of SW-1116 proliferation was measured by MTT assay. Morphological assessment of apoptosis was performed with fluorescence microscope and electron microscope. DNA fragmentation was visualized by agarose gel electrophoresis. The amount of apoptotic cells was measured by flow cytometry. RESULTS: PC-407 inhibited SW-1116 cell proliferation in a concentration-dependent manner after 3 d of treatment, and the IC50 for PC-407 inhibition of cell number was 16.67±0.17 μmol/L. After incubation of SW-1116 cells with PC-407 20 μmol/L for 24 h, morphological changes of typical apoptosis were observed by AO/EB staining or transmission electron microscopy. Flow cytometry analysis showed that PC-407 induced apoptosis in SW-1116 cells in a time- and concentration-dependant manner. The agarose gel electrophoresis of DN     

Nuclear factor-kappaB mediates cytoprotection of hydrogen peroxide preconditioning against apoptosis induced by oxidative stress in PC12 cells

1. Cytoprotection by H(2)O(2) preconditioning against oxidative stress-induced apoptosis of PC12 cells has been demonstrated previously. In the present study, we investigated the effects of H(2)O(2) preconditioning on nuclear factor (NF)-kappaB activation and the role of NF-kappaB in the adaptive cytoprotection of H(2)O(2) preconditioning in PC12 cells. 2. The PC12 cells were preconditioned with 100 micromol/L H(2)O(2) for 90 min, followed by 24 h recovery and subsequent exposure to 300 micromol/L H(2)O(2) for a further 12 h. 3. The results showed that preconditioning with 100 micromol/L H(2)O(2) upregulated NF-kappaB expression and enhanced its nuclear translocation and DNA binding activity. In addition to its own effects on NF-kappaB expression, H(2)O(2) preconditioning also promoted the overexpression of NF-kappaB induced by a lethal concentration of H(2)O(2) (300 micromol/L). 4. N-Tosyl-l-phenylalanine chloromethyl ketone (TPCK; 20 micromol/L), an inhibitor of NF-kappaB, was administered 20 min before preconditioning with 100 micromol/L H(2)O(2). At this concenteration, TPCK blocked the overexpression of NF-kappaB induced by H(2)O(2) preconditioning, accompanied by attenuation of H(2)O(2) preconditioning-induced cytoprotection. The inhibition of NF-kappaB by TPCK enhanced caspase 3 activity induced by 300 micromol/L H(2)O(2). 5. The findings of the present study provide novel evidence for the effects of preconditioning with H(2)O(2) on constitutive activation of NF-kappaB, which contributes to the adaptive cytoprotection of H(2)O(2) preconditioning against PC12 cells apoptosis.     

黄芩苷通过上调SIRT1保护SH-SY_5Y氧化应激的损伤

观察黄芩苷(baicalin,BL)对过氧化氢诱导SH-SY5Y细胞损伤的作用,并初步探讨SIRT1是否是其发挥作用的靶点及其可能机制。培养的人神经母细胞瘤细胞系SH-SY5Y细胞加入黄芩苷(25、50及100μmol·L-1)预孵育12 h,加入H2O2(150μmol·L-1)作用24 h诱导产生氧化损伤,应用MTT比色法检测细胞存活率,测定培养液中乳酸脱氢酶(LDH)漏出率、一氧化氮(NO)含量;并采用流式细胞仪检测细胞凋亡及应用免疫荧光组化法检测Caspase-3的活性、RT-PCR检测SIRT1水平。结果表明,与H2O2模型组比较,黄芩苷(50和100μmol·L-1)组的细胞存活率增高(P<0.05、P<0.01),而LDH、NO的释放量及细胞凋亡数(P<0.05、P<0.01)、Caspase-3的表达量均减少;SIRT1 mRNA表达明显(P<0.05、P<0.01)。黄芩苷对H2O2损伤的SY5Y细胞具有保护作用,可减轻神经细胞的损伤、抑制细胞的凋亡,其作用机制可能是通过上调SIRT1水平而抑制Caspase-3表达实现的。     

丹皮酚诱导K_(562)细胞凋亡的研究

目的　探讨丹皮酚 (Paeonol,Pae)对K562 细胞增殖和凋亡的影响。方法　采用MTT法检测丹皮酚对体外培养的K562 细胞的增殖抑制作用 ,通过HE染色和流式细胞仪定性和定量分析Pae的诱导凋亡作用。结果　Pae在 7 81～2 5 0mg·L-1浓度范围内对K562 细胞的增殖均有抑制作用 ,呈现明显的剂量依赖效应关系。HE染色光镜下可见典型的肿瘤细胞凋亡改变。Pae在 7 81、15 6 3、31 2 5、6 2 5及12 5mg·L-1浓度下作用 2 4h均可诱导K562 细胞凋亡 ,其凋亡率分别为 10 0 1%、 12 4 6 %、 17 10 %、 2 9 18%和34 16 % ,有明显的剂量效应关系 ,Pae 6 2 5、2 5、10 0mg·L-13种浓度分别作用于K562 细胞 6、12及 2 4h。发现以上各种浓度在 6h即可诱导细胞凋亡 ,作用时间越长 ,凋亡率越高 ,有明显的时间效应关系。结论　Pae能抑制K562 细胞增殖和诱导凋亡