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1.
 目的研究24-O-乙酰升麻醇-3-O-β-D-木糖苷对HepG2细胞的细胞毒性及其作用机制。方法利用MTT法进行细胞毒活性初筛;用荧光染色细胞形态学观察法、流式细胞术和蛋白质杂交技术从细胞和分子水平研究该化合物的细胞毒作用机制。结果24-O-乙酰升麻醇-3-O-β-D-木糖苷可以抑制HepG2细胞生长,IC50值为13μmol·L-1。该化合物可以诱导HepG2细胞凋亡和G2/M细胞周期阻滞。进一步分子水平研究表明,该化合物可使PARP蛋白裂解,抗凋亡蛋白bcl2下调,凋亡蛋白Bax上调,细胞周期素cyclinB和细胞周期素依赖性激酶cdc2表达下调。结论24-O-乙酰升麻醇-3-O-β-D-木糖苷通过诱导细胞凋亡和G2/M细胞周期阻滞来发挥细胞毒作用,其凋亡机制涉及caspases家族激活,bcl2下调和Bax表达上调,而G2/M周期阻滞与cdc2和cyclinB下调直接相关。  相似文献   

2.
白藜芦醇对Hepa 1-6肝癌细胞凋亡和ROS的影响   总被引:1,自引:0,他引:1  
Du Q  Shen KP  Hu B  Deng S 《中药材》2012,35(3):443-448
目的:观察白藜芦醇对小鼠肝癌Hepa 1-6细胞凋亡及活性氧(Reactive oxygen species,ROS)作用。方法:MTT比色法检测白藜芦醇对Hepa 1-6细胞增殖的影响;Hoechst 33258染色检测细胞凋亡形态;流式细胞术检测细胞凋亡;Western Blot法检测活化型Caspase-3;2',7'-二氯氢化荧光素乙二脂(DCF-DA)染色法结合荧光酶标仪检测细胞内ROS的产生。结果:与对照组比较,20、40、80μmol/L白藜芦醇作用24、48、72 h均可显著抑制肝癌Hepa1-6细胞增殖,呈一定的时间与剂量依赖性。不同浓度白藜芦醇作用48 h可促使Hepa 1-6细胞凋亡,呈现细胞凋亡形态改变,同时伴有活化型Caspase-3及ROS的产生。结论:白藜芦醇可以抑制Hepa 1-6细胞增殖,诱导肝癌细胞凋亡,可能与Caspase-3活化及细胞内ROS水平升高相关。  相似文献   

3.
Buddlejasaponin IV (BS-IV), a major component of Pleurospermum kamtschaticum, exerts antiinflammatory and cytotoxic effects against cancer cells. The study investigated whether BS-IV could prevent oral carcinogenesis by inhibiting the growth of immortalized human oral keratinocytes (IHOKs). BS-IV reduced cell viability and induced cell cycle arrest at G2/M phase and apoptotic morphological changes in IHOKs. BS-IV inhibited the levels of cyclin B1, Cdc2 and Cdc25C, but enhanced Chk2 phosphorylation. The increased levels of pRb and p21 protein and the activation of p53 were also noted in BS-IV-treated IHOKs. In addition, BS-IV induced cytochrome c release from mitochondria by reducing antiapoptotic Bcl-2 levels and increasing pro-apoptotic Bax levels. BS-IV treatment resulted in the activation of caspase-9 and caspase-3. PARP cleavage was also clearly observed in the BS-IV-treated IHOKs. Furthermore, the expression of the Fas death receptor and Fas ligand was induced and procaspase-8 level was suppressed by BS-IV treatment. Taken together, BS-IV treatment inhibited the growth of IHOK cells via the induction of p53-dependent cell cycle arrest at the G2/M phase and apoptosis via both mitochondrial-dependent and death receptor-mediated pathways. Thus, BS-IV can be considered an excellent candidate for a chemopreventive agent to block the progression of HPV-induced oral carcinogenesis.  相似文献   

4.
The effect of methanolic extracts of mycelia (MEM) from Antrodia camphorata (Polyporaceac, Aphyllophorales) of submerged culture (ACSC) on the inhibition of cell viability and the mechanism of MEM-induced cytotoxic in hepatoma cells were investigated. The IC(50) of MEM on the cytotoxicity of HepG2 (wild type p53) and Hep3B (delete p53) were 49.5 and 62.7 microg/ml, respectively, on 48 h incubation. There is no observable cytotoxicity of MEM in Chang liver cells and rat primary hepatocytes at the concentration of 100 microg/ml. Cell cycle analysis revealed that MEM induced apoptosis on HepG2 via G0/G1 cell cycle arrest. MEM (100 microg/ml) treated HepG2 and Hep3B for 72 h, the apoptotic cells were 98.3 and 39.5%, respectively. The activities of caspase-3, -8 and -9 in HepG2 induced by MEM (50 microg/ml) were increased 5.3, 6.7 and 2.2-fold, respectively. MEM-induced apoptotic cell death was accompanied by up-regulation of caspase-3 and -8 in HepG2 cells. Combined treatment with MEM and caspase-3, -8 and -9 inhibitors, the caspase-3 and -8 inhibitors were accounting for 63 and 47% inhibition in MEM-induced apoptosis, respectively; however, caspase-9 inhibitor exhibited no obvious inhibition effect on the apoptosis percentage (p>0.05). The results indicated that MEM induced HepG2 apoptosis through activation of caspase-3 and -8 cascades and regulation of the cell cycle progression to inhibit hepatoma cells proliferation.  相似文献   

5.
Objective Ovalitenin A(1-(4-methoxybenzofuran-5-yl)-3-phenyl-2-propen-1-one) is a chalcone isolated from Millettia pulchra. The aim of the study was to investigate the antitumor effect of ovalitenin A on apoptosis in vitro and in vivo and to identify the mechanism involved. Methods The effect of ovalitenin A in human cervical cancer HeL a cells was detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay, morphological observation, flow cytometric measurement, Western blotting, and xenograft model. Results Ovalitenin A inhibited the proliferation of He La cells in a dose-dependent manner in vitro and in vivo and induced the apoptosis evidenced by characteristic apoptotic morphological changes, phosphatidylserine externalization, and activation of caspase-3. In addition, ovalitenin A induced G2/M cell cycle arrest and up-regulation of the Bax/Bcl-2 ratio. Furthermore, ovalitenin A decreased protein level of COX-2 and induced the loss of mitochondrial membrane potential. Conclusion These data suggest that ovalitenin A has the potential of anticancer properties for the treatment of cervical cancer.  相似文献   

6.
藤黄酸诱导人胃腺癌SGC-7901细胞的凋亡作用   总被引:14,自引:1,他引:14  
目的:探讨藤黄酸(gambogic acid,GA)诱导体外培养人胃腺癌SGC-7901细胞凋亡的作用。方法:通过MTT比色法分析藤黄酸对人胃癌SGC-7901细胞在24,48,72 h增殖的影响,并通过光镜、电镜观察细胞形态学的改变及流式细胞术检测藤黄酸对SGC-7901肿瘤细胞周期动力学和凋亡诱导率的影响,用免疫组化方法检测凋亡相关基因bax和bcl-2的蛋白表达变化。结果:藤黄酸可明显抑制SGC-7901细胞的增殖,48h半数生长抑制剂量(IC50)为1.47,1.6 μmol/L的藤黄酸可导致7901细胞形态学的改变,流式细胞术显示细胞周期亦发生变化,G2/M期细胞增加,凋亡率呈时间-剂量相关性。同剂量的藤黄酸还可增加抑癌基因bax和减少诱癌基因bcl-2的蛋白表达量。结论:藤黄酸可明显抑制SGC-7901肿瘤细胞的生长,诱导细胞凋亡,其分子机制可能与其减少Bcl-2/Bax的比值相关。  相似文献   

7.
Mechanism of the anti-cancer activity of Zizyphus jujuba in HepG2 cells   总被引:1,自引:0,他引:1  
The Zizyphus jujuba fruit has been used as a traditional Chinese medicinal herb and considered to affect various physiological functions in the body for thousands of years. However, its anti-cancer activity and mechanism of action remain to be elucidated. We investigated the anti-cancer activity of Zizyphus jujuba Mill and its underlining mechanisms of action in human hepatoma cells (HepG2) and found that the extract of Z. jujuba decreased the viability of the cells. Further extraction of the initial Z. jujuba extract with organic solvents revealed that the chloroform fraction (CHCl(3)-F) was the most effective. Interestingly, the CHCl(3)-F induced not only apoptosis but also G1 arrest at a low concentration (100 mug/ml) and G2/M arrest at a higher concentration (200 mug/ml) by cell cycle assay. Apoptosis, an increase in intracellular ROS (reactive oxygen species) level, a decline of mitochondrial membrane potential at low Z. jujuba concentrations, and a ROS-independent mitochondrial dysfunction pathway at high concentrations were all observed. CHCl(3)-F-induced G1 arrest in HepG2 cells was associated with an increase in hypohosphorylation of Rb and p27(Kip1), and a decrease of phosphorylated Rb. However, CHCl(3)-F-induced G2/M arrest in HepG2 cells correlated with a decrease of the p27(Kip1) levels and generation of the phosphorylation of p27(Kip1), however the hypohosphorylation of Rb protein remained. Collectively, our findings suggest that the CHCl(3)-F extract of Z. jujuba extract induced a concentration dependent effect on apoptosis and a differential cell cycle arrest in HepG2 cells.  相似文献   

8.
目的探讨三氧化二砷(AS_2 O3)诱导人胃癌 SGC-7901细胞凋亡的可能机制。方法光学及电子显微镜观察细胞形态学变化,流式细胞术(flow cytometry,FCM)及末端脱氧核苷酸转移酶介导的脱氧三磷酸尿嘧啶缺口末端标记法(terminal deoxynucleotidy transferase-mediated dUTP nick end labeling,TUNEL)判定细胞凋亡;免疫组织化学 SABC 法检测凋亡相关基因蛋白 Bcl-2、Bax、c-Myc 及 P53的表述;流式细胞术检测Caspase-3蛋白表达;以二硫代苏糖醇(Dithiothreitol,DTT)为二硫键还原剂,观察其对 As_2O_3所致的 SGC-7901细胞凋亡的影响。结果 As_2O_3作用后光镜及电镜下观察到典型凋亡细胞的形态学特征;FCM 检测在细胞周期 G_1期前出现亚二倍体凋亡峰,同时见不同程度的 G_2/M 期阻滞;TUNEL 标记发现 DNA 链的断裂;As_2O_3 作用后 Bcl-2蛋白表达降低,Bax、Caspase-3蛋白表达明显升高,c-Myc 蛋白在 As_2O_3处理12、24 h 后表...  相似文献   

9.
The potential antitumor activity of timosaponin A-III (1), a steroidal saponin from the rhizomes of Anemarrhena asphodeloides, was investigated in human colorectal cancer HCT-15 cells both in cell culture and in an in vivo murine xenograft model. Compound 1 inhibited the proliferation of cancer cells with cell-cycle arrest and induction of apoptosis. Cell-cycle arrest in the G0/G1 and G2/M phase by 1 was correlated with the down-regulation of cyclin A, cyclin B1, cyclin-dependent kinase 2 (CDK2), CDK4, proliferating cell nuclear antigen, and c-Myc. The increase of the sub-G1 peak by 1 was also closely related to the induction of apoptosis, which was evidenced by the induction of DNA fragmentation, activation of caspases, induction of cleaved poly-(ADP ribose) polymerase, and suppression of Bcl-xL and Bcl-2 expression. In an in vivo xenograft model, treatment with 1 (2 or 5 mg/kg body weight, three times/week, ip administration) for four weeks significantly suppressed tumor growth in athymic nude mice bearing HCT-15 cells, without any overt toxicity. Cell-cycle arrest and induction of apoptosis might be plausible mechanisms of actions for the observed antineoplastic activity of 1.  相似文献   

10.
OBJECTIVE: To investigate the protective effect of curcumin extracted from Jianghuang(Rhizoma Curcumae Longae) against ultraviolet B(UVB) and the possible mechanism.METHODS: Effects of curcumin were detected in vivo and in vitro. Morphological changes of white guinea pig skin were assessed by hematoxylin and eosin staining. Ha CaT cell proliferation was measured by 3-[4,5-dimethylthylthiazol-2-yl]-2,5 diphenyltetrazolium broide(MTT) assays. The cell cycle distribution, apoptotic rate, level of reactive oxygen species(ROS), mitochondrial membrane potential, and intracellullar calcium ion concentration of Ha CaT cells were detected by flow cytometry. Antioxidant levels in skin tissues and Ha Cat cells were measured by biochemical methods.RESULTS: UVB inhibited in vitro cell proliferation by inducing G2/M arrest, increasing ROS, apoptosis,and necrosis, and decreasing B-cell lymphoma-2,and increasing Bax, cytochrome c, and caspase-3 levels.CONCLUSION: Curcumin blocks the effects of UVB by reducing ROS and apoptosis, and reversing UVB-induced changes in the expression of apoptotic proteins. The mitochondrial pathway is involved in curcumin-regulated apoptosis.  相似文献   

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