Xanthohumol induces apoptosis in human malignant glioblastoma cells by increasing reactive oxygen species and activating MAPK pathways

The effect of the biologically active prenylated chalcone and potential anticancer agent xanthohumol (1) has been investigated on apoptosis of the T98G human malignant glioblastoma cell line. Compound 1 decreased the viability of T98G cells by induction of apoptosis in a time- and concentration-dependent manner. Apoptosis induced by 1 was associated with activation of caspase-3, caspase-9, and PARP cleavage and was mediated by the mitochondrial pathway, as exemplified by mitochondrial depolarization, cytochrome c release, and downregulation of the antiapoptotic Bcl-2 protein. Xanthohumol induced intracellular reactive oxygen species (ROS), an effect that was reduced by pretreatment with the antioxidant N-acetyl-L-cysteine (NAC). Intracellular ROS production appeared essential for the activation of the mitochondrial pathway and induction of apoptosis after exposure to 1. Oxidative stress due to treatment with 1 was associated with MAPK activation, as determined by ERK1/2 and p38 phosphorylation. Phosphorylation of ERK1/2 and p38 was attenuated using NAC to inhibit ROS production. After treatment with 1, ROS provided a specific environment that resulted in MAPK-induced cell death, with this effect reduced by the ERK1/2 specific inhibitor PD98059 and partially inhibited by the p38 inhibitor SB203580. These findings suggest that xanthohumol (1) is a potential chemotherapeutic agent for the treatment of glioblastoma multiforme.     

Carvacrol induces cytotoxicity in human cervical cancer cells but causes cisplatin resistance: Involvement of MEK–ERK activation

Carvacrol has been shown to possess anticancer activity, but the mechanism is unknown, as well as the possibility of interaction with anticancer drugs. The aim of this study was to investigate the role of mitogen‐activated protein kinase kinase (MEK)/extracellular signal‐regulated kinase (ERK) signaling in carvacrol‐induced human cervical cancer HeLa cell cytotoxicity. In addition, we studied sensitization of HeLa cells to cisplatin (CP) by carvacrol. Both carvacrol and CP showed dose‐dependent cytotoxicity against HeLa cells and activated ERK1/2. The MEK inhibitor PD325901 suppressed ERK expression and further increased cytotoxicity of carvacrol but increased viability of CP‐treated cells by modulating apoptosis. The MEK inhibitor also increased microtubule‐associated protein 1A/1B‐light chain 3 beta expression in CP treatment. Cotreatment with CP and carvacrol resulted in increased viability of the cancer cells compared with CP treatment, which was associated with the suppression of apoptosis. MEK inhibition decreased the cell viability, without changes in apoptosis. Concomitantly, carvacrol increased CP‐induced expression of light chain 3 beta, which was enhanced by MEK inhibition. The results of the current study suggest the opposite role of ERK1/2 in carvacrol and CP‐induced HeLa cell cytotoxicity. Interestingly, carvacrol induced CP resistance in HeLa cells through ERK1/2‐independent suppression of apoptosis and ERK1/2‐dependent modulation of autophagy.     

七叶皂苷钠通过抑制AKT,ERK上游信号SRC活性诱导人乳腺癌MCF-7细胞凋亡

探讨七叶皂苷钠对乳腺癌MCF-7细胞的凋亡诱导作用及其可能的作用机制。运用MTT法检测七叶皂苷钠对MCF-7细胞的增殖抑制作用;倒置显微镜观察细胞形态学变化;DAPI染色后在荧光显微镜下检测细胞核变化;采用Annexin V-FITC/PI流式细胞术检测细胞凋亡率;采用Western blotting检测凋亡相关蛋白(PARP,cleaved caspase-8,pro-caspase-3)和细胞存活相关信号分子(AKT,ERK)及其共同上游激酶SRC的磷酸化变化情况。结果显示,不同浓度七叶皂苷钠作用于乳腺癌MCF-7细胞后,以剂量依赖方式抑制MCF-7细胞增殖;诱导细胞凋亡(典型的凋亡形态学变化、细胞核改变和细胞凋亡率显著增加);细胞凋亡相关蛋白PARP切割增加,cleaved caspase-8表达增加,pro-caspase-3表达减少进一步验证了七叶皂苷钠的凋亡诱导作用;七叶皂苷钠显著抑制细胞存活相关信号分子(AKT,ERK)的磷酸化,其共同上游激酶SRC的活化亦显著下降。结果表明,七叶皂苷钠通过抑制SRC的活化,阻断信号向下游信号分子AKT,ERK的传递,抑制乳腺癌细胞MCF-7增殖,诱导细胞凋亡。     

Effect of Salvianolic-acid B on inhibiting MAPK signaling induced by transforming growth factor-β1 in activated rat hepatic stellate cells

Aim of the study

Salvianolic-acid B (SA-B) is an effective component of Radix Salviae miltiorrhizae for anti-hepatic fibrotic herbs. MAPK signaling pathway has been implicated in hepatic stellate cells (HSC) stimulated by TGF-(1. We have investigated the effect of SA-B on MAPK pathway in rat HSC.

Materials and methods

To observe the pharmacological effect of SA-B on HSC, SA-B was added into the medium of primary HSC. TGF-(1 was added during last 2 h, and PD98059 (ERK inhibitor) and SB203580 (p38 inhibitor) were added just 30 min before adding TGF-(1. MEF2 and Col. I were measured by luciferase reporter gene assay and Western blot. (-SMA, MEF2, Raf, ERK, p-ERK, MEK, p-MEK, p38, p-p38, MKK3 and p-MKK3/6 were assayed by Western blot. Activity of MMP-2 and MMP-9 was analyzed by zymography. Each experiment was repeated for three times.

Results

The expression of (-SMA and Col. I in HSC was inhibited by SA-B. There was no effect of SA-B on the activity of MMP-2 or MMP-9 in the media of cultured HSC. Phosphorylation of ERK1/2 in HSC stimulated with or without TGF-(1 was inhibited by SA-B. Specifically, phosphorylation of MEK (upstream kinase of ERK pathway) was inhibited by SA-B. SA-B also inhibited phosphorylation of MKK3/6 (upstream kinases of p38 pathway) and inhibited the synthesis of MEF2.

Conclusions

SA-B performs anti-hepatic fibrosis through inhibiting ERK and p38 MAPK pathway in HSC. SA-B inhibits ERK pathway via inhibiting phosphorylation of MEK and inhibits p38 MAPK pathway via blocking phosphorylation of MKK3/6 and inhibiting expression of MEF2 in HSC with or without TGF-(1 stimulation.     

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??OBJECTIVE To investigate the apoptosis of the auction and mechanism of the hepatoma BEL-7402 cells induced by the ginseng polysaccharides(GPS). METHODS The hematoma cells BEL-7402 were incubated with GPS, cell viability was measured by CCK8, cell cycle distribution was assessed by fluorescence-activated cell sorting(FACS), the cell morphological changes were traced with TUNEL and scanning electron microscope, TNFR1, BCL-2 and Bax protein expression and ERK phosphorylation are tested by Western blot. RESULTS CCK8 results showed that GPS inhibited cells growth of BEL-7402 in dose-dependent and time-dependent. Flow cytometry found that S phase arrest was increased upon GPS concentrations. Obviously apoptotic sub-g peak was also found. And the peak was gradually enhanced with the concentration increased. TUNEL staining and SEM results showed that GPS led to significant cell morphology changes in hepatoma cells BEL-7402.And the apoptosis effect was increased upon the GPS concentrations. Western blot showed that level of apoptosis related protein Bax was increased, the expression of apoptosis-antagonizing protein Bcl-2 was decreased and the expression of death receptor TNFR1 appeared with GPS concentrations increased gradually,raise ERK phosphorylation. CONCLUSION GPS can induce apoptosis of hepatoma cells BEL-7402 by the mitochondrial pathway and the death receptor dependent pathway and ERK pathway.     

冬凌草甲素通过激活ERK途径诱导U937细胞凋亡

目的:研究冬凌草甲素诱导人组织淋巴瘤U937细胞凋亡的机制及ERK激酶在凋亡过程中的作用。方法:噻唑蓝(MTT)法,Hoechst 33258染色法,DNA凝胶电泳及Western blot检测法。结果:冬凌草甲素对U937细胞生长抑制作用呈时间剂量依赖性。27μmol.L^-1冬凌草甲素作用细胞12 h后,Hoechst 33258染色细胞,出现明显凋亡小体,并诱导ERK发生磷酸化。ERK磷酸化抑制剂PD98059阻断了冬凌草甲素诱导的细胞生长抑制及DNA片段化。细胞内抑制凋亡蛋白Bcl-X_L表达量时间依赖性减少,促凋亡蛋白Bax表达量增加,而ERK抑制剂可逆转这种作用。结论:冬凌草甲素(27μmol.L^-1)诱导U937细胞凋亡,这种作用是通过活化ERK激酶,改变其下游Bax/Bcl-X_L的表达比率,从而促进U937细胞发生凋亡。     

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??OBJECTIVE To study the anti-leukemia activities and mechanisms of bergenin derivative D-23. METHODS CCK-8 method was applied to investigate anti-tumor activities of D-23. Flow cytometry and immunofluorescence assay were used to observe the effects of D-23 on the apoptosis and autophagy in K562 and Jurkat human leukemia cell lines. Western blot analysis was used to investigate the mechanisms that compound D-23 induced tumor cell apoptosis and autophagy. RESULTS Bergenin derivative D-23 could significantly inhibit the proliferation of K562 and Jurkat cells by inducing cell apoptosis and autophagy. The mitochondrial membrane potential was decreased,protein kinase B(Akt)and heat shock protein 70 (Hsp70) were inhibited,and the expressions of apoptotic related proteins caspase 3 and caspase 9 were activated. In addition, mammalian target of rapamycin (P-mTOR)(Ser 2448 and Ser 2481)protein was inhibited. CONCLUSION Bergenin derivative D-23 shows obvious anti-leukemia activities by inducing cell apoptosis and autophagy. The apoptosis may be associated with the reduction of mitochondrial membrane potential and activation of caspase pathway. The autophagy may be related to the inhibition of Akt/mTOR signaling pathway.     

ERK/FoxO3a信号轴在牡荆脂素VB-1抑制肝癌HepG2细胞系增殖中的作用

目的： 探讨ERK/FoxO3a信号轴是否介导牡荆脂素（VB-1）对人肝癌HepG2细胞系增殖的抑制作用。方法：MTT法观察不同浓度VB-1对人肝癌HepG2细胞系和永生化人胚肝L-02细胞系增殖的影响,集落形成法检测细胞生长,Western blot检测ERK1/2,FoxO3a蛋白磷酸化水平。结果：VB-1以浓度依赖方式抑制HepG2细胞增殖活性,对L-02细胞作用微弱。VB-1有效抑制HepG2细胞锚定依赖生长,并降低p-ERK1/2,p-FoxO3a表达水平,呈浓度依赖性。MEK抑制剂PD98059增强VB-1抑制HepG2细胞增殖和ERK1/2,FoxO3a磷酸化的作用。结论：VB-1通过阻断ERK/FoxO3a信号轴抑制肝癌HepG2细胞增殖活性。     

龙葵碱体外诱导人结肠癌SW480细胞凋亡及其对相关因子的影响

  目的：观察龙葵碱对人结肠癌SW480细胞凋亡及ERK/MEK、PI3K/AKT信号通路中相关因子的影响。  方法：SW480结肠癌细胞培养后共设5组,分别为空白对照组、培养液对照组及龙葵碱不同剂量(4、8、16 mmol/L)组,各组进行相应干预。采用MTT法检测龙葵碱对结肠癌细胞株的增殖作用,流式细胞法检测龙葵碱对结肠癌细胞凋亡的影响,RT-PCR及Western blotting法检测龙葵碱处理的SW480细胞中ERK/MEK和PI3K/AKT的表达水平。  结果：MTT生长曲线显示,龙葵碱能抑制结肠癌SW480细胞株增殖。流式细胞仪检测显示,龙葵碱能够促进SW480的凋亡。RT-PCR结果显示,龙葵碱可以抑制ERK1/2 mRNA的表达。Western blotting结果表明,龙葵碱可以降低MEK/ERK和PI3K/AKT信号通路中相关蛋白的表达。  结论：龙葵碱可以抑制结肠癌细胞增殖,其对肿瘤的诱导凋亡作用可能是通过MEK/ERK和PI3K/AKT信号途径实现的。     

Harmine Hydrochloride Triggers G2 Phase Arrest and Apoptosis in MGC‐803 Cells and SMMC‐7721 Cells by Upregulating p21, Activating Caspase‐8/Bid,and Downregulating ERK/Bad Pathway

This study aimed to investigate the effects of harmine hydrochloride (HMH) on digestive tumor cells in vitro and its molecular mechanism. MTT assays showed that HMH inhibited the proliferation of some human cancer cell lines and had no obvious inhibitory effects on human LO2 cells. Flow cytometry assays showed that HMH trigged G2 phase arrest in MGC‐803 cells and SMMC‐7721 cells, while the expression of cyclin A, cyclin B, p21, Myt1, and p‐cdc2 (Tyr15) was upregulated. Flow cytometry assays also showed that the percentages of apoptotic cells were increased, the mitochondrial transmembrane potential (ΔΨm) decreased, and the cleavage of caspase‐9, caspase‐3, and poly (Adenosine diphosphate ribose) polymerase (PARP) were observed, the expression of Bad increased, phospho‐Bad (S112) decreased, pro‐caspase‐8 was cleaved, and Bid (22 kDa) was cleaved. The expression of p‐ERK decreased in both cells. In conclusion, these results demonstrated that HMH upregulates the expression of p21, activates Myt1 and inhibits cdc2 by phospho‐cdc2 (Y15), and triggers G2 phase arrest in both MGC‐803 cells and SMMC‐7721 cells. It can also activate the mitochondria‐related cell apoptosis pathway through the caspase‐8/Bid pathway, inhibiting the ERK/Bad pathway and promoting apoptosis in both of these two cell types. Copyright © 2015 John Wiley & Sons, Ltd.     

Dual inhibition of EGFR and MET by Echinatin retards cell growth and induces apoptosis of lung cancer cells sensitive or resistant to gefitinib

Patients with non‐small‐cell lung cancer (NSCLC) containing epidermal growth factor receptor (EGFR) amplification or sensitive mutations initially respond to tyrosine kinase inhibitor gefitinib; however, the treatment is less effective over time. Gefitinib resistance mechanisms include MET gene amplification. A therapeutic strategy targeting MET as well as EGFR can overcome resistance to gefitinib. In the present study we identified Echinatin (Ecn), a characteristic chalcone in licorice, which inhibited both EGFR and MET and strongly altered NSCLC cell growth. The antitumor efficacy of Ecn against gefitinib‐sensitive or –resistant NSCLC cells with EGFR mutations and MET amplification was confirmed by suppressing cell proliferation and anchorage‐independent colony growth. During the targeting of EGFR and MET, Ecn significantly blocked the kinase activity, which was validated with competitive ATP binding. Inhibition of EGFR and MET by Ecn decreases the phosphorylation of downstream target proteins ERBB3, AKT and ERK compared with total protein expression or control. Ecn induced the G2/M cell cycle arrest, and apoptosis via the intrinsic pathway of caspase‐dependent activation. Ecn induced ROS production and GRP78, CHOP, DR5 and DR4 expression as well as depolarized the mitochondria membrane potential. Therefore, our results suggest that Ecn is a promising therapeutic agent in NSCLC therapy.     

Verticinone induces cell cycle arrest and apoptosis in immortalized and malignant human oral keratinocytes

Although verticinone, a major alkaloid isolated from the bulbus of Fritillaria ussuriensis, has been shown to induce differentiation in human leukemia cells, the exact mechanism of this action is not completely understood in cancer cells. Verticinone was used to conduct growth and apoptosis-related experiments for two stages of oral cancer on immortalized human oral keratinocytes (IHOKs) and primary oral cancer cells (HN4). The procedures included MTT assay, three-dimensional (3-D) raft cultures, Western blotting, cell cycle analysis, nuclear staining and cytochrome c expression related to the apoptosis signaling pathway. Verticinone inhibited the proliferation of immortalized and malignant oral keratinocytes in a dose- and time-dependent manner. In 3-D organotypic culture, verticinone-treated cells were less mature than the control cells, displaying low surface keratinization and decreased epithelial thickness. The major mechanism by which verticinone inhibits growth appears to be induced apoptosis and G(0)G(1) cell cycle arrest. This finding is supported by the results of the cell cycle analysis, FITC-Annexin V staining, DNA fragmentation assay and Hoechst 33258 staining. Furthermore, the cytosolic level of cytochrome c was increased, while the expression of Bcl-2 protein was gradually down-regulated and Bax was up-regulated, accompanied by caspase-3 activation. The data suggests that verticinone may induce apoptosis through a caspase pathway mediated by mitochondrial damage in immortalized keratinocytes and oral cancer cells.     

Pachastrissamine from Pachastrissa sp. Inhibits Melanoma Cell Growth by Dual Inhibition of Cdk2 and ERK‐mediated FOXO3 Downregulation

Melanoma cells are relatively resistant to apoptosis compared with other tumor cell types, and thus, chemotherapy, radiotherapy and immunotherapy are not effective in treating melanoma. Pachastrissamine (PA) exhibits cytotoxic activity and promotes apoptosis in several cancer cells. However, its specific molecular mechanisms have not been characterized fully. This study investigated the antimelanoma effect of PA, an anhydrophytosphingosine derived from marine sponge, and its underlying molecular mechanisms. The data demonstrated that treatment with PA inhibited the phosphorylation of ERK and subsequent ERK‐mediated FOXO3 phosphorylation in melanoma cells. Interestingly, PA did not inhibit AKT‐mediated FOXO3 phosphorylation. Therefore, it appears that PA‐induced apoptosis results from the inhibition of ERK. Furthermore, intravenous administration of PA was found to suppress melanoma cell growth in a C57BL6 mouse without causing side effects. Additionally, PA inhibited the production of Cdk2, which is involved in cell cycle regulation. Taken together, inhibition of melanoma cell growth by PA is a result of the inhibition of ERK‐mediated FOXO3 downregulation and decreased Cdk2 levels. The results of this study imply that dual inhibition of the ERK pathway and cell cycle progression could be an effective approach to control the growth of melanoma cells. Copyright © 2012 John Wiley & Sons, Ltd.     

Triggering of p38 MAPK and JNK Signaling is Important for Oleanolic Acid‐Induced Apoptosis via the Mitochondrial Death Pathway in Hypertrophic Scar Fibroblasts

Hypertrophic scarring is characterized by collagen overproduction and excessive deposition of extracellular matrix. No consensus arises currently about the best therapeutics to produce complete and permanent improvement of scars with few side effects. In the present study, the mechanism of oleanolic acid (OA)‐induced apoptosis in hypertrophic scar fibroblasts (HSFs) was investigated for the first time. OA activated the protein phosphorylation of p38 MAPK and JNK but not ERK. OA did not antagonize the inhibitory effects of SB203580 on p38 MAPK pathway activity but sharply enhanced JNK phosphorylation when HSFs were pretreated with SB203580. Similarly, the inhibition of JNK signal pathway activation by pretreatment with SP600125 facilitated the protein phosphorylation of p38 MAPK caused by OA. Inhibition of p38 MAPK and/or JNK by inhibitors significantly enhanced cell viability and OA only partially depressed the increased cell viability. Moreover, OA increased Bax translocation, MMP loss, mitochondrial cytochrome c and AIF release, Bax and caspase‐3 protein expression and the ratio of Bax to Bcl‐2, decreased Bcl‐2 protein expression, and elevated the mRNA expression of Apaf‐1, caspase‐9, and capase‐3. These results suggest that OA elicits apoptosis through triggering of p38 MAPK and JNK signaling and activation of the mitochondrial death pathway. OA might be a good and useful natural drug against hypertrophic scars. Copyright © 2014 John Wiley & Sons, Ltd.     

地黄梓醇对椎间盘髓核细胞NLRP3炎性体的调控作用

目的研究地黄梓醇对椎间盘髓核细胞NLRP3炎性体的调控作用。方法采用H2O2刺激大鼠原代椎间盘髓核细胞建立细胞模型,地黄梓醇预给药。CCK8法测定细胞活力,流式细胞仪检测髓核细胞凋亡,ELISA测定细胞上清液T-SOD、MDA、IL-1β水平,实时荧光定量PCR测定TXNIP、NLRP3、caspase-1、IL-1β mRNA表达,Western blot检测TXNIP、NLRP3、caspase-1、IL-1β、NF-κB p65蛋白表达,免疫荧光法检测TXNIP、NLRP3表达。结果地黄梓醇(5、10μmol/L)能上调细胞上清液T-SOD水平,下调MDA、IL-1β水平(P<0.05),抑制H2O2诱导髓核细胞凋亡(P<0.05),降低髓核细胞TXNIP、NLRP3、caspase-1、IL-1β mRNA及蛋白表达(P<0.05,P<0.01),并且10μmol/L地黄梓醇能抑制NF-κB p65蛋白表达(P<0.05)。结论地黄梓醇可有效抑制H2O2导致的髓核细胞凋亡,可能与调控ROS/NLRP3/IL-1β通路轴有关。     

Growth inhibition and induction of apoptosis in human oral squamous cell carcinoma Tca-8113 cell lines by Shikonin was partly through the inactivation of NF-kappaB pathway

Shikonin, a naphthoquinone pigment isolated from the Chinese herbal therapeutic, Zicao, has been shown to exhibit antioxidant and anticancer effects. In this study, its ability to induce apoptosis in cultured Tca-8113 oral cancer cells was studied. Treatment of the Tca-8113 cells with a variety of concentrations of Shikonin (10-40 microm) resulted in dose- and time-dependent sequences of events marked by apoptosis, as shown by the loss of cell viability, chromatin condensation, internucleosomal DNA fragmentation and sub-G1 phase accumulation. Furthermore, apoptosis in the Tca-8113 cells was accompanied by the activation of protease caspase-8, -9, -3 and low expression of Bcl-2 protein. Interestingly, inactivation of the NF-kappaB pathway was found in shikonin-induced apoptosis in Tca-8113 cells. These results raise the possibility that the anti-tumor effects of Shikonin in Tca-8113 cells are at least partly through the inactivation of the NF-kappaB pathway and subsequent activation of protease caspase family. Pharmacological inhibition of the NF-kappaB activity by Shikonin might be a powerful treatment option for OSCC in which activation of NF-kappaB plays a critical role in tumor growth and progression.     

Mechanisms of pseudolaric acid B-induced apoptosis in Bel-7402 cell lines

Previous studies have shown that pseudolaric acid B (PB) would cause apoptosis in human tumor cell lines. However, the mechanisms of PB induced apoptosis are still unclear. In the present study, the mechanisms of PB induced apoptosis in the human hepatocellular carcinoma Bel-7402 cell line were investigated by measuring cell viability, rate of apoptosis, cell cycle, detecting DNA fragmentation, and measuring caspase-3 activation. The results indicated that PB inhibited Bel-7402 cell viability and induced cell death by causing DNA fragmentation, up regulating the early and late apoptotic rates, activating caspase-3 protein, and detaining the cell cycle in the G2/M phases. Additionally, PB-induced apoptosis was a dose- and time-dependent manner. These observations suggest that PB-induced apoptosis occurs through a caspase-dependent pathway and detains the cell cycle in the G2/M phase.     

油茶皂苷通过内质网应激途径诱导Jurkat细胞凋亡的研究

目的探讨油茶皂苷在体外诱导人白血病细胞Jurkat凋亡的作用及作用机制。方法将1～4μg/mL的油茶皂苷作用于人白血病Jurkat细胞,应用细胞计数考察油茶皂苷对细胞增殖的影响;用Western blot方法分析油茶皂苷对caspase-3、PARP、Bipc、hop、Perk、ATF6和IRE1蛋白表达的影响。结果油茶皂苷(1～4μg/mL)对Jurkat细胞的增殖产生明显的剂量依赖性抑制作用。免疫印迹结果显示,油茶皂苷可以使caspase-3激活,增加Cleaved PARP的表达量,而诱导Jurkat细胞发生凋亡;其作用机制是通过下调Bip和chop的表达,触发Perk、ATF6和IRE1 3个内质网应激跨膜蛋白而产生细胞凋亡的。结论 1～4μg/mL油茶皂苷具有抑制人白血病细胞增殖和诱导其凋亡的作用,其作用机制参与了细胞凋亡的内质网应激途径。     

银杏叶提取物EGb761抗大鼠脑缺血损伤的作用机制研究

目的 通过实验研究P38/MAPK和MEK/ERK在大鼠大脑中动脉栓塞模型中的变化及其与EGB761发挥药理作用的关系,探讨银杏叶制剂EGb761治疗脑缺血的机制.方法 大鼠连续1Od口服EGb761 50、100mg/kg后建立大脑中动脉栓塞-再灌模型,通过TTC染色,免疫组化和Westem blot方法检测大鼠脑组织细胞的形态变化和大鼠皮质Caspase -9,Caspase-3,P38/MAPK,MEK/ERK相应蛋白的表达变化.结果 EGb761给药可以减少脑缺血大鼠脑组织梗死面积,显著性抑制脑缺血大鼠海马Caspase-9和Caspase-3表达,显著性抑制大鼠海马神经细胞P-P38,P-MEK和P-ERK的表达水平.结论 EGb761可以减轻脑缺血缺氧引起的细胞损伤,其神经保护作用通过抑制内源性凋亡信号通路激活和P38/MAPK和MEK/ERK信号通路激活引起的细胞凋亡有关.     

褐藻素诱导肝癌HepG2细胞凋亡和自噬的机制

目的：通过c-Jun氨基末端激酶（c-jun N-terminal kinase,JNK）信号通路来研究蹄叶橐吾醇化乙酸乙酯萃取物的抗炎作用机制。方法：采用噻唑蓝比色法（MTT法）测定倍比稀释的蹄叶橐吾醇化乙酸乙酯萃取物（浓度区间为0~640 mg·L^-1）作用于密度为5×10⁴个/mL的RAW264.7细胞24 h后的细胞活力,计算出药物对细胞的无毒浓度;测定JNK抑制剂SP600125（终浓度分别为25,12.5,6.25 μmol·L^-1）作用于细胞密度为5×10⁴个/mL的RAW264.7细胞24 h后的细胞活力,计算出SP600125作用的安全有效浓度;测定蹄叶橐吾醇化乙酸乙酯萃取物（终质量浓度分别为5,2.5,1 mg·L^-1）作用于LPS诱导细胞密度为5×10⁴个/mL的RAW264.7细胞12,24,36,48 h后的细胞活力,计算出药物抑制细胞增殖的浓度。采用蛋白质印迹（Western-blot）法测定蹄叶橐吾醇化乙酸乙酯萃取物（5 mg·L^-1）作用于LPS诱导的RAW264.7细胞24 h后p-JNK（磷酸化c-Jun氨基末端激酶）蛋白、JNK蛋白和环氧化酶-2（COX-2）蛋白的表达变化。结果：蹄叶橐吾醇化乙酸乙酯萃取物作用于LPS诱导的RAW264.7细胞,测定p-JNK,JNK,COX-2相对灰度值分别为：0.12±0.03,0.48±0.03,0.18±0.04,无药物作用的LPS诱导的RAW264.7细胞,测定p-JNK,JNK,COX-2,相对灰度值分别为：0.68±0.05,0.83±0.04,0.58±0.04,两组数据比较具有明显差异（P<0.01）。蹄叶橐吾醇化乙酸乙酯萃取物抑制LPS诱导的RAW264.7细胞增殖,下调p-JNK,JNK,COX-2等炎性蛋白的表达。结论：蹄叶橐吾醇化乙酸乙酯萃取物抗炎机制通过JNK信号通路来完成。