Breviscapine‐induced apoptosis of human hepatocellular carcinoma cell line HepG2 was involved in its antitumor activity

Breviscapine is a flavonoid constituent isolated from a traditional Chinese herb Erigerin breviscapus (Vant.) Hand‐Mazz. To investigate the apoptosis‐inducing effect of breviscapine on human hepatocellular carcinoma cell line HepG2 and explore the relative molecular mechanisms. HepG2 cells were treated with breviscapine at different concentrations and the inhibitory rate was analyzed by MTT assay. The morphological changes in cells were observed under an inverted light microscope and a fluorescence microscope and the apoptosis rate were detected by flow cytometry. Western blot was used to evaluate the protein expression. The viability of HepG2 cells was markedly inhibited in a concentration‐dependent manner and obvious morphological changes were confirmed, including condensed chromatin and reduction in volume. The increased percentage of apoptotic cells was displayed by flow cytometry and the altered expression level of several apoptosis‐associated proteins, Bcl‐2, Bax and caspase‐3, was detected by western blot. It is first discovered that breviscapine exhibited potential antitumor activity, induces remarkable apoptosis in HepG2 cells and promises to be a new candidate in future cancer therapy. Copyright © 2010 John Wiley & Sons, Ltd.     

Emodin Regulates Apoptotic Pathway in Human Liver Cancer Cells

Emodin, a natural anthraquinone, has been reported to possess antiproliferative effects in many cancer cell lines. However, anticancer mechanism against human liver cancer remains unclear. In this study, we observed that emodin induced apoptosis in HepG2 cells and caused a significant accumulation of cells in the G1 phase. Western blot data showed that emodin treatment caused the increasing of release of cytochrome c into cytosol from mitochondria and the activation of caspase‐8 and caspase‐9, which suggest that the intrinsic and extrinsic pathways could be involved. Emodin treatment also resulted in a dose‐dependent accumulation of intracellular reactive oxygen species. Furthermore, emodin increased the protein level of p53 and decreased the protein level of NF‐κB/p65 in HepG2 cells, which indicated these two regulators might play a role in emodin‐induced apoptosis. Computational modeling showed that emodin could directly bind to the BH3 domain of Bcl‐2 through forming one hydrogen bond with Ala146 residue in Bcl‐2. From these examinations, emodin not only significantly downregulated expression of Bcl‐2 but also inhibited the heterodimerization of Bcl‐2 with Bax because of strong interaction between emodin and Bcl‐2. These suggest that emodin induces apoptosis in liver cancer cell line through a multifaceted complex cascade of events. Copyright © 2012 John Wiley & Sons, Ltd.     

Inhibitory Effects of Nobiletin on Hepatocellular Carcinoma In Vitro and In Vivo

Nobiletin (5, 6, 7, 8, 3′ 4′‐hexamethoxyflavone) is a major anticancer component in juice from zhishi (Rutaceae). This study aimed to investigate the inhibitory effect of Nobiletin on hepatic cancer cells both in vitro and in vivo. The 3‐(4, 5‐dimethylthiazol‐2‐yl)‐2, 5‐diphenyltetrazolium bromide (MTT), growth curve, and clonogenic assay showed that nobiletin inhibited the proliferation of SMMC‐7721 cells in vitro. Hoechst staining observed the characteristics of cell apoptosis in nobiletin‐treated cells, and the apoptotic rates of treated groups were increased in a dose‐dependent manner. Flow cytometric analysis demonstrated that nobiletin could block the cell cycle arrested at G2 phase. Cell cycle analysis was performed using flow cytometry. Results showed that cell cycle phase distribution analysis showed G2 arrest. It was found that nobiletin downregulated the expressions of Bcl‐2 and COX‐2 and up‐regulated the expressions of Bax and caspase‐3 in SMMC‐7721 cells by western blotting. The experiment in vivo demonstrated that nobiletin significantly inhibited the growth of H22 transplantable tumor, downregulated the expressions of COX‐2, up‐regulated the expressions of Bax and caspase‐3 detected by immunohistochemistry and western blotting, and the ratios of Bcl‐2/Bax were decreased. Our results suggest that nobiletin has significant inhibitory effects on hepatocellular carcinoma both in vitro and in vivo. Copyright © 2013 John Wiley & Sons, Ltd.     

异常黑胆质成熟剂黄酮类化合物诱导HepG2细胞凋亡机制的研究

目的：观察异常黑胆质成熟剂中黄酮类化合物对人肝癌细胞株(HepG2)体外生长、凋亡及相关基因表达的调控作用,探讨异常黑胆质成熟剂黄酮类化合物诱导癌细胞凋亡及抗癌活性的物质基础及其作用机制。方法：采用四氮甲基唑蓝法(MTT)、琼脂糖凝胶电泳技术、流式细胞术及逆转录-多聚酶链式反应技术(RT-PCR)等,观察异常黑胆质成熟剂黄酮类化合物对HepG2生长、凋亡及凋亡基因调控的影响。结果：异常黑胆质成熟剂黄酮类化合物明显抑制HepG2细胞体外生长,HepG2细胞在sub-G₁期受到阻滞,并能诱导细胞发生凋亡,明显下调Bcl-2 mRNA表达水平,同时可上调p53,p21,Bax基因mRNA表达水平。结论：异常黑胆质成熟剂黄酮类化合物对癌细胞体外生长、凋亡及凋亡基因表达具有明显的调控作用。黄酮类化合物可能是异常黑胆质成熟剂发挥抗癌作用的主要活性成分,而抑制细胞生长、诱导细胞凋亡及调控凋亡基因表达等可能是其发挥抗癌活性的重要途径。     

Mangosenone F,A Furanoxanthone from Garciana mangostana,Induces Reactive Oxygen Species‐Mediated Apoptosis in Lung Cancer Cells and Decreases Xenograft Tumor Growth

Mangosenone F (MSF), a natural xanthone, was isolated form Carcinia mangotana, and a few studies have reported its glycosidase inhibitor effect. In this study we investigated the anti lung cancer effect of MSF both in vitro and in vivo. MSF inhibited cancer cell cytotoxicity and induced and induced apoptosis via reactive oxygen species (ROS) generation in NCI‐H460. MSF treatment also showed in pronounced release of apoptogenic cytochrome c from the mitochondria to the cytosol, downregulation of Bcl‐2 and Bcl‐xL, and upregulation of Bax, suggesting that caspase‐mediated pathways were involved in MSF‐induced apoptosis. ROS activation of the mitogen‐activated protein kinase signaling pathway was shown to play a predominant role in the apoptosis mechanism of MSF. Compared with cisplatin treatment, MSF treatment showed significantly increased inhibition of the growth of NCI‐H460 cells xenografted in nude mice. Together, these results indicate the potential of MSF as a candidate natural anticancer drug by promoting ROS production. Copyright © 2015 John Wiley & Sons, Ltd.     

Suppressive Effect of Flavonoids from Korean Citrus aurantium L. on the Expression of Inflammatory Mediators in L6 Skeletal Muscle Cells

Citrus fruits (Citrus aurantium L.) have long been used as a traditional herbal medicine. The benefits of the flavonoids found in Citrus aurantium L. include anti‐inflammation, anti‐cancer, anti‐viral and anti‐bacterial activities, and enhancement of the immune response. The study investigated the effect of the flavonoids isolated from Citrus aurantium L. native to Korea on the production of pro‐inflammatory mediators by blocking signal transduction mediated by nuclear factor‐kappa B (NF‐κB) and mitogen‐activated protein kinases (MAPKs) in lipopolysaccharide (LPS)‐induced L6 skeletal muscle cells. The flavonoids decreased the production of inducible nitric oxide synthase, cyclooxygenase‐2, interleukin‐6 and tumor necrosis factor‐alpha by suppressing NF‐κB and MAPKs signal pathways in LPS‐induced L6 skeletal muscle cells. These findings suggest that the flavonoids isolated from Korea Citrus aurantium L. might have anti‐inflammatory effects that regulate the expression of inflammatory mediators in L6 skeletal muscle cells. Copyright © 2012 John Wiley & Sons, Ltd.     

Neohesperidin suppresses IgE‐mediated anaphylactic reactions and mast cell activation via Lyn‐PLC‐Ca2+ pathway

Mast cells play an essential role in IgE‐FcεR1‐mediated allergic diseases. Citrus aurantium is a prolific source of flavonoids with various biological activities, including anti‐inflammatory, antioxidant, and anti‐tumor efficacies. Neohesperidin is a novel flavonoid isolated from the leaves of C. aurantium. In this study, the anti‐allergic and anti‐inflammatory potentials of neohesperidin were investigated along with its molecular mechanism. The anti‐anaphylactic activity of neohesperidin was evaluated through hind paw extravasation study in mice. Calcium imaging was used to assess intracellular Ca²⁺ mobilization. The levels of cytokines and chemokines were measured using enzyme immunoassay kits. Western blotting was used to explore the related molecular signaling pathways. Neohesperidin suppressed IgE‐induced mast cell activations, including degranulation and secretion of cytokines and eicosanoids through inhibiting phosphorylation of Lyn kinase. Neohesperidin inhibited the release of histamine and other proinflammatory cytokines through a mast cell‐dependent passive cutaneous anaphylaxis animal model. Histological studies demonstrated that neohesperidin substantially inhibited IgE‐induced cellular infiltration and attenuated mast cell activation in skin tissue. In conclusion, our study revealed that neohesperidin could inhibit allergic responses in vivo and in vitro, and the molecule may be regarded as a novel agent for preventing mast cell‐immediate and delayed allergic diseases.     

Activation of Caspase‐9/3 and Inhibition of Epithelial Mesenchymal Transition are Critically Involved in Antitumor Effect of Phytol in Hepatocellular Carcinoma Cells

This study was designed to investigate the antitumor mechanism of Phytol in hepatocellular carcinomas including Huh7 and HepG2 cells in association with caspase dependent apoptosis and epithelial mesenchymal transition (EMT) signaling. Phytol significantly suppressed the viability of Huh7 and HepG2 cells. Also, Phytol significantly increased the sub G1 population and terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end labeling (TUNEL) positive cells in a concentration dependent manner in Huh7 and HepG2 cells. Consistently, Phytol cleaved poly (adenosine diphosphate‐ribose) polymerase (PARP), activated caspase‐9/3, and Bax attenuated the expression of survival genes such as Bcl‐2, Mcl‐1, and c‐Myc in Huh7 and HepG2 cells. Of note, Phytol also suppressed typical morphology change of EMT such as loss of cell adhesion and formation of fibroblast like mesenchymal cells in HepG2 cells. Furthermore, Phytol also reversed the loss of E‐cadherin and overexpression of p‐smad2/3, alpha‐smooth muscle actin, and Snail induced by EMT promoter transforming growth factor beta1 in HepG2 cells. Overall, our findings suggest that Phytol exerts antitumor activity via apoptosis induction through activation of caspas‐9/3 and inhibition of EMT in hepatocellular carcinoma cells as a potent anticancer candidate for liver cancer treatment. Copyright © 2015 John Wiley & Sons, Ltd.     

Rutin,a Quercetin Glycoside,Restores Chemosensitivity in Human Breast Cancer Cells

Several studies have documented the ability of flavonoids to sensitize cancer cells to chemotherapeutics and reverse multidrug resistance by inhibition of efflux pumps (adenosine triphosphate‐binding cassette transporters), apoptosis activation, and cell cycle arrest. In this study, the flavonoid rutin (quercetin 3‐O‐β‐d ‐rutinoside) was investigated as chemosensitizer towards two different human epithelial breast cancer cell lines: (i) MB‐MDA‐231, selected as representative for triple‐negative breast cancer and (ii) MCF‐7 used as a well‐characterized model of HER2‐negative breast cancer. To assess the cytocompatibility of rutin against non‐cancer cells, primary human mammary fibroblasts were used as control and non‐target cells. In MDA‐MB‐231 cells, 20 μM rutin enhanced cytotoxicity related to cyclophosphamide and methotrexate. Rutin significantly (p < 0.05) increased the anticancer activity of both chemotherapeutics, at 24–48–72 h, and decreased the activity of the adenosine triphosphate‐binding cassette transporters, namely, P‐glycoprotein (P‐gp) and breast cancer resistance protein (BCRP). Flow cytometry analysis showed 20 μM and 50 μM rutin arrested cell cycle at G2/M and G0/G1 phases, respectively, significantly promoting cell apoptosis. Rutin, via non‐selective inhibition of P‐gp and BCRP pumps, efficiently reverses multidrug resistance and restores chemosensitivity to cyclophosphamide and cyclophosphamide of human chemoresistant, triple‐negative breast cancer cells, successfully arresting cell cycle progression. Copyright © 2017 John Wiley & Sons, Ltd.     

Apoptotic Effect of Galbanic Acid via Activation of Caspases and Inhibition of Mcl‐1 in H460 Non‐Small Lung Carcinoma Cells

Galbanic acid (GBA), a major compound of Ferula assafoetida, was known to have cytotoxic, anti‐angiogenic and apoptotic effects in prostate cancer and murine Lewis lung cancer cells; the underling apoptotic mechanism of GBA still remains unclear so far. Thus, in the present study, the apoptotic mechanism of GBA was investigated mainly in H460 non‐small cell lung carcinoma (NSCLC) cells because H460 cells were most susceptible to GBA than A549, PC‐9 and HCC827 NSCLC cells. Galbanic acid showed cytotoxicity in wild EGFR type H460 and A549 cells better than other mutant type PC‐9 and HCC827 NSCLC cells. Also, GBA significantly increased the number of Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) positive cells and sub G1 population in H460 cells. Western blotting revealed that GBA cleaved poly (ADP‐ribose) polymerase (PARP), activated Bax and caspase 9, attenuated the expression of Bcl‐2, Bcl‐x_L, and Myeloid cell leukemia 1 (Mcl‐1) in H460 cells. However, interestingly, overexpression of Mcl‐1 blocked the ability of GBA to exert cytotoxicity, activate caspase9 and Bax, cleave PARP, and increase sub G1 accumulation in H460 cells. Overall, these findings suggest that GBA induces apoptosis in H460 cells via caspase activation and Mcl‐1 inhibition in H460 cells as a potent anticancer agent for NSCLC treatment. Copyright © 2015 John Wiley & Sons, Ltd.     

The Effect of the Ginkgo biloba Extract in the Expression of Bax,Bcl‐2 and Bone Mineral Content of Wistar Rats with Glucocorticoid‐Induced Osteoporosis

Objective: Evaluate the effects of the extract of Ginkgo biloba (EGb) in the glucocorticoid‐induced‐osteoporosis through the Bax and Bcl‐2 expressions by osteoblast cells, the x‐ray and bone density of the tibia. Method: Rats were divided into five groups: osteoporosis; EGb1 (28 mg/kg); EGb2 (56 mg/kg); alendronate (0.2 mg/animal) and control. The treatments were conducted for 20 (n = 30) and 30 days (n = 30). The Bax and Bcl‐2 expressions were evaluated in osteoblasts of the mandibular alveolar bone. The tibias were radiographed to evaluate the X‐ray and bone density. The control group was compared with the osteoporosis' (Student's t‐test/Mann‐Whitney). The other groups were analyzed by analysis of variance test followed by Dunnett/Dunnett T3 (p < 0.05). Results: When compared the osteoporosis to the control group (p <0.05): Bax and x‐ray density increased; Bcl‐2 and the bone density reduced. When compared with the osteoporosis group (p < 0.05), alendronate (30 days), EGb1 and EGb2 (20/30 days) increased the Bcl‐2 expression; EGb2 and alendronate (20 days) EGb1 and EGb2 (30 days) reduced the Bax expression; and EGb1 and EGb2 (20/30 days) reduced the X‐ray density. Conclusions: The EGb improved the Bcl‐2 and reduced the Bax expression by osteoblasts in the mandibular alveolar bone and recovered the mineral content in the tibia of rats with glucocorticoid‐induced‐osteoporosis. Copyright © 2012 John Wiley & Sons, Ltd.     

Anticancer activity and molecular mechanisms of α‐conidendrin,a polyphenolic compound present in Taxus yunnanensis,on human breast cancer cell lines

α‐Conidendrin is a polyphenolic compound found mainly in Taxus yunnanensis, as the source of chemotherapy drug paclitaxel, which has been used in traditional medicine for treatment of cancer. This study aimed to investigate the anticancer activity and molecular mechanisms of α‐conidendrin on breast cancer cell lines. The results of the present study show that α‐conidendrin possesses potent antiproliferative effects on breast cancer cell lines MCF‐7 and MDA‐MB‐231. α‐Conidendrin significantly induced apoptosis in breast cancer cells via reactive oxygen species generation, upregulation of p53 and Bax, downregulation of Bcl‐2, depolarization of mitochondrial membrane potential (MMP), release of cytochrome c from mitochondria, and activation of caspases‐3 and ‐9. α‐Conidendrin remarkably inhibited the proliferation of breast cancer cells through induction of cell cycle arrest by upregulating p53 and p21 and downregulating cyclin D1 and CDK4. Unlike breast cancer cells, the antiproliferative effect of α‐conidendrin on human foreskin fibroblast cells (normal cells) was very small. In normal cells, reactive oxygen species levels, loss of MMP, release of cytochrome c, mRNA expression of p53, p21, cyclin D1, CDK4, Bax, and Bcl‐2 as well as mRNA expression and activity of caspases‐3 and ‐9 were significantly less affected by α‐conidendrin compared with cancer cells. These results suggest that α‐conidendrin can be a promising agent for treatment of breast cancer with little or no toxicity against normal cells.     

Ramalin‐Mediated Apoptosis Is Enhanced by Autophagy Inhibition in Human Breast Cancer Cells

Breast cancer, the most commonly diagnosed cancer in women worldwide, is treated in various ways. Ramalin is a chemical compound derived from the Antarctic lichen Ramalina terebrata and is known to exhibit antioxidant and antiinflammatory activities. However, its effect on breast cancer cells remains unknown. We examined the ability of ramalin to induce apoptosis and its mechanisms in MCF‐7 and MDA‐MB‐231 human breast cancer cell lines. Ramalin inhibited cell growth and induced apoptosis in both cell lines in a concentration‐dependent manner. By upregulating Bax and downregulating Bcl‐2, ramalin caused cytochrome c and apoptosis‐inducing factor to be released from the mitochondria into the cytosol, thus activating the mitochondrial apoptotic pathway. In addition, activated caspase‐8 and caspase‐9 were detected in both types of cells exposed to ramalin, whereas ramalin activated caspase‐3 only in the MDA‐MB‐231 cells. Ramalin treatment also increased the levels of LC3‐II and p62. Moreover, the inhibition of autophagy by 3‐methyladenine or Atg5 siRNA significantly enhanced ramalin‐induced apoptosis, which was accompanied by a decrease in Bcl‐2 levels and an increase in Bax levels. Therefore, autophagy appears to be activated as a protective mechanism against apoptosis in cancer cells exposed to ramalin. These findings suggest that ramalin is a potential anticancer agent for the treatment of patients with non‐invasive or invasive breast cancer. Copyright © 2015 John Wiley & Sons, Ltd.     

[6]‐Shogaol Attenuates Neuronal Apoptosis in Hydrogen Peroxide‐Treated Astrocytes Through the Up‐Regulation of Neurotrophic Factors

Neuronal apoptosis induced by oxidative stress is a prominent feature of neurodegenerative disorders. [6]‐shogaol, a bio‐active compound in ginger, possesses potent anti‐inflammatory actions and has recently emerged as a potential therapeutic agent for neurodegenerative disorders. However, the effects of [6]‐shogaol on astroglial apoptosis following exogenously induced oxidative stress has not yet been investigated. Here, we show that the anti‐apoptotic activity of [6]‐shogaol in astrocytes following exposure to hydrogen peroxide (H₂O₂) involves a marked up‐regulation of neurotrophic factors such as nerve growth factor, glial cell line‐derived neurotrophic factor, and brain‐derived neurotrophic factor. Astrocytes co‐treated with [6]‐shogaol and H₂O₂ for 1 h showed decrease in reactive oxygen species production compared with those only treated with H₂O₂. Moreover, [6]‐shogaol counteracted the reduced expression of ERK1/2 in H₂O₂‐treated astrocytes and protected these cells from oxidative stress and apoptosis by attenuating the impairment of mitochondrial function proteins such as Bcl‐2 and Bcl‐xL. Additionally, [6]‐shogaol inhibits the expression of the apoptotic proteins Bax and caspase‐3 in H₂O₂‐treated astrocytes. This data suggest that following oxidative stress, [6]‐shogaol protects astrocytes from oxidative damage through the up‐regulating levels of neurotrophic factors. These findings provide further support for the use of [6]‐shogaol as a therapeutic agent in neurodegenerative disorders. Copyright © 2013 John Wiley & Sons, Ltd.     

Auraptene Induces Apoptosis via Myeloid Cell Leukemia 1‐Mediated Activation of Caspases in PC3 and DU145 Prostate Cancer Cells

Although auraptene, a prenyloxy coumarin from Citrus species, was known to have anti‐oxidant, anti‐bacterial, antiinflammatory, and anti‐tumor activities, the underlying anti‐tumor mechanism of auraptene in prostate cancers is not fully understood to date. Thus, in the present study, we have investigated the anti‐tumor mechanism of auraptene mainly in PC3 and DU145 prostate cancer cells, because auraptene suppressed the viability of androgen‐independent PC3 and DU145 prostate cancer cells better than androgen‐sensitive LNCaP cells. Also, auraptene notably increased sub‐G1 cell population and terminal deoxynucleotidyl transferase dUTP nick end labeling‐positive cells as features of apoptosis in two prostate cancer cells compared with untreated control. Consistently, auraptene cleaved poly(ADP‐ribose) polymerase, activated caspase‐9 and caspase‐3, suppressed the expression of anti‐apoptotic proteins, including Bcl‐2 and myeloid cell leukemia 1 (Mcl‐1), and also activated pro‐apoptotic protein Bax in both prostate cancer cells. However, Mcl‐1 overexpression reversed the apoptotic effect of auraptene to increase sub‐G1 population and induce caspase‐9/3 in both prostate cancer cells. Taken together, the results support scientific evidences that auraptene induces apoptosis in PC3 and DU145 prostate cancer cells via Mcl‐1‐mediated activation of caspases as a potent chemopreventive agent for prostate cancer prevention and treatment. Copyright © 2017 John Wiley & Sons, Ltd.     

Morin enhances auranofin anticancer activity by up‐regulation of DR4 and DR5 and modulation of Bcl‐2 through reactive oxygen species generation in Hep3B human hepatocellular carcinoma cells

Evidence suggests that auranofin (AF) exhibits anticancer activity by inhibiting thioredoxin reductase (TrxR). Here, in this study, we have investigated the synergistic effects of AF and morin and their mechanism for the anticancer effects focusing on apoptosis in Hep3B human hepatocellular carcinoma cells. We assessed the anticancer activities by annexin V/PI double staining, caspase, and TrxR activity assay. Morin enhances the inhibitory effects on TrxR activity of AF as well as reducing cell viability. Annexin V/PI double staining revealed that morin/AF cotreatment induced apoptotic cell death. Morin enhances AF‐induced mitochondrial membrane potential (ΔΨm) loss and cytochrome c release. Further, morin/AF cotreatment upregulated death receptor DR4/DR5, modulated Bcl‐2 family members (upregulation of Bax and downregulation of Bcl‐2), and activated caspase‐3, ‐8, and ‐9. Morin also enhances AF‐induced reactive oxygen species (ROS) generation. The anticancer effects results from caspase‐dependent apoptosis, which was triggered via extrinsic pathway by upregulating TRAIL receptors (DR4/DR5) and enhanced via intrinsic pathway by modulating Bcl‐2 and inhibitor of apoptosis protein family members. These are related to ROS generation. In conclusion, this study provides evidence that morin can enhance the anticancer activity of AF in Hep3B human hepatocellular carcinoma cells, indicating that its combination could be an alternative treatment strategy for the hepatocellular carcinoma.     

Caffeoylserotonin Protects Human Keratinocyte HaCaT Cells against H2O2‐Induced Oxidative Stress and Apoptosis through Upregulation of HO‐1 Expression via Activation of the PI3K/Akt/Nrf2 Pathway

Caffeoylserotonin (CaS) has strong radical scavenging activity as well as antioxidant activities, protecting cells from lipid peroxidation, intracellular reactive oxygen species generation, DNA damage, and cell death. The molecular mechanism by which CaS protects against oxidative stress is not well understood. Here, we analyzed the cytoprotective activity of CaS in hydrogen peroxide (H₂O₂)‐treated keratinocyte HaCaT cells. H₂O₂ induced apoptosis in the cells through activation of pro‐apoptotic p21, Bax, and caspase‐3. Pretreatment with CaS inhibited apoptotic gene expression and activated the anti‐apoptotic gene, Bcl‐xL. Although CaS did not directly affect heme oxygenase‐1 (HO‐1) expression, pretreatment with CaS augmented HO‐1 expression through an increase in NF‐E2‐related factor (Nrf2) stability and stimulation of Nrf2 translocation to the nucleus upon H₂O₂ exposure. H₂O₂ also induced the phosphorylation and subsequent activation of ERK, p38 MAPK, and Akt. Analysis using specific inhibitors of p38 MAPK and Akt demonstrated that only Akt activation was involved in HO‐1 and Nrf2 expressions. In addition, PI3K and PKC inhibitors suppressed HO‐1/Nrf2 expression and Akt phosphorylation. These results demonstrate that CaS protects against oxidative stress‐induced keratinocyte cell death in part through the activation of Nrf2‐mediated HO‐1 induction via the PI3K/Akt and/or PKC pathways, but not MAPK signaling. Copyright © 2013 John Wiley & Sons, Ltd.     

山楂乙醇提取物对肝癌细胞HepG2凋亡及相关因子表达的影响

目的:探讨山楂提取物体外对肝癌细胞株HepG2凋亡的影响。方法:山楂乙醇提取,并采用不同质量浓度(0.1,0.2,0.4,0.8 g·L-1)山楂提取物处理HepG2细胞24,48,72 h。四甲基偶氮唑盐比色(MTT)法检测提取物对肝癌细胞活力的影响;流式细胞术检测提取物处理细胞48 h后的凋亡率;实时定量荧光PCR(real-time PCR)检测半胱氨酸蛋白酶-3(Caspase-3),B淋巴细胞瘤-2(Bcl-2),Bcl-2相关X蛋白(Bax)基因表达;免疫印迹法(Western blot)检测激活型Caspase-3(CleavedCaspase-3),Bcl-2,Bax蛋白表达。结果:山楂提取物对HepG2细胞的活力有显著抑制作用(P0.05),并以浓度及时间依赖的形式诱导细胞凋亡。山楂提取物可以显著促进Bax和Cleaved-Caspase-3基因和蛋白表达,抑制Bcl-2基因和蛋白表达。结论:山楂提取物抑制肝癌细胞HepG2的增殖,促进其发生凋亡,与Bax和Cleaved-Caspase-3的表达增加,Bcl-2/Bax降低有关。