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1.
《Toxicology in vitro》2014,28(2):156-163
Atrazine (ATZ) is probably the most widely used herbicide in the world. However there are still many controversies regarding its impacts on human health. Our investigations on the role of pesticides in liver dysfunctions have led us to detect an inhibition of FSP1 expression of 70% at 50 μm and around 95% at 500 μM of ATZ (p < 0.01). This gene encodes the protein S100a4 and is a clinical biomarker of epithelial–mesenchymal transition (EMT), a key step in the metastatic process. Here we investigated the possible effect of ATZ on cell migration and noticed that it prevents the EMT and motility of the HepG2 cells induced by the phorbol ester TPA. ATZ decreases Fak pathway activation but has no effect on the Erk1/2 pathway known to be involved in metastasis in this cell line. These results suggest that ATZ could be involved in cell homeostasis perturbation, potentially through a S100a4-dependant mechanism.  相似文献   

2.
The aim of this work was to compare the preventing capacity of quercetin with Cu/Zn superoxide dismutase (Cu/Zn SOD), ascorbic acid and glutathione on nitric oxide (NO)-induced relaxation in mouse gastric fundus. Furthermore, the effects of the quercetin on the tissue level of total oxidant and antioxidant was investigated. Nitrergic stimulation (4 Hz, 25 V, 0.1 ms, 10 s-train) and exogenous NO (10 μM) induced relaxation. Pyrogallol (10 μM), hydroquinone (100 μM) and LY83583 (6-Anilino-quinolin-5,8-quinone, 5 μM) inhibited nitrergic relaxations. The inhibition observed with pyrogallol, hydroquinone and LY83583 was prevented by quercetin (0.1 μM). Also, ascorbic acid (500 μM), glutathione (100 μM) and Cu/Zn SOD (100 U/ml) prevented the inhibitory effect of superoxide anion generators on the relaxation to nitrergic stimulation and NO. Diethyldithiocarbamic acid (DETCA; 8 mM) inhibited nitrergic relaxations. DETCA-induced inhibition on nitrergic stimulation and NO-induced relaxation was prevented by quercetin, ascorbic acid, glutathione or Cu/Zn SOD. DETCA plus pyrogallol, hydroquinone or LY83583 strengthened the inhibition on the relaxations. Also, pre-treatment with quercetin, ascorbic acid and glutathione prevented the inhibitory effect of DETCA plus LY-83583 on the relaxation to nitrergic stimulation and NO but Cu/Zn SOD did not prevent this inhibition. Also, quercetin increased tissue total antioxidant capacity and decreased tissue oxidant level and oxidative stress index in DETCA-treatment group. These results indicate that quercetin has antioxidant effect and protects NO from endogenous superoxide anion-driven inactivation and enhances its biological activity, suggesting that quercetin may scavenge superoxide anion in a Cu/Zn SOD, glutathione or ascorbic acid-inhibitable manner.  相似文献   

3.
Transient developmental exposure to 0.1 μM bisphenol A (BPA) results in larval zebrafish hyperactivity and learning impairments in the adult, while exposure to 80 μM BPA results in teratogenic responses, including craniofacial abnormalities and edema. The mode of action underlying these effects is unclear. We used global gene expression analysis to identify candidate genes and signaling pathways that mediate BPA's developmental toxicity in zebrafish. Exposure concentrations were selected and anchored to the positive control, 17β-estradiol (E2), based on previously determined behavioral or teratogenic phenotypes. Functional analysis of differentially expressed genes revealed distinct expression profiles at 24 h post fertilization for 0.1 μM versus 80 μM BPA and 0.1 μM versus 15 μM E2 exposure, identification of prothrombin activation as a top canonical pathway impacted by both 0.1 μM BPA and 0.1 μM E2 exposure, and suppressed expression of several genes involved in nervous system development and function following 0.1 μM BPA exposure.  相似文献   

4.
One new naturally isoflavone compound, 5,7,2′,3′,4′ penta hydroxyl isoflavone-4′-O-β-glucopyranoside (1) was isolated from the aqueous methanol extract (AME) of Pulicaria undulata subsp. undulata, together with seven known compounds: kaempferol (2), kaempferol 3-O-β-glucoside (3), quercetin (4), quercetin 3-O-β-glucoside (5), quercetin 3-O-β-galactoside (6), quercetin 3,7-di OCH3 (7), and caffeic acid (8). Their structures were established through chemical (acid hydrolysis) and spectral analysis (UV, NMR, and ESIM). The AME and some isolated compounds were evaluated as protective agents. Free radical scavenging using a microscaled 2,2-diphenyl-1-picrylhydrazyl assay was used to assess the direct antioxidant properties that were evaluated by the ability to protect murine Hepa1c1c7 liver cells against damage induced by the organic peroxide tert-butyl hydroperoxide. The neutral red uptake assay (NRU) was used to record the activity. Results of the 2,2-diphenyl-1-picrylhydrazyl assay recorded differential scavenging properties in ascending order: 5,7,2′,3′,4′ penta hydroxyl isoflavone-4′-O-β-glucopyranoside > quercetin > quercetin 3-O-galactoside > caffeic acid > quercetin 3,7-di-OCH3 > kaempferol with 50% inhibitory concentrations of 3.9 μM, 7.5 μM, 11.4 μM, 12.2 μM, 78.1 μM, and 252.3 μM, respectively. The antioxidative potential reveals the potency of AME, quercetin, and quercetin 3,7-di-OCH3. The latter compound showed full protection at 100 μM (33 μg/mL) against the induced toxicant effect where the 50% effective concentration was calculated as 33.6 ± 1.7 μM (11.1 μg/mL). In addition to quercetin, which was extensively shown previously as a cytoprotective agent, AME was less potent; it was capable of protecting 75% at 100 μg/mL with 50% effective concentration of 92.3 ± 4 μg/mL. Moreover, the isolated flavonoids were found to be significantly chemosystematic markers.  相似文献   

5.
《Toxicology in vitro》2010,24(2):516-522
The pathogenesis and progression of alcoholic liver disease (ALD) are associated with free radical injury and oxidative stress, which could be partially attenuated by antioxidants and free radical scavengers. Quercetin, one of the most widely distributed flavonoids in plants, is a natural antioxidant. The hypothesis that quercetin could prevent the ethanol-induced oxidative damage in hepatocytes was investigated. The ethanol-intoxicated (100 mM for 8 h) rat primary hepatocytes were post-treated (2 h), simultaneously treated or pre-treated (2 h) with quercetin respectively, while the time-dependent (0.5–8 h) and dose-dependent (25–200 μM) quercetin pre-treatment were used in the present study. The parameters of lactate dehydrogenase (LDH), aspartate transaminase (AST), malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) were determined to address the alterations of cell damage and antioxidant state after quercetin intervention. The toxic insult of ethanol to hepatocytes was challenged by quercetin and these parameters almost returned to the level of control group when hepatocytes were pre-treated with quercetin at the dose of 50 μM for 2–4 h before ethanol exposure. In conclusion, quercetin pre-treatment provided protection against ethanol-induced oxidative stress in hepatocytes and may be used as a new natural drug for the prevention and/or treatment of ALD.  相似文献   

6.
We investigated the anti-fibrotic mechanism of tetrandrine, a bisbenzylisoquinoline alkaloid from the Chinese herb, Stephania tetrandra, on the immortalized HSC-T6 rat hepatic stellate cell line. Tetrandrine (0.39–50 μM) dose- and time-dependently inhibited HSC-T6 cell viability within 24 h and exhibited almost no cytotoxicity at concentrations lower than 6.25 μM in the presence of tumor necrosis factor-α (TNF-α). At a much high concentration (50 μM), tetrandrine caused fatal cytotoxity in both HSCs and hepatocytes. TNF-α time-dependently increased α-smooth muscle actin (α-SMA) expression, while a lower concentration of tetrandrine (6.25 μM) prior to TNF-α treatment reduced the expression of α-SMA and TNFR-1-associated death domain (TRADD). TNF-α treatment induced TGF-β-activated kinase-1 (TAK1) and c-Jun N-terminal kinase (JNK) phosphorylation, which were attenuated by tetrandrine. Furthermore, TNF-α treatment activated nuclear factor-κB (NF-κB) nuclear translocation and IκB-α degradation. Tetrandrine treatment prior to TNF-α reduced nuclear phosphorylated and total NF-κB p65, while the cytosolic IκB-α and NF-κB p65 levels significantly increased. In addition, treatment with only tetrandrine induced the cleavage of caspase-3 and PARP within a range of higher concentrations. Tetrandrine-induced apoptosis was confirmed by the TUNEL assay and flow-cytometric analysis. Treatment with only tetrandrine markedly reduced α-SMA expression, except for at lower concentrations of tetrandrine. A higher concentration of tetrandrine (25 μM) induced a significant increase in JNK and extracellular signal-regulated kinase (ERK) phosphorylation, NF-κB nuclear translocation and IκB-α degradation. In conclusion, the anti-fibrogenic effects of tetrandrine on HSCs involved a dosage-dependent signaling pathway, based on the tetrandrine concentration, by regulating TAK1, JNK and NF-κB. The present data provides strong evidence for the anti-fibrotic dosage-dependent signaling pathway of tetrandrine.  相似文献   

7.
Zinc (Zn) is an essential trace elements, its deficiency is associated with increased incidence of human breast cancer. We aimed to study the effect of Zn on human breast cancer MCF-7 cells cultured in Zn depleted and Zn adequate medium. We found increased cancer cell growth in zinc depleted condition, further Zn supplementation inhibits the viability of breast cancer MCF-7 cell cultured in Zn deficient condition and the IC25, IC50 value for Zn is 6.2 μM, 15 μM, respectively after 48 h. Zn markedly induced apoptosis through the characteristic apoptotic morphological changes and DNA fragmentation after 48 h. In addition, Zn deficient cells significantly triggered intracellular ROS level and develop oxidative stress induced DNA damage; it was confirmed by elevated expression of CYP1A, GPX, GSK3β and TNF-α gene. Zinc depleted MCF-7 cells expressed significantly (p  0.001) decreased levels of CDKN2A, pRb1, p53 and increased the level of mdm2 expression. Zn supplementation (IC50 = 15 μM), increased significantly CDKN2A, pRB1 & p53 and markedly reduced mdm2 expression; also protein expression levels of CDKN2A and pRb1 was significantly increased. In addition, intrinsic apoptotic pathway related genes such as Bax, caspase-3, 8, 9 & p21 expression was enhanced and finally induced cell apoptosis. In conclusion, physiological level of zinc is important to prevent DNA damage and MCF-7 cell proliferation via regulation of tumor suppressor gene.  相似文献   

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10.
Folic acid (FA) is crucial for fetal development. We aimed to study the modulation of FA placental uptake by: hyperserotoninemia and hyperglycaemia, anti-hypertensives, insulin and drugs of abuse. For this, we characterized 3H-FA uptake by primary cultures of human cytotrophoblasts (TB cells) and tested the effects of these compounds upon 3H-FA uptake, TB cell viability and gene expression. Our results show that: (a) acutely, 3H-FA uptake was decreased by labetalol (0.1–1000 μM), ecstasy and amphetamine (0.025–25 μM); and (b) chronically, 3H-FA uptake was decreased by high glucose (30 mM), atenolol, nicotine (0.1 and 10 μM), ethanol (0.01 and 10 mM), ecstasy, amphetamine (0.25 and 1 μM) and tetrahydrocannabinol (1 and 100 nM). Moreover, many of these drugs were cytotoxic and they differentially modulated the mRNA expression of FA placental transport systems. Our results suggest that inhibition of FA placental uptake may constitute one of the mechanisms involved in the fetotoxicity of many of the compounds tested.  相似文献   

11.
Endocrine disrupting chemicals (EDCs) have the potential to interfere with the hormonal system and may negatively influence human health. Microarray analysis was used in this study to investigate differential gene expression in human peripheral blood cells (PBMCs) after in vitro exposure to EDCs. PBMCs, isolated from blood samples of four male and four female healthy individuals, were exposed in vitro for 18 h to either a dioxin-like polychlorinated biphenyl (PCB126, 1 μM), a non-dioxin-like polychlorinated biphenyl (PCB153, 10 μM), a brominated flame retardant (BDE47, 10 μM), a perfluorinated alkyl acid (PFOA, 10 μM) or bisphenol (BPA, 10 μM). ANOVA analysis revealed a significant change in the expression of 862 genes as a result of EDC exposure. The gender of the donors did not affect gene expression. Hierarchical cluster analysis created three groups and clustered: (1) PCB126-exposed samples, (2) PCB153 and BDE47, (3) PFOA and BPA. The number of differentially expressed genes varied per compound and ranged from 60 to 192 when using fold change and multiplicity corrected p-value as filtering criteria. Exposure to PCB126 induced the AhR signaling pathway. BDE47 and PCB153 are known to disrupt thyroid metabolism and exposure influenced the expression of the nuclear receptors PPARγ and ESR2, respectively. BPA and PFOA did not induce significant changes in the expression of known nuclear receptors. Overall, each compound produced a unique gene expression signature affecting pathways and GO processes linked to metabolism and inflammation. Twenty-nine genes were significantly altered in expression under all experimental conditions. Six of these genes (HSD11B2, MMP11, ADIPOQ, CEL, DUSP9 and TUB) could be associated with obesity and metabolic syndrome. In conclusion, microarray analysis identified that PBMCs altered their gene expression response in vitro when challenged with EDCs. Our screening approach has identified a number of gene candidates that warrant further study.  相似文献   

12.
The presented study investigates and compares the estrogenic and androgenic activities of commonly used diesters of phthalic acid (phthalates) using the XenoScreen YES/YAS assay. Phthalates are commonly used plasticizers in polymers dedicated for i.e. food and drug containers. Since phthalates are not chemically bonded to the polymer, they can leach or migrate from the polymer. Therefore, phthalates are identified as contaminants in a variety of consumer products. Investigation of estrogenic and androgenic activities of phthalates (DEP, DBP, BBP, DEHP and DINP) showed no significant effect of tested substances either on hERα or hAR receptors. Phthalates exhibited strong anti-estrogenic (IC50 for BBP = 8.66 μM, IC50 for DEHP = 3.61 μM and IC50 for DINP = 0.065 μM) and anti-androgenic (IC50 for BBP = 5.30 μM, IC50 for DEHP = 2.87 μM and IC50 for DINP = 0.068 μM) activities.  相似文献   

13.
ContextCurrently, there is a dramatically growing interest in Chinese traditional medicines, especially in the therapy of inflammatory diseases. Taurocholic acid (TCA), as a kind of natural bioactive substance of animal bile acid, has medicinal applications to treat a wide range of inflammatory diseases.ObjectiveThe study was designed to evaluate the effects of TCA on cytokine secretion, such as TNF-α and IL-1β and on the ratio of CD4+/CD8+, which is beneficial for understanding the mechanism of TCA on immunoregulation preliminarily, and also will benefit our further research.Materials and methodsThe gene and protein expressions of TNF-α and IL-1β were measured by real time RT-PCR and ELISA in serum, spleen and lymphocytes respectively. The ratio of CD4+/CD8+ in peripheral blood and lymphocytes was measured by flow cytometry.ResultsOur present study has shown that lipopolysaccharide (LPS) and cyclosporin A (CsA) could increase or decrease the gene and protein expressions of TNF-α and IL-1β respectively. TCA (0.25 g/kg, 0.125 g/kg) could recover the suppressed expressions of TNF-α and IL-1β and increase the ratio of CD4+/CD8+. In vitro, TCA (15 μg/mL) could inhibit the increased production of TNF-α and IL-1β; TCA (0.15 μg/mL–15 μg/mL) could inhibit the increased gene expressions of IL-1β and TNF-α. TCA (0.15 μg/mL) could recover the suppressed expressions of TNF-α and IL-1β.ConclusionThe function of immunoregulation of TCA may be accomplished through modulating the gene and protein expressions of TNF-α and IL-1β and elevating CD4+/CD8+ T-cell ratio.  相似文献   

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16.
《Vascular pharmacology》2011,54(5-6):239-249
KMUP-1 inhibits monocrotaline (MCT)-induced pulmonary artery (PA) proliferation by targeting serotonin (5-HT) receptors, inactivating RhoA and reducing phosphorylation of AKT/ERK. In MCT-treated rats, KMUP-1 f (5 mg/kg p.o.; 1 mg/kg i.p. × 21 days) decreased proliferation (PCNA-positive) cells and 5-HTT-expression in lung and 5-HT levels in plasma. In isolated PA, KMUP-1 and simvastatin (0.1–100 μM) inhibited 5-HT (10 μM)-induced PA constriction. l-NAME-pretreatment reduced KMUP-1-induced relaxation. In pulmonary arterial smooth muscle cells (PASMCs), KMUP-1 (1–100 μM) and simvastatin (10 μM) inhibited 5-HT-induced cell migration and proliferation and KMUP-1 (1–100 μM) inhibited 5-HT-induced Ca2+ influx. Similar to Y27632, KMUP-1 (1–100 μM) inhibited 5-HT-induced RhoA/ROCK expression, while KMUP-1, Y27632 and simvastatin at 10 μM inhibited 5-HT-induced 5-HTT expression and KMUP-1 inhibited 5-HT-induced phosphorylation of AKT and ERK1/2 in PASMCs. In human pulmonary arterial endothelial cell (HPAEC), KMUP-1 (1–100 μM) increased the expression of eNOS and 5-HT2B and also at 10 μM augmented eNOS expression and production of nitric oxide (NO) in 5-HT-treated HPAEC. In radioligand binding, the IC50/Ki values of KMUP-1 for 5-HT2A, 5-HT2B and 5-HT2C receptors were 0.34/0.0971, 0.04/0.0254, and 0.408/0.214 μM respectively. In conclusion, KMUP-1 inhibits MCT-induced PA proliferation by binding to 5-HT2A, 5-HT2B and 5-HT2C receptors, increasing endothelial eNOS/5-HT2B receptor expression and NO release and inhibiting 5-HTT/RhoA/ROCK expression and AKT/ERK phosphorylation. KMUP-1 is suggested to be useful in the treatment of 5-HT-induced pulmonary artery proliferation.  相似文献   

17.
The objectives were to assess the potential of dietary flavonoids apigenin (Api) and luteolin (Lut) to enhance the anti-proliferative effects of chemotherapeutic drugs on BxPC-3 human pancreatic cancer cells and to investigate the potential molecular mechanism of action. Simultaneous treatment or pretreatment (0, 6, 24 and 42 h) of flavonoids and chemotherapeutic drugs at various concentrations (0–50 μM) were assessed using the MTS cell proliferation assay. Simultaneous treatment with either flavonoid (13, 25 or 50 μM) and chemotherapeutic drugs 5-fluorouracil (5-FU, 50 μM) or gemcitabine (Gem, 10 μM) for 60 h resulted in mostly less-than-additive effects (p < 0.05). Pretreatment for 24 h with 13 μM of either Api or Lut, followed by Gem for 36 h was optimal to inhibit cell proliferation. Pretreatment of cells with 11–19 μM of either flavonoid for 24 h resulted in 59–73% growth inhibition when followed by Gem (10 μM, 36 h). Lut (15 μM, 24 h) pretreatment followed by Gem (10 μM, 36 h), significantly decreased protein expression of nuclear GSK-3β and NF-κB p65 and increased pro-apoptotic cytosolic cytochrome c. Pretreatment of BxPC-3 human pancreatic cancer cells with low concentrations of Api or Lut effectively aid in the anti-proliferative activity of chemotherapeutic drugs.  相似文献   

18.
The hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are expressed in pacemaker cells very early during cardiogenesis. This work aimed at determining to what extent these channels are implicated in the electromechanical disturbances induced by a transient oxygen lack which may occur in utero.Spontaneously beating hearts or isolated ventricles and outflow tracts dissected from 4-day-old chick embryos were exposed to a selective inhibitor of HCN channels (ivabradine 0.1–10 μM) to establish a dose–response relationship. The effects of ivabradine on electrocardiogram, excitation–contraction coupling and contractility of hearts submitted to anoxia (30 min) and reoxygenation (60 min) were also determined. The distribution of the predominant channel isoform, HCN4, was established in atria, ventricle and outflow tract by immunoblotting.Intrinsic beating rate of atria, ventricle and outflow tract was 164 ± 22 (n = 10), 78 ± 24 (n = 8) and 40 ± 12 bpm (n = 23, mean ± SD), respectively. In the whole heart, ivabradine (0.3 μM) slowed the firing rate of atria by 16% and stabilized PR interval. These effects persisted throughout anoxia-reoxygenation, whereas the variations of QT duration, excitation–contraction coupling and contractility, as well as the types and duration of arrhythmias were not altered. Ivabradine (10 μM) reduced the intrinsic rate of atria and isolated ventricle by 27% and 52%, respectively, whereas it abolished activity of the isolated outflow tract. Protein expression of HCN4 channels was higher in atria and ventricle than in the outflow tract.Thus, HCN channels are specifically distributed and control finely atrial, ventricular and outflow tract pacemakers as well as conduction in the embryonic heart under normoxia and throughout anoxia-reoxygenation.  相似文献   

19.
We evaluated whether exposure to bisphenol A (BPA) disrupts neonatal follicle development in rats. From postnatal day 1 (PND1) to PND7, pups received corn oil (control), diethylstilbestrol (DES20: 20 μg/kg-d, DES0.2: 0.2 μg/kg-d), or BPA (BPA20: 20 mg/kg-d, BPA0.05: 0.05 mg/kg-d). We examined follicular dynamics, multioocyte follicles (MOFs) incidence, proliferation and apoptosis rates, expression of steroid receptors (ERα, ERβ, PR, AR) and cyclin-dependent kinase inhibitor 1B (p27) in PND8 ovaries. DES20, DES0.2 and BPA20-ovaries showed fewer primordial follicles and increased growing follicles. DES20-ovaries exhibited increased incidence of MOFs. Oocyte survival, AR, PR and apoptosis were not changed. Primordial and recruited follicles from BPA20-ovaries showed higher p27, whereas ERβ and proliferation were both increased in recruited follicles. ERα positive primary follicles increased in BPA 20-ovaries. Results show that BPA reduces the primordial follicle pool by stimulating the neonatal initial recruitment, associated with an increased proliferation rate likely mediated by an estrogenic pathway.  相似文献   

20.
Recent studies suggest that endocrine disrupting chemicals (EDCs) may form a risk factor for obesity by altering energy metabolism through epigenetic gene regulation. The goal of this study is to investigate the effects of a range of EDCs with putative obesogenic properties on global DNA methylation and adipocyte differentiation in vitro. Murine N2A and human SK-N-AS neuroblastoma cells and murine preadipocyte fibroblasts (3T3-L1) were exposed to tributyltin (TBT), diethylstilbestrol (DES), bisphenol A (BPA), 2,3,7,8-tetrachlorodibenzo-[p]-dioxin (TCDD), 2,2′,4,4′,5,5′-hexachlorobiphenyl (PCB-153), hexachlorobenzene (HCB), hexabromocyclododecane (HBCD), 2,2′,4,4′-tetrabrominated diphenyl ether (BDE-47) , perfluorinated octyl acid (PFOA) and perfluorinated octyl sulfonate (PFOS). A modest decrease in global DNA methylation was observed in N2A cells exposed to 10 μM DES, BPA, TCDD, BDE-47, PCB-153 and 1 μM HCB, but no changes were found in the human SK-N-AS cells. We reveal for the first time that BDE-47 increases adipocyte differentiation in a dose-dependent manner (2.5–25 μM). Adipocyte differentiation was also enhanced by TBT (?10 nM) and BPA (>10 μM) and inhibited by TCDD (?0.1 nM). The other chemicals showed either modest or no effects on adipocyte differentiation at the concentrations tested (PFOA, PFOS and HBCD at 10 μM; PCB-153, 3.4 μM and HCB, 1 μM). This study demonstrates that selected EDCs can induce functional changes in murine adipocyte differentiation in vitro which are accompanied by decreased global DNA methylation.  相似文献   

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