Role of the necrosis factor-κB pathway in dibutyl phthalate mediated effects on human glioma cells

Abstract

The human glioma cell line U251 was incubated for 12?h and 24?h in medium containing dibutyl phthalate at concentrations of 25?µmol/L and 100?µmol/L. Decreased cell viability and increased oxidative stress show the cytotoxicity of dibutyl phthalate. Nuclear factor-κB and nuclear factor-κB pathway-related proteins were altered, which could be attenuated by vitamin E at 20?µmol/L. Thus, dibutyl phthalate induces cytotoxicity through activation of nuclear factor-κB and vitamin E exerts neuroprotection against dibutyl phthalate-mediated cytotoxicity in vitro.     

Acrylamide and its metabolite glycidamide can affect antioxidant defenses and steroidogenesis in Leydig and Sertoli cells

Acrylamide, which is commonly used in various industries, may also form in food products cooked in high temperatures. Glycidamide, the ultimate genotoxic metabolite of acrylamide, is generated within cells through CYP4502E1-mediated epoxidation. Recent studies have shown that acrylamide and/or glycidamide may cause infertility by disrupting spermatogenesis, decreasing germ cell production and sperm fertilization ability due to their toxic effects on the male reproductive system. This study aimed to determine some direct effects of acrylamide and glycidamide on antioxidant defenses and on steroidogenic enzymes of Leydig and Sertoli cells. For this purpose, mouse Leydig and Sertoli cells were exposed to acrylamide (0.01 or 1?mmol/L) or to glycidamide (0.001 or 0.5?mmol/L) for 24?h. Following the exposure, antioxidant enzyme activities (catalase, superoxide dismutase, glutathione peroxidase and γ-glutamyl transpeptidase), cellular antioxidant levels (glutathione) and steroidogenic enzyme activities (3β-hydroxysteroid dehydrogenase and 17β-hydroxysteroid dehydrogenase) were calculated. It was shown that acrylamide and glycidamide may cause inhibition of antioxidant and steroidogenic enzymes in Leydig and Sertoli cells. In conclusion, acrylamide and glycidamide may alter testicular function, thereby disrupting male reproduction.     

Microwave-assisted synthesized zinc nanoparticles attenuate cisplatin-induced testicular toxicity in mice

Abstract

The purpose of this study was to investigate the protective effects of zinc nanoparticles against cisplatin-induced testicular toxicity in mice. Zinc nanoparticles were produced by microwave-assisted synthesis using Lavandula vera extract as reducing agent. Single doses of cisplatin (7?mg/kg, intraperitoneally) and ZnSO₄ (10?mg/kg, orally), and various doses of zinc nanoparticles (10???50?mg/kg, orally) and vitamin E (100?mg/kg, interaperitoneally) were administered. The protective role of zinc nanoparticles was determined biochemically and histologically. Gradual reduction in malondialdehyde levels and elevation in glutathione levels and in the activities of superoxide dismutase and catalase upon administration of zinc nanoparticles were observed. The pathology of mice treated with cisplatin/vitamin E and cisplatin/zinc nanoparticles were apparently equal, but vitamin E treatment was more effective in lowering oxidative stress markers than zinc nanoparticles. These findings suggest that co-administration of zinc nanoparticles with cisplatin could prevent adverse effects on the male reproductive system via their potential antioxidant properties.     

Mitochondrial toxicity and in vitro biological effects of ambient PM2.5 from an urban site in China

Abstract

The roles of PM_2.5-induced mitochondrial damage and oxidative stress on mast cell degranulation were examined in vitro. Mast cells were treated with suspensions of PM_2.5 in Dulbecco’s modified Eagle’s medium at concentrations from 25 to 200?mg/L in the absence or presence of 10?mmol/L N-acetyl-L-cysteine. Biological effects and mitochondrial function were assessed by determining cell viability, β-hexosaminidase release, interleukin-4 secretion, reactive oxygen species generation, adenosine triphosphate production, potential alteration of mitochondrial membrane, and activities of mitochondrial electron transport chain complexes I and III. Exposure of mast cells to PM_2.5 induced reduction of adenosine triphosphate production, collapse of mitochondrial membrane potential, and inhibition of the activity of complex III. Co-treatment of mast cells exposed to PM_2.5 with N-acetyl-L-cysteine attenuated cytotoxicity and the production of reactive oxygen species, and decreased the release of β-hexosaminidase and interleukin-4. Evidently, PM_2.5-induced oxidative stress plays an essential role in mitochondrial toxicity and mast cell activation.     

Antioxidant enzymatic activities and lipid peroxidation in liver and ovary of zebrafish (Danio rerio) exposed to deltamethrin

Deltamethrin (DM) is being used as a substitute for organochlorines and organophosphates in pest control because of its low environmental persistence and toxicity. But it has become an environmental contaminant as it has been used widely. In this study, we investigated the effect of DM (technical grade) on the antioxidant system of adult zebrafish. For this, six-month-old fish were exposed to 2, 4 and 6?μg/L of DM for 96?h. The tissues selected were liver and ovary. Our data showed that exposure to DM increases CAT (catalase), SOD (superoxide dismutase), GPx (glutathione peroxidase, antioxidant enzymes), LPO (lipid peroxidation, non-enzymatic antioxidant) and GST (glutathione S-transferase, detoxifying enzyme) in liver and ovary. Increased GST could detoxify the toxicant; still there could be enough DM to cause oxidative stress. It appears from our study that zebrafish used compensatory mechanisms in eliminating reactive oxygen species. These data will be useful as oxidative stress is being used as a biomarker for aquatic pollution.     

Effects of mercury graded doses on redox status,metallothionein levels and genotoxicity in the intestine of sea cucumber Holothuria forskali

Mercury (Hg) is a ubiquitous and a major environmental metal pollutant in the aquatic ecosystem. The present study was performed to evaluate the effect of mercury graded doses exposure on oxidative stress, redox status, metallothionein levels and genotoxicity in the intestine of sea cucumber Holothuria forskali. Specimens were exposed for 96?h to three concentrations of Hg (40, 80 and 160?µg/L). Exposure of H. forskali to Hg promoted oxidative stress with an increase in malondialdehyde (MDA), protein carbonyl (PCO) and advanced oxidation protein products (AOPP) levels. An increase of glutathione (GSH), vitamin C (ViteC) and non-protein thiols (NPSH) contents was also observed. Additionally, antioxidant activities of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) increased especially with the highest doses of Hg indicating a great defense of the antioxidant system. Our investigation revealed an increase in total Metallothionein (MT) content which was more pronounced at the sharpest concentrations of Hg. A significant decline of AChE activity was also observed. In the intestine of Hg-treated H. forskali genotoxicity was confirmed by DNA degradation.     

Cytotoxicity of benalaxyl,metalaxyl, and triadimefon on Chinese hamster ovary cells

The cytotoxicity of the fungicides benalaxyl, metalaxyl, and triadimefon was evaluated in vitro using the Chinese hamster ovary (CHO-K1) cell line. The midpoint cytotoxicity values of neutral red (NR) incorporation (NRI₅₀), total cellular protein content (TCP₅₀), and the methyl tetrazolium assay (MTT₅₀) were estimated. Benalaxyl was the most cytotoxic fungicide, followed by metalaxyl and triadimefon. Fetal calf serum (10%) caused a reduction in benalaxyl, metalaxyl, and triadimefon cytotoxicity by factors of 1.8, 1.3, and 1.3. The effects of sublethal concentrations (NRI₂₅) of the three fungicides on the glutathione redox cycle components glutathione S-transferase, glutathione reductase, glutathione peroxidase, and total glutathione content were studied. The ameliorative effects of extracellular glutathione (1 mmol L^?1), vitamin C (70 µmol L^?1), and vitamin E (30 µmol L^?1) were also investigated. The three antioxidants led to significant effects on the glutathione redox cycle components.     

微囊藻毒素对束丝藻细胞生长和抗氧化系统的影响

为从活性氧(ROS)角度探讨微囊藻毒素(MC)导致藻类细胞死亡的机理及揭示藻细胞对MC诱发的氧化胁迫的响应机制,采用50和500μg·L-1的微囊藻毒素LR(MC-LR)处理束丝藻(Aphanizomenon sp. DC01)细胞,测定了细胞生长、细胞内活性氧(ROS)含量及抗氧化系统的变化.结果表明,50μg·L-1的MC-LR处理对藻细胞的生长无显著影响,而500μg·L-1的MC-LR处理可诱导藻细胞死亡.50μg·L-1的MC-LR处理的藻细胞ROS含量在处理第2d显著高于对照;但藻细胞能通过还原型谷胱甘肽(GSH)含量,超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GPX)活性改变修复氧化损伤,使ROS水平在处理第3d恢复到对照水平.500μg·L-1的MC-LR处理可显著降低藻细胞GSH含量和SOD与GPX活性,刺激藻细胞生成过量的ROS;ROS在毒素处理4d后突然暴发,过量的ROS引起膜质过氧化,并最终导致藻细胞死亡。     

Effect of Zinc Oxide nanoparticles on cellular oxidative stress and antioxidant defense mechanisms in mouse liver

Zinc oxide nanoparticles (ZnO₂), a common ingredient of cosmetics has a huge variety of applications. Previous studies reported oxidative stress mediated toxicity of ZnO₂ nanoparticles on various mammalian cell lines. Although zinc (Zn) is an essential mineral at higher concentrations this metal is toxic. The present study focused on size determination by monitoring changes in activities of antioxidant defense mechanism in response to oxidative stress induced by ZnO₂ nanoparticles using mouse liver tissue homogenates. The study also investigated effects of oxidative stress induced DNA damage by determining formation of 8-OHdG in mouse liver homogenate. A cytotoxicity assay was also carried out in L929 cells to determine cell viability. The results of the study indicated that 50μg/ml of ZnO₂ nanoparticles induced 50% cell death. Alterations in antioxidant parameters and 8-OHdG were also noted. Data showed that there was a concentration-dependent fall in cell viability, decrease antioxidant enzyme levels and increase formation of DNA adduct (8-OHdG) when mouse liver tissue homogenate were exposed to ZnO₂ nanoparticles.     

In vitro anti-inflammatory and free radical scavenging properties of Oldenlandia auricularia

Abstract

The in vitro anti-inflammatory and antioxidant properties of extract of Oldenlandia auricularia with 70% aqueous alcohol have been evaluated. The inhibition of nuclear translocation of nuclear factor kappa-light-chain-enhancer of activated B cells in lipopolysaccharide stimulated murine macrophage cells was evaluated. Messenger ribonucleic acid levels of tumor necrosis factor-α and cyclooxygenase-2 were analysed by quantitative real time polymerase chain reaction. O. auricularia (100?mg/L) showed better anti-inflammatory and antioxidant activities when compared to its lower doses, whereas the standard drugs curcumin and diclofenac sodium showed significant anti-inflammatory and antioxidant potential. Treatment at this concentration inhibited the signalling pathway of nuclear factor kappa-light-chain-enhancer of activated B cells and messenger ribonucleic acid expression of tumor necrosis factor- α, and cyclooxygenase-2. Liquid chromatography/quadrupole time-of-flight mass spectrometry revealed the presence of previously reported compounds auricularine, ursolic acid and β-sitosterol. The observed anti-inflammatory property of O. auricularia could be due to the inhibition of nuclear factor kappa-light-chain-enhancer of activated B cells p65 sub unit nuclear translocation and inhibition of its signalling pathway.     

Antioxidant enzymes and compounds complement each other during arsenic detoxification in shoots of Isatis cappadocica Desv.

Isatis cappadocica has been reported to be an arsenic (As) hyperaccumulator. Antioxidant enzymes and compounds have been proposed to play an important role in the detoxification and tolerance of As. In the present study, As-induced oxidative stress and antioxidant responses were investigated on I. cappadocica grown hydroponically in response to application of arsenate (0–1200?μmol). As accumulation increased with an increase in arsenate concentration in the medium. Along with a significant increase in arsenate concentration, a build up in hydrogen peroxide, indicators of oxidative stress, was observed. The activity of superoxide dismutase and peroxidase was induced after arsenate treatment, reached a maximal value at 800?μmol arsenate and then declined at the highest arsenate treatment. Glutathione reductase activity and contents of non-enzymatic antioxidants (carotenoids, flavonoids and anthocyanins) increased significantly as arsenate concentration augmented. These results indicated that high efficient antioxidant system may play significant roles in As detoxification and improve I. cappadocica tolerance against As toxicity.     

DNA fragmentation,apoptosis and cell cycle arrest induced by sodium arsenite in cultured murine Sertoli cells: prevention by curcumin

Arsenic is a significant environmental concern worldwide, primarily due to geo physiochemical contamination of drinking water, and a major public health hazard in both developing and developed countries. The present study was aimed to investigate ameliorative effects of curcumin (Cur) against sodium arsenite (SA)-induced toxicity in cultured murine Sertoli cells. The cells were treated with SA (5 μM) and Cur (5 μg/ml and 10 μg/ml) alone or in combination for 12 hr. The SA treatment decreased cell viability, produced oxidative stress, and induced apoptosis as reflected by reactive oxygen species (ROS) generation, loss of mitochondrial transmembrane potential, DNA fragmentation, and apoptotic cells. Moreover, the SA-induced cell cycle arrest in the cells is characterized by a rise in the number of cells in the sub G1 phase of the cell cycle. The Cur was found to be effective in reversing all these arsenic (As)-induced cellular events. Data suggest that Cur modulates As-mediated oxidative stress, apoptosis, DNA fragmentation, and cell cycle arrest through suppression of excessive ROS generation. Evidence indicates that Cur may emerge as a useful protective agent against As-induced Sertoli cells toxicity by inhibiting As-induced damage in testes.     

铅与纳米SiO2联合染毒对A549细胞氧化损伤的影响

为了研究铅与纳米SiO2联合染毒所致的细胞损伤特征,并从氧化应激方面探讨其可能的作用机制。用铅和SiO2处理A549细胞,采用四唑盐(MTT)比色法检测细胞存活率,评价铅和SiO2联合染毒所致的细胞损伤特征;采用硫代巴比妥酸(TBA)比色法检测细胞内丙二醛(MDA)含量,评价铅与SiO2联合染毒所致细胞的氧化应激状态;检测了细胞内抗氧化物还原型谷胱甘肽(GSH)含量以及细胞内抗氧化酶的活性,以评价铅与SiO2联合染毒对细胞抗氧化系统的影响。将实验数据进行ANOVA分析。结果表明,铅、SiO2单独染毒组各指标没有明显改变;而联合染毒能造成细胞氧化损伤,表现为细胞存活率、GSH水平、超氧化物歧化酶(SOD)及谷胱甘肽过氧化物酶(GSH-Px)活性显著低于对照组及2个单独染毒组(P<0.05),细胞内MDA含量显著高于对照组及各单独染毒组(P<0.05)。可见,联合染毒可引起明显的细胞毒性,氧化损伤可能是铅与SiO联合染毒致肺细胞毒性损伤的作用机制之一。     

三邻甲苯磷酸酯对大鼠C6星形胶质细胞的氧化损伤和细胞周期阻滞作用

三邻甲苯磷酸酯(tri-o-cresyl phosphate,TOCP)是一种有机磷酸酯类化合物,具神经毒性作用。研究表明星形胶质细胞是有机磷化合物(organophosphorus compounds,OPs)神经毒性作用的靶点之一。为了探讨TOCP对星形胶质细胞的毒性作用,采用大鼠C6星形胶质细胞分别经0.1、0.3、1.0和3.0 mmol·L-1TOCP染毒处理24 h,应用MTT比色法和乳酸脱氢酶(LDH)活力分析法检测细胞活力,在电子相差显微镜下观察细胞形态,二硫代二硝基苯甲酸(DNTB)比色法测定谷胱甘肽(GSH)含量和谷胱甘肽过氧化物酶(GSH-Px)活性,流式细胞仪检测分析细胞周期。结果显示,经TOCP处理24 h后,大鼠C6星形胶质细胞存活率降低,LDH释放增加,细胞形态也发生了明显的变化。GSH含量和GSH-Px活性降低,G1期细胞数量也逐渐增加。上述结果表明,TOCP对星形胶质细胞具有毒性作用,引起氧化损伤和细胞周期阻滞。     

Evaluation of antioxidant potentials of Morinda morindoides leaf extract

This study investigated antioxidant status of animals given aqueous extract of Morinda morindoides leaves using the levels of reduced glutathione, total-thiol, vitamin C, and vitamin E as well as malondialdehyde concentrations as indices, and its in vitro antioxidant capacity. Thirty rats divided into five groups were used. Group A served as control and were administered distilled water while groups B, C, D, and E were given 100, 200, 400, and 800 mg per kilogram body weight of water-extracted constituents of M. morindoides for 28 days. Total phenolic compounds amounted to 83.6 ± 5.9 mg g^?1 gallic acid equivalent, while total flavonoid content was 9.5 ± 0.9 mg g^?1 pyrocathecol equivalent. Malondialdehyde in plasma was significantly decreased in a dose-dependent manner, ranging from 21% in groups B and C to 84% in groups D and E. Vitamins C and E were significantly increased, in group E by 91% and 17% compared with control. Total thiols and glutathione in plasma were significantly increased, with group E having 2.5-fold and 4.2-fold higher values than control.     

Effects of melatonin on cadmium accumulation in the accumulator plant Perilla frutescens

To enhance the phytoremediation ability of the heavy metal accumulator Perilla frutescens, melatonin (MT) was applied at different concentrations (0, 25, 50, 100, 150, and 200?μmol/L) to P. frutescens growing in cadmium (Cd) contaminated soil (10?mg/kg). The MT treatments increased the root and shoot biomasses of P. frutescens, with the maximum increase in the 150?μmol/L MT treatment (79.51% and 36.18% higher, respectively, than those of the control). The MT treatments also enhanced superoxide dismutase activity, peroxidase activity, and the soluble protein concentration of P. frutescens, and 100–200?μmol/L MT increased the chlorophyll a, chlorophyll b, and total chlorophyll concentrations in P. frutescens. The MT treatments increased the Cd concentrations in roots and shoots of P. frutescens in a dose-dependent manner. Different MT concentrations increased the Cd accumulation amounts of roots and shoots of P. frutescens, with the maxima accumulation amounts in the 150?μmol/L MT treatment (226.98% and 85.89% higher, respectively, than those of the control). These results show that MT can promote the growth and phytoremediation ability of P. frutescens growing in Cd-contaminated soil, and the optimum MT dose is 150?μmol/L.     

ROS介导的氧化应激在INH诱导的细胞毒性中的作用及槲皮素的干预

为探讨ROS介导的氧化应激在异烟肼(INH)诱导L-02细胞毒性中的作用及槲皮素的干预作用,建立体外培养INH诱导L-02细胞氧化损伤模型,实验分为对照组(A)、INH组(B)、槲皮素低剂量组(C)及槲皮素高剂量组(D)。采用生化分析法检测L-02细胞培养液中天冬氨酸氨基转移酶(AST)和丙氨酸氨基转移酶(ALT)的活性;利用荧光探针检测L-02细胞线粒体内活性氧(ROS)水平;应用比色法检测L-02细胞内丙二醛(MDA)、谷胱甘肽(GSH)的含量以及主要抗氧化物酶的活性。结果表明,与对照组相比,INH能显著增加L-02细胞培养液中AST和ALT的活性、细胞线粒体内ROS水平及细胞内MDA的含量(P0.01),并显著减少L-02细胞内GSH的含量及超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)的活性(P0.01)。与INH组比较,槲皮素低剂量组L-02细胞培养液中AST的活性、线粒体内ROS水平及细胞内MDA的含量明显降低(P0.05),而细胞内SOD的活性明显增加(P0.05);高剂量槲皮素能显著降低L-02细胞培养液中AST和ALT的活性、细胞线粒体内ROS水平及细胞内MDA的含量(P0.01),并能显著增高L-02细胞内GSH的含量和主要抗氧化物酶的活性(P0.01)。与槲皮素低剂量组相比,槲皮素高剂量组的保护效应更明显(P0.05)。可见,ROS介导的氧化应激在INH诱导的L-02细胞毒性中发挥了重要作用,且槲皮素对INH诱导的L-02细胞氧化损伤具有保护作用。     

Toxic effect of microcystin-LR on blood vessel development

Abstract

The effect of microcystin-LR (MC-LR) at 50–1000?nmol/L on blood vessel development of zebrafish embryos has been explored. Upon exposure 72-h-post-fertilization (hpf), the hatching rate was significantly reduced and malformation and fatality rates were increased in a dose-dependent manner. MC-LR induced cell cycle arrest in the G0/G1-phase and damaged DNA structure in a dose-dependent manner. In human umbilical vein endothelial cells (HUVECs), MC-LR led to decreased activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) and increased lipid peroxidation. These findings indicated that MC-LR could cause oxidative DNA damage, which mediated cell cycle arrest and inhibited cell proliferation afterwards, and retarded the blood vessel development.     

Nanosilica exerts cytotoxicity and apoptotic response via oxidative stress in mouse embryonic fibroblasts

Nanoscale silica is an important industrial material and extensively used in medicines. The objective of this study was to determine potential cytotoxicity and genotoxic effects attributed to nanosilica exposure in mouse embryonic fibroblasts (L929) cells. Nanosilica produced mild cytotoxicity in L929 cells. Results showed that nanosilica increased thiobarbituric acid reactive substance levels and enhanced superoxide dismutase activity but decreased levels of glutathione. This was accompanied by a concomitant generation of reactive oxygen species, loss of mitochondrial membrane potential, and activation of caspase-3 activity. In addition, in the single-cell gel test, nanosilica (50–300 μg/ml) at two treatment times 24 and 48 hr produced concentration- and time-dependent increase of DNA damage. Therefore, the obtained results indicate that nanosilica may induce genotoxic effects in cultured L929 cells associated with induction of oxidative stress.     

Dichloroacetate- and trichloroacetate-induced modulation of superoxide dismutase,catalase, and glutathione peroxidase activities and glutathione level in the livers of mice after subacute and subchronic exposures

Dichloroacetate (DCA) and trichloroacetate (TCA) were previously found to induce various levels of oxidative stress in the hepatic tissues of mice after subacute and subchronic exposures. The cells are known to have several protective mechanisms against production of oxidative stress by different xenobiotics. To assess the roles of the antioxidant enzymes and glutathione (GSH) in DCA- and TCA-induced oxidative stress, groups of B6C3F1 mice were administered either DCA or TCA at doses of 7.7, 77, 154, and 410 mg kg^?1 day^?1, by gavage for 4 weeks (4-W) and 13 weeks (13-W), and superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities, as well as GSH were determined in the hepatic tissues. DCA at doses ranging between 7.7–410, and 7.7–77 mg kg^?1 day^?1, given for 4-W and 13-W, respectively, resulted in either suppression or no change in SOD, CAT, and GSH-Px activities, but doses of 154–410 mg DCA kg^?1 day^?1 administered for 13-W were found to result in a significant induction of the three enzyme activities. TCA administration on the other hand, resulted in increases in the SOD and CAT activities, but caused suppression of GSH-Px activity in both the periods. Except for the DCA doses of 77–154 mg kg^?1 day^?1 administered for 13-W that resulted in a significant reduction in the GSH levels, all other DCA as well as TCA treatments produced no changes in GSH. Since these enzymes are involved in the detoxification of the reactive oxygen species (ROS), superoxide anion (SA), and H₂O₂, it is concluded that SA is the main contributor to DCA-induced oxidative stress, while both ROS contribute to that of TCA. The increase in the enzyme activities associated with 154–410 mg DCA kg^1? day^?1 in the 13-W period suggest their role as protective mechanisms contributing to the survival of cells modified in response to those treatments.