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Sample records for biodegradation du 2-ethylhexyl

  1. Di(2-ethylhexyl) phthalate biodegradation and denitrification by a Pseudoxanthomonas sp. strain.

    PubMed

    Meng, Xuezheng; Niu, Guilong; Yang, Weiming; Cao, Xiangsheng

    2015-03-01

    A bacterial strain (designated as N4) of Pseudoxanthomonas was isolated from a denitrification biofilter reactor. This study examined its degradation capability of di(2-ethylhexyl) phthalate (DEHP) and its denitrification ability. All results showed that, strain N4 could use DEHP as a carbon and energy source. Strain N4 demonstrated good DEHP degradation ability over a broad pH and temperature range. The optimal temperature and pH for DEHP degradation were 32°C and 6.0, respectively. The kinetics of DEHP degradation by strain N4 were exponential in nature. Strain N4 showed denitrification ability and could reduce nitrate and nitrite but not with DEHP as its carbon source. PMID:25596917

  2. Synergistic effect using vermiculite as media with a bacterial biofilm of Arthrobacter sp. for biodegradation of di-(2-ethylhexyl) phthalate.

    PubMed

    Wen, Zhi-Dan; Wu, Wei-Min; Ren, Nan-Qi; Gao, Da-Wen

    2016-03-01

    Vermiculite is one of matrix material used for constructed wetland (CW) for the treatment of municipal wastewater. Arthrobacter sp. strain C21 (CGMCC No. 7671), isolated from a constructed wetland receiving municipal wastewater, forms biofilm on the surface of vermiculite. Di-(2-ethylhexyl) phthalate (DEHP), a typical phthalate pollutant in environment, can be degraded by the biofilm of strain C21 formed on vermiculite. Results of laboratory studies indicated that DEHP was removed from aqueous phase via biodegradation, adsorption by vermiculite, and adsorption by biofilm biomass. Synergistic effect of these three reactions enhanced the overall DEHP removal efficiency. During a batch incubation test with vermiculite and the cell suspension, bacterial adhesion to the media surface occurred within 5h and the phthalate esters (PEs) removal was due to both biodegradation and vermiculite adsorption. As the biofilm developed on surface of vermiculite (5-36 h), biodegradation became the predominance for PEs removal. As mature biofilm was formed (36-54 h), the adsorption of PEs by biofilm biomass became a main driving force for the removal of PEs from aqueous phase. The content of extracellular polymers (EPS) of the biofilm and DEHP removal performance showed a significant positive correlation (rp>0.86). PMID:26547620

  3. Effect of ultrasonication and Fenton oxidation on biodegradation of bis(2-ethylhexyl) phthalate (DEHP) in wastewater sludge.

    PubMed

    Pham, T T H; Tyagi, R D; Brar, S K; Surampalli, R Y

    2011-02-01

    The presence of bis(2-ethylhexyl) phthalate (DEHP) and its metabolites, i.e. 2-ethylhexanol, 2-ethylhexanal, and 2-ethylhexanoic acid in wastewater sludge (WWS) were investigated during aerobic digestion and Bacillus thuringiensis (Bt)-based fermentation of WWS. Ultrasonication and Fenton oxidation pre-treatment was applied to improve biodegradability of WWS and bioavailability of the target compounds for digestion and fermentation. DEHP and 2-ethylhexanoic acid were observed at higher concentration, meanwhile 2-ethylhexanol and 2-ethylhexanal were observed at lower concentration in WWS. After 20-day aerobic digestion, DEHP removal was 72%, 89%, and 85%, and 2-ethylhexanoic acid removal was 71%, 84%, 79%, respectively for raw, ultrasonicated, and Fenton-oxidized sludges. Bt was found to degrade DEHP, leading to DEHP removal of 21%, 40%, and 30%, respectively for raw, ultrasonicated, and Fenton-oxidized sludges in the fermentation. The results suggested that aerobic stabilization and Bt-based fermentation can remove the phthalates, and pre-treatment of WWS was also effective in improvement of DEHP biodegradation. Hence, Bt-based biopesticide production from WWS can be applied safely when taking into consideration the phthalate contaminants. PMID:21094970

  4. Di(2-ethylhexyl)adipate

    Integrated Risk Information System (IRIS)

    Di ( 2 - ethylhexyl ) adipate ; CASRN 103 - 23 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Non

  5. Di (2-ethylhexyl)phthalate (DEHP)

    Integrated Risk Information System (IRIS)

    Di ( 2 - ethylhexyl ) phthalate ( DEHP ) ; CASRN 117 - 81 - 7 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessme

  6. 40 CFR 721.10131 - Isononanamide, N-(2-ethylhexyl)-.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Isononanamide, N-(2-ethylhexyl)-. 721... Substances § 721.10131 Isononanamide, N-(2-ethylhexyl)-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as isononanamide, N-(2-ethylhexyl)- (PMN...

  7. 40 CFR 721.10131 - Isononanamide, N-(2-ethylhexyl)-.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Isononanamide, N-(2-ethylhexyl)-. 721... Substances § 721.10131 Isononanamide, N-(2-ethylhexyl)-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as isononanamide, N-(2-ethylhexyl)- (PMN...

  8. 40 CFR 721.10131 - Isononanamide, N-(2-ethylhexyl)-.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Isononanamide, N-(2-ethylhexyl)-. 721... Substances § 721.10131 Isononanamide, N-(2-ethylhexyl)-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as isononanamide, N-(2-ethylhexyl)- (PMN...

  9. 40 CFR 721.10131 - Isononanamide, N-(2-ethylhexyl)-.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Isononanamide, N-(2-ethylhexyl)-. 721... Substances § 721.10131 Isononanamide, N-(2-ethylhexyl)-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as isononanamide, N-(2-ethylhexyl)- (PMN...

  10. Effects of 2-Ethylhexyl Nitrate on Diesel-Spray Processes

    SciTech Connect

    Higgins, B.; Mueller, C.; Siebers, D.

    1998-08-01

    Diesel fuel ignition-enhancing additives, such as 2-ethylhexyl nitrate, are known to reduce emissions from diesel engines; however, the mechanisms by which the emissions reduction occur are not understood. This report covers the first phase of a research project supported by Ethyl Corporation that is aimed at developing a detailed understanding of how 2-ethylhexyl nitrate alters in-cylinder injection, ignition, and combustion processes to reduce diesel engine emissions.

  11. 40 CFR 721.10131 - Isononanamide, N-(2-ethylhexyl)-.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Isononanamide, N-(2-ethylhexyl)-. 721.10131 Section 721.10131 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10131 Isononanamide,...

  12. Physical proprieties of low viscosity estolide 2-ethylhexyl esters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Acetic- and butyric-capped oleic estolide 2-ethylhexyl (2-EH) esters were synthesized in a perchloric acid catalyzed (0.05 equiv) one-pot process from industrial 90% oleic acid and either acetic or butyric fatty acids at two different ratios. This was directly followed by the esterification process ...

  13. 40 CFR 180.1274 - Tris (2-ethylhexyl) phosphate; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Tris (2-ethylhexyl) phosphate... RESIDUES IN FOOD Exemptions From Tolerances § 180.1274 Tris (2-ethylhexyl) phosphate; exemption from the requirement of a tolerance. Tris (2-ethylhexyl) phosphate (TEHP, CAS Reg. No. 78-42-2) is exempt from...

  14. 40 CFR 180.1274 - Tris (2-ethylhexyl) phosphate; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Tris (2-ethylhexyl) phosphate... RESIDUES IN FOOD Exemptions From Tolerances § 180.1274 Tris (2-ethylhexyl) phosphate; exemption from the requirement of a tolerance. Tris (2-ethylhexyl) phosphate (TEHP, CAS Reg. No. 78-42-2) is exempt from...

  15. 40 CFR 180.1274 - Tris (2-ethylhexyl) phosphate; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Tris (2-ethylhexyl) phosphate... RESIDUES IN FOOD Exemptions From Tolerances § 180.1274 Tris (2-ethylhexyl) phosphate; exemption from the requirement of a tolerance. Tris (2-ethylhexyl) phosphate (TEHP, CAS Reg. No. 78-42-2) is exempt from...

  16. Estimation of human percutaneous uptake for two novel brominated flame retardants, 2-ethylhexyl tetrabromobenzoate (TBB) and bis(2-ethylhexyl) tetrabromophthalate (TBPH) using the parallelogram method

    EPA Science Inventory

    2-ethylhexyl- tetrabromobenzoate (TBB) and bis(2-ethylhexyl)-tetrabromobenzoate (TBPH) are novel brominated flame retardants (FRs). TBPH is used as a plasticizer or with TBB in polyurethane foam FRs. TBB & TBPH have been detected in both indoor and outdoor environmental sampl...

  17. Biotransformation of di(2-ethylhexyl)phthalate by rainbow trout

    SciTech Connect

    Barron, M.G.; Hayton, W.L.

    1995-05-01

    The biotransformation of di(2-ethylhexyl)phthalate (DEHP) was studied in rainbow trout (Oncorhynchus mykiss) following intravascular administration. Methyl-esterified metabolites were identified using rodent-derived standards and non-linear gradient elution HPLC; metabolites were confirmed by gas chromatography. Similarities between the biotransformation of DEHP by rainbow trout and mammalian species included (a) mono-ethylhexyl phthalate (MEHP) appeared to be the obligatory first step in DEHP metabolism; (b) the phthalate ring was not oxidized; (c) phthalic acid was a minor metabolite; and (d) several metabolites contained multiple oxidations of the 2-ethylhexyl moiety of MEHP. No metabolites unique to rainbow trout were identified. However, fewer oxidized metabolites were identified in rainbow trout than in mammalian species, possibly due to limited mitochondrial metabolism of MEHP in rainbow trout. The amount of biliary MEHP glucuronide after intravascular administration of DEHP was substantially less than reported in rainbow trout exposed to DEHP via the water. Results confirmed that DEHP metabolism in rainbow trout proceeds by initial rapid formation of MEHP, followed by excretion or extensive oxidation by microsomal P450.

  18. Fetotoxic effects of mono-2-ethylhexyl phthalate (MEHP) in mice.

    PubMed Central

    Tomita, I; Nakamura, Y; Yagi, Y; Tutikawa, K

    1986-01-01

    Mono(2-ethylhexyl) phthalate (MEHP), one of the main metabolites of di(2-ethylhexyl) phthalate (DEHP), exerted embryo/fetotoxic effects similar to those of DEHP at lower doses. Oral administration of MEHP (1 mL/kg) to the mice of 8 days gestation resulted in less than 32% of live fetuses, all of which were deformed. When DEHP (10 mL/kg) was given to the pregnant mice of 8 days gestation, approximately 0.03% and 0.003% of the administered dose was found in fetuses as DEHP and MEHP, respectively, after 12 hr. The presence of the MEHP in fetuses is probably due to the transplacental crossing of the MEHP formed in the maternal body, since the fetuses of mice up to day 9 of pregnancy showed no hydrolytic activity of DEHP to MEHP. Crossing of MEHP through the placenta was proven by an experiment in which MEHP was administered in pregnant mice. A single injection of MEHP (25 or 50 mg/kg), but not DEHP (500 mg/kg) into pregnant mice, induced a significantly high incidence of somatic mutations in the coat hair of offspring of mice (KYG, female X PW, male; C57BL/6Crj, female X PW, male). All these data suggest that MEHP could be responsible for the embryotoxic/fetotoxic effects observed with DEHP. PMID:3709449

  19. Di-(2-ethylhexyl) phthalate and mono-(2-ethylhexyl) phthalate inhibit growth and reduce estradiol levels of antral follicles in vitro

    SciTech Connect

    Gupta, Rupesh K.; Singh, Jeffery M.; Leslie, Tracie C.; Meachum, Sharon; Flaws, Jodi A.; Yao, Humphrey H-C

    2010-01-15

    Any insult that affects survival of ovarian antral follicles can cause abnormal estradiol production and fertility problems. Phthalate esters (PEs) are plasticizers used in a wide range of consumer and industrial products. Exposure to these chemicals has been linked to reduced fertility in humans and animal models. Di-(2-ethylhexyl) phthalate (DEHP) and mono-(2-ethylhexyl) phthalate (MEHP) decrease serum estradiol levels and aromatase (Arom) expression, prolong estrous cycles, and cause anovulation in animal and culture models. These observations suggest PEs directly target antral follicles. We therefore tested the hypothesis that DEHP (1-100 mug/ml) and MEHP (0.1-10 mug/ml) directly inhibit antral follicular growth and estradiol production. Antral follicles from adult mice were cultured with DEHP or MEHP, and/or estradiol for 96 h. During culture, follicle size was measured every 24 h as a measurement of follicle growth. After culture, media were collected for measurement of estradiol levels and follicles were subjected to measurement of cylin-D-2 (Ccnd2), cyclin-dependant-kinase-4 (Cdk4), and Arom. We found that DEHP and MEHP inhibited growth of follicles and decreased estradiol production compared to controls at the highest doses. DEHP and MEHP also decreased mRNA expression of Ccnd2, Cdk4, and Arom at the highest dose. Addition of estradiol to the culture medium prevented the follicles from DEHP- and MEHP-induced inhibition of growth, reduction in estradiol levels, and decreased Ccnd2 and Cdk4 expression. Collectively, our results indicate that DEHP and MEHP may directly inhibit antral follicle growth via a mechanism that partially includes reduction in levels of estradiol production and decreased expression of cell cycle regulators.

  20. Toxicogenomic Screening of Replacements for Di(2-Ethylhexyl) Phthalate (DEHP) Using the Immortalized TM4 Sertoli Cell Line.

    PubMed

    Nardelli, Thomas C; Erythropel, Hanno C; Robaire, Bernard

    2015-01-01

    Phthalate plasticizers such as di(2-ethylhexyl) phthalate (DEHP) are being phased out of many consumer products because of their endocrine disrupting properties and their ubiquitous presence in the environment. The concerns raised from the use of phthalates have prompted consumers, government, and industry to find alternative plasticizers that are safe, biodegradable, and have the versatility for multiple commercial applications. We examined the toxicogenomic profile of mono(2-ethylhexyl) phthalate (MEHP, the active metabolite of DEHP), the commercial plasticizer diisononyl cyclohexane-1,2-dicarboxylate (DINCH), and three recently proposed plasticizers: 1,4-butanediol dibenzoate (BDB), dioctyl succinate (DOS), and dioctyl maleate (DOM), using the immortalized TM4 Sertoli cell line. Results of gene expression studies revealed that DOS and BDB clustered with control samples while MEHP, DINCH and DOM were distributed far away from the control-DOS-BDB cluster, as determined by principle component analysis. While no significant changes in gene expression were found after treatment with BDB and DOS, treatment with MEHP, DINCH and DOM resulted in many differentially expressed genes. MEHP upregulated genes downstream of PPAR and targeted pathways of cholesterol biosynthesis without modulating the expression of PPAR's themselves. DOM upregulated genes involved in glutathione stress response, DNA repair, and cholesterol biosynthesis. Treatment with DINCH resulted in altered expression of a large number of genes involved in major signal transduction pathways including ERK/MAPK and Rho signalling. These data suggest DOS and BDB may be safer alternatives to DEHP/MEHP than DOM or the commercial alternative DINCH. PMID:26445464

  1. Critical cleaning agents for Di-2-ethylhexyl sebacate.

    SciTech Connect

    Hartley, Mya; Archuleta, Kim M.

    2013-08-01

    It is required that Di-2-ethylhexyl Sebacate oil, also commonly known as Dioctyl Sebacate oil, be thoroughly removed from certain metals, in this case stainless steel parts with narrow, enclosed spaces. Dioctyl Sebacate oil is a synthetic oil with a low compressibility. As such, it is ideally used for high pressure calibrations. The current method to remove the Dioctyl Sebacate from stainless steel parts with narrow, enclosed spaces is a labor-intensive, multi-step process, including a detergent clean, a deionized (DI) water rinse, and several solvent rinses, to achieve a nonvolatile residue of0.04 mg per 50 mL rinse effluent. This study was undertaken to determine a superior detergent/solvent cleaning method for the oil to reduce cleaning time and/or the amount of detergent/solvent used. It was determined that while some detergent clean the oil off the metal better than the current procedure, using only solvents obtained the best result. In addition, it can be inferred, based on elevated temperature test results, that raising the temperature of the oil-contaminated stainless steel parts to approximately 50%C2%B0C will provide for improved cleaning efficacy.

  2. Contemporary carbon content of bis (2-ethylhexyl) phthalate in butter.

    PubMed

    Tong, T; Ondov, J M; Buchholz, B A; VanDerveer, M C

    2016-01-01

    The fraction of naturally produced bis (2-ethylhexyl) phthalate (DEHP), a ubiquitous plasticizer known to contaminate packaged foods, was determined for each of five 1.10 kg samples of unsalted market butter by accelerator mass spectrometry (AMS). After extraction and concentration enrichment with liquid-liquid extraction, flash column chromatography, and preparative-scale high performance liquid chromatography, each sample provided ≈ 250 μg extracts of DEHP with carbon purity ranging from 92.5 ± 1.2% (n = 3, 1σ) to 97.1 ± 0.8% (n = 3, 1σ) as measured with gas chromatography mass spectrometry (GC-MS). After corrections for method blank DEHP, co-eluting compounds, and unidentified carbon, the mean fraction of naturally produced DEHP in butter was determined to be 0.16 ± 0.12 (n = 5, 1σ). To our knowledge, this is the first report of the contemporary fraction of DEHP isolated from market butter in the U.S. PMID:26213077

  3. Skin permeation and metabolism of di(2-ethylhexyl) phthalate (DEHP).

    PubMed

    Hopf, N B; Berthet, A; Vernez, D; Langard, E; Spring, P; Gaudin, R

    2014-01-01

    Phthalates are suspected to be endocrine disruptors. Di(2-ethylhexyl) phthalate (DEHP) is assumed to have low dermal absorption; however, previous in vitro skin permeation studies have shown large permeation differences. Our aims were to determine DEHP permeation parameters and assess extent of skin DEHP metabolism among workers highly exposed to these lipophilic, low volatile substances. Surgically removed skin from patients undergoing abdominoplasty was immediately dermatomed (800 μm) and mounted on flow-through diffusion cells (1.77 cm(2)) operating at 32°C with cell culture media (aqueous solution) as the reservoir liquid. The cells were dosed either with neat DEHP or emulsified in aqueous solution (166 μg/ml). Samples were analysed by HPLC-MS/MS. DEHP permeated human viable skin only as the metabolite MEHP (100%) after 8h of exposure. Human skin was able to further oxidize MEHP to 5-oxo-MEHP. Neat DEHP applied to the skin hardly permeated skin while the aqueous solution readily permeated skin measured in both cases as concentration of MEHP in the receptor liquid. DEHP pass through human skin, detected as MEHP only when emulsified in aqueous solution, and to a far lesser degree when applied neat to the skin. Using results from older in vitro skin permeation studies with non-viable skin may underestimate skin exposures. Our results are in overall agreement with newer phthalate skin permeation studies. PMID:24140552

  4. Fourier transform infrared spectroscopic study on microemulsion systems of alkali metal salts of 2-ethylhexyl phosphonic acid mono 2-ethylhexyl ester

    NASA Astrophysics Data System (ADS)

    Zhou, Weijin; Shi, Nai; Xu, Zhen-hua; Wu, JinGuang

    1994-01-01

    There has recently been a growing interest in the reverse micelle and microemulsion formation in the solvent extraction process. In our previous papers, the formation of W/O type microemulsions in the organic phase of sodium or potassium salt of 2-ethylhexyl phosphonic acid mono 2-ethylhexyl ester was investigated by using the subtraction technique on FTIR. In this paper, the conductance and the FTIR spectroscopic study on the microemulsion systems of Li, Na, and K salts of this acidic extractant was reported.

  5. Extraction equilibria of rare earths by a new reagent (2-ethylhexyl-3-pentadecylphenyl) phosphoric acid.

    PubMed

    Sreelatha, S; Rao, T P; Narayanan, C S; Damodaran, A D

    1994-03-01

    A new reagent (2-ethylhexyl-3-pentadecylphenyl) phosphoric acid (EPPA = HR) was synthesized from cardanol (I, 37300-39-5) and was used to investigate the extraction behaviour of lanthanum(III), europium(III) and lutetium(III) from hydrochloric acid solutions. The species extracted were found to be Ln(HR(2))(3) (where Ln = La(III) or Eu(III) or Lu(III)). The extraction behaviour of the above lanthanides has also been compared with yttrium and other rare earths. It was observed that the extraction increases with increase in atomic number of rare earths. In addition, the extraction efficiency of EPPA has also been compared with well known acidic organophosphorus extractants like di-2-ethylhexyl phosphoric acid (DEHPA), 2-ethylhexyl-mono-2-ethylhexyl phosphoric acid (EHEHPA). PMID:18965945

  6. Risk assessment of di(2-ethylhexyl) phthalate in the workplace

    PubMed Central

    2016-01-01

    Objectives A hazard assessment of di(2-ethylhexyl) phthalate (DEHP), a commonly used workplace chemical, was conducted in order to protect the occupational health of workers. A literature review, consisting of both domestic and international references, examined the chemical management system, working environment, level of exposure, and possible associated risks. This information may be utilized in the future to determine appropriate exposure levels in working environments. Methods Hazard assessment was performed using chemical hazard information obtained from international agencies, such as Organization for Economic Cooperation and Development-generated Screening Information Data Set and International Program on Chemical Safety. Information was obtained from surveys conducted by the Minister of Employment and Labor (“Survey on the work environment”) and by the Ministry of Environment (“Survey on the circulation amount of chemicals”). Risk was determined according to exposure in workplaces and chemical hazard. Results In 229 workplaces over the country, 831 tons of DEHP have been used as plasticizers, insecticides, and ink solvent. Calculated 50% lethal dose values ranged from 14.2 to 50 g/kg, as determined via acute toxicity testing in rodents. Chronic carcinogenicity tests revealed cases of lung and liver degeneration, shrinkage of the testes, and liver cancer. The no-observed-adverse-effect level and the lowest-observed-adverse-effect level were determined to be 28.9 g/kg and 146.6 g/kg, respectively. The working environment assessment revealed the maximum exposure level to be 0.990 mg/m3, as compared to the threshold exposure level of 5 mg/m3. The relative risk of chronic toxicity and reproductive toxicity were 0.264 and 0.330, respectively, while the risk of carcinogenicity was 1.3, which is higher than the accepted safety value of one. Conclusions DEHP was identified as a carcinogen, and may be dangerous even at concentrations lower than the

  7. Simultaneous determination of polyvinylchloride plasticizers di(2-ethylhexyl) phthalate and tri(2-ethylhexyl) trimellitate and its degradation products in blood by liquid chromatography-tandem mass spectrometry.

    PubMed

    Eckert, Elisabeth; Müller, Johannes; Göen, Thomas

    2015-09-01

    Di(2-ethylhexyl) phthalate (DEHP) and tri(2-ethylhexyl) trimellitate (TEHTM or TOTM) are common plasticizers that are also largely used for PVC medical devices, e.g. bags and tubing for blood transfusions and infusions. The leachability of medical devices is a well-known situation of increasing toxicological concern. To assess the migration of plasticizers from PVC medical devices into human blood we developed and validated an analytical method for the determination of DEHP and TOTM in combination with the determination of their primary degradation products mono(2-ethylhexyl) phthalate (MEHP), 1,2-di(2-ethylhexyl) trimellitate (1,2-DEHTM) and 2-mono(2-ethylhexyl) trimellitate (2-MEHTM). The presented method involves liquid-liquid extraction of the analytes from the blood followed by the subsequent analytical separation and detection using LC-MS/MS analysis. The validation of the procedure showed a good precision in the range of 1.8 to 5.3%. Mean accuracy ranged from 86% for 1,2-DEHTM to 109% for MEHP. LOQ was found to be 2 to 5μg/L for each of the analytes. Additionally, the method is characterised by its wide linear range up to 2mg/L each for the degradation products of TOTM to 100mg/L for the parent plasticizer DEHP. The presented method promises to be of major advantage for further studies as it allows for the first time the simultaneous determination of DEHP and TOTM in human blood in combination with the analysis of their degradation products that render possible to investigate the leachability of a broad range of PVC medical devices in human blood using only one analytical method. PMID:26243703

  8. Toxicogenomic Screening of Replacements for Di(2-Ethylhexyl) Phthalate (DEHP) Using the Immortalized TM4 Sertoli Cell Line

    PubMed Central

    Nardelli, Thomas C.; Erythropel, Hanno C.; Robaire, Bernard

    2015-01-01

    Phthalate plasticizers such as di(2-ethylhexyl) phthalate (DEHP) are being phased out of many consumer products because of their endocrine disrupting properties and their ubiquitous presence in the environment. The concerns raised from the use of phthalates have prompted consumers, government, and industry to find alternative plasticizers that are safe, biodegradable, and have the versatility for multiple commercial applications. We examined the toxicogenomic profile of mono(2-ethylhexyl) phthalate (MEHP, the active metabolite of DEHP), the commercial plasticizer diisononyl cyclohexane-1,2-dicarboxylate (DINCH), and three recently proposed plasticizers: 1,4-butanediol dibenzoate (BDB), dioctyl succinate (DOS), and dioctyl maleate (DOM), using the immortalized TM4 Sertoli cell line. Results of gene expression studies revealed that DOS and BDB clustered with control samples while MEHP, DINCH and DOM were distributed far away from the control-DOS-BDB cluster, as determined by principle component analysis. While no significant changes in gene expression were found after treatment with BDB and DOS, treatment with MEHP, DINCH and DOM resulted in many differentially expressed genes. MEHP upregulated genes downstream of PPAR and targeted pathways of cholesterol biosynthesis without modulating the expression of PPAR’s themselves. DOM upregulated genes involved in glutathione stress response, DNA repair, and cholesterol biosynthesis. Treatment with DINCH resulted in altered expression of a large number of genes involved in major signal transduction pathways including ERK/MAPK and Rho signalling. These data suggest DOS and BDB may be safer alternatives to DEHP/MEHP than DOM or the commercial alternative DINCH. PMID:26445464

  9. Characterization and application of sodium di(2-ethylhexyl) sulfosuccinate and sodium di(2-ethylhexyl) phosphate surfactants as pseudostationary phases in micellar electrokinetic chromatography.

    PubMed

    Akbay, Cevdet; Wilmot, Nathan; Agbaria, Rezik A; Warner, Isiah M

    2004-12-17

    Sodium di(2-ethylhexyl) sulfosuccinate (DOSS) and sodium di(2-ethylhexyl) phosphate (NaDEHP) surfactants, with double alkyl chains and negatively charged headgroups, were characterized using fluorescence quenching, densitometry, and tensiometry techniques to determine their aggregation number, partial specific volume, and critical aggregation concentration. These two surfactants were then applied as pseudostationary phases in micellar electrokinetic chromatography (MEKC) for separations of alkyl phenyl ketones. The aggregation number of NaDEHP was found to be more than two-fold higher than that of DOSS. The partial specific volumes of NaDEHP and DOSS were found to be 0.9003 and 0.8371 mL/g, respectively. The critical aggregation concentrations are 5.12 and 1.80 mM for NaDEHP and DOSS, respectively. The DOSS surfactant provided a wider separation window and had a greater hydrophobic environment than the NaDEHP surfactant under the MEKC experimental conditions studied. PMID:15633750

  10. Extraction kinetics of rare earth metals with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester using a hollow fiber membrane extractor

    SciTech Connect

    Kubota, Fukiko; Goto, Masahiro; Nakashio, Fumiyuki; Hano, Tadashi

    1995-03-01

    A kinetic study concerning chemical complexation-based solvent extraction of rare earth metals with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester dissolved as an extractant in n-heptane was carried out using a microporous hydrophobic hollow fiber membrane extractor. The effects of concentration of chemical species in aqueous and organic feed solutions on the apparent permeabilities of metal species for extraction and stripping, respectively, were investigated to clarify the permeation mechanism. From the experimental results it was predicted that the permeation rate is controlled by diffusion of the chemical species in aqueous and organic phases and by interfacial chemical reaction. The experimental data were analyzed by the diffusion model accompanied with an interfacial reaction, taking into account the velocity distributions of the aqueous and organic phases through the inner and outer sides of the hollow fiber.

  11. Phase equilibrium of sodium bis(2-ethylhexyl) phosphate/water/n-heptane/sodium chloride microemulsion

    SciTech Connect

    Shioi, Akihisada; Harada, Makoto; Matsumoto, Keishi )

    1991-09-19

    The microemulsion phase diagram for the sodium bis(2-ethylhexyl) phosphate (SDEHP)/water/n-heptane/sodium chloride system is reported. The salinity effects on the phase diagram are discussed in detail. Cylindrical aggregates were found to exist in the oil-rich region and disklike aggregates in the brine-rich region. The middle-phase microemulsion in equilibrium with both the excess brine and oil phases was concluded to be composed of these microstructures. Sodium bis(2-ethylhexyl) phosphate has a common hydrocarbon tail with sodium bis(2-ethylhexyl) sulfosuccinate (AOT), but the phase equilibrium and the structures of the microemulsion phases in SDEHP system were much different from those in the AOT case. The differences were attributed to those in the shapes of aggregates for the two cases.

  12. PERIPUBERTAL DI (2-ETHYLHEXYL) PHTHALATE EXPOSURE INHIBITS ANDROGEN SENSITIVE TISSUE DEVELOPMENT AND DELAYS PUBERTY IN MALE SPRAGUE-DAWLEY RATS

    EPA Science Inventory

    PERIPUBERTAL DI (2-ETHYLHEXYL) PHTHALATE EXPOSURE INHIBITS ANDROGEN SENSITIVE TISSUE DEVELOPMENT AND DELAYS PUBERTY IN MALE SPRAGUE-DAWLEY RATS

    Nigel Noriega, Jonathan Furr, Christy Lambright, Vickie Wilson, L. Earl Gray Jr.

    The plasticizer Di (2-ethylhexyl) phtha...

  13. Dose Reconstruction of Di-2-Ethylhexyl Phthalate Using a Simple Pharmacokinetic Model [Manuscript

    EPA Science Inventory

    Background In 2005, eight adults provided full volumes and times of urine voids during one normal work week. These samples were analyzed for four di-2-ethylhexyl phthalate (DEHP) metabolites. Participants also provided diary information on their diet, driving, and out¬door a...

  14. Endoplasmic reticulum stress as a novel cellular response to di (2-ethylhexyl) phthalate exposure.

    PubMed

    Peropadre, Ana; Fernández Freire, Paloma; Pérez Martín, José Manuel; Herrero, Óscar; Hazen, María José

    2015-12-25

    Di (2-ethylhexyl) phthalate is a high-production chemical widely used as a plasticizer for polyvinyl chloride products. Due to its ubiquitous presence in environmental compartments and the constant exposure of the general population through ingestion, inhalation, and dermal absorption, this compound has been subjected to extensive in vivo and in vitro toxicological studies. Despite the available information, research on the cytotoxicity of di (2-ethylhexyl) phthalate in mammalian cells is relatively limited.In this paper, an in vitro multi-parametric approach was used to provide further mechanistic data on the toxic activity of this chemical in Vero and HaCaT cells. Our results reveal that a 24 h exposure to di (2-ethylhexyl) phthalate causes, in both cell lines, an inhibition of cell proliferation that was linked to cell cycle delay at the G1 phase. Concomitantly, the tested compound induces mild endoplasmic reticulum stress which leads to an adaptive rather than a pro-apoptotic response in mammalian cells. These findings demonstrate that there are multiple potential cellular targets of di (2-ethylhexyl) phthalate-induced toxicity and the need to develop further experimental studies for the risk assessment of this ubiquitous plasticizer. PMID:26514933

  15. VITELLOGENIN GENE EXPRESSION IN MALE FATHEAD MINNOWS EXPOSED TO DI(2-ETHYLHEXYL)PHTHALATE

    EPA Science Inventory

    Di(2-ethylhexyl) phthalate (DEHP) is a plasticizer used extensively in the plastics industry. DEHP has been shown to be ubiquitous in the environment and has been detected in ground and surface waters, sediment sludge and at several Superfund sites. Previous studies using rats ...

  16. MODULATION OF RAT LEYDIG CELL STEROIDOGENIC FUNCTION BY DI(2-ETHYLHEXYL)PHTHALATE

    EPA Science Inventory

    Modulation of rat Leydig cell steroidogenic function by di(2-ethylhexyl)phthalate.

    Akingbemi BT, Youker RT, Sottas CM, Ge R, Katz E, Klinefelter GR, Zirkin BR, Hardy MP.

    Center for Biomedical Research, Population Council, New York, New York 10021, USA. benson@popcbr...

  17. MECHANISTIC CONSIDERATIONS FOR HUMAN RELEVANCE OF CANCER HAZARD OF DI(2-ETHYLHEXYL) PHTHALATE

    EPA Science Inventory

    Di(2-ethylhexyl) phthalate (DEHP) is a peroxisome proliferator agent that is widely used as a plasticizer to soften polyvinylchloride plastics and non-polymers. Both occupational (e.g., by inhalation during its manufacture and use as a plasticizer of polyvinylchloride) and enviro...

  18. EFFECTS OF SEWAGE SLUDGE ON DI-(2-ETHYLHEXYL) PHTHALATE UPTAKE BY PLANTS

    EPA Science Inventory

    Di-(2-ethylhexyl) phthalate (DEHP) is a priority organic pollutant frequently found in municipal sludges. reenhouse study was conducted to determine the effects of sludge on plant uptake of 14 C-DEHP (carbonyl labeled). lants grown included three food chain crops, lettuce (Lactuc...

  19. Separation of carrier-free {sup 90}Y from high level waste by extraction chromatographic technique using 2-ethylhexyl-2-ethylhexyl phosphonic acid (KSM-17)

    SciTech Connect

    Achuthan, P.V.; Dhami, P.S.; Kannan, R.; Gopalakrishnan, V.; Ramanujam, A.

    2000-01-01

    An extraction chromatographic technique has been developed for the separation of carrier-free {sup 90}Y from the {sup 90}Sr present in the high level waste (HLW) of the Purex process. When a Purex HLW solution in 2--3 M HNO{sub 3} is passed through a CMPO-Chromosorb-102 (CAC) column, all the trivalent, tetravalent, and hexavalent ions are sorbed. The effluent from this experiment, after adjusting the pH to 2 with NaOH, was passed through a 2-ethylhexyl-2-ethylhexyl phosphonic acid (KSM-17)-Chromosorb-102 (KSMC) extraction chromatographic column where only {sup 90}Y was sorbed. All the other ions ({sup 90}Sr, {sup 137}Cs, {sup 125}Sb, {sup 106}Ru, {sup 106}Rh, etc.) were washed off with dilute HNO{sub 3} (pH 2), and carrier-free {sup 90}Y was eluted with 0.5 M HNO{sub 3}. This technique can yield {sup 90}Y in mCi levels in pure form for medical applications. The {sup 90}Sr can be used repeatedly after allowing for {sup 90}Y buildup.

  20. Identification of di-2-ethylhexyl terephthalate (DEHTP) metabolites using human liver microsomes for biomonitoring applications.

    PubMed

    Silva, Manori J; Samandar, Ella; Calafat, Antonia M; Ye, Xiaoyun

    2015-06-01

    Di-2-ethylhexyl terephthalate (DEHTP), a structural isomer of the plasticizer di-2-ethylhexyl phthalate (DEHP), is used in food packaging and medical devices, among other applications, and is a potential replacement for DEHP and other ortho-phthalate plasticizers. Identifying sensitive and specific biomarkers of DEHTP is necessary to assess humans' background exposure to DEHTP. Using mass spectrometry, we investigated the metabolism of DEHTP by human liver microsomes to identify in vitro DEHTP metabolites. We unequivocally identified terephthalic acid (TPA) and mono-2-ethylhydroxyhexyl terephthalate (MEHHTP), using authentic standards, and tentatively identified mono-2-ethylhexyl terephthalate (MEHTP) and two other oxidative metabolites of DEHTP: mono-2-ethyloxohexyl terephthalate (MEOHTP), and mono-2-ethyl-5-carboxypentyl terephthalate (MECPTP) from their mass spectrometry fragmentation patterns. We also evaluated the formation of in vitro metabolites of DEHP. DEHTP and DEHP produced similar metabolites, but their metabolite profiles differed considerably. DEHTP metabolized to form TPA, a metabolite of several terephthalates, as the major in vitro metabolite, followed by MEHTP, MEHHTP, MEOHTP and MECPTP. MEHTP, MEHHTP, MEOHTP and MECPTP, which are specific metabolites of DEHTP, may be suitable biomarkers for assessing exposure to DEHTP. Nonetheless, data on the urinary excretion fraction and temporal stability of these metabolites, among other considerations, are needed to demonstrate their utility as exposure biomarkers. PMID:25687528

  1. Uptake of di-(2-ethylhexyl) phthalate of vegetables from plastic film greenhouses.

    PubMed

    Fu, Xiaowei; Du, Qizhen

    2011-11-01

    Uptake of di-(2-ethylhexyl) phthalate (DEHP) of nine vegetables including potherb mustard, bok choy, celery, spinach, cabbage, leaf of tube, lettuce, garlic, and edible amaranth in plastic film greenhouses with different plastic films, film thickness, greenhouse age, and greenhouse height was studied. The results showed that the higher the DEHP content of film, the thicker the film, the lower the height of the greenhouse, and the younger the age of the greenhouse were, the higher the DEHP concentration of vegetables was. The results afford significant information for production of safe vegetables with low level DEHP contamination. PMID:21958198

  2. Influence of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) on zinc electrodeposition

    NASA Astrophysics Data System (ADS)

    Lehr, I. L.; Saidman, S. B.

    2012-03-01

    This work is a study of the electrodeposition of zinc onto SAE 4140 steel electrodes using solutions containing zinc sulfate and bis(2-ethylhexyl) sodium sulfosuccinate (AOT). The influence of different parameters such as electrolyte concentration, electrodeposition time and temperature on the morphology of the electrodeposits was analyzed. The deposits were characterized by scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and X-ray diffraction. The variation of open circuit potential over time in chloride solutions was also evaluated. The nucleation-growth process and consequently the morphology of the electrodeposits are modified in the presence of AOT. The surfactant induces the formation of a porous deposit.

  3. The effect of mono-(2-ethylhexyl) phthalate on apoptosis of rat ovarian granulosa cells in vitro.

    PubMed

    Li, Na; Liu, Keqiang; Yuan, Haitao; Zhu, Jian; Yu, Guangyan; Xie, Jingli; Fu, Songpo; Guo, Kun; Ye, Lin

    2015-03-01

    Mono-(2-ethylhexyl) phthalate (MEHP), the active metabolite of di-(2-ethylhexyl) phthalate (DEHP), is considered to be a reproductive toxicant. This study was performed to evaluate the effect of MEHP on apoptosis of rat ovarian granulosa cells and explore potential mechanism. Granulosa cells were treated with MEHP (0, 25, 50, and 100 μmol/l). Inhibited cell viability and increased apoptosis rate were observed in 50 and 100 μmol/l groups. CASPASE3 activity and BAX expression were significantly raised in all MEHP-treated groups; BCL2 expression was elevated in 25 μmol/l group, while inhibited in 50 and 100 μmol/l groups; BAX/BCL2 ratio was increased in a typical dose-effect relationship. In conclusion, this study showed that MEHP exposure induced cell viability decrease and apoptosis, associated with increase of CASPASE3 activity and BAX/BCL2 ratio. Moreover, CASPASE3 activity showed a reversed dose-dependent effect in MEHP-treated groups, indicating there might exist other CASPASE-independent pathway involved in MEHP-induced apoptosis. PMID:25681707

  4. The endocrine disruptor mono-(2-ethylhexyl) phthalate promotes adipocyte differentiation and induces obesity in mice.

    PubMed

    Hao, Chanjuan; Cheng, Xuejia; Xia, Hongfei; Ma, Xu

    2012-12-01

    The environmental obesogen hypothesis proposes that exposure to endocrine disruptors during developmental 'window' contributes to adipogenesis and the development of obesity. MEHP [mono-(2-ethylhexyl) phthalate], a metabolite of the widespread plasticizer DEHP [di-(2-ethylhexyl) phthalate], has been found in exposed organisms and identified as a selective PPARγ (peroxisome-proliferator-activated receptor γ) modulator. However, implication of MEHP on adipose tissue development has been poorly investigated. In the present study, we show the dose-dependent effects of MEHP on adipocyte differentiation and GPDH (glycerol-3-phosphate dehydrogenase) activity in the murine 3T3-L1 cell model. MEHP induced the expression of PPARγ as well as its target genes required for adipogenesis in vitro. Moreover, MEHP perturbed key regulators of adipogenesis and lipogenic pathway in vivo. In utero exposure to a low dose of MEHP significantly increased b.w. (body weight) and fat pad weight in male offspring at PND (postnatal day) 60. In addition, serum cholesterol, TAG (triacylglycerol) and glucose levels were also significantly elevated. These results suggest that perinatal exposure to MEHP may be expected to increase the incidence of obesity in a sex-dependent manner and can act as a potential chemical stressor for obesity and obesity-related disorders. PMID:22953781

  5. Achromobacter denitrificans strain SP1 efficiently remediates di(2-ethylhexyl)phthalate.

    PubMed

    Pradeep, S; Josh, M K Sarath; Binod, P; Devi, R Sudha; Balachandran, S; Anderson, Robin C; Benjamin, Sailas

    2015-02-01

    This study describes how Achromobacter denitrificans strain SP1, a novel isolate from heavily plastics-contaminated sewage sludge efficiently consumed the hazardous plasticizer, di(2-ethylhexyl)phthalate (DEHP) as carbon source supplemented in a simple basal salt medium (BSM). Response surface methodology was employed for the statistical optimization of the process parameters such as temperature (32°C), agitation (200 rpm), DEHP concentration (10 mM), time (72 h) and pH (8.0). At these optimized conditions, experimentally observed DEHP degradation was 63%, while the predicted value was 59.2%; and the correlation coefficient between them was 0.998, i.e., highly significant and fit to the predicted model. Employing GC-MS analysis, the degradation pathway was partially deduced with intermediates such as mono(2-ethylhexyl)phthalate and 2-ethyl hexanol. Briefly, this first report describes A. denitrificans strain SP1 as a highly efficient bacterium for completely remediating the hazardous DEHP (10 mM) in 96 h in BSM (50% consumed in 60 h), which offers great potentials for efficiently cleaning the DEHP-contaminated environments such as soil, sediments and water upon its deployment. PMID:25463861

  6. Giant rodlike reversed micelles formed by sodium bis(2-ethylhexyl) phosphate in n-heptane

    SciTech Connect

    Yu, Z.J.; Neuman, R.D. )

    1994-08-01

    The solution behaviors of sodium bis(2-ethylhexyl) phosphate (NaDEHP) in n-heptane were investigated by light-scattering and viscosity measurements. NaDEHP forms giant rodlike reversed micelles, with a radius of gyration as large as 53 nm, which violently contrasts with the literature view that the average micellar aggregation numbers in nonaqueous or apolar media are much smaller (seldom exceeding 20) than those in aqueous media. Significantly, a small amount of water plays the role of an antimicellar growth agent; i.e., the reversed micellar size decreases remarkably when [open quotes]dry[close quotes] solutions are exposed to humid air from which water vapor is absorbed or when bulk water is directly added - a behavior which is distinctly opposite to that for sodium bis(2-ethylhexyl) sulfosuccinate/apolar medium systems. Thus, the literature views that large micelles can only be found in aqueous media and that the surfactant headgroups in reversed micelles are linked together by hydrogen bonds are misleading. It is suggested that the primary contribution to the driving force for the growth of rodlike NaDEHP reversed micelles is long-range electrostatic interactions among the headgroups of the surfactant molecules and their counterions, and a possible mechanism for the effect of water is also discussed. 27 refs., 7 figs., 1 tab.

  7. Inhibition of human platelet phospholipase A/sub 2/ by mono(2-ethylhexyl)phthalate

    SciTech Connect

    Labow, R.S.; Meek, E.; Adams, G.A.; Rock, G.

    1988-06-01

    There is evidence that the carcinogenic and teratogenic effects attributed to the plasticizer di(2-ethylhexyl)phthalate (DEHP) are due to its major metabolite mono(2-ethylhexyl)phthalate (MEHP). MEHP is also formed ex vivo by a plasma enzyme in blood products stored in polyvinyl chloride (PVC) DEHP plastic containers. People who receive large amounts of blood products, such as hemophiliacs or patients undergoing hemodialysis, cardiopulmonary bypass, or massive transfusion, are exposed to significant levels of plasticizer. In this study, the platelet was used to show that MEHP inhibits phospholipase A/sub 2/ (PLA/sub 2/), one of the enzymes important in the release of arachidonic acid from membrane phospholipids. PLA/sub 2/ was measured by the liberation of /sup 14/C-arachidonic acid from 1-stearoyl-2-(1-/sup 14/C)arachidonyl-L-3-phosphatidylcholine. MEHP inhibits PLA/sub 2/ activity noncompetitively in intact human platelets and lysates with a K/sub i/ of 3.7 x 10/sup -4/ M. DEHP does not inhibit PLA/sub 2/ in whole platelets. Inhibition of PLA/sub 2/ by MEHP occurs at only three times the circulating level of MEHP measured in neonates undergoing exchange transfusion and 20-fold the levels experienced by patients during cardiopulmonary bypass. Therefore, infants and adult patients with multisystem failure who accumulate MEHP in their blood may be at risk for decreased platelet function.

  8. Mono-(2-ethylhexyl) phthalate targets glycogen debranching enzyme and affects glycogen metabolism in rat testis.

    PubMed

    Kuramori, Chikanori; Hase, Yasuyoshi; Hoshikawa, Koichi; Watanabe, Keiko; Nishi, Takeyuki; Hishiki, Takako; Soga, Tomoyoshi; Nashimoto, Akihiro; Kabe, Yasuaki; Yamaguchi, Yuki; Watanabe, Hajime; Kataoka, Kohsuke; Suematsu, Makoto; Handa, Hiroshi

    2009-05-01

    Phthalate esters are commonly used plasticizers; however, some are suspected to cause reproductive toxicity. Administration of high doses of di-(2-ethylhexyl) phthalate (DEHP) induces germ cell death in male rodents. Mono-(2-ethylhexyl) phthalate (MEHP), a hydrolyzed metabolite of DEHP, appears to be responsible for this testicular toxicity; however, the underlying mechanism of this chemical's action remains unknown. Here, using a one-step affinity purification procedure, we identified glycogen debranching enzyme (GDE) as a phthalate-binding protein. GDE has oligo-1,4-1,4-glucanotransferase and amylo-1,6-glucosidase activities, which are responsible for the complete degradation of glycogen to glucose. Our findings demonstrate that MEHP inhibits the activity of oligo-1,4-1,4-glucanotransferase, but not of amylo-1,6-glucosidase. Among various phthalate esters tested, MEHP specifically binds to and inhibits GDE. We also show that DEHP administration affects glycogen metabolism in rat testis. Thus, inhibition of GDE by MEHP may play a role in germ cell apoptosis in the testis. PMID:19240039

  9. Effects of maternal exposure to di(2-ethylhexyl)phthalate (DEHP) during pregnancy on susceptibility to neonatal asthma

    SciTech Connect

    Shin, In-Sik; Lee, Mee-Young; Cho, Eun-Sang; Choi, Eun-young; Son, Hwa-Young; Lee, Kyoung-Youl

    2014-02-01

    Di(2-ethylhexyl) phthalate (DEHP) is used as a plasticizer and is widely dispersed in the environment. In this study, we investigated the effects of maternal exposure to DEHP during pregnancy on neonatal asthma susceptibility using a murine model of asthma induced by ovalbumin (OVA). Pregnant BALB/c mice received DEHP from gestation day 13 to lactation day 21. Their offspring were sensitized on postnatal days (PNDs) 9 and 15 by intraperitoneal injection of 0.5 μg OVA with 200 μg aluminum hydroxide. On PNDs 22, 23 and 24, live pups received an airway challenge of OVA for 30 min. Offspring from pregnant mice that received DEHP showed reductions in inflammatory cell count, interleukin (IL)-4, IL-13, and eotaxin in their bronchoalveolar lavage fluid and in total immunoglobulin E and OVA-specific IgE in their plasma compared with offspring from pregnant mice that did not receive DEHP treatment. These results were consistent with histological analysis and immunoblotting. Maternal exposure to DEHP reduces airway inflammation and mucus production in offspring, with a decrease in inducible nitric oxide synthase (iNOS) in the lung tissue. This study suggests that maternal exposure to DEHP during pregnancy reduces asthmatic responses induced by OVA challenge in offspring. These effects were considered to be closely related to the suppression of Th2 immune responses and iNOS expression. - Highlights: • Maternal exposure to di(2-ethylhexyl)phthalate reduces asthmatic response in pups. • Di(2-ethylhexyl)phthalate reduces eosinophilia induced by ovalbumin exposure. • Di(2-ethylhexyl)phthalate reduces T-helper type 2 cytokine production. • Di(2-ethylhexyl)phthalate attenuates airway inflammation and mucus production. • Di(2-ethylhexyl)phthalate suppresses inducible nitric oxide synthase in lung tissue.

  10. Comparison of the release behaviors of di (2-ethylhexyl) phthalate and tri(2-ethylhexyl) trimellitate from the polyvinyl-chloride infusion set into pharmaceutical solutions.

    PubMed

    Zhang, Hong; Yang, Fengmin; Shen, Gang; Yang, Yueyang; Tang, Yalin

    2015-05-01

    Polyvinyl-chloride (PVC) with plasticizers of di(2-ethylhexyl) phthalate (DEHP) and tris(2-ethyl- hexyl) trimellitate (TOTM) is widely used in medical and paramedical appliances. However, such plasticizers can leach from PVC products into contact solutions. The aim of this study is to investigate the release behaviors of DEHP and TOTM from the PVC intravenous infusion set into various pharmaceutical solutions under the simulated clinical conditions, such as the lipophilic substances (paclitaxel) , parenteral nutrition (fat emulsion injection) , acid and alkali pharmaceutical solution (levofloxacin hydrochloride injection, pH 3.0-5.0 and furosemide, pH 8.0-9.0). A simple and rapid high-performance liquid chromatographic method with UV detection (HPLC-UV) for the determination of DEHP or TOTM released from PVC medical devices into the above intravenous preparations was developed. The cumulative amounts of DEHP or TOTM released in 24 h were in the same following order: paclitaxel > fat emulsion injection levofloxacin hydrochloride > furosemide solution. From a comparison of the cumulative amounts of released DEHP and TOTM from the above solutions, we found that the cumulative amount of TOTM is far less than that of DEHP, under the same conditions. The cumulative amount of the DEHP released in 24 h in the paclitaxel solution was 21. 14 mg, while under the same conditions, the cumulative amount of TOTM was only 0. 078 mg. The cumulative amount of DEHP is assumed to be about 270 times that of the released TOTM. Thus TOTM could be a superior alternative to DEHP for use in medical devices because of its potential lower leachability. PMID:26387211

  11. Bis-(2-ethylhexyl) Phthalate Increases Insulin Expression and Lipid Levels in Drosophila melanogaster.

    PubMed

    Cao, Hao; Wiemerslage, Lyle; Marttila, Petra S K; Williams, Michael J; Schiöth, Helgi B

    2016-09-01

    Bis-(2-ethylhexyl) phthalate (DEHP) is one of the most widely used plasticizers, and human beings are exposed to DEHP via polyvinyl chloride (PVC) materials, medical equipment and even drinking water. While DEHP has been implicated to influence metabolism and endocrine functions, important questions remain about the molecular mechanisms of these effects. We employed the model organism Drosophila melanogaster and examined physiological, molecular and behavioural effects from DEHP-contaminated food. We found that DEHP, at levels comparable to human exposure, made male flies more resistant to starvation and increased lipid levels, while decreasing circulating carbohydrates. Moreover, DEHP-fed male flies had higher expression levels of an insulin-like peptide known to regulate metabolism, as well as the insulin receptor. Our results suggest that long-term DEHP feeding may induce diabetes-like dysfunctions. These findings provide a molecular background of how DEHP may have detrimental effects on metabolic functions. PMID:27009472

  12. N-(2-Ethylhexyl)carbazole: A New Fluorophore Highly Suitable as a Monomolecular Liquid Scintillator.

    PubMed

    Montbarbon, Eva; Sguerra, Fabien; Bertrand, Guillaume H V; Magnier, Élodie; Coulon, Romain; Pansu, Robert B; Hamel, Matthieu

    2016-08-16

    The synthesis, photophysical properties, and applications in scintillation counting of N-(2-ethylhexyl)carbazole (EHCz) are reported. This molecule displays all of the required characteristics for an efficient liquid scintillator (emission wavelength, scintillation yield), and can be used without any extra fluorophores. Thus, its scintillation properties are discussed, as well as its fast neutron/gamma discrimination. For the latter application, the material is compared with the traditional liquid scintillator BC-501 A, and other liquid fluorescent molecules classically used as scintillation solvents, such as xylene, pseudocumene (PC), linear alkylbenzenes (LAB), diisopropylnaphthalene (DIN), 1-methylnaphthalene (1-MeNapht), and 4-isopropylbiphenyl (iPrBiph). For the first time, an excimeric form of a molecule has been advantageously used in scintillation counting. A moderate discrimination between fast neutrons and gamma rays was observed in bulk EHCz, with an apparent neutron/gamma discrimination potential half of that of BC-501 A. PMID:27406840

  13. The Adverse Cardiac Effects of Di(2-ethylhexyl) phthalate and Bisphenol A

    PubMed Central

    Posnack, Nikki Gillum

    2014-01-01

    The ubiquitous nature of plastics has raised concerns pertaining to continuous exposure to plastic polymers and human health risks. Of particular concern is the use of endocrine-disrupting chemicals (EDCs) in plastic production, including Di(2-ethylhexyl) phthalate (DEHP) and Bisphenol A (BPA). Widespread and continuous exposure to DEHP and BPA occurs through dietary intake, inhalation, dermal and intravenous exposure via consumer products and medical devices. This article reviews the literature examining the relationship between DEHP and BPA exposure and cardiac toxicity. In vitro and in vivo experimental reports are outlined, as well as epidemiological studies which examine the association between these chemicals and cardiovascular outcomes. Gaps in our current knowledge are also discussed, along with future investigative endeavors that may help resolve whether DEHP and/or BPA exposure has a negative impact on cardiovascular physiology. PMID:24811950

  14. An Advanced TALSPEAK Concept Using 2-Ethylhexylphosphonic Acid Mono-2-Ethylhexyl Ester as the Extractant

    SciTech Connect

    Lumetta, Gregg J.; Casella, Amanda J.; Rapko, Brian M.; Levitskaia, Tatiana G.; Pence, Natasha K.; Carter, Jennifer C.; Niver, Cynthia M.; Smoot, Margaret R.

    2014-12-21

    A method for separating the trivalent actinides and lanthanides is being developed using 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP]) as the extractant. The method is based on the preferential binding of the actinides in the aqueous phase by N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetic acid (HEDTA), which serves to keep the actinides in the aqueous phase while the lanthanides are extracted into an organic phase containing HEH[EHP]. The process is very robust, showing little dependence upon the pH or the HEH[EHP], HEDTA, and citrate concentrations over the ranges that might be expected in a nuclear fuel recycling plant. Single-stage runs with a 2-cm centrifugal contactor indicate that modifications to the process chemistry may be needed to increase the extraction rate for Sm, Eu, and Gd. The hydraulic properties of the system are favorable to application in centrifugal contactors.

  15. Biochar reduces the bioavailability of di-(2-ethylhexyl) phthalate in soil.

    PubMed

    He, Lizhi; Fan, Shiliang; Müller, Karin; Hu, Guotao; Huang, Huagang; Zhang, Xiaokai; Lin, Xiaoming; Che, Lei; Wang, Hailong

    2016-01-01

    A pot experiment was conducted to evaluate the effect of biochars on the bioavailability of di-(2-ethylhexyl) phthalate (DEHP) in two soils using Brassica chinensis L. as an indicator plant. The residual concentrations of DEHP tended to be higher in the biochar-amended soils than in the control soils. They were lower (p<0.05) in the high organic carbon content soil (HOC; 2.2%C) than in the low organic carbon content soil (LOC; 0.35%C). The DEHP concentrations in plant shoots grown in the HOC soils were lower than those in the LOC soils (p<0.05). Compared to the control, the biochar addition decreased the DEHP concentrations in shoots grown in the LOC soils; whereas there was no significant difference in the HOC soils. Our results showed that soil OC content as well as biochar properties are the key factors influencing the bioavailability of DEHP in soils. PMID:26037111

  16. [Accumulation of di-(2-ethylhexyl) phthalate in various genotype Ipomoea aquatica-paddy soil system].

    PubMed

    Cai, Quanying; Mo, Cehui; Zeng, Qiaoyun; Li, Yunhui; Xiao, Kai'en; Li, Haiqin; Xu, Guosheng; Wang, Boguang; Wu, Qingzhu

    2004-08-01

    Various genotypes of Ipomoea aquatica were pot-cultured on paddy soils with different pollution level of di-(2-ethylhexyl) phthalate (DEHP), and the concentrations of DEHP in plant and soil were determined by GC/MS. The results showed that the concentration of DEHP in plant varied directly with soil pollution level, and different genotypes of Ipomoea aquatica had significantly different concentrations of DEHP, which varied directly with leaf area. Soils grown with various genotypes of Ipomoea aquatica also had significantly different DEHP concentrations. The soil DEHP bioaccumulation factors (BCFs) of various Ipomoea aquatica genotypes were all under 1.0 and in inverse proportion to soil pollution level. The BCFs varied significantly among the genotypes of Ipomoea aquatica, with a relatively higher value for those genotypes with middle size leaves. PMID:15574007

  17. Sodium bis(2-ethylhexyl)sulfosuccinate self-aggregation in vacuo: molecular dynamics simulation.

    PubMed

    Longhi, Giovanna; Fornili, Sandro L; Liveri, Vincenzo Turco; Abbate, Sergio; Rebeccani, Davide; Ceraulo, Leopoldo; Gangemi, Fabrizio

    2010-05-14

    Molecular dynamics (MD) simulations were conducted for systems in vacuo consisting of n AOT(-) anions (bis(2-ethylhexyl)sulfosuccinate ions) and n+/- 1 or n Na(+) ions up to n = 20. For n = 15, positively charged systems with Li(+), K(+), and Cs(+) cations were also considered. All systems were observed to form reverse micelle-like aggregates whose centre is occupied by cations and polar heads in a very compact solid-like way, while globally the aggregate has the form of an elongated and rather flat ellipsoid. Various types of statistical analyses were carried out on the systems to enlighten structural and dynamical properties including gyration radius, atomic pair correlation functions, atomic B-factor and moment of inertia tensor. For completeness and comparison the stability of reverse micelle is tested in the case of neutral n = 20 system in CCl(4) solution. PMID:20428549

  18. Survey of di-(2-ethylhexyl)phthalate plasticizer contamination of retail Danish milks.

    PubMed

    Petersen, J H

    1991-01-01

    An investigation of residues of di-(2-ethylhexyl)-phthalate (DEHP) in retail whole milk in samples from one German and 14 Danish dairies is reported. The investigation was performed about six months after the use of DEHP-plasticized milk tubing was banned in Denmark. The results indicate a mean concentration of DEHP lower than 50 micrograms/litre in retail whole milk. Based on these data and the Tolerable Daily Intake (TDI) for DEHP of 25 micrograms/kg body weight laid down by the EEC Scientific Committee for Food, it is concluded that the intake of DEHP from milk and milk products does not, even through a whole life, constitute a danger to health for the Danish population. PMID:1812016

  19. Protein extraction using the sodium bis(2-ethylhexyl) phosphate (NaDEHP) reverse micellar system.

    PubMed

    Hu, Z; Gulari, E

    1996-04-20

    The reverse micellar system of sodium bis(2-ethylhexyl) phosphate (NaDEHP)/isooctane/brine was used for liquid-liquid extraction of proteins. We investigated the solubilization of cytochrome-c and alpha-chymotrypsin into the NaDEHP reverse micellar phase by varying the pH and NaCl concentration in the aqueous phase. At neutral pH and relatively low ionic strength, the proteins are extracted into the micellar phase with high yield. By contacting the micellar phase with a divalent cation (e.g., Ca(2+)) aqueous solution, the reverse micelles are destabilized and release the protein molecules back into an aqueous solution for recovery. This method separates the proteins from the surfactant with very high overall efficiencies. PMID:18626936

  20. Oil Induced Spontaneous Flow in Water- Bis(2-ethylhexyl)Sulfosuccinat (AOT) system

    NASA Astrophysics Data System (ADS)

    Kalakonda, Parvathalu

    Instability and evaporation rates of oils within the layers of vesicles of a surfactants trigger the spontaneous (second flow) flow. The incorporation of oils into bis(2-ethylhexyl)sulfosuccinat (AOT) system remains incompletely characterized. We show that the second flow has a finite size that show a minimum at a particular concentration (mM) of surfactant solution. As a result, the layers are destabilized lead to ``explode'' and create the second flow. The fluorescence emission spectra and evaporation rates show that the oil diffuses into the layers of vesicles of a surfactant. We have characterized evaporation rates of oils on various concentrations (mM) of surfactant solution and observed that oils evaporation rates depend on volume and remain constant as the function of concentration of surfactant. We believe that second flow is new feature and brings a new insight into the fluid flow dynamics.

  1. The extraction of water, nitric acid, and uranyl nitrate by di-2-ethylhexyl sulfoxide in dodecane

    SciTech Connect

    Moyer, B.A.; Baes, C.F. Jr.; McDowell, W.J.; Caley, C.E.; Case, G.N. )

    1989-01-01

    The extraction of water, nitric acid, and uranyl nitrate by di-2-ethylhexyl sulfoxide (DEHSO) in dodecane has been measured. Using the program SXLSQA, the data were modeled with correction for nonideality effects (treatments of Hildebrand and Scott and of Pitzer) in terms of the organic-phase species (DEHSO)(H{sub 2}O), (DEHSO){sub 2}(H{sub 2}O), (DEHSO)(HNO{sub 3}), (DEHSO){sub 2}(HNO{sub 3})(H{sub 2}O), (DEHSO)(HNO{sub 3}){sub 2}(H{sub 2}O), and UO{sub 2}(NO{sub 3}){sub 2}(DEHSO){sub 2}(H{sub 2}O){sub w}. 11 refs., 4 figs.

  2. Structuring and relaxation effects in monolayers of di(2-ethylhexyl) phosphate

    SciTech Connect

    Uphaus, R.A.; Vandegrift, G.F.; Horwitz, E.P.

    1980-01-01

    Results of film compression studies on monolayers of di(2-ethylhexyl)phosphate (HDEHP) and other alkyl phosphoric acid derivatives are reported. HDEDP was found to form coherent monolayers below room temperature with apparent molecular areas which progressively decreased with increasing cycles of compression. Marked hysterisis was noted upon expansion and recompression of a compressed film. Expanded layers of HDEHP were found to gradually lose coherency and become destructured if left expanded for hours or days. This behavior was attributed to molecular disengagement due to weakly interacting alkyl chains and the presence of chain branching. Results of studies of other alkyl phosphoric acid derivatives indicate similar behavior, but the consequences of branching were apparently more important than the physical state (solid or liquid) of the monolayer. (BLM)

  3. Mono-2-Ethylhexyl Phthalate Induces Oxidative Stress Responses in Human Placental Cells In Vitro

    PubMed Central

    Tetz, Lauren M; Cheng, Adrienne A.; Korte, Cassandra S.; Giese, Roger W.; Wang, Poguang; Harris, Craig; Meeker, John D; Loch-Caruso, Rita

    2013-01-01

    Di-2-ethylhexyl phthalate (DEHP) is an environmental contaminant commonly used as a plasticizer in polyvinyl chloride products. Exposure to DEHP has been linked to adverse pregnancy outcomes in humans including preterm birth, low birth-weight, and pregnancy loss. Although oxidative stress is linked to the pathology of adverse pregnancy outcomes, effects of DEHP metabolites, including the active metabolite, mono-2-ethylhexyl phthalate (MEHP), on oxidative stress responses in placental cells have not been previously evaluated. The objective of the current study is to identify MEHP-stimulated oxidative stress responses in human placental cells. We treated a human placental cell line, HTR-8/SVneo, with MEHP and then measured reactive oxygen species (ROS) generation using the dichlorofluorescein assay, oxidized thymine with mass-spectrometry, redox-sensitive gene expression with qRT-PCR, and apoptosis using a luminescence assay for caspase 3/7 activity. Treatment of HTR-8 cells with 180 μM MEHP increased ROS generation, oxidative DNA damage, and caspase 3/7 activity, and resulted in differential expression of redox-sensitive genes. Notably, 90 and 180 μM MEHP significantly induced mRNA expression of prostaglandin-endoperoxide synthase 2 (PTGS2), an enzyme important for synthesis of prostaglandins implicated in initiation of labor. The results from the present study are the first to demonstrate that MEHP stimulates oxidative stress responses in placental cells. Furthermore, the MEHP concentrations used were within an order of magnitude of the highest concentrations measured previously in human umbilical cord or maternal serum. The findings from the current study warrant future mechanistic studies of oxidative stress, apoptosis, and prostaglandins as molecular mediators of DEHP/MEHP-associated adverse pregnancy outcomes. PMID:23360888

  4. Dose Reconstruction of Di(2-ethylhexyl) Phthalate Using a Simple Pharmacokinetic Model

    PubMed Central

    Calafat, Antonia M.

    2012-01-01

    Background: Di(2-ethylhexyl) phthalate (DEHP), used primarily as a plasticizer for polyvinyl chloride, is found in a variety of products. Previous studies have quantified human exposure by back calculating intakes based on DEHP metabolite concentrations in urine and by determining concentrations of DEHP in exposure media (e.g., air, food, dust). Objectives: To better understand the timing and extent of DEHP exposure, we used a simple pharmacokinetic model to “reconstruct” the DEHP dose responsible for the presence of DEHP metabolites in urine. Methods: We analyzed urine samples from eight adults for four DEHP metabolites [mono(2-ethylhexyl) phthalate, mono(2-ethyl-5-hydroxyhexyl) phthalate, mono(2-ethyl-5-oxohexyl) phthalate, and mono(2-ethyl-5-carboxypentyl) phthalate]. Participants provided full volumes of all voids over 1 week and recorded the time of each void and information on diet, driving, and outdoor activities. Using a model previously calibrated on a single person self-dosed with DEHP in conjunction with the eight participants’ data, we used a simple trial-and-error method to determine times and doses of DEHP that resulted in a best fit of predicted and observed urinary concentrations of the metabolites. Results: The average daily mean and median reconstructed DEHP doses were 10.9 and 5.0 µg/kg-day, respectively. The highest single modeled dose of 60 µg/kg occurred when one study participant reported consuming coffee and a bagel with egg and sausage that was purchased at a gas station. About two-thirds of all modeled intake events occurred near the time of reported food or beverage consumption. Twenty percent of the modeled DEHP exposure occurred between 2200 hours and 0500 hours. Conclusions: Dose reconstruction using pharmacokinetic models—in conjunction with biomonitoring data, diary information, and other related data—can provide a powerful means to define timing, magnitude, and possible sources of exposure to a given contaminant. PMID

  5. Thyroid endocrine disruption in zebrafish larvae after exposure to mono-(2-ethylhexyl) phthalate (MEHP).

    PubMed

    Zhai, Wenhui; Huang, Zhigang; Chen, Li; Feng, Cong; Li, Bei; Li, Tanshi

    2014-01-01

    Phthalates are extensively used as plasticizers in a variety of daily-life products, resulting in widespread distribution in aquatic environments. However, limited information is available on the endocrine disrupting effects of phthalates in aquatic organisms. The aim of the present study was to examine whether exposure to mono-(2-ethylhexyl) phthalate (MEHP), the hydrolytic metabolite of di-(2-ethylhexyl) phthalate (DEHP) disrupts thyroid endocrine system in fish. In this study, zebrafish (Danio rerio) embryos were exposed to different concentrations of MEHP (1.6, 8, 40, and 200 μg/L) from 2 h post-fertilization (hpf) to 168 hpf. The whole-body content of thyroid hormone and transcription of genes involved in the hypothalamic-pituitary-thyroid (HPT) axis were examined. Treatment with MEHP significantly decreased whole-body T4 contents and increased whole-body T3 contents, indicating thyroid endocrine disruption. The upregulation of genes related to thyroid hormone metabolism (Dio2 and UGT1ab) might be responsible for decreased T4 contents. Elevated gene transcription of Dio1 was also observed in this study, which might assist to degrade increased T3 contents. Exposure to MEHP also significantly induced transcription of genes involved in thyroid development (Nkx2.1 and Pax8) and thyroid hormone synthesis (TSHβ, NIS and TG). However, the genes encoding proteins involved in TH transport (transthyretin, TTR) was transcriptionally significantly down-regulated after exposure to MEHP. Overall, these results demonstrate that acute exposure to MEHP alters whole-body contents of thyroid hormones in zebrafish embryos/larvae and changes the transcription of genes involved in the HPT axis, thus exerting thyroid endocrine toxicity. PMID:24658602

  6. Effect of mono-(2-ethylhexyl) phthalate on steroid production of human granulosa cells

    SciTech Connect

    Reinsberg, Jochen Wegener-Toper, Petra; Ven, Katrin van der; Ven, Hans van der; Klingmueller, Dietrich

    2009-08-15

    The phthalate ester mono-(2-ethylhexyl) phthalate (MEHP) is the active metabolite of di-(2-ethylhexyl) phthalate, a high-production-volume chemical used as a plasticizer and solvent in numerous consumer products. MEHP has been demonstrated to be a reproductive toxicant in rodents decreasing estradiol and progesterone production in preovulatory granulosa cells. In the present study, we examined the effect of MEHP on steroid production of human granulosa-lutein (GL) cells. Human GL cells collected from women undergoing in vitro fertilization were cultured in medium containing FSH, hCG and 8-Br-cAMP, respectively, together with various concentrations of MEHP (0-500 {mu}mol L{sup -1}). After incubation for 48 h estradiol and progesterone were assayed in the spent culture medium. Furthermore, aromatase activity and mRNA levels of GL cells were determined. Basal as well as FSH-, hCG- and 8-Br-cAMP-stimulated estradiol production of GL cells was suppressed by MEHP in a dose-dependent manner (IC{sub 50} = 105 {mu}mol L{sup -1}, 138 {mu}mol L{sup -1}, 49 {mu}mol L{sup -1} and 78 {mu}mol L{sup -1}). Furthermore aromatase activity and mRNA levels were reduced in GL cells cultured with MEHP. In contrast, MEHP did not alter the production of progesterone up to a concentration of 167 {mu}mol L{sup -1}. The present data indicate that MEHP is a specific inhibitor of estradiol production in human GL cells with a post-cAMP site of action. The inhibition of estradiol production obviously results from a reduction of aromatase activity on the transcript level. As the in vitro effective doses of MEHP are within the range of real environmental exposure levels an inhibitory effect on estrogen production in vivo seems to be possi0009b.

  7. Re-characterization of mono-2-ethylhexyl phthalate hydrolase belonging to the serine hydrolase family.

    PubMed

    Iwata, Makoto; Imaoka, Takuya; Nishiyama, Takashi; Fujii, Takao

    2016-08-01

    A novel bacterium assimilating di-2-ethylhexyl phthalate as a sole carbon source was isolated, and identified as a Rhodococcus species and the strain was named EG-5. The strain has a mono-2-ethylhexyl phthalate (MEHP) hydrolase (EG-5 MehpH), which exhibits some different enzymatic features when compared with the previously reported MEHP hydrolase (P8219 MehpH) from Gordonia sp. These differences include different pH optimum activity, maximal reaction temperature and heat stability. The Km and Vmax values of EG-5 MehpH were significantly higher than those of P8219 MehpH. The primary structure of EG-5 MehpH showed the highest sequence identity to that of P8219 MehpH (39%) among hydrolases. The phylogenetic tree suggested that EG-5 MehpH and P8219 MehpH were categorized in different groups of the novel MEHP hydrolase family. Mutation of a conserved R(109) residue of EG-5 MehpH to a hydrophobic residue resulted in a dramatic reduction in the Vmax value towards MEHP without affecting the Km value. These results indicate that this residue may neutralize the negative charge of a carboxylate anion of MEHP, and thus inhibit the catalytic nucleophile from attacking the ester bond. In other words, the R residue blocks inhibition from the carboxylate anion of MEHP. Recently, registered hypothetical proteins exhibiting 98% or 99% identities for EG-5 MehpH or for P8219 MehpH were found from some pathogens belonging to Actinomycetes. The protein may have other activities besides MEHP hydrolysis and function in other physiological reactions in some Actinomycetes. PMID:26868518

  8. Mono-2-ethylhexyl phthalate induces oxidative stress responses in human placental cells in vitro

    SciTech Connect

    Tetz, Lauren M.; Cheng, Adrienne A.; Korte, Cassandra S.; Giese, Roger W.; Wang, Poguang; Harris, Craig; Meeker, John D.; Loch-Caruso, Rita

    2013-04-01

    Di-2-ethylhexyl phthalate (DEHP) is an environmental contaminant commonly used as a plasticizer in polyvinyl chloride products. Exposure to DEHP has been linked to adverse pregnancy outcomes in humans including preterm birth, low birth-weight, and pregnancy loss. Although oxidative stress is linked to the pathology of adverse pregnancy outcomes, effects of DEHP metabolites, including the active metabolite, mono-2-ethylhexyl phthalate (MEHP), on oxidative stress responses in placental cells have not been previously evaluated. The objective of the current study is to identify MEHP-stimulated oxidative stress responses in human placental cells. We treated a human placental cell line, HTR-8/SVneo, with MEHP and then measured reactive oxygen species (ROS) generation using the dichlorofluorescein assay, oxidized thymine with mass-spectrometry, redox-sensitive gene expression with qRT-PCR, and apoptosis using a luminescence assay for caspase 3/7 activity. Treatment of HTR-8 cells with 180 μM MEHP increased ROS generation, oxidative DNA damage, and caspase 3/7 activity, and resulted in differential expression of redox-sensitive genes. Notably, 90 and 180 μM MEHP significantly induced mRNA expression of prostaglandin-endoperoxide synthase 2 (PTGS2), an enzyme important for synthesis of prostaglandins implicated in initiation of labor. The results from the present study are the first to demonstrate that MEHP stimulates oxidative stress responses in placental cells. Furthermore, the MEHP concentrations used were within an order of magnitude of the highest concentrations measured previously in human umbilical cord or maternal serum. The findings from the current study warrant future mechanistic studies of oxidative stress, apoptosis, and prostaglandins as molecular mediators of DEHP/MEHP-associated adverse pregnancy outcomes. - Highlights: ► MEHP increased reactive oxygen species, oxidative DNA damage, and caspase activity. ► MEHP induced expression of PTGS2, a gene

  9. Associations between urinary metabolites of di(2-ethylhexyl) phthalate and reproductive hormones in fertile men

    PubMed Central

    Mendiola, J.; Jørgensen, N.; Andersson, A.-M.; Calafat, A. M.; Silva, M.J.; Redmon, J.B.; Sparks, A.; Drobnis, E.Z.; Wang, C.; Liu, F.; Swan, S.H.

    2012-01-01

    Summary Widely used man-made chemicals, including phthalates, can induce hormonal alterations through a variety of cellular and molecular mechanisms. A number of rodent and observational studies have consistently demonstrated the anti-androgenic effect of several phthalates. However, there are only limited data on the relationship between exposure to these chemicals and reproductive hormone levels in men. All men (n = 425) were partners of pregnant women who participated in the Study for Future Families in five US cities and provided urine and serum samples on the same day. Eleven phthalate metabolites were measured in urine and serum samples were analysed for reproductive hormones, including follicle-stimulating hormone, luteinizing hormone, testosterone, inhibin B and oestradiol and sex hormone-binding globulin (SHBG). Pearson correlations and parametric tests were used for unadjusted analyses, and multiple linear regression analysis was performed controlling for appropriate covariates. We observed weak or no associations with urinary phthalates other than di(2-ethylhexyl) phthalate (DEHP). All measures of testosterone [total, calculated free testosterone and the free androgen index (FAI)] were inversely correlated with the urinary concentrations of four DEHP metabolites. After adjustment by appropriate covariates, there was no longer an association between urinary DEHP metabolite concentrations and total testosterone levels; however, FAI was significantly associated with the urinary concentrations of several DEHP metabolites. SHBG was positively related to the urinary concentrations of mono(2-ethylhexyl) phthalate, but not with other DEHP metabolites, an association that was attenuated after adjustment. Our results suggest that DEHP exposure of fertile men is associated with minor alterations of markers of free testosterone. PMID:20633195

  10. URINARY AND AMNIOTIC FLUID LEVELS OF PHTHALATE MONOESTERS IN RATS AFTER THE ORAL ADMINISTRATION OF DI(2-ETHYLHEXYL) PHTHALATE AND DI-N-BUTYL PHTHALATE

    EPA Science Inventory

    Two studies were designed to examine amniotic fluid and maternal urine concentrations of the di(2-ethylhexyl) phthalate (DEHP) metabolite mono(2-ethylhexyl) phthalate (MEHP) and the di-n-butyl phthalate (DBP) metabolite monobutyl phthalate (MBP) after administration of DEHP and D...

  11. Achromobactor denitrificans SP1 produces pharmaceutically active 25C prodigiosin upon utilizing hazardous di(2-ethylhexyl)phthalate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Achromobacter denitrificans SP1 isolated from soil sludge heavily contaminated with plastic waste produced a novel pharmaceutically-active 25C prodigiosin analog during growth in a simple mineral salt medium supplemented with hazardous di(2-ethylhexyl)phthalate (DEHP) blended PVC plastics (in situ) ...

  12. Effective remediation of phenol,2,4-bis(1,1-dimethylethyl) and bis(2-ethylhexyl) phthalate in farm effluent using Guar gum--A plant based biopolymer.

    PubMed

    Kee, Yang Ling; Mukherjee, Sumona; Pariatamby, Agamuthu

    2015-10-01

    This study was carried out to evaluate the efficiency of Guar gum in removing Persistent Organic Pollutants (POPs), viz. phenol,2,4-bis(1,1-dimethylethyl) and bis(2-ethylhexyl) phthalate (DEHP), from farm effluent. The removal efficiency was compared with alum. The results indicated that 4.0 mg L(-1) of Guar gum at pH 7 could remove 99.70% and 99.99% of phenol,2,4-bis(1,1-dimethylethyl) and DEHP, respectively. Box Behnken design was used for optimization of the operating parameters for optimal POPs removal. Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) spectroscopy studies were conducted on the flocs. SEM micrographs showed numerous void spaces in the flocs produced by Guar gum as opposed to those produced by alum. This indicated why Guar gum was more effective in capturing and removal of suspended particles and POPs as compared to alum. FTIR spectra indicated a shift in the bonding of functional groups in the flocs produced by Guar gum as compared to raw Guar gum powder signifying chemical attachment of the organics present in the effluent to the coagulant resulting in their removal. Guar gum is highly recommended as a substitute to chemical coagulant in treating POPs due to its non-toxic and biodegradable characteristics. PMID:25966329

  13. Peroxisome proliferation due to di(2-ethylhexyl) phthalate (DEHP): species differences and possible mechanisms.

    PubMed Central

    Elcombe, C R; Mitchell, A M

    1986-01-01

    The exposure of cultured rat hepatocytes to mono(2-ethylhexyl)phthalate (MEHP) for 72 hr resulted in marked induction of peroxisomal enzyme activity (beta-oxidation; cyanide-insensitive palmitoyl CoA oxidase) and concomitant increases in the number of peroxisomes. Similar treatment of cultured guinea pig, marmoset, or human hepatocytes revealed little or no effect of MEHP. In order to eliminate possible confounding influences of biotransformation, the proximate peroxisome proliferator(s) derived from MEHP have been identified. Using cultured hepatocytes these agents were found to be metabolite VI [mono(2-ethyl-5-oxohexyl) phthalate] and metabolite IX [mono(2-ethyl-5-hydroxyhexyl) phthalate]. The addition of these "active" metabolites to cultured guinea pig, marmoset, or human hepatocytes again revealed little effect upon peroxisomes or related enzyme activities (peroxisomal beta-oxidation or microsomal lauric acid hydroxylation). These studies demonstrate a marked species difference in the response of hepatocytes to MEHP-elicited peroxisome proliferation. Preliminary studies have also suggested that peroxisome proliferation due to MEHP may be due to an initial biochemical lesion of fatty acid metabolism. Images FIGURE 4. a FIGURE 4. b PMID:3104023

  14. Prepubertal exposure to genistein alleviates di-(2-ethylhexyl) phthalate induced testicular oxidative stress in adult rats.

    PubMed

    Zhang, Lian-Dong; Li, He-Cheng; Chong, Tie; Gao, Ming; Yin, Jian; Fu, De-Lai; Deng, Qian; Wang, Zi-Ming

    2014-01-01

    Di-(2-ethylhexyl) phthalate (DEHP) is the most widely used plastizer in the world and can suppress testosterone production via activation of oxidative stress. Genistein (GEN) is one of the isoflavones ingredients exhibiting weak estrogenic and potentially antioxidative effects. However, study on reproductive effects following prepubertal multiple endocrine disrupters exposure has been lacking. In this study, DEHP and GEN were administrated to prepubertal male Sprague-Dawley rats by gavage from postnatal day 22 (PND22) to PND35 with vehicle control, GEN at 50 mg/kg body weight (bw)/day (G), DEHP at 50, 150, 450 mg/kg bw/day (D50, D150, D450) and their mixture (G + D50, G + D150, G + D450). On PND90, general morphometry (body weight, AGD, organ weight, and organ coefficient), testicular redox state, and testicular histology were studied. Our results indicated that DEHP could significantly decrease sex organs weight, organ coefficient, and testicular antioxidative ability, which largely depended on the dose of DEHP. However, coadministration of GEN could partially alleviate DEHP-induced reproductive injuries via enhancement of testicular antioxidative enzymes activities, which indicates that GEN has protective effects on DEHP-induced male reproductive system damage after prepubertal exposure and GEN may have promising future in its curative antioxidative role for reproductive disorders caused by other environmental endocrine disruptors. PMID:25530965

  15. Prepubertal Exposure to Genistein Alleviates Di-(2-ethylhexyl) Phthalate Induced Testicular Oxidative Stress in Adult Rats

    PubMed Central

    Zhang, Lian-Dong; Li, He-Cheng; Chong, Tie; Gao, Ming; Yin, Jian; Fu, De-Lai; Deng, Qian; Wang, Zi-Ming

    2014-01-01

    Di-(2-ethylhexyl) phthalate (DEHP) is the most widely used plastizer in the world and can suppress testosterone production via activation of oxidative stress. Genistein (GEN) is one of the isoflavones ingredients exhibiting weak estrogenic and potentially antioxidative effects. However, study on reproductive effects following prepubertal multiple endocrine disrupters exposure has been lacking. In this study, DEHP and GEN were administrated to prepubertal male Sprague-Dawley rats by gavage from postnatal day 22 (PND22) to PND35 with vehicle control, GEN at 50 mg/kg body weight (bw)/day (G), DEHP at 50, 150, 450 mg/kg bw/day (D50, D150, D450) and their mixture (G + D50, G + D150, G + D450). On PND90, general morphometry (body weight, AGD, organ weight, and organ coefficient), testicular redox state, and testicular histology were studied. Our results indicated that DEHP could significantly decrease sex organs weight, organ coefficient, and testicular antioxidative ability, which largely depended on the dose of DEHP. However, coadministration of GEN could partially alleviate DEHP-induced reproductive injuries via enhancement of testicular antioxidative enzymes activities, which indicates that GEN has protective effects on DEHP-induced male reproductive system damage after prepubertal exposure and GEN may have promising future in its curative antioxidative role for reproductive disorders caused by other environmental endocrine disruptors. PMID:25530965

  16. The therapeutic applications of celery oil seed extract on the plasticizer di(2-ethylhexyl) phthalate toxicity.

    PubMed

    El-Shinnawy, Nashwa A

    2015-04-01

    The present study investigated the impact of two doses, 500 mg/kg and 1000 mg/kg, of di(2-ethylhexyl) phthalate (DEHP) and studied the possible therapeutic dose of celery oil seed extract for 6 weeks on some atheroscelerogenic, obesogenic, antioxidant and liver functions in rats. Both doses of DEHP caused over-expression of peroxisome proliferator-activated receptor alpha (PPARα) messenger RNA with significant increase in liver weights, relative liver weights, serum cholesterol (Chol), triglycerides, low-density lipoprotein Chol, liver total lipids, along with an increase in the activities of serum aspartate aminotransferase, alanine aminotransferase, serum endothelin 1 and liver tissue thiobarbituric acid reactive substances (TBARS). Additionally, DEHP administration to rats resulted in significant decrease in final body weights, serum total protein, albumin, liver total protein and serum total nitric oxide. Our study confirmed the role of oral combination of Apium graveolens (celery) oil seed extract at small cumulative doses (50 µl/kg for 6 weeks) with DEHP in ameliorating the toxicological effects of DEHP, which was revealed in reducing the expression of PPARα, lipid profile, with restoring liver functions, vascular oxidative stress and inhibition of TBARS activity. PMID:23377116

  17. Effects of early pubertal exposure to di-(2-ethylhexyl) phthalate on social behavior of mice.

    PubMed

    Wang, Ran; Xu, Xiaohong; Weng, Huifang; Yan, Shengyao; Sun, Yangyang

    2016-04-01

    Di-(2-ethylhexyl) phthalate (DEHP), a main member of phthalates used as plasticizer in PVC plastics, is an environmental endocrine disrupter. The present study investigated the effect of DEHP on social behavior of mice following pubertal exposure (1, 10, 50, and 200mg/kg/d) from postnatal day 28 through postnatal day 42. The results showed that, in pubertal females, DEHP reduced the time spent in social play and social investigation and inhibited sociability, but a contrary effect was found in pubertal males, suggesting that the effect of DEHP on pubertal social behavior displays sex differences. In adults, DEHP reduced sociability in females and inhibited social play and social investigation in males, suggesting that early pubertal exposure to DEHP not only plays a significant role in puberty but also alters social behavior in adults. In addition, the present study showed that the higher dose of DEHP (50, 200mg/kg/d) reduced the relative weight of bilateral testis and anogenital distance of pubertal or adult males, suggesting an anti-androgenic activity of DEHP. These results suggest that early pubertal exposure to DEHP sex- and age- specifically affected the social behaviors of pubertal and even adult mice. PMID:26844866

  18. Effects of mono(2-ethylhexyl)phthalate on cytoplasmic maturation of oocytes--The bovine model.

    PubMed

    Kalo, D; Roth, Z

    2015-06-01

    Phthalates are known reproductive toxicants, but their intracellular disruptive effects on oocyte maturation competence are less known. We studied the potential risk associated with acute exposure of oocytes to mono(2-ethylhexyl)phthalate (MEHP). First, bovine oocytes were matured in vitro with or without 50 μM MEHP and examined for mitochondrial features associated with DNA fragmentation. MEHP increased reactive oxygen species levels and reduced the proportion of highly polarized mitochondria along with alterations in genes associated with mitochondrial oxidative phosphorylation (CYC1, MT-CO1 and ATP5B). In a second set of experiments, we associated the effects of MEHP on meiotic progression with those on cytoplasmic maturation. MEHP impaired reorganization of cytoplasmic organelles in matured oocytes reflected by reductions in category I mitochondria, type III cortical granules and class I endoplasmic reticulum. These alterations are associated with the previously reported reduced developmental competence of MEHP-treated bovine oocytes, and reveal the risk associated with acute exposure. PMID:25900598

  19. Immunotoxic effects of perfluorooctane sulfonate and di(2-ethylhexyl) phthalate on the marine fish Oryzias melastigma.

    PubMed

    Huang, Qiansheng; Chen, Yajie; Chi, Yulang; Lin, Yi; Zhang, Huanteng; Fang, Chao; Dong, Sijun

    2015-05-01

    Perfluorooctane sulfonate (PFOS) and di(2-ethylhexyl) phthalate (DEHP) have both been reported to induce adverse effects including immunotoxicity. Despite the widespread presence of these two chemicals in estuaries and seawater, their health effects on marine fish have received little attention. Oryzias melastigma is a potential marine fish model for immunological studies. In the present study, immune-related genes in O. melastigma were enriched at the transcriptome level. Three-month-old fish were exposed to PFOS and DEHP (single or combined) for one week. The liver index-hepatosomatic index (HSI) of the fish was higher in the PFOS-exposed group and combined group than in the control group. This result indicates that PFOS might lead to liver toxicity. The mRNA level of interleukin-1 beta (IL1β) was upregulated after exposure. For catalase (CAT), glutathione peroxidase (GPx) and cluster of differentiation 3 (CD3), single exposure did not affect mRNA levels, but the combined exposure did significantly alter the expression of these genes. In all, our study provides a useful reference for immunotoxicological studies with O. melastigma; it also highlights the importance of assessing the combined effects of pollutant mixtures when determining the risk to aquatic organisms. PMID:25687394

  20. Altered Hippocampal Lipid Profile Following Acute Postnatal Exposure to Di(2-Ethylhexyl) Phthalate in Rats.

    PubMed

    Smith, Catherine A; Farmer, Kyle; Lee, Hyunmin; Holahan, Matthew R; Smith, Jeffrey C

    2015-10-01

    Slight changes in the abundance of certain lipid species in the brain may drastically alter normal neurodevelopment via membrane stability, cell signalling, and cell survival. Previous findings have demonstrated that postnatal exposure to di (2-ethylhexyl) phthalate (DEHP) disrupts normal axonal and neural development in the hippocampus. The goal of the current study was to determine whether postnatal exposure to DEHP alters the lipid profile in the hippocampus during postnatal development. Systemic treatment with 10 mg/kg DEHP during postnatal development led to elevated levels of phosphatidylcholine and sphingomyelin in the hippocampus of female rats. There was no effect of DEHP exposure on the overall abundance of phosphatidylcholine or sphingomyelin in male rats or of lysophosphatidylcholine in male or female rats. Individual analyses of each identified lipid species revealed 10 phosphatidylcholine and six sphingomyelin lipids in DEHP-treated females and a single lysophosphatidylcholine in DEHP-treated males with a two-fold or higher increase in relative abundance. Our results are congruent with previous work that found that postnatal exposure to DEHP had a near-selective detrimental effect on hippocampal development in males but not females. Together, results suggest a neuroprotective effect of these elevated lipid species in females. PMID:26516880

  1. Di (2-ethylhexyl) phthalate exposure during pregnancy disturbs temporal sex determination regulation in mice offspring.

    PubMed

    Wang, Yongan; Liu, Wei; Yang, Qing; Yu, Mingxi; Zhang, Zhou

    2015-10-01

    Animal researches and clinical studies have supported the relevance between phthalates exposure and testicular dysgenesis syndrome (TDS). These disorders may comprise common origin in fetal life, especially during sex determination and differentiation, where the mechanism remains unclear. The present study evaluated the disturbances in gene regulatory networks of sex determination in fetal mouse by in utero Di (2-ethylhexyl) phthalate (DEHP) exposure. Temporal expression of key sex determination genes were examined during the critical narrow time window, using whole-mount in situ hybridization and quantitative-PCR. DEHP exposure resulted in significant reduction in mRNA of Sry during sex determination from gestation day (GD) 11.0 to 11.5 in male fetal mice, and the increasing of Sry expression to threshold level on GD 11.5 was delayed. Meanwhile, Gadd45g and Gata4, the upstream genes of Sry, and downstream gene Sox9 were also significantly downregulated in expression. In fetal females, the expression of Wnt4 and beta-catenin were up-regulated by DEHP exposure. Taken together, the results suggest that the potential mechanism of gonadal development disorder by DEHP may origin from repression of important male sex determination signaling pathway, involving Gadd45g → Gata4 → Sry → Sox9. The results would promote a better understanding of the association between phthalate esters (PAEs) exposure and the reductive disorder. PMID:26219507

  2. Maternal exposure to di-(2-ethylhexyl) phthalate disrupts placental growth and development in pregnant mice.

    PubMed

    Zong, Teng; Lai, Lidan; Hu, Jia; Guo, Meijun; Li, Mo; Zhang, Lu; Zhong, Chengxue; Yang, Bei; Wu, Lei; Zhang, Dalei; Tang, Min; Kuang, Haibin

    2015-10-30

    Di-(2-ethylhexyl) phthalate (DEHP) is used as a plasticizer and widely dispersed in the environment. DEHP exposure reduces embryo implantations, increases embryonic loss, and decreases fetal body weights. However, no detailed information is available about the effect of DEHP on the placentation during pregnancy. Thus, our aim was to explore the effect of DEHP on the growth and development of placenta in vivo. Mice were administered DEHP by gavages at 125, 250, 500 mg/kg/day from gestational days (GD) 1 until sacrifice. Results showed that DEHP treatment significantly reduced the weight of placenta at GD 13. Histopathologically, in DEHP-treated group, the ectoplacental cones significantly became smaller at GD9, and total area of placenta and area of spongiotrophoblast were significantly reduced at GD 13. Expression levels of Ascl2, Esx1 and Fosl1 mRNA dramatically decreased in DEHP-treated placenta at GD 13. DEHP administration disrupted labyrinth vascularization of placentas, and inhibited proliferation and induced apoptosis of placenta by the activation of caspase-3 and -8, up-regulation of Bax and down-regulation of Bcl-2 mRNA and protein at GD 13. In conclusion, these results suggest that adverse pregnancy outcomes including low birth-weight and pregnancy loss exposed to DEHP are possibly mediated, at least in part, via the suppression of placental growth and development. PMID:25935407

  3. Oxidative DNA damage induced by di-(2-ethylhexyl) phthalate in HEK-293 cell line.

    PubMed

    Wang, Xuan; Jiang, Lijie; Ge, Lan; Chen, Min; Yang, Guang; Ji, Fang; Zhong, Laifu; Guan, Yingjie; Liu, Xiaofang

    2015-05-01

    Di-(2-ethylhexyl) phthalate (DEHP) is commonly employed as a plasticizer. We have found that exposure of human embryonic kidney cell line 293 (HEK-293) to DEHP resulted in a crucial dose-dependent increase of DNA strand breaks in a comet assay. To elucidate the role of glutathione (GSH) in the DNA damage, the cells were pretreated with buthionine-(S,R)-sulfoximine (BSO) and pretreated with N-acetylcysteine (NAC), a GSH precursor. Here we show that depletion of GSH in HEK-293 cells with BSO dramatically increased the susceptibility of HEK-293 cells to DEHP-induced DNA damage. Furthermore, when the intracellular GSH content was elevated by NAC, the DNA damage induced by DEHP was almost completely abolished. In addition, DEHP had effect on lysosomal or mitochondrial damage at high dose level. These results indicate that DEHP exerts genotoxic effects in HEK-293 cells, probably through DNA damage induced by oxidative stress; GSH is responsible for cellular defense against DEHP-induced DNA damage; lysosome and mitochondria may be the vital targets in DEHP-induced DNA damage. PMID:25899473

  4. Di-(2-ethylhexyl)-phthalate induces oxidative stress in human endometrial stromal cells in vitro.

    PubMed

    Cho, Yeon Jean; Park, Seung Bin; Han, Myoungseok

    2015-05-15

    Di-(2-ethylhexyl)-phthalate (DEHP) accumulates in the environment, and its exposure is possibly associated with endocrine-related disease in women of reproductive age. The effects of DEHP on human endometrial cells are unknown. We treated human endometrial stromal cells with 10, 100, and 1000 pmol of DEHP and measured reactive oxygen species (ROS) generation, expression levels of antioxidant enzymes, alteration of MAPK/NF-κB signaling and hormonal receptors. DEHP increased reactive oxygen species (ROS) generation and decreased expression of superoxide dismutase (SOD), glutathione peroxidase (GPX), heme oxygenase (HO), and catalase (CAT). By DEHP exposure, p-ERK/p-p38 and NF-κB mediated transcription was increased. Additionally, DEHP induced estrogen receptor-α (ER-α) expression in a dose-dependent manner. This study shows the need for future mechanistic studies of oxidative stress, MAPK/NF-κB signaling, and ER-α as molecular mediators of DEHP-associated endometrial stromal cell alterations, which may be associated with the development of endocrine-related disease such as endometriosis. PMID:25766500

  5. Experimental density measurements of bis(2-ethylhexyl) phthalate at elevated temperatures and pressures

    SciTech Connect

    Bamgbade, Babatunde A; Wu, Yue; Baled, Hseen O; Enick, Robert M; Burgess, Ward A

    2013-08-01

    Experimental high-temperature, high-pressure (HTHP) density data for bis(2-ethylhexyl) phthalate (DEHP) are reported in this study. DEHP is a popular choice as a reference fluid for viscosity calibrations in the HTHP region. However, reliable HTHP density values are needed for accurate viscosity calculations for certain viscometers (e.g. rolling ball). HTHP densities are determined at T = (373, 424, 476, 492, and 524) K and P to 270 MPa using a variable-volume, high-pressure view cell. The experimental density data are satisfactorily correlated by the modified Tait equation with a mean absolute percent deviation (δ) of 0.15. The experimental data are modeled with the Peng–Robinson (PREoS), volume-translated PREoS (VT-PREoS), and perturbed chain statistical associating fluid theory (PC-SAFT EoS) models. The required parameters for the two PREoS and the PC-SAFT EoS models are determined using group contribution methods. The PC-SAFT EoS performs the best of the three models with a δ of 2.12. The PC-SAFT EoS is also fit to the experimental data to obtain a new set of pure component parameters that yield a δ of 0.20 for these HTHP conditions.

  6. Effects of airway exposure to di-(2-ethylhexyl) phthalate on allergic rhinitis.

    PubMed

    He, Miao; Inoue, Ken-Ichiro; Yoshida, Seiichi; Tanaka, Michitaka; Takano, Hirohisa; Sun, Guifan; Ichinose, Takamichi

    2013-06-01

    Recent epidemiological studies have suggested a positive link between atopy morbidity and exposure to phthalate esters, which are environmental chemicals mainly involved in house dust. Nevertheless, experimental studies applying several allergic in vivo models (in addition to epidemiological studies) are needed to prove the precise correlation between phthalates and facilitation of the allergic response/pathophysiology. Among the phthalate esters, di-(2-ethylhexyl) phthalate (DEHP) has been widely used in flexible polyvinyl chloride products, including vinyl flooring and wall covering, and has been widely suggested to have immunomodulating potential. In the present study, we examined the effects of airway exposure to DEHP on allergen (ovalbumin: OVA)-induced rhinitis in mice. The repeated administration of OVA via an intranasal route induced nasal inflammation characterized by the infiltration of granulocytes (neutrophils and eosinophils) into the nasal cavity. In this experimental setting, DEHP did not exaggerate OVA-related inflammatory pathology. However, local (nasal) IL-13 levels were significantly higher in mice treated with allergen plus DEHP than with allergen alone. Taken together, phthalate esters including DEHP have the potential to exacerbate the allergic milieu in the nasal system, as well as dermal and respiratory systems. PMID:23672524

  7. In vivo immunoamplifying effects of di-(2-ethylhexyl) phthalate on cytokine response.

    PubMed

    Tanaka, Michitaka; Inoue, Ken-ichiro; Momoi, Takashi; Takano, Hirohisa

    2013-02-01

    A recent epidemiological study has revealed the positive association between atopy morbidity in children and phthalate esters, environmental chemicals in house dust. Nonetheless, experimental and molecular evidences regarding the correlation between phthalates and allergic response/pathophysiology are not fully investigated. Among phthalate esters, di-(2-ethylhexyl) phthalate (DEHP) has been widely used for flexible polyvinyl chloride products including vinyl flooring and wall covering. In the present study, we examined the effects of exposure to DEHP on allergen (ovalbumin: OVA) -induced peritonitis in ICR mice. Repeated administration of OVA via intraperitoneal route induced peritoneal inflammation characterized by infiltration of granulocytes (neutrophils and eosinophils) into the cavity. DEHP synergistically exaggerated the OVA-related neutrophilic inflammation. Furthermore, DEHP + OVA profoundly amplified OVA-elicited inflammation- and allergy-related molecules such as interleukin-5, eotaxin, and keratinocyte-derived chemoattractant production/release in the peritoneal cavity. Taken together, DEHP aggravated OVA-related peritoneal inflammation, which is concomitant with local enhanced production/release of inflammation- and allergy-related molecules. PMID:23098214

  8. Effect of Di(2-ethylhexyl)phthalate on Helicobacter pylori-Induced Apoptosis in AGS Cells

    PubMed Central

    Wu, Chien-Yi; Kou, Hwang-Shang; Chen, Chiao-Yun; Huang, Meng-Chuan; Hu, Huang-Ming; Wu, Meng-Chieh; Lu, Chien-Yu; Wu, Deng-Chyang; Wu, Ming-Tsang; Kuo, Fu-Chen

    2013-01-01

    Plastic products are wildly used in human life. Di(2-ethylhexyl)phthalate (DEHP) is an essential additive in plastic manufacturing and is used as plasticizer for many products including plastic food packaging. DEHP is a teratogenic compound and can cause potent reproductive toxicity. DEHP can also cause liver damage, peroxisome proliferation, and carcinogenesis. DEHP is also strongly associated with peptic ulcers and gastric cancer; however, the underlying effect and mechanism of DEHP on the gastrointestinal tract are not entirely clear. The oral infection route of H. pylori parallels the major ingestion route of DEHP into the human body. Therefore, we wanted to study the effect of DEHP and H. pylori exposure on the human gastric epithelial cell line, AGS (gastric adenocarcinoma). The viability of the AGS cell line was significantly lower in 80 μM-DEHP and H. pylori (MOI = 100 : 1) coexposure than DEHP or H. pylori alone. DEHP and H. pylori coexposure also induced caspase-3 activation, and increased Bax/Bcl-2 ratio and DNA fragmentation in AGS cells. These results indicate that DEHP can enhance H. pylori cytotoxicity and induce gastric epithelial cell apoptosis. Therefore, it is possible that DEHP and H. pylori coexposure might enhance the disruption of the gastric mucosa integrity and potentially promote the pathogenesis of gastric carcinogenesis. PMID:24454344

  9. Phase behavior of AOT microemulsions in compressible liquids. [AOT = bis(2-ethylhexyl) sodium sulfosuccinate

    SciTech Connect

    McFann, G.J.; Johnston, K.P. )

    1991-06-13

    The phase behavior of bis(2-ethylhexyl) sodium sulfosuccinate (AOT)-alkane-brine systems is described over a wide range of pressure, temperature, and salinity for alkanes from ethane to dodecane. The partitioning of AOT between the oil, middle, and brine phases is reported for propane in order to determine the natural curvature. This is important for understanding separation processes with water-in-oil microemulsions. For the lighter, more compressible alkanes, the pressure effect on the hydrophilicity of the surfactant is much larger and in the opposite direction as for the heavier, less compressible ones. In propane at constant temperature and salinity, water-in-oil (w/o) microemulsions have been converted to middle phase microemulsions and then to oil-in-water (o/w) microemulsions by decreasing the pressure. These phase inversions are described in terms of the immiscibilities in the binary systems, and the molecular interactions at the surfactant interface. Although temperature and salinity are used commonly to manipulate interactions primarily on the water side of the interface, these results show it is possible to control interactions on the oil side by adjusting the pressure. The well-established trends in the phase behavior and size of microemulsion drops for dodecane through hexane are not observed for the lighter alkanes. For butane through ethane, a new unusual behavior is identified and attributed to a significant decrease in the strength of the attractive interactions between the surfactant tails and the alkane.

  10. Physicochemical investigation of acrylamide solubilization in sodium bis(2-ethylhexyl)sulfosuccinate and lecithin reversed micelles.

    PubMed

    Calandra, P; Giordano, C; Ruggirello, A; Turco Liveri, V

    2004-09-01

    The state of acrylamide confined within dry sodium bis(2-ethylhexyl)sulfosuccinate (AOT) and lecithin reversed micelles dispersed in CCl(4) has been investigated by FTIR and (1)H NMR spectroscopy. Measurements have been performed at 25 degrees C as a function of the acrylamide-to-surfactant molar ratio (R) at a fixed surfactant concentration (0.1 mol kg(-1)). The analysis of experimental data, corroborated by the results of SAXS measurements, is consistent with the hypothesis that acrylamide is quite uniformly distributed among reversed micelles mainly located in proximity to the surfactant head-group region and that its presence induces significant unidimensional growth of micellar aggregates. Moreover, the confinement of acrylamide within reversed micelles involves some changes of the typical H-bonded structure of pure solid acrylamide attributable to the establishment of system-specific acrylamide/surfactant head group interactions. Preliminary experiments showed that, by exposure to X-rays, the polymerization of acrylamide can be induced in the confined space of dry AOT and lecithin reversed micelles. PMID:15276058

  11. Reverse micellar extraction and precipitation of lysozyme using sodium di(2-ethylhexyl) sulfosuccinate.

    PubMed

    Shin, Youn-Ok; Weber, Martin E; Vera, Juan H

    2003-01-01

    Sodium di(2-ethylhexyl) sulfosuccinate, referred to as Aerosol-OT or AOT, was used to remove lysozyme from an aqueous phase via reverse micellar extraction and precipitation method. For both methods, when the surfactant was in excess, a complete removal of lysozyme from the aqueous phase was obtained at the values of pH below the pI of lysozyme. However, for the reverse micellar method, a solubilization limit of lysozyme in the organic phase was observed, and a white precipitate was formed at the aqueous-organic interface. This observation suggested using AOT directly as a precipitating ligand. The lysozyme precipitated with AOT was fully recovered, with its original enzymatic activity, using acetone as a recovery solvent. A mechanism is suggested to explain the solubilization of lysozyme in an AOT reverse micellar system. It is shown that a direct precipitation method can be used with advantage instead of using the reverse micellar extraction method to recover lysozyme from an aqueous phase. PMID:12790659

  12. Clinically relevant concentrations of di (2-ethylhexyl) phthalate (DEHP) uncouple cardiac syncytium

    SciTech Connect

    Gillum, Nikki; Karabekian, Zaruhi; Swift, Luther M.; Brown, Ronald P.; Kay, Matthew W.; Sarvazyan, Narine

    2009-04-01

    Di(2-ethylhexyl) phthalate (DEHP) is a widely used plasticizer found in a variety of polyvinyl chloride (PVC) medical products. The results of studies in experimental animals suggest that DEHP leached from flexible PVC tubing may cause health problems in some patient populations. While the cancerogenic and reproductive effects of DEHP are well recognized, little is known about the potential adverse impact of phthalates on the heart. This study examined the effects of clinically relevant concentrations of DEHP on neonatal rat cardiomyocytes. It was found that application of DEHP to a confluent, synchronously beating cardiac cell network, leads to a marked, concentration-dependent decrease in conduction velocity and asynchronous cell beating. The mechanism behind these changes was a loss of gap junctional connexin-43, documented using Western blot analysis, dye-transfer assay and immunofluorescence. In addition to its effect on electrical coupling, DEHP treatment also affected the mechanical movement of myocyte layers. The latter was linked to the decreased stiffness of the underlying fibroblasts, as the amount of triton-insoluble vimentin was significantly decreased in DEHP-treated samples. The data indicate that DEHP, in clinically relevant concentrations, can impair the electrical and mechanical behavior of a cardiac cell network. Applicability of these findings to human patients remains to be established.

  13. Altered Hippocampal Lipid Profile Following Acute Postnatal Exposure to Di(2-Ethylhexyl) Phthalate in Rats

    PubMed Central

    Smith, Catherine A.; Farmer, Kyle; Lee, Hyunmin; Holahan, Matthew R.; Smith, Jeffrey C.

    2015-01-01

    Slight changes in the abundance of certain lipid species in the brain may drastically alter normal neurodevelopment via membrane stability, cell signalling, and cell survival. Previous findings have demonstrated that postnatal exposure to di (2-ethylhexyl) phthalate (DEHP) disrupts normal axonal and neural development in the hippocampus. The goal of the current study was to determine whether postnatal exposure to DEHP alters the lipid profile in the hippocampus during postnatal development. Systemic treatment with 10 mg/kg DEHP during postnatal development led to elevated levels of phosphatidylcholine and sphingomyelin in the hippocampus of female rats. There was no effect of DEHP exposure on the overall abundance of phosphatidylcholine or sphingomyelin in male rats or of lysophosphatidylcholine in male or female rats. Individual analyses of each identified lipid species revealed 10 phosphatidylcholine and six sphingomyelin lipids in DEHP-treated females and a single lysophosphatidylcholine in DEHP-treated males with a two-fold or higher increase in relative abundance. Our results are congruent with previous work that found that postnatal exposure to DEHP had a near-selective detrimental effect on hippocampal development in males but not females. Together, results suggest a neuroprotective effect of these elevated lipid species in females. PMID:26516880

  14. Solvent extraction of holmium and yttrium with bis(2-ethylhexyl)phosphoric acid

    SciTech Connect

    Yoshizuka, K.; Sakamoto, Y.; Baba, Y.; Inoue, K. ); Nakashio, F. )

    1992-05-01

    This paper discusses a kinetic study on the solvent extraction of holmium(III) and yttrium(III) with bis(2-ethylhexyl) phosphoric acid (D2EHPA) from nitrate media conducted at 303 K using a hollow fiber membrane extractor. Also studied were the distribution equilibria of these metals and interfacial adsorption equilibria of D2EHPA and its metal complexes between the organic and aqueous phases. It was found that the metals (M{sup 3+}) were extracted with D2EHPA (HR) ad MR{sub 3} {center dot} 3HR into the organic phase, and the extraction equilibrium constants were evaluated. Furthermore, it was established that dimeric D2EHPA can be adsorbed at the interface between the organic and aqueous phases, while the interfacial activities of D2EHPA-metal complexes were negligibly small. The apparent orders 2, 1, and 2 of the permeabilities for the extraction of both metals were found with respect to the pH of the aqueous solution and the concentrations of the metal ion and dimeric D2EHPA, while the orders 1, 1, and {minus}1 of the permeabilities for the stripping of both metals were found with respect to the hydrogen ion activity and the concentrations of the metal complex and dimeric D2EHPA, respectively. The diffusional effects were reasonably explained by the diffusion model accompanied by an interfacial reaction, taking into account the velocity distributions of the aqueous and organic phases through the inner and outer sides of a hollow fiber.

  15. Effect of Di(2-ethylhexyl)phthalate on Helicobacter pylori-Induced Apoptosis in AGS Cells.

    PubMed

    Lin, Chuang-Hao; Wu, Chien-Yi; Kou, Hwang-Shang; Chen, Chiao-Yun; Huang, Meng-Chuan; Hu, Huang-Ming; Wu, Meng-Chieh; Lu, Chien-Yu; Wu, Deng-Chyang; Wu, Ming-Tsang; Kuo, Fu-Chen

    2013-01-01

    Plastic products are wildly used in human life. Di(2-ethylhexyl)phthalate (DEHP) is an essential additive in plastic manufacturing and is used as plasticizer for many products including plastic food packaging. DEHP is a teratogenic compound and can cause potent reproductive toxicity. DEHP can also cause liver damage, peroxisome proliferation, and carcinogenesis. DEHP is also strongly associated with peptic ulcers and gastric cancer; however, the underlying effect and mechanism of DEHP on the gastrointestinal tract are not entirely clear. The oral infection route of H. pylori parallels the major ingestion route of DEHP into the human body. Therefore, we wanted to study the effect of DEHP and H. pylori exposure on the human gastric epithelial cell line, AGS (gastric adenocarcinoma). The viability of the AGS cell line was significantly lower in 80  μ M-DEHP and H. pylori (MOI = 100 : 1) coexposure than DEHP or H. pylori alone. DEHP and H. pylori coexposure also induced caspase-3 activation, and increased Bax/Bcl-2 ratio and DNA fragmentation in AGS cells. These results indicate that DEHP can enhance H. pylori cytotoxicity and induce gastric epithelial cell apoptosis. Therefore, it is possible that DEHP and H. pylori coexposure might enhance the disruption of the gastric mucosa integrity and potentially promote the pathogenesis of gastric carcinogenesis. PMID:24454344

  16. Antifertility and mutagenic effects in mice from parenteral administration of di-2-ethylhexyl phthalate (DEHP)

    SciTech Connect

    Agarwal, D.K.; Lawrence, W.H.; Autian, J.

    1985-01-01

    The subcutaneous administration of 1-10 mg of undiluted di-(2-ethylhexyl)phthalate (DEHP) to adult male ICR mice on d 1, 5, and 10 was followed by mating, one to one, with untreated adult virgin females. A single mating at d 21 resulted in a reduction in the incidence of pregnancies in the DEHP-treated groups. On the other hand, repeated matings with fresh females starting on d 2, 6, 11, 16, and 21, and at weekly intervals through 8 wk, revealed no perceptible effect of DEHP on the incidence of pregnancy. Examination of surgically exposed uteri and ovaries of pregnant females on d 13 of gestation revealed an increase in the incidence of preimplantation losses and early fetal deaths in the DEHP-treated groups; consequently, there were fewer viable fetuses per pregnancy. Mutagenic indices for DEHP, calculated as percent ratios of (1) preimplantation losses/implantations per pregnancy and (2) early fetal deaths/implantations per pregnancy, suggested a dominant lethal mutation effect in the treated mice. These effects tend to be more pronounced on the postmiotic stage of germ-cell development.

  17. Health hazard assessment of occupationally di-(2-ethylhexyl)-phthalate-exposed workers in China.

    PubMed

    Wang, Wenxin; Xu, Xiaobing; Fan, Chinbay Q

    2015-02-01

    Di-(2-ethylhexyl)-phthalate (DEHP) is a potential hazard to human health. The effects of occupational high level DEHP exposure on human health were evaluated by measuring the plasma cholinesterase, residues, renal and hepatic biochemical markers. The study was conducted in three representative polyvinyl chloride manufacturing facilities from large size (S1), medium side (S2) to small size (S3). Total 456 adult males including 352 exposed workers (occupational) and 104 control workers (background) were selected. The average DEHP concentrations in respirable particulate matter were 233, 291, and 707 μg m(-3) for S1-S3, respectively, compared with 0.26 μg m(-3) in the background atmosphere (labeled by S4). The results showed significant decreases in post exposure plasma cholinesterase (PChE) levels (<30%) from the exposed workers as compared to baseline. These exposed workers had been evaluated for plasma DEHP residues. Regression analyses explored that PChE decreased significantly with increasing plasma DEHP residues. Serum aspartate aminotransferase, alanine aminotransferase, creatinine, urea, gamma glutamyltransferase, malondialdehyde, total antioxidant and C-reactive protein were significantly raised as compared to the controls. Of the 352 exposed workers, 116 (33.0%) had a daily DEHP intake 22.7 μg kg bw(-1)d(-1) , which is more than 20 μg kg bw(-1)d(-1) specified by the US Environmental Protection Agency. The study demonstrated that occupational phthalate exposure produces health hazards. PMID:24974312

  18. Structure and growth of bis(2-ethylhexyl) sulfosuccinate micelles in aqueous solutions

    SciTech Connect

    Sheu, E.Y.; Chen, S.; Huang, J.S.

    1987-06-04

    The structure and growth of micelles formed by anionic surfactant sodium bis(2-ethylhexyl) sulfosuccinate (AOT) in aqueous solutions have been studied by small angle neutron scattering (SANS). They used the contrast variation technique to determine the aggregation number, the effective charge, and two molecular parameters of the micelles in solutions of 0.8 g/dL surfactant concentration. They then used these two molecular parameters to analyze micellar solutions at other concentrations. Two micellar parameters, the mean aggregation number n and the effective charge z0, have been extracted from experimental data for solutions with surfactant concentrations ranging from 0.2 to 1.0 g/dL. The minimum micellar aggregation number is predicted to be 15 at the critical micellar concentration (cmc) and the structure is a compact spherical aggregate having well-defined hydrophobic and hydrophilic regions. The micelles grow moderately as the surfactant concentration increases, transforming from a spherical to an oblate spheroidal shape in a manner describable by the ladder model.

  19. Surface properties and conductivity of bis(2-ethylhexyl) sulfosuccinate-containing polypyrrole

    NASA Astrophysics Data System (ADS)

    Boukerma, Kada; Omastová, Mária; Fedorko, Pavol; Chehimi, Mohamed M.

    2005-08-01

    Polypyrrole (PPy) was chemically synthesized by oxidative polymerization of pyrrole in aqueous solution containing an oxidant, ferric chloride, and an anionic surfactant, sodium bis(2-ethylhexyl) sulfosuccinate (AOT). The results of elemental analysis confirmed that the surfactant is incorporated into the PPy structure. The presence of the anionic surfactant AOT in polymerization mixture influences the properties of chemically prepared polypyrrole due to bonding the anionic part of the surfactant molecule to the PPy chains as proved by X-ray photoelectron spectroscopy (XPS) analysis. Scanning electron microscopy study showed that the presence of the AOT affects the morphology of the product. A more compact powder morphology and reduced size of the PPy globules were revealed. The addition of AOT to the reaction mixture results in a significantly increased conductivity: PPy synthesized in polymerization solution containing molar ratio [pyrrole]/[AOT] = 7 reached conductivity as high as 27 S cm -1, while the same experiment performed in the absence of AOT yielded a polymer with conductivity of 3.9 S cm -1 only.

  20. Teratogenicity of di(2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DBP) in mice.

    PubMed Central

    Shiota, K; Nishimura, H

    1982-01-01

    Di(2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DBP) were mixed with diet at graded levels of 0.05, 0.1, 0.2. 0.4 and 1.0 wt-% and given to pregnant ICR mice throughout gestation. Maternal weight gain was suppressed and fetal resorption increased at 0.2, 0.4 and 1.0% levels of DEHP and 1.0% level of DBP. All the implanted ova died early in rats fed 0.4 and 1.0% levels of DEHP. External malformations increased significantly by 0.2% DEHP, and 1.0% DBP showed borderline significance. The major malformations in treated groups were neural tube defects (exencephaly and myeloschisis), suggesting that the phthalic acid esters (PAEs) affect neural tube closure in developing embryos. Treatment with the compounds caused intrauterine growth retardation and delayed ossification with an apparently dose-related response pattern. These results indicate that a high dose of DEHP and DBP might be embryotoxic and teratogenic in mice. The maximum nonembryotoxic doses of PAEs in mice were more than 2000 times the estimated level of human intake through the food chain. Thus it is assumed that the current "normal" exposure level of PAEs dose not pose an imminent threat to human fetal development. PMID:7140698

  1. Mono-2-ethylhexyl phthalate disrupts neurulation and modifies the embryonic redox environment and gene expression.

    PubMed

    Sant, Karilyn E; Dolinoy, Dana C; Jilek, Joseph L; Sartor, Maureen A; Harris, Craig

    2016-08-01

    Mono-2-ethylhexl phthalate (MEHP) is the primary metabolite of di-2-ethylhexyl phthalate (DEHP), a ubiquitous contaminant in plastics. This study sought to determine how structural defects caused by MEHP in mouse whole embryo culture were related to temporal and spatial patterns of redox state and gene expression. MEHP reduced morphology scores along with increased incidence of neural tube defects. Glutathione (GSH) and cysteine (Cys) concentrations fluctuated spatially and temporally in embryo (EMB) and visceral yolk sac (VYS) across the 24h culture. Redox potentials (Eh) for GSSG/GSH were increased by MEHP in EMB (12h) but not in VYS. CySS/CyS Eh in EMB and VYS were significantly increased at 3h and 24h, respectively. Gene expression at 6h showed that MEHP induced selective alterations in EMB and VYS for oxidative phosphorylation and energy metabolism pathways. Overall, MEHP affects neurulation, alters Eh, and spatially alters the expression of metabolic genes in the early organogenesis-stage mouse conceptus. PMID:27167697

  2. Highly Efficient Synthesis of an Emerging Lipophilic Antioxidant: 2-Ethylhexyl Ferulate.

    PubMed

    Huang, Kuo-Chuan; Li, Ying; Kuo, Chia-Hung; Twu, Yawo-Kuo; Shieh, Chwen-Jen

    2016-01-01

    Ferulic acid in ester form has shown a stronger ability in ameliorating certain pathological conditions and inhibiting lipid oxidation. In present study, a solvent-free and reduced pressure evaporation system was developed for lipase-catalyzed synthesis of 2-ethylhexyl ferulate (2-EF) from ferulic acid and 2-ethylhexanol. A Box-Behnken design with response surface methodology (RSM) and artificial neural network (ANN) was selected to model and optimize the process. Based on the yields of 2-EF, reaction temperature was shown to be the most important process factor on the molar conversion among all variables. The residual values and the coefficient of determination (R²) calculated from the design data indicated that ANN was better than RSM in data fitting. Overall, the present lipase-catalyzed approach for 2-EF synthesis at low reaction temperature in a reduced pressure evaporation system shows high 2-EF production efficiency. Notably, this approach can reduce the enzyme denaturation and ferulic acid oxidation that usually occur during long-term biosynthetic operations at high temperature. PMID:27077838

  3. Molecular dynamics of electrosprayed water nanodroplets containing sodium bis(2-ethylhexyl)sulfosuccinate.

    PubMed

    Longhi, Giovanna; Ceselli, Alberto; Fornili, Sandro L; Abbate, Sergio; Ceraulo, Leopoldo; Liveri, Vincenzo Turco

    2013-04-01

    The behavior of aqueous solutions of sodium bis(2-ethylhexyl)sulfosuccinate (AOTNa) subject to electrospray ionization (ESI) has been investigated by molecular dynamics (MD) simulations at three temperatures (350, 500 and 800 K). We consider several types of water nanodroplets containing AOTNa molecules and composed of a fixed number of water molecules (1000), N(AOT)(0) AOT(-) anions (N(AOT)(0) =  0, 5, 10) and N(Na)(0) sodium ions (N(Na)(0) =  0, 5, 10, 15, 20): in a short time scale (less than 1 ns), the AOTNa molecules, initially forming direct micelles in the interior of the water nanodroplets, are observed in all cases to diffuse nearby the nanodroplet surface, so that the hydrophilic heads and sodium ions become surrounded by water molecules, whereas the alkyl chains lay at the droplet surface. Meanwhile, evaporation of water molecules and of solvated sodium ions occurs, leading to a decrease of the droplet size and charge. At 350 K, no ejection of neutral or charged surfactant molecules is observed, whereas at 500 K, some fragmentation occurs, and at 800 K, this event becomes more frequent. The interplay of all these processes, which depend on the values of temperature, N(AOT)(0) and N(Na)(0) eventually leads to anhydrous charged surfactant aggregates with prevalence of monocharged ones, in agreement with experimental results of ESI mass spectrometry. The quantitative analysis of the MD trajectories allows to evidence molecular details potentially useful in designing future ESI experimental conditions. PMID:23584941

  4. Developmental changes in the conversion rates of di(2-ethylhexyl)phthalate to monoethylhexyl phthalate in rats

    SciTech Connect

    Gollamudi, R.; Hanumantha, R.; Lawrence, W.H.; Autian, J.

    1985-01-01

    The activities of liver, lung, and kidney of rats of various age groups and that of placenta in hydrolyzing di(2-ethylhexyl) phthalate to mono(2-ethylhexyl) phthalate have been measured. Male and female rats of 45 d of age, neonatal rats within 12 h of parturition, and fetuses and placenta on d 19 of gestation were used. The liver was most active in all age groups; however, the lung and the kidney also had considerable activity. The tissues of the fetuses and the neonate had significant activity. The k/sub m/ values of the enzyme were 4mM in the neonatal liver and 5.9 mM in the adult liver.

  5. Performance of electrochemical oxidation process for removal of di (2-ethylhexyl) phthalate.

    PubMed

    Espinoza, Josué Daniel García; Drogui, Patrick; Zolfaghari, Mehdi; Dirany, Ahmad; Ledesma, Maria Teresa Orta; Gortáres-Moroyoqui, Pablo; Buelna, Gerardo

    2016-06-01

    Di (2-ethylhexyl) phthalate (DEHP) is the most detected and concentrated plasticizer in environment and wastewaters, worldwide. In this study, different operating parameters such as current intensity, treatment time, type of anodes, and supporting electrolytes were tested to optimized the electro-oxidation process (EOP) for the removal of DEHP in the presence of methanol as a dissolved organic matter. Among the anodes, the Nb/BDD showed the best degradation rate of DEHP, at low current intensity of 0.2 A after 90 min of treatment time with a percentage of degradation recorded of 81 %, compared to 70 % obtained with the Ti/IrO2-RuO2. Furthermore, due to the combination of direct and indirect oxidation, the removal of DEHP in the presence of 1 g/L Na2SO4 was higher than NaBr, even though the oxidant production of NaBr was 11.7 mmol/L against 3.5 mmol/L recorded in the presence of sulfate at 0.5 A and after 60 min of electrolysis time. Under optimal condition (current intensity = 0.5 A, time = 120 min, using Nb/BDD anode and Na2SO4 as supporting electrolyte), the removal of 87.2 % of DEHP was achieved. The total cost of 0.106 US$/m(3) of treated water was achieved based on economical optimization of reactor with current intensity of 0.2 A and 1 g/L Na2SO4. PMID:26971515

  6. Transgenerational Effects of Di-(2-Ethylhexyl) Phthalate (DEHP) on Stress Hormones and Behavior.

    PubMed

    Quinnies, Kayla M; Doyle, Timothy J; Kim, Kwan Hee; Rissman, Emilie F

    2015-09-01

    Exposure to di-(2-ethylhexyl) phthalate (DEHP) has been linked to male reproductive abnormalities. Here, we assessed transgenerational actions of DEHP on several behaviors and stress responses. We used 2 doses of DEHP (150- and 200-mg/kg body weight) and a treatment regimen previously shown to produce transgenerational effects on male reproduction. Mice, 3 generations removed from DEHP exposure (F3), were tested for social behavior and anxiety on the elevated plus maze. We collected blood and pituitaries from undisturbed and restrained mice. Body weights, anogenital distances, and reproductive organ weights were collected at killing. In social interaction tests juvenile males from the DEHP lineage (200 mg/kg) displayed more digging and less self-grooming than did controls. Interestingly, 150-mg/kg lineage males, killed in early puberty, had smaller seminal vesicle weights than their controls. However, the 200-mg/kg males (killed on average 10 d later) did not show this effect. Females from a DEHP lineage had lower corticosterone concentrations than controls after restraint stress. We also found sex- and DEHP-specific mRNA expression changes in the pituitary in 2 of the 6 stress-related genes we measured. In particular, Gnas mRNA was elevated by the combination of DEHP lineage and stress. Thus, transgenerational effects of DEHP are noted in male behavior, and in females, DEHP had transgenerational effects on levels of corticosterone. Both of these results may be related to transgenerational modifications in the expression of several pituitary hormones involved in the hypothalamic-pituitary-adrenal axis. PMID:26168342

  7. Perinatal exposure to di-(2-ethylhexyl) phthalate affects anxiety- and depression-like behaviors in mice.

    PubMed

    Xu, Xiaohong; Yang, Yanling; Wang, Ran; Wang, Yu; Ruan, Qin; Lu, Yang

    2015-04-01

    Di-(2-ethylhexyl) phthalate (DEHP) is an environmental endocrine disrupter. The present study investigated the effect of DEHP on emotional behavior of mice following perinatal exposure (10, 50, and 200 mg kg(-1) d(-1)) from gestation day 7 through postnatal day 21. The results showed that, in pubertal males (6-w-old), DEHP decreased the time spent in the open arms and the number of entries into them in elevated plus maze and decreased the time in the mirrored chamber and in the light-box; in pubertal females, DEHP decreased the time spent in the open arms and the number of entries into them, suggesting that DEHP exposure made a anxiogenic effect in pubertal offspring regardless of sex. While DEHP effect on anxiety of adult (12-w-old) displayed sex differences, with decreased time spent in the open arms in the adult females. Perinatal exposure to DEPH significantly extended the time of immobility in forced swim task of pubertal offspring and adulthood regardless of sex. Furthermore, DEHP down-regulated the expressions of androgen receptor (AR) in pubertal male hippocampus and of estrogen receptor (ER) β in pubertal female and adult hippocampus of both sexes and inhibited the phosphorylation of ERK1/2 of hippocampus in pubertal mice and adult males. These results suggest that exposure to DEHP early in life affected the anxiety- and depressive-like behaviors of pubertal offspring and even adult. The disruption of gonadal hormones' modulation of behaviors due to down-regulation of AR or ERβ in the hippocampus may be associated with the aggravated anxiety- and depression-like status induced by DEHP. PMID:25441928

  8. Kinetics of di-(2-ethylhexyl)phthalate mineralization in sludge-amended soil

    SciTech Connect

    Madsen, P.L.; Thyme, J.B.; Henriksen, K.; Moeldrup, P.; Roslev, P. . Environmental Engineering Lab.)

    1999-08-01

    Sewage sludge is frequently used as a soil fertilizer although it may contain elevated concentrations of priority pollutants including di-(2-ethylhexyl)phthalate (DEHP). In the present study, the kinetics of microbial [[sup 14]C]DEHP mineralization was studied in laboratory microcosms with sewage sludge and agricultural soil. A biphasic model with two independent kinetic expressions was used to fit the mineralization data. The initial mineralization activity was described well by first-order kinetics, whereas mineralization in long-term incubations was described better by fractional power kinetics. The mineralization activity was much lower in the late phase presumably due to a decline in the bioavailability of DEHP caused by diffusion-limited desorption. The initial DEHP mineralization rate in sludge-amended soil varied between 3.7 and 20.3 ng of DEHP (g dw)[sup [minus]1]d[sup [minus]1] depending on incubation conditions. Aerobic DEHP mineralization was 4--5 times faster than anaerobic mineralization, DEHP mineralization in sludge-amended soil was much more temperature sensitive than was DEHP mineralization in soil without sludge. Indigenous microorganisms in the sewage sludge appeared to dominate DEHP degradation in sludge-amended soil. It was estimated that > 41% of the DEHP in sludge-amended soil will have escaped mineralization after 1 year. In the absence of oxygen, > 68% of the DEHP will not be mineralized within 1 year. Collectively, the data suggest that a significant fraction of the DEHP in sludge-amended soils may escape mineralization under in situ conditions.

  9. p53-dependent apoptosis contributes to di-(2-ethylhexyl) phthalate-induced hepatotoxicity.

    PubMed

    Ha, Mei; Wei, Li; Guan, Xie; Li, Lianbing; Liu, Changjiang

    2016-01-01

    Di-(2-ethylhexyl) phthalate (DEHP) is used extensively in many personal care and consumer products, resulting in widespread non-occupational human exposure through multiple routes and media. DEHP has various deleterious effects including hepatotoxicity. p53 protein is a central sensor in cell apoptosis. In order to clarify the roles of p53 in DEHP-induced hepatotoxicity, Sprague-Dawley (SD) rats were dosed daily with DEHP by gavage for 30 days; BRL cells (rat liver cell line) were treated with DEHP for 24 h after pretreatment with NAC or small interfering RNA (siRNA). Results indicated that after exposure to DEHP, hepatic histological changes such as hepatocyte edema, vacuolation and hepatic sinusoidal dilation, and increased apoptosis index were observed. In the liver, DEHP induced oxidative stress and DNA damage, which activated p53 in vivo and in vitro. Pretreatment with NAC significantly reduced ROS level and p53 expression in BRL cells. The suppressed Mdm2 also contributed to p53 accumulation. Activated p53 mediated hepatocyte apoptosis via the intrinsic mitochondrial pathway, inhibiting anti-apoptotic Bcl-2 and Bcl-xL and inducing pro-apoptotic Bax, cytochrome c and caspases. In p53-silenced BRL cells, hepatocyte apoptosis mediated by p53 was attenuated. PCNA protein level was upregulated after p53 gene silencing. However, the Fas/FasL apoptotic pathway did not exhibit activated signs in DEHP-caused hepatotoxicity. Taken together, DEHP-caused oxidative stress and Mdm2 downregulation contribute to p53 activation. The p53-dependent apoptotic pathway plays critical and indispensable roles in DEHP-induced hepatotoxicity, while the Fas/FasL pathway does not involve in this molecular event. PMID:26549752

  10. Mono-2-ethylhexyl phthalate (MEHP) alters histiotrophic nutrition pathways and epigenetic processes in the developing conceptus.

    PubMed

    Sant, Karilyn E; Dolinoy, Dana C; Jilek, Joseph L; Shay, Brian J; Harris, Craig

    2016-01-01

    Histiotrophic nutrition pathways (HNPs) are processes by which the organogenesis-stage conceptus obtains nutrients, amino acids, vitamins and cofactors required for protein biosynthesis and metabolic activities. Nutrients are captured from the maternal milieu as whole proteins and cargoes via receptor-mediated endocytosis in the visceral yolk sac (VYS), degraded by lysosomal proteolysis and delivered to the developing embryo (EMB). Several nutrients obtained by HNPs are required substrates for one-carbon (C1) metabolism and supply methyl groups required for epigenetic processes, including DNA and histone methylation. Increased availability of methyl donors has been associated with reduced risk for neural tube defects (NTDs). Here, we show that mono-2-ethylhexyl phthalate (MEHP) treatment (100 or 250μM) alters HNPs, C1 metabolism and epigenetic programming in the organogenesis-stage conceptus. Specifically, 3-h MEHP treatment of mouse EMBs in whole culture resulted in dose-dependent reduction of HNP activity in the conceptus. To observe nutrient consequences of decreased HNP function, C1 components and substrates and epigenetic outcomes were quantified at 24h. Treatment with 100-μM MEHP resulted in decreased dietary methyl donor concentrations, while treatment with 100- or 250-μM MEHP resulted in dose-dependent elevated C1 products and substrates. In MEHP-treated EMBs with NTDs, H3K4 methylation was significantly increased, while no effects were seen in treated VYS. DNA methylation was reduced in MEHP-treated EMB with and without NTDs. This research suggests that environmental toxicants such as MEHP decrease embryonic nutrition in a time-dependent manner and that epigenetic consequences of HNP disruption may be exacerbated in EMB with NTDs. PMID:26507544

  11. Transgenerational Effects of Di-(2-Ethylhexyl) Phthalate (DEHP) on Stress Hormones and Behavior

    PubMed Central

    Quinnies, Kayla M.; Doyle, Timothy J.; Kim, Kwan Hee

    2015-01-01

    Exposure to di-(2-ethylhexyl) phthalate (DEHP) has been linked to male reproductive abnormalities. Here, we assessed transgenerational actions of DEHP on several behaviors and stress responses. We used 2 doses of DEHP (150- and 200-mg/kg body weight) and a treatment regimen previously shown to produce transgenerational effects on male reproduction. Mice, 3 generations removed from DEHP exposure (F3), were tested for social behavior and anxiety on the elevated plus maze. We collected blood and pituitaries from undisturbed and restrained mice. Body weights, anogenital distances, and reproductive organ weights were collected at killing. In social interaction tests juvenile males from the DEHP lineage (200 mg/kg) displayed more digging and less self-grooming than did controls. Interestingly, 150-mg/kg lineage males, killed in early puberty, had smaller seminal vesicle weights than their controls. However, the 200-mg/kg males (killed on average 10 d later) did not show this effect. Females from a DEHP lineage had lower corticosterone concentrations than controls after restraint stress. We also found sex- and DEHP-specific mRNA expression changes in the pituitary in 2 of the 6 stress-related genes we measured. In particular, Gnas mRNA was elevated by the combination of DEHP lineage and stress. Thus, transgenerational effects of DEHP are noted in male behavior, and in females, DEHP had transgenerational effects on levels of corticosterone. Both of these results may be related to transgenerational modifications in the expression of several pituitary hormones involved in the hypothalamic-pituitary-adrenal axis. PMID:26168342

  12. Micellar electrokinetic chromatography with bis(2-ethylhexyl)sodium sulfosuccinate vesicles determination of synthetic food antioxidants.

    PubMed

    Delgado-Zamarreño, M M; Sánchez-Pérez, A; Ganzález Maza, I; Hernández-Méndez, J

    2000-02-25

    Capillary electrokinetic chromatography is suitable for the separation of mixtures of uncharged and charged solutes. In the present work the behavior of six synthetic food antioxidants--2[3]-tert.-butyl-4-hydroxyanisole, 2,6-di-tert.-butyl-p-cresol, tercbutylhydroquinone, 3,4,5-trihydroxybenzoic acid propyl ester, 3,4,5-trihydroxybenzoic acid octyl ester and 3,4,5-trihydroxybenzoic acid dodecyl ester--was studied in a capillary electrophoresis system using capillary electrokinetic chromatography with vesicles of the surfactant bis(2-ethylhexyl)sodium sulfosuccinate (AOT). Several studies aimed at calculating the critical aggregation concentration of the surfactant were conducted to check that under the conditions used the AOT was in a state of aggregation. Having checked the association shown by the surfactant, we then explored the greater or lesser capacity of the antioxidants to interact with this compound. We followed the evolution of the molecular absorption spectra of each of the antioxidants in the presence of the surfactant at different concentrations and the retention factors were calculated at different pH values. Additionally, in order to determine which species--anionic or neutral--was present at the pH of the buffer used (boric/borate), the pKa values in acetonitrile-water (20:80) were obtained. Resolution and quantification of the antioxidants demand optimization of the variables involved in the system, such as the percentage of acetonitrile, the concentration of AOT and boric/borate buffer, pH, voltage, etc. When this part of the study had been completed, calibrations were obtained for each of the antioxidants, obtaining good linear correlation coefficients in all cases. Finally, we propose a method that allows the resolution of the six most employed antioxidants in a capillary electrophoretic system in 15 min, using electrokinetic chromatography with AOT as the pseudostationary phase. PMID:10735321

  13. Di (2-ethylhexyl) Phthalate Exposure Impairs Growth of Antral Follicle in Mice.

    PubMed

    Li, Lan; Liu, Jing-Cai; Lai, Fang-Nong; Liu, Huan-Qi; Zhang, Xi-Feng; Dyce, Paul W; Shen, Wei; Chen, Hong

    2016-01-01

    Di (2-ethylhexyl) phthalate (DEHP) is a widely used plastic additive. As an environmental endocrine disruptor, it has been shown to be harmful to the mammalian reproductive system. Previous studies indicated that DEHP inhibited the development of mouse ovarian follicles. However, the mechanisms by which DEHP affects ovarian antral follicle development during the pre-puberty stage are poorly understand. Thus, we investigated the effects of direct DEHP exposure on antral follicle growth in pre-pubescent mice by use of intraperitoneal injection. Our results demonstrated that the percentage of large antral follicles was significantly reduced when mice were exposed to 20 or 40 μg/kg DEHP every 5 days from postnatal day 0 (0 dpp) to 15 dpp. In 20 dpp, we performed microarray of these ovaries. The microarray results indicated that mRNA levels of apoptosis related genes were increased. The mRNA levels of the apoptosis and cell proliferation (negative) related genes Apoe, Agt, Glo1 and Grina were increased after DEHP exposure. DEHP induced the differential gene expression of Hsp90ab1, Rhoa, Grina and Xdh which may play an important role in this process. In addition, TUNEL staining and immunofluorescence showed that DEHP exposure significantly increased the number of TUNEL, Caspase3 and γH2AX positive ovarian somatic cells within the mouse ovaries. Flow cytometer analyses of redox-sensitive probes showed that DEHP caused the accumulation of reactive oxygen species. Moreover, the mRNA expression of ovarian somatic cell antioxidative enzymes was down-regulated both in vivo and in vitro. In conclusion, our data here demonstrated that DEHP exposure induced oxidative stress and ovarian somatic cell apoptosis, and thus may impact antral follicle enlargement during the pre-pubertal stage in mice. PMID:26845775

  14. Ion pairs of crystal violet in sodium bis(2-ethylhexyl)sulfosuccinate reverse micelles.

    PubMed

    Oliveira, Carla S; Bastos, Erick L; Duarte, Evandro L; Itri, Rosangela; Baptista, Mauricio S

    2006-10-10

    The interfacial localization and the ion pair formation of the positively charged dye crystal violet (CV) in sodium bis(2-ethylhexyl)sulfosuccinate reverse micelles (AOT RMs) were studied by several structural and spectroscopic techniques and by quantum chemical calculations. The size and shape of the AOT RMs in the presence of CV were investigated by small-angle X-ray scattering, showing that CV does not significantly change the RM structure. CV localization as a function of the water to surfactant molar ratio (w(0)) was characterized by H(1) and (13)C NMR, indicating the close proximity of CV to the sulfosuccinate group of AOT at small and large w(0) values. These results were confirmed by calculation of magnetic shielding constants using the gauge-independent atomic orbital method with the HF/6-31G(d) basis set. Two different types of ion pairs between AOT and CV, i.e., contact ion pair (CIPs) and solvent-separated ion pair (SSIPs), were characterized by UV-vis spectroscopy and quantum chemical calculations using the semiempirical ZINDO-CI method. In nonpolar isotropic solvents CIPs are formed with an association constant (K(ASSOC)) of 2 x 10(4) mol(-1) L in isooctane and 750 mol(-1) L in chloroform. In AOT RMs at low w(0), CV-AOT CIPs are also formed. By increasing w(0), there is a sharp decrease in the CIP association free energy, and SSIPs are formed. (CV(+))(H(2)O)(AOT(-)) SSIPs are stable in the AOT RM up to the largest w(0) tested (w(0) = 33). PMID:17014109

  15. Di-(2-Ethylhexyl)-Phthalate (DEHP) Causes Impaired Adipocyte Function and Alters Serum Metabolites

    PubMed Central

    Klöting, Nora; Hesselbarth, Nico; Gericke, Martin; Kunath, Anne; Biemann, Ronald; Chakaroun, Rima; Kosacka, Joanna; Kovacs, Peter; Kern, Matthias; Stumvoll, Michael; Fischer, Bernd; Rolle-Kampczyk, Ulrike; Feltens, Ralph; Otto, Wolfgang; Wissenbach, Dirk K.; von Bergen, Martin; Blüher, Matthias

    2015-01-01

    Di-(2-ethylhexyl)-phthalate (DEHP), an ubiquitous environmental contaminant, has been shown to cause adverse effects on glucose homeostasis and insulin sensitivity in epidemiological studies, but the underlying mechanisms are still unknown. We therefore tested the hypothesis that chronic DEHP exposure causes impaired insulin sensitivity, affects body weight, adipose tissue (AT) function and circulating metabolic parameters of obesity resistant 129S6 mice in vivo. An obesity-resistant mouse model was chosen to reduce a potential obesity bias of DEHP effects on metabolic parameters and AT function. The metabolic effects of 10-weeks exposure to DEHP were tested by insulin tolerance tests and quantitative assessment of 183 metabolites in mice. Furthermore, 3T3-L1 cells were cultured with DEHP for two days, differentiated into mature adipocytes in which the effects on insulin stimulated glucose and palmitate uptake, lipid content as well as on mRNA/protein expression of key adipocyte genes were investigated. We observed in female mice that DEHP treatment causes enhanced weight gain, fat mass, impaired insulin tolerance, changes in circulating adiponectin and adipose tissue Pparg, adiponectin and estrogen expression. Serum metabolomics indicated a general increase in phospholipid and carnitine concentrations. In vitro, DEHP treatment increases the proliferation rate and alters glucose uptake in adipocytes. Taken together, DEHP has significant effects on adipose tissue (AT) function and alters specific serum metabolites. Although, DEHP treatment led to significantly impaired insulin tolerance, it did not affect glucose tolerance, HOMA-IR, fasting glucose, insulin or triglyceride serum concentrations. This may suggest that DEHP treatment does not cause impaired glucose metabolism at the whole body level. PMID:26630026

  16. Di (2-ethylhexyl) Phthalate Exposure Impairs Growth of Antral Follicle in Mice

    PubMed Central

    Li, Lan; Liu, Jing-Cai; Lai, Fang-Nong; Liu, Huan-Qi; Zhang, Xi-Feng; Dyce, Paul W.; Shen, Wei; Chen, Hong

    2016-01-01

    Di (2-ethylhexyl) phthalate (DEHP) is a widely used plastic additive. As an environmental endocrine disruptor, it has been shown to be harmful to the mammalian reproductive system. Previous studies indicated that DEHP inhibited the development of mouse ovarian follicles. However, the mechanisms by which DEHP affects ovarian antral follicle development during the pre-puberty stage are poorly understand. Thus, we investigated the effects of direct DEHP exposure on antral follicle growth in pre-pubescent mice by use of intraperitoneal injection. Our results demonstrated that the percentage of large antral follicles was significantly reduced when mice were exposed to 20 or 40 μg/kg DEHP every 5 days from postnatal day 0 (0 dpp) to 15 dpp. In 20 dpp, we performed microarray of these ovaries. The microarray results indicated that mRNA levels of apoptosis related genes were increased. The mRNA levels of the apoptosis and cell proliferation (negative) related genes Apoe, Agt, Glo1 and Grina were increased after DEHP exposure. DEHP induced the differential gene expression of Hsp90ab1, Rhoa, Grina and Xdh which may play an important role in this process. In addition, TUNEL staining and immunofluorescence showed that DEHP exposure significantly increased the number of TUNEL, Caspase3 and γH2AX positive ovarian somatic cells within the mouse ovaries. Flow cytometer analyses of redox-sensitive probes showed that DEHP caused the accumulation of reactive oxygen species. Moreover, the mRNA expression of ovarian somatic cell antioxidative enzymes was down-regulated both in vivo and in vitro. In conclusion, our data here demonstrated that DEHP exposure induced oxidative stress and ovarian somatic cell apoptosis, and thus may impact antral follicle enlargement during the pre-pubertal stage in mice. PMID:26845775

  17. Resveratrol and curcumin ameliorate di-(2-ethylhexyl) phthalate induced testicular injury in rats.

    PubMed

    Abd El-Fattah, Amal Ahmed; Fahim, Atef Tadros; Sadik, Nermin Abdel Hamid; Ali, Bassam Mohamed

    2016-01-01

    The present study aimed to evaluate the protective role of resveratrol and curcumin on oxidative testicular damage induced by di-(2-ethylhexyl) phthalate (DEHP). Male Wistar rats were divided into six groups; three groups received oral daily doses of DEHP (2g/kgBW) for 45days to induce testicular injury. Two of these groups received either resveratrol (80mg/kgBW) or curcumin (200mg/kgBW) orally for 30days before and 45days after DEHP administration. A vehicle-treated control group was also included. Another two groups of rats received either resveratrol or curcumin alone. Oxidative damage was observed by decreased levels of total antioxidant capacity (TAC) and glutathione (GSH) and increased malondialdehyde (MDA) level in the testes of DEHP-administered rats. Serum testosterone level as well as testicular marker enzymes activities; acid and alkaline phosphatases (ACP and ALP) and lactate dehydrogenase (LDH) showed severe declines. DEHP administration caused significant increases in the testicular gene expression levels of Nrf2, HO-1, HSP60, HSP70 and HSP90 as well as a significant decrease in c-Kit protein when compared with the control group. Histopathological observations provided evidence for the biochemical and molecular analysis. These DEHP-induced pathological alterations were attenuated by pretreatment with resveratrol and curcumin. We conclude that DEHP-induced injuries in biochemical, molecular and histological structure of testis were recovered by pretreatment with resveratrol and curcumin. The chemoprotective effects of these compounds may be due to their intrinsic antioxidant properties along with boosting Nrf2, HSP 60, HSP 70 and HSP 90 gene expression levels and as such may be useful potential tools in combating DEHP-induced testicular dysfunction. PMID:26361869

  18. Chronic exposure to mono-(2-ethylhexyl)-phthalate causes endocrine disruption and reproductive dysfunction in zebrafish.

    PubMed

    Zhu, Yongtong; Hua, Rui; Zhou, Yao; Li, Hong; Quan, Song; Yu, Yanhong

    2016-08-01

    Phthalic acid esters are frequently detected in aquatic environments. In the present study, zebrafish were exposed to low concentrations (0 µg/L, 0.46 µg/L, 4.0 µg/L, and 37.5 µg/L) of mono-(2-ethylhexyl) phthalate (MEHP) for 81 d, and the effects on reproduction, gamete quality, plasma vitellogenin (VTG), sex steroids, and transcriptional profiles of key genes involved in steroidogenesis were investigated. The results demonstrated that egg production and sperm quality were decreased after exposure to MEHP, which also resulted in reduced egg diameter and eggshell as well as decreased egg protein content. Significant inductions in plasma testosterone and 17β-estradiol (E2) were observed in females, which might have resulted from up-regulation of CYP19a and 17β-HSD gene transcription in the ovary. A significant increase in plasma E2 along with a decrease in plasma 11-keto testosterone was also observed in males, which was accompanied by up-regulation of CYP19a and inhibition of CYP11b transcription in the testis. In addition, plasma vitellogenin levels were significantly increased after MEHP exposure in both sexes. Moreover, continuous MEHP exposure in the F1 embryos resulted in worse hatching rates and increased malformation rates compared with embryos without MEHP exposure. Taken together, these results demonstrate that MEHP has the potential to cause reproductive dysfunction and impair the development of offspring. However, it should be noted that most of the significant effects were observed at higher concentrations, and MEHP at typically measured concentrations may not have major effects on fish reproduction and development. Environ Toxicol Chem 2016;35:2117-2124. © 2016 SETAC. PMID:26762230

  19. Progress in the removal of di-[2-ethylhexyl]-phthalate as plasticizer in blood bags.

    PubMed

    Simmchen, Juliane; Ventura, Rosa; Segura, Jordi

    2012-01-01

    Polyvinylchloride (PVC) is used in blood component containers as well as in many other medical devices because it shows optimal inertness, durability, and resistance to heat and chemicals. However, the polymer itself does not provide good handling characteristics or the necessary properties for red blood cell (RBC) survival. PVC thus needs to be plasticized, and di-(2-ethylhexyl)phthalate (DEHP) has been the most common plasticizer to produce the required flexibility to PVC. However, DEHP has been found to leach out from the containers, causing toxic effects, as demonstrated mainly in rodents. It is considered to be a possible carcinogen and suspected to also produce endocrine effects especially in young males. Although controversial, it is commonly accepted that in vulnerable patients such as newborns, trauma patients, or pregnant women, high exposure to DEHP should be avoided. The replacement of the common PVC + DEHP blood bags poses technical challenges due to the positive influence of the DEHP molecules on the red blood cell (RBC) membrane, and thus it has been shown to affect RBC storage and survival after transfusion. Different approaches are thus being taken to find a suitable alternative to DEHP for blood components bags. Environmentalists even favor the substitution of the PVC to avoid not only the plasticizers but even the other residues contained in the polymer material. Consequently, whereas the simplest solution is the substitution of the DEHP by other plasticizers, alternative plasticizer-free materials are becoming explored. Even modifications of existing materials are being presented by some research groups, ranging from covering of the DEHP-containing materials to alloys or special additive solutions. Different strategies as well as the most promising approaches are presented in this review. In any case, the degree of stabilization of RBCs undergoing prolonged storage will dictate the final acceptance for such alternatives. PMID:21820855

  20. MECHANISTIC CONSIDERATIONS FOR HUMAN RELEVANCE OF CANCER HAZARD OF DI(2-ETHYLHEXYL) PHTHALATE

    PubMed Central

    Rusyn, Ivan; Corton, J. Christopher

    2012-01-01

    Di(2-ethylhexyl) phthalate (DEHP) is a peroxisome proliferator agent that is widely used as a plasticizer to soften polyvinylchloride plastics and non-polymers. Both occupational (e.g., by inhalation during its manufacture and use as a plasticizer of polyvinylchloride) and environmental (medical devices, contamination of food, or intake from air, water and soil) routes of exposure to DEHP are of concern for human health. There is sufficient evidence for carcinogenicity of DEHP in the liver in both rats and mice; however, there is little epidemiological evidence on possible associations between exposure to DEHP and liver cancer in humans. Data are available to suggest that liver is not the only target tissue for DEHP-associated toxicity and carcinogenicity in both humans and rodents. The debate regarding human relevance of the findings in rats or mice has been informed by studies on the mechanisms of carcinogenesis of the peroxisome proliferator class of chemicals, including DEHP. Important additional mechanistic information became available in the past decade, including, but not limited to, sub-acute, sub-chronic and chronic studies with DEHP in peroxisome proliferator-activated receptor (PPAR) α-null mice, as well as experiments utilizing several transgenic mouse lines. Activation of PPARα and the subsequent downstream events mediated by this transcription factor represent an important mechanism of action for DEHP in rats and mice. However, additional data from animal models and studies in humans exposed to DEHP from the environment suggest that multiple molecular signals and pathways in several cell types in the liver, rather than a single molecular event, contribute to the cancer in rats and mice. In addition, the toxic and carcinogenic effects of DEHP are not limited to liver. The International Agency for Research on Cancer working group concluded that the human relevance of the molecular events leading to cancer elicited by DEHP in several target tissues (e

  1. Adsorption of sodium bis(2-ethylhexyl) sulfosuccinate and wettability in polytetrafluoroethylene solution air system

    NASA Astrophysics Data System (ADS)

    Harkot, Joanna; Jańczuk, Bronisław

    2007-06-01

    The role of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) adsorption at water-air and polytetrafluoroethylene-water (PTFE) interfaces in wetting of low energy PTFE was established from measurements of the contact angle of aqueous AOT solutions in PTFE-solution drop-air systems and the aqueous AOT solution surface tension measurements. For calculations of the adsorption at these interfaces the relationship between adhesion tension ( γLV cos θ) and surface tension ( γLV), and the Gibbs and Young equations were taken into account. On the basis of the measurements and calculations the slope of the γLV cos θ- γLV curve was found to be constant and equal -1 over the whole range of surfactant concentration in solution. It means that the amount of surfactant adsorbed at the PTFE-water interface, ΓSL, is essentially equal to its amount adsorbed at water-air interface, ΓLV. By extrapolating the linear dependence between γLV cos θ and γLV to cos θ = 1 the determined value of critical surface tension of PTFE surface wetting, γC, was obtained (23.6 mN/m), and it was higher than the surface tension of PTFE (20.24 mN/m). Using the value of PTFE surface tension and the measured surface tension of aqueous AOT solution in Young equation, the PTFE-solution interface tension, γSL, was also determined. The shape of the γSL-log C curve occurred to be similar to the isotherm of AOT adsorption at water-air interface, and a linear dependence existed between the PTFE-solution interfacial tension and polar component of aqueous AOT solution. The dependence was found to be established by the fact that the work of adhesion of AOT solution to the PTFE surface was practically constant amounting 46.31 mJ/m 2 which was close to the work of water adhesion to PTFE surface.

  2. Mechanisms of toxicity of di(2-ethylhexyl) phthalate on the reproductive health of male zebrafish.

    PubMed

    Uren-Webster, Tamsyn M; Lewis, Ceri; Filby, Amy L; Paull, Gregory C; Santos, Eduarda M

    2010-09-01

    Phthalates are ubiquitous in the aquatic environment and are known to adversely affect male reproductive health in mammals through interactions with multiple receptor systems. However, little is known about the risks they pose to fish. This project investigated the effects of di(2-ethylhexyl) phthalate (DEHP), the most commonly used phthalate, on the reproductive health of male zebrafish (Danio rerio). Males were treated with 0.5, 50 and 5000 mg DEHP kg(-1) (body weight) for a period of 10 days via intraperitoneal injection. The effects of the exposure were assessed by analysing fertilisation success, testis histology, sperm DNA integrity and transcript profiles of the liver and testis. A significant increase in the hepatosomatic index and levels of hepatic vitellogenin transcript were observed following exposure to 5000 mg DEHP kg(-1). Exposure to 5000 mg DEHP kg(-1) also resulted in a reduction in fertilisation success of oocytes spawned by untreated females. However, survival and development of the resulting embryos were unaffected by all treatments, and no evidence of DEHP-induced sperm DNA damage was observed. Exposure to 50 and 5000 mg DEHP kg(-1) caused alterations in the proportion of germ cells at specific stages of spermatogenesis in the testis, including a reduction in the proportion of spermatozoa and an increase in the proportion of spermatocytes, suggesting that DEHP may inhibit the progression of meiosis. In parallel, exposure to 5000 mg DEHP kg(-1) increased the levels of two peroxisome proliferator-activated receptor (PPAR) responsive genes (acyl-coenzyme A oxidase 1 (acox1) and enoyl-coenzyme A, hydratase/3-hydroxyacyl coenzyme A dehydrogenase (ehhadh). These data demonstrated that exposure to high concentrations of DEHP disrupts spermatogenesis in adult zebrafish with a consequent decrease in their ability to fertilise oocytes spawned by untreated females. Furthermore, our data suggest that the adverse effects caused by exposure to DEHP are

  3. Di (2-ethylhexyl) phthalate inhibits growth of mouse ovarian antral follicles through an oxidative stress pathway

    SciTech Connect

    Wang, Wei Craig, Zelieann R. Basavarajappa, Mallikarjuna S. Gupta, Rupesh K. Flaws, Jodi A.

    2012-01-15

    Di (2-ethylhexyl) phthalate (DEHP) is a plasticizer that has been shown to inhibit growth of mouse antral follicles, however, little is known about the mechanisms by which DEHP does so. Oxidative stress has been linked to follicle growth inhibition as well as phthalate-induced toxicity in non-ovarian tissues. Thus, we hypothesized that DEHP causes oxidative stress and that this leads to inhibition of the growth of antral follicles. To test this hypothesis, antral follicles isolated from CD-1 mice (age 31–35 days) were cultured with vehicle control (dimethylsulfoxide [DMSO]) or DEHP (1–100 μg/ml) ± N-acetyl cysteine (NAC, an antioxidant at 0.25–1 mM). During culture, follicles were measured daily. At the end of culture, follicles were collected and processed for in vitro reactive oxygen species (ROS) assays to measure the presence of free radicals or for measurement of the expression and activity of various key antioxidant enzymes: Cu/Zn superoxide dismutase (SOD1), glutathione peroxidase (GPX) and catalase (CAT). The results indicate that DEHP inhibits the growth of follicles compared to DMSO control and that NAC (0.25–1 mM) blocks the ability of DEHP to inhibit follicle growth. Furthermore, DEHP (10 μg/ml) significantly increases ROS levels and reduces the expression and activity of SOD1 compared to DMSO controls, whereas NAC (0.5 mM) rescues the effects of DEHP on ROS levels and SOD1. However, the expression and activity of GPX and CAT were not affected by DEHP treatment. Collectively, these data suggest that DEHP inhibits follicle growth by inducing production of ROS and by decreasing the expression and activity of SOD1. -- Highlights: ► DEHP inhibits growth and increases reactive oxygen species in ovarian antral follicles in vitro. ► NAC rescues the effects of DEHP on the growth and reactive oxygen species levels in follicles. ► DEHP decreases the expression and activity of Cu/Zn superoxide dismutase, which can be rescued by NAC, in antral

  4. A novel sodium bis(2-ethylhexyl) sulfosuccinate-PAGE system suitable for the separation of small peptides.

    PubMed

    Lu, Xuemei; Yao, Yao; Zhang, Weican

    2007-09-01

    A novel sodium bis(2-ethylhexyl) sulfosuccinate-PAGE (AOT-PAGE) system which delivers high resolution and sensitivity for small peptides with molecular masses of 0.8-17 kDa is described. Small peptides migrate more slowly and are less prone to leakage than in conventional SDS-PAGE, thus allowing for the in-gel detection with CBB R 250 of 0.5 mug of peptide. The system is also compatible with electroblotting, activity staining in renatured gels, and the peptide analysis by MALDI-MS. AOT-PAGE is simpler, more rapid, and cheaper than the generally adopted Tricine-SDS-PAGE method. PMID:17854120

  5. FT-IR investigation of the partitioning of sodium bis(2-ethylhexyl) sulfosuccinate between an aqueous and a propane phase

    SciTech Connect

    Yee, G.G.; Fulton, J.L.; Blitz, J.P.; Smith, R.D. )

    1991-02-07

    The partitioning of the surfactant sodium bis(2-ethylhexyl) sulfosuccinate (AOT) from a buffered aqueous phase into a near-critical propane phase was investigated by using Fourier transform infrared spectroscopy. The partitioning of AOT is shown to be dependent upon the fluid pressure as well as upon the molar water-to-surfactant ratio, W. The uptake of water into the propane microemulsion phase coincides with the partitioning of AOT. The phase behavior of this system appears to be controlled by the attractive interactions between droplets in the microemulsion phase, as well as from limitations upon the curvature of the interfacial surfactant layer. Potential application of these systems for separations are discussed.

  6. Human biofluid concentrations of mono(2-ethylhexyl)phthalate extrapolated from pharmacokinetics in chimeric mice with humanized liver administered with di(2-ethylhexyl)phthalate and physiologically based pharmacokinetic modeling.

    PubMed

    Adachi, Koichiro; Suemizu, Hiroshi; Murayama, Norie; Shimizu, Makiko; Yamazaki, Hiroshi

    2015-05-01

    Di(2-ethylhexyl)phthalate (DEHP) is a reproductive toxicant in male rodents. The aim of the current study was to extrapolate the pharmacokinetics and toxicokinetics of mono(2-ethylhexyl)phthalate (MEHP, a primary metabolite of DEHP) in humans by using data from oral administration of DEHP to chimeric mice transplanted with human hepatocytes. MEHP and its glucuronide were detected in plasma from control mice and chimeric mice after single oral doses of 250mg DEHP/kg body weight. Biphasic plasma concentration-time curves of MEHP and its glucuronide were seen only in control mice. MEHP and its glucuronide were extensively excreted in urine within 24h in mice with humanized liver. In contrast, fecal excretion levels of MEHP glucuronide were high in control mice compared with those with humanized liver. Adjusted animal biomonitoring equivalents from chimeric mice studies were scaled to human biomonitoring equivalents using known species allometric scaling factors and in vitro metabolic clearance data with a simple physiologically based pharmacokinetic (PBPK) model. Estimated urine MEHP concentrations in humans were consistent with reported concentrations. This research illustrates how chimeric mice transplanted with human hepatocytes in combination with a simple PBPK model can assist evaluations of pharmacokinetics or toxicokinetics of the primary or secondary metabolites of DEHP. PMID:25867688

  7. The thermodynamic properties of 2-ethylhexyl acrylate over the temperature range from T → 0 to 350 K

    NASA Astrophysics Data System (ADS)

    Kulagina, T. G.; Samosudova, Ya. S.; Letyanina, I. A.; Sevast'yanov, E. V.; Smirnova, N. N.; Smirnova, L. A.; Mochalova, A. E.

    2012-05-01

    The temperature dependence of the heat capacity C {/p o}= f( T) 2 of 2-ethylhexyl acrylate was studied in an adiabatic vacuum calorimeter over the temperature range 6-350 K. Measurement errors were mainly of 0.2%. Glass formation and vitreous state parameters were determined. An isothermic shell calorimeter with a static bomb was used to measure the energy of combustion of 2-ethylhexyl acrylate. The experimental data were used to calculate the standard thermodynamic functions C {/p o}( T), H o( T)- H o(0), S o( T)- S o(0), and G o( T)- H o(0) of the compound in the vitreous and liquid states over the temperature range from T → 0 to 350 K, the standard enthalpies of combustion Δc H o, and the thermodynamic characteristics of formation Δf H o, Δf S o, and Δf G o at 298.15 K and p = 0.1 MPa.

  8. Do diethyl phthalate (DEP) and di-2-ethylhexyl phthalate (DEHP) influence the metabolic syndrome parameters? Pilot study.

    PubMed

    Medic Stojanoska, Milica; Milankov, Andrijana; Vukovic, Bojan; Vukcevic, Dejan; Sudji, Jan; Bajkin, Ivana; Curic, Nikola; Icin, Tijana; Kovacev Zavisic, Branka; Milic, Natasa

    2015-08-01

    The study objective was to determine if the healthy participants were exposed to diethyl phthalate (DEP) and di (2-ethylhexyl) phthalate (DEHP) and if this exposure could be linked to the development of metabolic syndrome. The study included 103 healthy volunteers of similar age with normal BMI values, waist circumference, total cholesterol, HDL, LDL, and triglycerides. DEP and DEHP were measured in the morning urine samples to detect monoethyl phthalate (MEP) and mono-2-ethylhexyl phthalate (MEHP). Two phthalate groups and a control group were formed. Both MEP group and control group had similar results. The correlations between MEP and the measured parameters were insignificant. The correlation between the MEHP group and the age was significantly negative, but between the MHEP group and the waist circumference the correlation was significantly positive. Lipids and lipoproteins were within the reference values and equal in both groups. The significant negative correlation was observed only between MEHP and HDL. Our population is exposed to DEP and DEHP. There was only a significant correlation between DEHP and the observed metabolic syndrome components. Its negative impact was higher as the participants were younger. PMID:26210228

  9. ATSDR evaluation of health effects of chemicals. VI. Di(2-ethylhexyl)phthalate. Agency for Toxic Substances and Disease Registry.

    PubMed

    Fay, M; Donohue, J M; De Rosa, C

    1999-12-01

    Di(2-ethylhexyl)phthalate (also known as DEHP, bis(2-ethylhexyl)phthalate, or BEHP; CAS Registry Number 117-81-7) is a widely-used plasticizer. It is found in numerous plastic articles, such as paints, inks, floor tiles, upholstery, shower curtains, footwear, plastic bags, food-packaging materials, toys, and medical tubing. Not surprisingly, DEHP appears at many waste sites. As part of its mandate, the Agency for Toxic Substances and Disease Registry (ATSDR) prepares toxicological profiles on hazardous chemicals that are of greatest public health concern at Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) National Priority List (NPL) sites. These profiles comprehensively summarize toxicological and environmental information. This article constitutes the release of the bulk of ATSDR's profile for DEHP (ATSDR, 1993) into the mainstream scientific literature. An extensive listing of human and animal health effects, organized by route, duration, and endpoint, is presented. Toxicological information on toxicokinetics, biomarkers, interactions, sensitive subpopulations, reducing toxicity after exposure, and relevance to public health is also included. Environmental information encompasses physical properties, production and use, environmental fate, levels seen in the environment, analytical methods, and a listing of regulations. ATSDR, at the behest of Congress and therefore the citizenry, prepares these profiles to inform the public about site contaminants. PMID:10786378

  10. Electrochemical and photophysical behavior of 1-naphthol in benzyl-n-hexadecyldimethylammonium 1,4-bis(2-ethylhexyl)sulfosuccinate large unilamellar vesicles.

    PubMed

    Cobo Solis, Airam K; Mariano Correa, N; Molina, Patricia G

    2016-06-21

    In the present contribution, 1-naphthol is investigated in large unilamellar vesicles formed from a new catanionic surfactant, benzyl-n-hexadecyldimethylammonium 1,4-bis(2-ethylhexyl)sulfosuccinate, by electrochemical and spectroscopic techniques. The electrochemical results show that 1-naphthol experiences a partition process between the water phase and the large unilamellar vesicle bilayer phase, which is corroborated by absorption spectroscopic studies at pH = 6.40 and pH = 10.75. Interestingly, studies of 1-naphthol emission in benzyl-n-hexadecyldimethylammonium 1,4-bis(2-ethylhexyl)sulfosuccinate large unilamellar vesicles at pH = 10.75 and in sodium 1,4-bis(2-ethylhexyl)sulfosuccinate water solution show that when the 1,4-bis(2-ethylhexyl)sulfosuccinate moiety is part of the bilayer, the 1,4-bis(2-ethylhexyl)sulfosuccinate polar head interacts strongly with 1-naphthol, by favoring emission from the excited neutral species resulting in the appearance of a new band close to λ = 355 nm. It seems that the large unilamellar vesicle bilayer of the catanionic vesicle slows down the proton transfer process observed in water, where only emission from 1-naphtholate is detected. PMID:27221948

  11. In utero exposure to di-(2-ethylhexyl) phthalate induces testicular effects in neonatal rats that are antagonized by genistein cotreatment.

    PubMed

    Jones, Steven; Boisvert, Annie; Francois, Sade; Zhang, Liandong; Culty, Martine

    2015-10-01

    Fetal exposure to endocrine disruptors (EDs) is believed to predispose males to reproductive abnormalities. Although males are exposed to combinations of chemicals, few studies have evaluated the effects of ED mixtures at environmentally relevant doses. Our previous work showed that fetal exposure to a mixture of the phytoestrogen genistein (GEN) and the plasticizer di-(2-ethylhexyl) phthalate (DEHP) induced unique alterations in adult testis. In this follow-up study, we examined Postnatal Day 3 (PND3) and PND6 male offspring exposed from Gestational Day 14 to parturition to corn oil, 10mg/kg GEN, DEHP, or their combination, to gain insight into the early molecular events driving long-term alterations. DEHP stimulated the mRNA and protein expression of the steroidogenic enzyme HSD3B, uniquely at PND3. DEHP also increased the mRNA expression of Nestin, a Leydig progenitor/Sertoli cell marker, and markers of Sertoli cell (Wt1), gonocyte (Plzf, Foxo1), and proliferation (Pcna) at PND3, while these genes were unchanged by the mixture. Redox (Nqo1, Sod2, Sod3, Trx, Gst, Cat) and xenobiotic transporter (Abcb1b, Abcg2) gene expression was also increased by DEHP at PND3, while attenuated when combined with GEN, suggesting the involvement of cellular stress in short-term DEHP effects and a protective effect of GEN. The direct effects of GEN and mono-(2-ethylhexyl) phthalate, the principal bioactive metabolite of DEHP, on testis were investigated in PND3 organ cultures, showing a stimulatory effect of 10 μM mono-(2-ethylhexyl) phthalate on basal testosterone production that was normalized by GEN. These effects contrasted with previous reports of androgen suppression and decreased gene expression in perinatal rat testis by high DEHP doses, implying that neonatal effects are not predictive of adult effects. We propose that GEN, through an antioxidant action, normalizes reactive oxygen species-induced neonatal effects of DEHP. The notion that these EDs do not follow classical

  12. Evaluation of cytotoxicity and oxidative DNA damaging effects of di(2-ethylhexyl)-phthalate (DEHP) and mono(2-ethylhexyl)-phthalate (MEHP) on MA-10 Leydig cells and protection by selenium

    SciTech Connect

    Erkekoglu, Pinar; Rachidi, Walid; Giray, Belma; Favier, Alain; Hincal, Filiz

    2010-10-01

    Di(2-ethylhexyl)-phthalate (DEHP) is the most abundantly used phthalate derivative, inevitable environmental exposure of which is suspected to contribute to the increasing incidence of testicular dysgenesis syndrome in humans. Oxidative stress and mitochondrial dysfunction in germ cells are suggested to contribute to phthalate-induced disruption of spermatogenesis in rodents, and Leydig cells are one of the main targets of phthalates' testicular toxicity. Selenium is known to be involved in the modulation of intracellular redox equilibrium, and plays a critical role in testis, sperm, and reproduction. This study was aimed to investigate the oxidative stress potential of DEHP and its consequences in testicular cells, and examine the possible protective effects of selenium using the MA-10 mouse Leydig tumor cell line as a model. In the presence and absence of selenium compounds [30 nM sodium selenite (SS), and 10 {mu}M selenomethionine (SM)], the effects of exposure to DEHP and its main metabolite mono(2-ethylhexyl)-phthalate (MEHP) on the cell viability, enzymatic and non-enzymatic antioxidant status, ROS production, p53 expression, and DNA damage by alkaline Comet assay were investigated. The overall results of this study demonstrated the cytotoxicity and genotoxicity potential of DEHP, where MEHP was found to be more potent than the parent compound. SS and SM produced almost the same level of protection against antioxidant status modifying effects, ROS and p53 inducing potentials, and DNA damaging effects of the two phthalate derivatives. It was thus shown that DEHP produced oxidative stress in MA-10 cells, and selenium supplementation appeared to be an effective redox regulator in the experimental conditions used in this study, emphasizing the critical importance of the appropriate selenium status.

  13. Hierarchical Structure of Supramolecular Polymers Formed by N,N'-Di(2-ethylhexyl)urea in Solutions.

    PubMed

    Świergiel, Jolanta; Bouteiller, Laurent; Jadżyn, Jan

    2015-10-01

    Supramolecular chain polymers formed by N,N'-di(2-ethylhexyl)urea (EHU) dissolved at low concentrations (up to 0.1 mole fraction) in heptane were investigated with the use of the dielectric spectroscopy. The experimental data show an exceptional ability of the chains for the antiparallel self-aggregation due to dipole-dipole interactions, leading to an anomalous dependence of the static permittivity of EHU + heptane solutions on temperature and concentration of the urea. The primary molecular assembly into polymeric chains is therefore followed by a secondary bundling of the chains which facilitates a longitudinal translation of the chains. That peculiarity and an asymmetry of the alkyl substituent in the EHU molecule making the system a mixture of diastereoisomers of unfavorable packing of the side group, are the most probable molecular mechanisms which prevent the crystallization of EHU-the only known liquid urea derivative. PMID:26371560

  14. Determination of Activity Coefficients of di-(2-ethylhexyl) Phosphoric Acid Dimer in Select Organic Solvents Using Vapor Phase Osmometry

    SciTech Connect

    Michael F. Gray; Peter Zalupski; Mikael Nilsson

    2013-08-01

    Effective models for solvent extraction require accurate characterization of the nonideality effects for each component, including the extractants. In this study, the nonideal behavior of the industrial extractant di(2-ethylhexyl) phosphoric acid has been investigated using vapor pressure osmometry (VPO). From the osmometry data, activity coefficients for the HDEHP dimer were obtained based on a formulation of the regular solution theory of Scatchard and Hildebrand, and the Margules two- and three-suffix equations. The results show similarity with a slope-analysis based relation from previous literature, although important differences are highlighted. The work points towards VPO as a useful technique for this type of study, but care must be taken with the choice of standard and method of analysis.

  15. Health hazards associated with the use of di-(2-ethylhexyl) phthalate (commonly referred to as DOP) in HEPA filter test

    SciTech Connect

    1995-01-01

    Di-(2-ethylhexyl) phthalate (DEHP), commonly referred to as di-octyl phthalate, is an important production chemical in the US. In addition to its major use as an additive in plastics, DEHP is widely used to evaluate the effectiveness of high efficiency particulate air (HEPA) filters. Historically, DEHP was also used in quantitative fit testing for respirators. Evaluations of this compound a decade ago showed that it can induce hepatocellular carcinomas in laboratory animals. Although most Department of Energy (DOE) facilities have since discontinued using DEHP in respirator fit testing, DEHP continues to be used for evaluating HEPA filters. This report summarizes available information on the toxicity, mutagenicity, carcinogenicity, and other hazards and problems posed by DEHP, specifically with reference to HEPA filter testing. Information on work practice improvements as well as the availability and suitability of DEHP substitutes are also presented. This material should assist the DOE in the safe use of this material.

  16. Characterizing interfacial friction in bis(2-ethylhexyl) sodium sulfosuccinate reverse micelles from photoisomerization studies of carbocyanine derivatives

    SciTech Connect

    Gangamallaiah, V.; Dutt, G. B.

    2011-01-14

    Photoisomerization of two carbocyanine derivatives has been examined in bis(2-ethylhexyl) sodium sulfosuccinate (AOT) reverse micelles to understand the factors that govern this process in the interfacial region of organized assemblies. To this effect, fluorescence lifetimes and quantum yields of 3,3{sup '}-diethyloxadicarbocyanine iodide and merocyanine 540 have been measured in AOT/isooctane/water and AOT/cyclohexane/water reverse micellar systems as a function of the mole ratio of water to the surfactant, W. The nonradiative rate constants, which have been identified as the rates of photoisomerization for these solutes, were obtained from the experimentally measured parameters. The steady rise and subsequent saturation observed in the nonradiative rate constants upon increasing W has been rationalized in terms of micellar packing. An inverse correlation has been obtained between the nonradiative rate constants and the critical packing parameter, indicating that the interfacial friction experienced by the solute molecule is essentially described by this parameter.

  17. Characterizing interfacial friction in bis(2-ethylhexyl) sodium sulfosuccinate reverse micelles from photoisomerization studies of carbocyanine derivatives.

    PubMed

    Gangamallaiah, V; Dutt, G B

    2011-01-14

    Photoisomerization of two carbocyanine derivatives has been examined in bis(2-ethylhexyl) sodium sulfosuccinate (AOT) reverse micelles to understand the factors that govern this process in the interfacial region of organized assemblies. To this effect, fluorescence lifetimes and quantum yields of 3,3(')-diethyloxadicarbocyanine iodide and merocyanine 540 have been measured in AOT∕isooctane∕water and AOT∕cyclohexane∕water reverse micellar systems as a function of the mole ratio of water to the surfactant, W. The nonradiative rate constants, which have been identified as the rates of photoisomerization for these solutes, were obtained from the experimentally measured parameters. The steady rise and subsequent saturation observed in the nonradiative rate constants upon increasing W has been rationalized in terms of micellar packing. An inverse correlation has been obtained between the nonradiative rate constants and the critical packing parameter, indicating that the interfacial friction experienced by the solute molecule is essentially described by this parameter. PMID:21241145

  18. Characterizing interfacial friction in bis(2-ethylhexyl) sodium sulfosuccinate reverse micelles from photoisomerization studies of carbocyanine derivatives

    NASA Astrophysics Data System (ADS)

    Gangamallaiah, V.; Dutt, G. B.

    2011-01-01

    Photoisomerization of two carbocyanine derivatives has been examined in bis(2-ethylhexyl) sodium sulfosuccinate (AOT) reverse micelles to understand the factors that govern this process in the interfacial region of organized assemblies. To this effect, fluorescence lifetimes and quantum yields of 3,3'-diethyloxadicarbocyanine iodide and merocyanine 540 have been measured in AOT/isooctane/water and AOT/cyclohexane/water reverse micellar systems as a function of the mole ratio of water to the surfactant, W. The nonradiative rate constants, which have been identified as the rates of photoisomerization for these solutes, were obtained from the experimentally measured parameters. The steady rise and subsequent saturation observed in the nonradiative rate constants upon increasing W has been rationalized in terms of micellar packing. An inverse correlation has been obtained between the nonradiative rate constants and the critical packing parameter, indicating that the interfacial friction experienced by the solute molecule is essentially described by this parameter.

  19. Copper mediated controlled radical copolymerization of styrene and 2-ethylhexyl acrylate and determination of their reactivity ratios.

    NASA Astrophysics Data System (ADS)

    Koiry, Bishnu; Singha, Nikhil

    2014-10-01

    Copolymerization is an important synthetic tool to prepare polymers with desirable combination of properties which are difficult to achieve from the different homopolymers concerned. This investigation reports the copolymerization of 2-ethylhexyl acrylate (EHA) and styrene using copper bromide (CuBr) as catalyst in combination with N,N,N’,N”,N”- pentamethyldiethylenetriamine (PMDETA) as ligand and 1-phenylethyl bromide (PEBr) as initiator. Linear kinetic plot and linear increase in molecular weights versus conversion indicate that copolymerization reactions were controlled. The copolymer composition was calculated using 1H NMR studies. The reactivity ratio of styrene and EHA (r1 and r2) were determined using the Finemann-Ross (FR), inverted Finemann-Ross (FR) and Kelen-Tudos (KT) methods. Thermal properties of the copolymers were also studied by using TGA and DSC analysis.

  20. Copper mediated controlled radical copolymerization of styrene and 2-ethylhexyl acrylate and determination of their reactivity ratios.

    PubMed

    Koiry, Bishnu P; Singha, Nikhil K

    2014-01-01

    Copolymerization is an important synthetic tool to prepare polymers with desirable combination of properties which are difficult to achieve from the different homopolymers concerned. This investigation reports the copolymerization of 2-ethylhexyl acrylate (EHA) and styrene using copper bromide (CuBr) as catalyst in combination with N,N,N',N″,N″- pentamethyldiethylenetriamine (PMDETA) as ligand and 1-phenylethyl bromide (PEBr) as initiator. Linear kinetic plot and linear increase in molecular weights vs. conversion indicate that copolymerization reactions were controlled. The copolymer composition was calculated using (1)H NMR studies. The reactivity ratio of styrene and EHA (r1 and r2) were determined using the Finemann-Ross (FR), inverted Finemann-Ross (IFR), and Kelen-Tudos (KT) methods. Thermal properties of the copolymers were also studied by using TGA and DSC analysis. PMID:25368866

  1. Mono(2-ethylhexyl) phthalate accelerates early folliculogenesis and inhibits steroidogenesis in cultured mouse whole ovaries and antral follicles.

    PubMed

    Hannon, Patrick R; Brannick, Katherine E; Wang, Wei; Flaws, Jodi A

    2015-05-01

    Humans are ubiquitously exposed to di(2-ethylhexyl) phthalate (DEHP), which is an environmental toxicant present in common consumer products. DEHP potentially targets the ovary through its metabolite mono(2-ethylhexyl) phthalate (MEHP). However, the direct effects of MEHP on ovarian folliculogenesis and steroidogenesis, two processes essential for reproductive and nonreproductive health, are unknown. The present study tested the hypotheses that MEHP directly accelerates early folliculogenesis via overactivation of phosphatidylinositol 3-kinase (PI3K) signaling, a pathway that regulates primordial follicle quiescence and activation, and inhibits the synthesis of steroid hormones by decreasing steroidogenic enzyme levels. Neonatal ovaries from CD-1 mice were cultured for 6 days with vehicle control, DEHP, or MEHP (0.2-20 μg/ml) to assess the direct effects on folliculogenesis and PI3K signaling. Further, antral follicles from adult CD-1 mice were cultured with vehicle control or MEHP (0.1-10 μg/ml) for 24-96 h to establish the temporal effects of MEHP on steroid hormones and steroidogenic enzymes. In the neonatal ovaries, MEHP, but not DEHP, decreased phosphatase and tensin homolog levels and increased phosphorylated protein kinase B levels, leading to a decrease in the percentage of germ cells and an increase in the percentage of primary follicles. In the antral follicles, MEHP decreased the mRNA levels of 17alpha-hydroxylase-17,20-desmolase, 17beta-hydroxysteroid dehydrogenase, and aromatase leading to a decrease in testosterone, estrone, and estradiol levels. Collectively, MEHP mediates the effect of DEHP on accelerated folliculogenesis via overactivating PI3K signaling and inhibits steroidogenesis by decreasing steroidogenic enzyme levels. PMID:25810477

  2. Formation of chlorinated breakdown products during degradation of sunscreen agent, 2-ethylhexyl-4-methoxycinnamate in the presence of sodium hypochlorite.

    PubMed

    Gackowska, Alicja; Przybyłek, Maciej; Studziński, Waldemar; Gaca, Jerzy

    2016-01-01

    In this study, a new degradation path of sunscreen active ingredient, 2-ethylhexyl-4-methoxycinnamate (EHMC) and 4-methoxycinnamic acid (MCA) in the presence of sodium hypochlorite (NaOCl), was discussed. The reaction products were detected using gas chromatography-mass spectrometry (GC-MS). Since HOCl treatment leads to more polar products than EHMC, application of polar extracting agents, dichloromethane and ethyl acetate/n-hexane mixture, gave better results in terms of chlorinated breakdown products identification than n-hexane. Reaction of EHMC with HOCl lead to the formation of C=C bridge cleavage products such as 2-ethylhexyl chloroacetate, 1-chloro-4-methoxybenzene, 1,3-dichloro-2-methoxybenzene, and 3-chloro-4-methoxybenzaldehyde. High reactivity of C=C bond attached to benzene ring is also characteristic for MCA, since it can be converted in the presence of HOCl to 2,4-dichlorophenole, 2,6-dichloro-1,4-benzoquinone, 1,3-dichloro-2-methoxybenzene, 1,2,4-trichloro-3-methoxybenzene, 2,4,6-trichlorophenole, and 3,5-dichloro-2-hydroxyacetophenone. Surprisingly, in case of EHMC/HOCl/UV, much less breakdown products were formed compared to non-UV radiation treatment. In order to describe the nature of EHMC and MCA degradation, local reactivity analysis based on the density functional theory (DFT) was performed. Fukui function values showed that electrophilic attack of HOCl to the C=C bridge in EHMC and MCA is highly favorable (even more preferable than phenyl ring chlorination). This suggests that HOCl electrophilic addition is probably the initial step of EHMC degradation. PMID:26408113

  3. Mono-(2-ethylhexyl) phthalate (MEHP) regulates glucocorticoid metabolism through 11{beta}-hydroxysteroid dehydrogenase 2 in murine gonadotrope cells

    SciTech Connect

    Hong, Dun; Li, Xing-Wang; Lian, Qing-Quan; Lamba, Pankaj; Bernard, Daniel J.; Hardy, Dianne O.; Chen, Hai-Xiao; Ge, Ren-Shan

    2009-11-13

    Di-(2-ethylhexyl) phthalate (DEHP) and its metabolite mono-(2-ethylhexyl) phthalate (MEHP) have been classified as toxicants to the reproductive system at the testis level and DEHP may also impair reproductive axis function at the pituitary levels. However, MEHP is 10-fold more potent than DEHP in toxicity and little is known about the toxicological effect of MEHP on pituitary. In this study, we demonstrated that 11{beta}-hydroxysteroid dehydrogenase type 2 (11{beta}-HSD2), not 11{beta}-HSD1, is strongly expressed in murine gonadotrope L{beta}T2 cells. Interestingly, MEHP inhibited Hsd11b2 mRNA level and 11{beta}-HSD2 enzyme activity in L{beta}T2 cells at as low as 10{sup -7} M. Corticosterone (CORT) at a concentration of 10{sup -6} M significantly inhibited L{beta}T2 cell proliferation after 2-day culture, and 10{sup -6} M RU486, an antagonist of glucocorticoid receptor (GR), reversed this inhibition. However, in the presence of 10{sup -5} or 10{sup -4} M MEHP, the minimal concentration of CORT to inhibit the proliferation of L{beta}T2 cells was lowered to 10{sup -7} M, and 10{sup -6} M RU486 was not able to completely reverse the CORT effect. In conclusion, along with the regulation of GR, 11{beta}-HSD2 may have a key role in glucocorticoid metabolism in L{beta}T2 cells. MEHP may participate in the glucocorticoid metabolism in L{beta}T2 cells through inhibition of 11{beta}-HSD2 enzyme activity. Such perturbation may be of pathological significance as MEHP may interfere with the reproductive system at pituitary level through regulation of glucocorticoid metabolism, especially in neonates with higher risk of phthalates exposure.

  4. Mono(2-Ethylhexyl) Phthalate Accelerates Early Folliculogenesis and Inhibits Steroidogenesis in Cultured Mouse Whole Ovaries and Antral Follicles1

    PubMed Central

    Hannon, Patrick R.; Brannick, Katherine E.; Wang, Wei; Flaws, Jodi A.

    2015-01-01

    Humans are ubiquitously exposed to di(2-ethylhexyl) phthalate (DEHP), which is an environmental toxicant present in common consumer products. DEHP potentially targets the ovary through its metabolite mono(2-ethylhexyl) phthalate (MEHP). However, the direct effects of MEHP on ovarian folliculogenesis and steroidogenesis, two processes essential for reproductive and nonreproductive health, are unknown. The present study tested the hypotheses that MEHP directly accelerates early folliculogenesis via overactivation of phosphatidylinositol 3-kinase (PI3K) signaling, a pathway that regulates primordial follicle quiescence and activation, and inhibits the synthesis of steroid hormones by decreasing steroidogenic enzyme levels. Neonatal ovaries from CD-1 mice were cultured for 6 days with vehicle control, DEHP, or MEHP (0.2–20 μg/ml) to assess the direct effects on folliculogenesis and PI3K signaling. Further, antral follicles from adult CD-1 mice were cultured with vehicle control or MEHP (0.1–10 μg/ml) for 24–96 h to establish the temporal effects of MEHP on steroid hormones and steroidogenic enzymes. In the neonatal ovaries, MEHP, but not DEHP, decreased phosphatase and tensin homolog levels and increased phosphorylated protein kinase B levels, leading to a decrease in the percentage of germ cells and an increase in the percentage of primary follicles. In the antral follicles, MEHP decreased the mRNA levels of 17alpha-hydroxylase-17,20-desmolase, 17beta-hydroxysteroid dehydrogenase, and aromatase leading to a decrease in testosterone, estrone, and estradiol levels. Collectively, MEHP mediates the effect of DEHP on accelerated folliculogenesis via overactivating PI3K signaling and inhibits steroidogenesis by decreasing steroidogenic enzyme levels. PMID:25810477

  5. Data from one test "Semi-Volatile Organic Compound Small Chamber for bis (2-Ethylhexyl) phthalate in Vinyl Flooring Test 2"

    EPA Science Inventory

    This data was generated from a small chamber bis(2-ethylhexyl) phthalate (DEHP) emission test. It was to participate an interaboratory study of DEHP emissions from vinyl flooring in a SVOC emission chamber organized by Virginia Polytechnic Institute and State University (VT).

  6. Use of Mass Spectrometry for Identification of Biomarkers of Exposure to the Flame Retardant DI(2-Ethylhexyl)-2,3,4,5-Tetrabromophthlate

    EPA Science Inventory

    Di-(2-ethylhexyl)-2,3,4,5-tetrabromophthalate (TBPH) is one component in the technical formulation of Firemaster 550, a fire retardant used after phasing out certain polybrominated diphenyl ethers. Firemaster 550 is used widely and its use may result in human exposure to TBPH. To...

  7. Hepatic and intestinal glucuronidation of mono(2-ethylhexyl) phthalate, an active metabolite of di(2-ethylhexyl) phthalate, in humans, dogs, rats, and mice: an in vitro analysis using microsomal fractions.

    PubMed

    Hanioka, Nobumitsu; Isobe, Takashi; Kinashi, Yu; Tanaka-Kagawa, Toshiko; Jinno, Hideto

    2016-07-01

    Mono(2-ethylhexyl) phthalate (MEHP) is an active metabolite of di(2-ethylhexyl) phthalate (DEHP) and has endocrine-disrupting effects. MEHP is metabolized into glucuronide by UDP-glucuronosyltransferase (UGT) enzymes in mammals. In the present study, the hepatic and intestinal glucuronidation of MEHP in humans, dogs, rats, and mice was examined in an in vitro system using microsomal fractions. The kinetics of MEHP glucuronidation by liver microsomes followed the Michaelis-Menten model for humans and dogs, and the biphasic model for rats and mice. The K m and V max values of human liver microsomes were 110 µM and 5.8 nmol/min/mg protein, respectively. The kinetics of intestinal microsomes followed the biphasic model for humans, dogs, and mice, and the Michaelis-Menten model for rats. The K m and V max values of human intestinal microsomes were 5.6 µM and 0.40 nmol/min/mg protein, respectively, for the high-affinity phase, and 430 µM and 0.70 nmol/min/mg protein, respectively, for the low-affinity phase. The relative levels of V max estimated by Eadie-Hofstee plots were dogs (2.0) > mice (1.4) > rats (1.0) ≈ humans (1.0) for liver microsomes, and mice (8.5) > dogs (4.1) > rats (3.1) > humans (1.0) for intestinal microsomes. The percentages of the V max values of intestinal microsomes to liver microsomes were mice (120 %) > rats (57 %) > dogs (39 %) > humans (19 %). These results suggest that the metabolic abilities of UGT enzymes expressed in the liver and intestine toward MEHP markedly differed among species, and imply that these species differences are strongly associated with the toxicity of DEHP. PMID:26514348

  8. Kinetics of di(2-ethylhexyl) phthalate (DEHP) and mono(2-ethylhexyl) phthalate in blood and of DEHP metabolites in urine of male volunteers after single ingestion of ring-deuterated DEHP

    SciTech Connect

    Kessler, Winfried; Numtip, Wanwiwa; Völkel, Wolfgang; Seckin, Elcim; Csanády, György A.; Pütz, Christian; and others

    2012-10-15

    The plasticizer di(2-ethylhexyl) phthalate (DEHP) is suspected to induce antiandrogenic effects in men via its metabolite mono(2-ethylhexyl) phthalate (MEHP). However, there is only little information on the kinetic behavior of DEHP and its metabolites in humans. The toxikokinetics of DEHP was investigated in four male volunteers (28–61 y) who ingested a single dose (645 ± 20 μg/kg body weight) of ring-deuterated DEHP (DEHP-D{sub 4}). Concentrations of DEHP-D{sub 4}, of free ring-deuterated MEHP (MEHP-D{sub 4}), and the sum of free and glucuronidated MEHP-D{sub 4} were measured in blood for up to 24 h; amounts of the monoesters MEHP-D{sub 4}, ring-deuterated mono(2-ethyl-5-hydroxyhexyl) phthalate and ring-deuterated mono(2-ethyl-5-oxohexyl) phthalate were determined in urine for up to 46 h after ingestion. The bioavailability of DEHP-D{sub 4} was surprisingly high with an area under the concentration-time curve until 24 h (AUC) amounting to 50% of that of free MEHP-D{sub 4}. The AUC of free MEHP-D{sub 4} normalized to DEHP-D{sub 4} dose and body weight (AUC/D) was 2.1 and 8.1 times, that of DEHP-D{sub 4} even 50 and 100 times higher than the corresponding AUC/D values obtained earlier in rat and marmoset, respectively. Time courses of the compounds in blood and urine of the volunteers oscillated widely. Terminal elimination half-lives were short (4.3–6.6 h). Total amounts of metabolites in 22-h urine are correlated linearly with the AUC of free MEHP-D{sub 4} in blood, the parameter regarded as relevant for risk assessment. -- Highlights: ► After DEHP intake, DEHP and MEHP in blood show oscillating time courses. ► Dose-related blood levels of DEHP are 50 times higher in humans than in rats. ► Dose-related blood levels of free MEHP are 2 times higher in humans than in rats. ► Elimination of DEHP and its metabolites is short with half-lives of 4.3-6.6 h.

  9. Metabolism and urinary excretion kinetics of di(2-ethylhexyl) terephthalate (DEHTP) in three male volunteers after oral dosage.

    PubMed

    Lessmann, Frederik; Schütze, André; Weiss, Tobias; Langsch, Angelika; Otter, Rainer; Brüning, Thomas; Koch, Holger M

    2016-07-01

    Di(2-ethylhexyl) terephthalate (DEHTP) is used as a substitute for di(2-ethylhexyl) phthalate (DEHP), an ortho-phthalate-based plasticizer that is classified and labeled due to its toxicity to reproduction. In this study the metabolism and urinary excretion kinetics of DEHTP were investigated by single oral dosage of 50 mg DEHTP to three male volunteers (resulting in individual dosages between 0.55 and 0.59 mg/kg body weight). Separate urine samples were consecutively collected for 48 h. In analogy to DEHP, we quantified specific side-chain-oxidized monoester metabolites of DEHTP (5OH-MEHTP, 5oxo-MEHTP, 5cx-MEPTP and 2cx-MMHTP) by HPLC-MS/MS with online sample clean-up and isotope dilution. All postulated metabolites were detectable in all samples after dosage. The predominant, specific urinary metabolite was 5cx-MEPTP representing about 13.0 % of the applied dose as mean of the three volunteers (range 7.0-20.4 %) in urine, followed by 5OH-MEHTP (mean: 1.8 %; range 1.3-2.4 %) and 5oxo MEHTP (mean: 1.0 %; range 0.6-1.6 %). 2cx-MMHTP was a minor metabolite representing only 0.3 % (range 0.2-0.4 %). In total, about 16.1 % of the dose was recovered in urine as the above investigated specific metabolites within 48 h with the major share (95 %) being excreted within the first 24 h. Investigation of the glucuronidation patterns revealed that the carboxy-metabolites are excreted almost completely in their free form (>90 %), whereas for 5OH-MEHTP and 5oxo-MEHTP, glucuronidation is preferred (>70 %). With this study we provide reliable urinary excretion factors to calculate DEHTP intakes based on metabolite concentrations in environmental and occupational studies. PMID:27116293

  10. Estimating Emissions and Environmental Fate of Di-(2-ethylhexyl) Phthalate in Yangtze River Delta, China: Application of Inverse Modeling.

    PubMed

    Zhan, Yu; Sun, Jianteng; Luo, Yuzhou; Pan, Lili; Deng, Xunfei; Wei, Zi; Zhu, Lizhong

    2016-03-01

    A georeferenced multimedia model was developed for evaluating the emissions and environmental fate of di-2-ethylhexyl phthalate (DEHP) in the Yangtze River Delta (YRD), China. Due to the lack of emission inventories, the emission rates were estimated using the observed concentrations in soil as inputs for the multimedia model solved analytically in an inverse manner. The estimated emission rates were then used to evaluate the environmental fate of DEHP with the regular multimedia modeling approach. The predicted concentrations in air, surface water, and sediment were all consistent with the ranges and spatial variations of observed data. The total emission rate of DEHP in YRD was 13.9 thousand t/year (95% confidence interval: 9.4-23.6), of which urban and rural sources accounted for 47% and 53%, respectively. Soil in rural areas and sediment stored 79% and 13% of the total mass, respectively. The air received 61% of the total emissions of DEHP but was only associated with 0.2% of the total mass due to fast degradation and intensive deposition. We suggest the use of an inverse modeling approach under a tiered risk assessment framework to assist future development and refinement of DEHP emission inventories. PMID:26861906

  11. The extraction of americium and strontium by P,P'-Di(2-ethylhexyl) benzene-1,2- diphosphonic acid.

    SciTech Connect

    Otu, E. O.; Chiarizia, R.; Rickert, P. G.; Nash, K. L.; Chemistry; Indiana Univ. Southeast

    2002-01-01

    A new acidic organophosphorus extractant, P,P'-di(2-ethylhexyl) benzene-1,2-diphosphonic acid (H2DEH[1,2-BzDP]), has been synthesized. Though the extractant proved unstable with respect to acid hydrolysis upon storage at room temperature, it was sufficiently stable in o-xylene solution under refrigeration to determine its aggregation and extraction properties for Sr{sup 2+} and Am{sup 3+} between 25 and 60 C. Slope analysis of radioanalytical data and the results of osmometric measurements indicate that the dominant extraction reaction for both metal ions is M{sup n+}+n HL{l_equilibrium}ML{sub n}+n H{sup +} where n=2 for Sr(II) and 3 for Am(III). In the Sr system there is also evidence for the extraction of SrNO{sub 3}{sup +}. As the extractant aggregation and extraction stoichiometries do not change significantly with temperature, it was possible to derive enthalpies and entropies of extraction from the temperature dependence of the metal extraction equilibrium constants between 25.0 and 60.0 C. The extraction of both metal ions is driven by an exothermic enthalpy and opposed by unfavorable entropies. The thermodynamic data are discussed in comparison with earlier data on the thermodynamics of extraction of these metal ions by analogous ligands containing aliphatic alkyl linkages between the functional groups and other data from the literature.

  12. Maternal exposure to di-(2-ethylhexyl) phthalate exposure deregulates blood pressure, adiposity, cholesterol metabolism and social interaction in mouse offspring.

    PubMed

    Lee, Kuan-I; Chiang, Chin-Wei; Lin, Hui-Ching; Zhao, Jin-Feng; Li, Cheng-Ta; Shyue, Song-Kun; Lee, Tzong-Shyuan

    2016-05-01

    Long-term exposure to di-(2-ethylhexyl) phthalate (DEHP) is highly associated with carcinogenicity, fetotoxicity, psychological disorders and metabolic diseases, but the detrimental effects and mechanisms are not fully understood. We investigated the effect of exposing mouse mothers to DEHP, and the underlying mechanism, on blood pressure, obesity and cholesterol metabolism as well as psychological and learning behaviors in offspring. Tail-cuff plethysmography was used for blood pressure measurement; Western blot used was for phosphorylation and expression of protein; hematoxylin and eosin staining, Nissl staining and Golgi staining were used for histological examination. The serum levels of cholesterol, triglycerides and glucose were measured by blood biochemical analysis. Hepatic cholesterol and triglyceride levels were assessed by colorimetric assay kits. Offspring behaviors were evaluated by open-field activity, elevated plus maze, social preference test and Morris water maze. Maternal DEHP exposure deregulated the phosphorylation of endothelial nitric oxide synthase and upregulated angiotensin type 1 receptor in offspring, which led to increased blood pressure. It led to obesity in offspring by increasing the size of adipocytes in white adipose tissue and number of adipocytes in brown adipose tissue. It increased the serum level of cholesterol in offspring by decreasing the hepatic capacity for cholesterol clearance. The impaired social interaction ability induced by maternal DEHP exposure might be due to abnormal neuronal development. Collectively, our findings provide new evidence that maternal exposure to DEHP has a lasting effect on the physiological functions of the vascular system, adipose tissue and nerve system in offspring. PMID:25995009

  13. Mono-2-ethylhexyl phthalate stimulates androgen production but suppresses mitochondrial function in mouse leydig cells with different steroidogenic potential.

    PubMed

    Savchuk, Iuliia; Söder, Olle; Svechnikov, Konstantin

    2015-05-01

    Numerous studies have reported on testicular toxicity of phthalates in different experimental paradigms and showed that Leydig cells (LCs) were one of the main targets of phthalate actions. Adverse effects of phthalates on LCs steroidogenesis have been attributed to their metabolites, monophthalates. This study focuses on investigation whether LCs responsiveness to monophthalates action is associated with their potential to produce androgens. We found that of 3 monophthalates investigated [ie, mono-2-ethylhexyl phthalate (MEHP), mono-n-butyl phthalate, and mono-n-benzyl phthalate] only MEHP caused biological effects on the mouse LCs function. This monophthalate stimulated basal steroidogenesis associated with upregulation of StAR protein expression with no effect on hCG-stimulated androgen production by LCs from CBA/Lac and C57BL/6j mouse genotypes were observed. Further, MEHP attenuated ATP production and increased superoxide generation by both phenotypes of mouse LCs that indicated on mitochondrial dysfunction induced by the monophthalate. All together, our data indicate that MEHP-mediated stimulation of steroidogenesis and perturbation in mitochondrial function are not associated with the capacity of the LCs to synthesize androgens. We suggest that this effect of MEHP observed in LCs of rodent origin needs to be taken into consideration in analysis of earlier start of puberty in boys and may highlight a possible influence of phthalates on reproductive health in males. PMID:25677926

  14. Spectroscopic and molecular simulation studies on the interaction of di-(2-ethylhexyl) phthalate and human serum albumin.

    PubMed

    Wang, Yaping; Zhang, Guowen

    2015-03-01

    Di-(2-ethylhexyl) phthalate (DEHP) is widely used as a plasticizer in industrial production, but may have a potential health risk. In this study, the binding characteristics of DEHP with human serum albumin (HSA) in aqueous solution at pH 7.4 were determined using UV/vis absorption, fluorescence, Fourier transform infrared (FTIR) spectroscopy and circular dichroism (CD), along with a molecular simulation technique. Analysis of the fluorescence titration data at different temperatures suggested that the fluorescence quenching mechanism of HSA by DEHP was static. The calculated thermodynamic parameters indicated that hydrophobic forces played a predominant role in formation of the DEHP-HSA complex, but hydrogen bonds could not be omitted. Site marker competitive experiments and denaturation studies showed that the binding of DEHP to HSA primarily took place in subdomain IIA of HSA, and molecular docking results further corroborated the binding sites. The synchronous fluorescence, UV/vis absorption, FTIR and CD spectra revealed that the addition of DEHP induced changes in the secondary structure of HSA. Protein surface hydrophobicity (PSH) tests indicated that DEHP binding to HSA caused an increase in the PSH. Moreover, the effects of some metal ions on the binding constant of DEHP - HSA interaction were also investigated. PMID:24913815

  15. Prevention of di (2-ethylhexyl) Phthalate-induced Testicular Disturbance in Mice by Co-administration of L-carnitine

    PubMed Central

    Zare, Zohre; Mohammadi, Moslem; Eimani, Hossein; Shafaroudi, Majid Malekzadeh

    2011-01-01

    Background di (2-ethylhexyl) phthalate (DEHP) is widely used in the plastic industry and can induce reproductive toxicity. On the other hand, L-carnitine (LC) plays a crucial role in sperm metabolism and maturation. This study evaluates the effect of LC on body and testis weight, testis tissue, count, motility, viability, morphology, and chromatin quality of epididymal sperm, testicular spermatid number (TSN) per gram testis and daily sperm production (DSP) in LC-treated mice. Materials and Methods In this experimental study, adult male NMRI mice (mean age: 4 weeks) were given doses of DEHP and LC by gavaging for 2 weeks. All samples were assessed according to World Health Organization (WHO) criteria. Sperm morphology was assessed using Papanicolaou staining and sperm chromatin quality by aniline-blue staining. The left testes were fixed in Bouinś solution for histological examination and the end slices were stained with hematoxylin and eosin (H&E). The right testes were homogenized, and then TSN and DSP were calculated with an improved Neubauer haemocytometer and respective frames. Paired t-test, ANOVA, and Kruskal-Wallis tests were utilized for data analysis. Results Co-administration of DEHP and LC not only prevented significant gains in testicular weight, but also maintained the sperm’s normal morphology and chromatin quality (p<0.05). In addition, LC recovered histological changes, TSN, DSP, and sperm count. Conclusion These results demonstrated that oral administration of LC partially or generally protects spermatogenesis from DEHP-toxicity in mice. PMID:25101163

  16. Effects of in vitro exposure to butylparaben and di-(2 ethylhexyl) phthalate, alone or in combination, on ovarian function.

    PubMed

    Guerra, Marina T; Furlong, Hayley C; Kempinas, Wilma G; Foster, Warren G

    2016-09-01

    Parabens and phthalates are commercial chemicals widely used in the manufacture of industrial and consumer products frequently found as contaminants in biological fluids. We evaluated the effects of di-(2-ethylhexyl) phthalate (DEHP) (ranging from 10(-9) to 10(-7) m [1-100 nm; 0.39-39 ng ml(-1) ]) and butylparaben (BP) (ranging from 10(-8) to 10(-5) m [10 nm-10 μm; 1.9 ng ml(-1) to 1.9 μg ml(-1) ]), alone and in combination, on isolated mouse preantral follicle and human granulosa cell (hGC) cultures to study direct effects on follicle growth and ovarian steroidogenesis. Our results revealed that, in follicle culture, DEHP and BP attenuate estradiol output but only when present together. DEHP decreases progesterone concentrations in the spent media of hGC cultures, an effect that was attenuated when BP was added together with DEHP. Although changes in steroidogenesis were observed, no effects on follicular development or survival were noted in the culture systems. We suggest that BP and DEHP act with additive effect to decrease estradiol production whereas at later stages of follicle development BP blocks the effect of DEHP in hGCs resulting in decreased progesterone output. Taken together our results suggest that DEHP and BP adversely affect steroidogenesis from the preantral stage onward and the effects of these chemicals are both stage-dependent and modified by co-exposure. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27135907

  17. Lactational Exposure to Di (2-ethylhexyl) Phthalate Impairs the Ovarian and Uterine Function of Adult Offspring Rat.

    PubMed

    Somasundaram, Dinesh Babu; Selvanesan, Benson Chellakkan; Ramachandran, Ilangovan; Bhaskaran, Ravi Sankar

    2016-04-01

    Phthalates, a class of chemicals used as plasticizers, are economically important due to several industrial applications. Di-(2-ethylhexyl) phthalate (DEHP) is the most commonly used phthalate plasticizer, and it has been described as a potent antiandrogen in males. In this study, lactating dams were exposed via oral gavage to corn oil (vehicle) and DEHP (1, 10, and 100 mg/kg body weight) from postnatal day 1 to 21, and the effects were evaluated in the ovary and uterus of F1 progeny. DEHP exposure significantly decreased the body weight and organ weight in a dose-dependent manner. Serum levels of estradiol, testosterone, and progesterone were decreased but anogenital distance was unaffected. The mRNA expressions of luteinizing hormone receptor, follicle-stimulating hormone receptor, androgen receptor, estrogen receptor (ERα and ERβ), progesterone receptor, peroxisome proliferator-activated receptor γ, 3β hydroxysteroid dehydrogenase, aromatase, and steroidogenic acute regulatory protein were altered in the ovary of F1 progeny rats. Our finding suggest that lactational exposure to DEHP has transgenerational effect on female reproductive system. PMID:26482208

  18. Degradation of phthalate and di-(2-ethylhexyl)phthalate by indigenous and inoculated microorganisms in sludge-amended soil

    SciTech Connect

    Roslev, P.; Madsen, P.L.; Thyme, J.B.; Henriksen, K.

    1998-12-01

    The metabolism of phthalic acid (PA) and di-(2-ethylhexyl) (DEHP) in sludge-amended agricultural soil was studied with radiotracer techniques. The initial rates of metabolism of PA and DEHP were estimated to be 731.8 and 25.6 pmol/g (dry weight) per day, respectively. Indigenous microorganisms assimilated 28 and 17% of the carbon in [{sup 14}C]PA and [{sup 14}C]DEHP, respectively, into microbial biomass. The rates of DEHP metabolism were much greater in sludge assays without soil than in assays with sludge-amended soil. Mineralization of [{sup 14}C]DEHP to {sup 14}CO{sub 2} increased fourfold after inoculation of sludge and soil samples with DEHP-degrading strain SDE 2. The elevated mineralization potential was maintained for more than 27 days. Experiments performed with strain SDE 2 suggested that the bioavailability and mineralization of DEHP decreased substantially in the presence of soil and sludge components. The microorganisms metabolizing PA and DEHP in sludge and sludge-amended soil were characterized by substrate-specific radiolabelling, followed by analysis of {sup 14}C-labelled phospholipid ester-linked fatty acids ({sup 14}C-PLFAs).

  19. Spectroscopic study of the melting and reconstruction of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) reverse micelles from their frozen states.

    PubMed

    Suzuki, Akira; Yui, Hiroharu

    2015-04-01

    The confinement of water in organic self-assemblies with nanometer-sized pores is ubiquitous in nature. Water pools in sodium bis(2-ethylhexyl) sulfosuccinate (AOT) reverse micelles have been intensively studied as a representative model of such confined water. However, the freezing and melting behavior of such water pools is poorly understood owing to their poor structural stability under phase transition. In the present work, the melting of iced water pools accompanied by a reconstruction of AOT reverse micelles was studied with infrared spectroscopy. For all AOT reverse micelles tested (Rw: 1.2-4.4 nm), a characteristic ice-water coexistence phase was observed during melting. The results provide experimental evidence of the previously proposed core-shell structure of the water pool. For larger frozen reverse micelles (Rw>2.3 nm), shifts of the υ(OH) bands were observed. The spectra of the shifted υ(OH) bands were similar to those for the melted water pools in the smaller micelles. The mechanism of the reconstruction of AOT reverse micelles from their frozen states and the corresponding transient changes in the local environments were also discussed. PMID:25569193

  20. Interactions and aggregations in aqueous and brine solutions of poly(diallydimethylammonium chloride)/sodium bis(2-ethylhexyl) sulfosuccinate.

    PubMed

    Zheng, Peizhu; An, Xueqin; Peng, Xuhong; Shen, Weiguo

    2009-10-15

    The interactions between the anionic surfactant sodium bis(2-ethylhexyl) sulfosuccinate (AOT) and the polycation poly(diallydimethylammonium chloride) (PDDAC), the aggregations of AOT and PDDAC-bound AOT in PDDAC/AOT aqueous solutions, and the influence of salt on the interactions and aggregations have been studied by isothermal titration calorimetry (ITC), dynamic light scattering (DLS), and negative staining transmission electron microscopy (TEM). The adsorptions of AOT onto PDDAC and the formations of PDDAC-bound AOT micelles, free AOT micelles, and AOT vesicles were examined, and the corresponding critical concentrations were determined. Combining calculations of thermodynamic parameters with the above three experimental techniques, it was shown that the micellization of free AOT is driven by entropy gain, while the adsorption of AOT onto PDDAC and the micellization of PDDAC-bound AOT are driven by both enthalpy and entropy. It was also found that addition of salt enhances the binding of AOT onto PDDAC through the ion exchange and favors the formations of PDDAC/AOT micelles, free AOT micelles, and free AOT vesicles but prevents the transition of PDDAC/AOT micelles to the vesicles. Thermodynamic analysis suggested that the adsorption of AOT onto PDDAC and the micellization of PDDAC/AOT in PDDAC/AOT brine solutions are different in mechanism compared with that in corresponding aqueous solutions. PMID:19772316

  1. Conformational changes of beta-lactoglobulin in sodium bis(2-ethylhexyl) sulfosuccinate reverse micelles. A fluorescence and CD study.

    PubMed

    Andrade, Suzana M; Carvalho, Teresa I; Viseu, M Isabel; Costa, Sílvia M B

    2004-02-01

    The effect of beta-lactoglobulin encapsulation in sodium bis(2-ethylhexyl) sulfosuccinate reverse micelles on the environment of protein and on Trp was analysed at different water contents (omega0). CD data underlined the distortion of the beta-sheet and a less constrained tertiary structure as the omega0 increased, in agreement with a concomitant red shift and a decrease in the signal intensity obtained in steady-state fluorescence measurements. Fluorescence lifetimes, evaluated by biexponential analysis, were tau1 = 1.28 ns and tau2 = 3.36 ns in neutral water. In reverse micelles, decay-associated spectra indicated the occurrence of important environmental changes associated with omega0. Bimolecular fluorescence quenching by CCl4 and acrylamide was employed to analyse alterations in the accessibility of the two Trp residues in beta-lactoglobulin, induced by changes in omega0. The average bimolecular quenching constant was found not to depend on omega0, confirming the insolubility of this quencher in the aqueous interface, while increases with omega0. The drastic decrease with omega0 of kq, associated with the longest lifetime kq2(CCl4), comparatively to the increase of kq2(acrylamide), emphasizes the location of beta-lactoglobulin in the aqueous interfacial region especially at omega0> or = 10. The fact that (omega0 = 30) > kq2(acrylamide) (water) also confirms the important conformational changes of encapsulated beta-lactoglobulin. PMID:14764089

  2. Isolation and molecular identification of landfill bacteria capable of growing on di-(2-ethylhexyl) phthalate and deteriorating PVC materials

    PubMed Central

    Latorre, Isomar; Hwang, Sangchul; Montalvo-Rodriguez, Rafael

    2012-01-01

    Waste materials containing Di-(2-ethylhexyl) phthalate (DEHP), a suspected endocrine disruptor and reasonably anticipated human carcinogen, are typically disposed of in landfills. Despite this, very few studies had been conducted to isolate and identify DEHP-degrading bacteria in landfill leachate. Therefore, this study was conducted to isolate and characterize bacteria in landfill leachate growing on DEHP as the sole carbon source and deteriorating PVC materials. Four strains LHM1, LHM2, LHM3 and LHM4, not previously reported as DEHP-degraders, were identified via 16S rRNA gene sequence. Gram-positive strains LHM1 and LHM2 had a greater than 97% similarity with Chryseomicrobium imtechense MW 10(T) and Lysinibacillus fusiformis NBRC 15717(T), respectively. Gram-negative strains LHM3 and LHM4 were related to Acinetobacter calcoaceticus DSM 30006(T) (90.7% similarity) and Stenotrophomonas pavanii ICB 89(T) (96.0% similarity), respectively. Phylogenetic analysis also corroborated these similarities of strains LHM1 and LHM2 to the corresponding bacteria species. Strains LHM2 and LHM4 grew faster than strains LHM1 and LHM3 in the enrichment where DEHP was the sole carbon source. When augmented to the reactors with PVC shower curtains containing DEHP, strains LHM1 and LHM2 developed greater optical densities in the solution phase and thicker biofilm on the surfaces of the shower curtains. PMID:22934997

  3. Reversed micellar solution-to-bicontinuous microemulsion transition in sodium bis(2-ethylhexyl) phosphate/n-heptane/water system

    SciTech Connect

    Yu, Z.J.; Neuman, R.D.

    1995-04-01

    The solution structures in the three-component system sodium bis(2-ethylhexyl) phosphate (NaDEHP)/n-heptane/water have been investigated by dynamic and static light-scattering, electrical conductivity, and {sup 31}P-NMR spectroscopic and viscometric measurements. A transition in the physicochemical properties was observed over a rather narrow range of W{sub o} (molar ratio of water to NaDEHP) values. Rodlike reversed micelles and swollen rodlike reversed micelles form when W{sub o}< 4. Beyond this W{sub o} range, phase separation occurs at low NaDEHP concentrations, and homogeneous one-phase microemulsions form at high NaDEHP concentrations. It is suggested that the n-heptane-continuous solution of water-swollen reversed micelles transforms to a bicontinuous microemulsion when W{sub o} increases beyond W{sub o} {approx} 4. The bicontinuous microemulsion region ranges between two local viscosity maxima at W{sub o}{approx} 4 and W{sub o}{approx} 100, and an oil-in-water (O/W) microemulsion exists when W{sub o}> 100. Local dynamic domain structures consistent with the bicontinuous microemulsion behaviors are proposed and discussed. 29 refs., 7 figs., 1 tab.

  4. Effect of di(2-ethylhexyl) phthalate (DEHP) on lipolysis and lipoprotein lipase activities in adipose tissue of rats.

    PubMed

    Martinelli, Marcela I; Mocchiutti, Norberto O; Bernal, Claudio A

    2010-09-01

    The di(2-ethylhexyl) phthalate (DEHP) is an ubiquitous environmental chemical with detrimental health effects. The present work was designed to asses some potential mechanisms by which DEHP causes, among others, a reduced body fat retention. Since this effect could be related to an alteration of adipocyte triacylglycerol (TG) metabolism, we evaluated the effects of dietary DEHP in adipose tissues upon (1) the number and size of fat cells; (2) the basal and stimulated lipolysis and (3) the lipoprotein lipase (LPL) activity. Groups of male Wistar rats were fed for 21 days a control diet alone (control group) or the same control diet supplemented with 2% (w/w) of DEHP (DEHP group). The LPL activity of DEHP-fed rats was increased in lumbar and epididymal adipose tissues. These rats had significantly reduced weight in epididymal and lumbar tissues, together with reduced size of epididymal adipocytes. These alterations do not seem to be associated with higher lipid mobility because neither basal lipolysis nor 'in vitro' stimulated lipolysis by noradrenaline (NA) showed to be modified by DEHP. Based on these results, we concluded that the adipose tissue size reduction induced by DEHP intake is not due to changes in lipolysis nor to a decreased LPL activity. More research is needed to achieve a comprehensive understanding of the potential mechanisms by which DEHP causes, among others, a reduced body fat retention. PMID:20144957

  5. Structure, Stability, and Fragmentation of Sodium bis(2-ethylhexyl)Sulfosuccinate Negatively Charged Aggregates In Vacuo by MD Simulations

    NASA Astrophysics Data System (ADS)

    Longhi, Giovanna; Abbate, Sergio; Ceselli, Alberto; Ceraulo, Leopoldo; Fornili, Sandro L.; Turco Liveri, Vincenzo

    2014-09-01

    Negatively charged supramolecular aggregates formed in vacuo by n bis(2-ethylhexyl)sulfosuccinate (AOT-) anions and n + n c sodium counterions (i.e., [AOT n Na n+nc ] nc ) have been investigated by molecular dynamics (MD) simulations for n = 1 to 20 and n c = -1 to -5. By comparing the maximum excess charge values of negatively and positively charged AOTNa aggregates, it is found that the charge storage capability is higher for the latter systems, the difference decreasing as the aggregation number increases. Statistical analysis of physical properties like gyration radii and moment of inertia tensors of aggregates provides detailed information on their structural properties. Even for n c = -5, all stable aggregates show a reverse micelle-like structure with an internal core, including sodium counterions and surfactant polar heads, surrounded by an external layer consisting of the surfactant alkyl chains. Interestingly, the reverse micelle-like structure is retained also in proximity of fragmentation. Moreover, the aggregate shapes may be approximated by elongated ellipsoids whose longer axis increases with n and | n c |. The fragmentation patterns of a number of these aggregates have also been examined and have been found to markedly depend on the aggregate charge state. The simulated fragmentation patterns of a representative aggregate show good agreement with experimental data obtained using low collision voltages.

  6. Di-(2-ethylhexyl) phthalate induces apoptosis of GC-2spd cells via TR4/Bcl-2 pathway.

    PubMed

    Zhu, Lishan; Lu, Jinchang; Tang, Xiao; Fu, Guoqing; Duan, Peng; Quan, Chao; Zhang, Ling; Zhang, Zhibing; Chang, Wei; Shi, Yuqin

    2016-06-01

    Di-(2-ethylhexyl) phthalate (DEHP) is a widely used environmental endocrine disruptor. Many studies have reported that DEHP exposure causes reproductive toxicity and cells apoptosis. However, the mechanism by which DEHP exposure causes male reproductive toxicity remains unknown. This study investigated the role of the testicular orphan nuclear receptor4 (TR4)/Bcl-2 pathway in apoptosis induced by DEHP, which resulted in reproductive damage. To elucidate the mechanism underpinning the male reproductive toxicity of DEHP, we sought to investigate apoptotic effects, expression levels of TR4/Bcl-2 pathway in GC-2spd cells, including TR4, Bcl-2 and caspase-3. GC-2spd cells were exposed to various concentrations of DEHP (0, 50, 100, or 200μM). The results indicated that, with the increase of the concentrations of DEHP, the survival rate of cell decreased gradually. DEHP exposure at over 100μM significantly induced apoptotic cell death. DEHP decreased SOD and GSH-Px activity in 200μM group. Compared to the control group, the mRNA levels of caspase-3 increased significantly, however, Bcl-2 mRNA decreased (P<0.05). In addition, there was a significant reduction in TR4, Bcl-2 and procaspase-3 protein levels. Taken together, these results lead us to speculate that in vitro exposure to DEHP might induce apoptosis in GC-2spd cells through the TR4/Bcl-2 pathway. PMID:27084994

  7. Fourier transform infrared study on microemulsion system of potassium salt of bis(2-ethylhexyl) phosphinic acid (HA)

    NASA Astrophysics Data System (ADS)

    Zhou, Weijin; Shi, Nai; Wang, Yi; Chang, Zhiyuan; Wu, JinGuang

    1994-01-01

    To study microemulsion formation in a solvent extraction system is to probe into some basic principles of extraction chemistry in the light of combining extraction chemistry with surface chemistry. In our previous investigations, the microemulsions of the salts of HDEHP and PC88A have been studied systematically by FT-IR. In the experiment, we observed the change of peak positions and intensities of P equals O, P-O-C and P-O-H groups during saponification and hydration, and discovered that the peak of P-O-C splits apart into 1045 and 1075 cm-1. The vibration frequency of the P-O-C group in HDEHP and PC88A is quite close to the symmetric stretching frequency of the POO- group, and thus causes difficulties in the study of their peak position and absorbance variation. For this reason we synthesized bis(2-ethylhexyl) phosphinic acid without the P-O-C group. Infrared spectra in the range of 800 - 4000 cm-1 of this microemulsion system was studied.

  8. Structure, stability, and fragmentation of sodium bis(2-ethylhexyl)sulfosuccinate negatively charged aggregates in vacuo by MD simulations.

    PubMed

    Longhi, Giovanna; Abbate, Sergio; Ceselli, Alberto; Ceraulo, Leopoldo; Fornili, Sandro L; Turco Liveri, Vincenzo

    2014-09-01

    Negatively charged supramolecular aggregates formed in vacuo by n bis(2-ethylhexyl)sulfosuccinate (AOT(-)) anions and n + n(c) sodium counterions (i.e., [AOT(n) Na(n+nc)](nc)) have been investigated by molecular dynamics (MD) simulations for n = 1 to 20 and n(c) = -1 to -5. By comparing the maximum excess charge values of negatively and positively charged AOTNa aggregates, it is found that the charge storage capability is higher for the latter systems, the difference decreasing as the aggregation number increases. Statistical analysis of physical properties like gyration radii and moment of inertia tensors of aggregates provides detailed information on their structural properties. Even for n(c) = -5, all stable aggregates show a reverse micelle-like structure with an internal core, including sodium counterions and surfactant polar heads, surrounded by an external layer consisting of the surfactant alkyl chains. Interestingly, the reverse micelle-like structure is retained also in proximity of fragmentation. Moreover, the aggregate shapes may be approximated by elongated ellipsoids whose longer axis increases with n and |n(c)|. The fragmentation patterns of a number of these aggregates have also been examined and have been found to markedly depend on the aggregate charge state. The simulated fragmentation patterns of a representative aggregate show good agreement with experimental data obtained using low collision voltages. PMID:24969925

  9. CO2 foam properties and the stabilizing mechanism of sodium bis(2-ethylhexyl)sulfosuccinate and hydrophobic nanoparticle mixtures.

    PubMed

    Zhang, Chao; Li, Zhaomin; Sun, Qian; Wang, Peng; Wang, Shuhua; Liu, Wei

    2016-01-21

    In this work, we have prepared CO2-in-water foam by mixing partially hydrophobic SiO2 nanoparticles and sodium bis(2-ethylhexyl)sulfosuccinate (AOT) and studied its properties. The observation of the appearance of the foam revealed that, with the continuous addition of AOT, the phase behavior of the SiO2 nanoparticle and the AOT mixed system transformed from that of a two-phase system of aggregated nanoparticles into that of a uniform dispersed phase. Both foaming ability and foam stability were optimized when the nanoparticles and the AOT were mixed in a proportion of 1 : 5. On the basis of our findings from measurements of the dispersion properties, including measurements of the adsorption isotherm of the surfactant on the nanoparticles, zeta potentials, interfacial tension and the three-phase contact angle, we concluded that the synergistic interactions between the SiO2 nanoparticles and the AOT led to the adsorption of nanoparticles around the bubble surface and the formation of a spatial network structure of nanoparticles in the film, thereby enhancing the mechanical strength of the bubble and improving the resistance to outside disturbances, deformation and drainage. Laser scanning confocal microscopy (LCSM) analysis of the same foams further confirmed the existence of a "viscoelastic shell" wrapped around and protecting the bubble. PMID:26563818

  10. A review of alternatives to di (2-ethylhexyl) phthalate-containing medical devices in the neonatal intensive care unit

    PubMed Central

    Van Vliet, EDS; Reitano, EM; Chhabra, JS; Bergen, GP; Whyatt, RM

    2012-01-01

    Objective To conduct an extensive literature and toxicological database review on substitute compounds and available alternative medical products to replace polyvinyl chloride (PVC) and/or di(2-ethylhexyl) phthalate (DEHP), and conduct a DEHP-medical inventory analysis at a large metropolitan neonatal intensive care unit (NICU). Study Design A systematic search for DEHP-free alternative products was performed using online databases. An informal audit of a large metropolitan NICU was undertaken in 2005 and 2006; 21 products were identified that could potentially contain DEHP. Availability of DEHP-free alternatives was determined through company websites and phone interviews. Result Two alternative approaches are available for replacing DEHP in NICU medical products: (1) replacement by DEHP-free plasticizers; and (2) replacement of PVC entirely through the use of other polymers. Both approaches seem to provide less harmful substitutes to DEHP, but support PVC-free polymers as the preferred alternative. However, significant data gaps exist, particularly for the alternative polymers. In all, 10 out of 21 (48%) products in the NICU audit were DEHP-free; six consisted of alternative polymers and four of alternative plasticizers. Of the remaining 11 products, only three were available without DEHP at the time of the audit. Conclusion Because of significant data gaps, systematic toxicological testing of DEHP-free alternatives is imperative. Continued development of alternative products is also needed. PMID:21311501

  11. Combined small-angle x-ray scattering/extended x-ray absorption fine structure study of coated Co nanoclusters in bis(2-ethylhexyl)sulfosuccinate

    NASA Astrophysics Data System (ADS)

    Longo, A.; Giordano, F.; Giannici, F.; Martorana, A.; Portale, G.; Ruggirello, A.; Turco Liveri, V.

    2009-06-01

    Chemically stable cobalt nanostructures have been prepared with Co(II) reduction in the confined space of cobalt bis(2-ethylhexyl)sulfosuccinate, Co(AOT)2, reverse micelles dispersed in n-heptane. The reaction was carried out by adding a solution of sodium borohydride in ethanol (1% weight) to a 0.2M micellar solution of Co(AOT)2 in n-heptane at a reductant to Co(II) molar ratio of 4. This procedure involves the rapid formation of surfactant-coated Co nanoparticles followed by their slow separation as nanostructures embedded in a sodium bis(2-ethylhexyl)sulfosuccinate matrix. The resulting composites, characterized by extended x-ray absorption fine structure and small-angle x-ray scattering, showed the presence of subnanometer sized cobalt nanoparticles aggregated together to form elongated structures coated by the surfactant molecules.

  12. Mycelial fungi completely remediate di(2-ethylhexyl)phthalate, the hazardous plasticizer in PVC blood storage bag.

    PubMed

    Pradeep, S; Benjamin, Sailas

    2012-10-15

    This pioneering work describes how simply, inexpensively and efficiently novel fungi utilize the alarming plasticizer, di(2-ethylhexyl)phthalate (DEHP) blended in PVC blood storage bags (BB). In order to quantify total DEHP (33.5%, w/w) present in BB, it was extracted using n-hexane and confirmed by GC-MS. Three mycelial fungi, viz., Aspergillus parasiticus, Fusarium subglutinans and Penicillium funiculosum isolated in our laboratory form heavily plastics-contaminated soil - either singly or in consortium - completely consumed intact DEHP physically bound to BB by static submerged growth (28 °C) in simple basal salt medium (BSM). A two-stage cultivation strategy was adopted for the complete removal of DEHP from BB in situ. During the first growth stage, almost 70% DEHP contained in the BB was consumed in 2 weeks, accompanied by increased fungal biomass (~0.15-0.35 g/g BB; OD ~7 at 600 nm) and a sharp declining (3.3) of initial pH (7.2). Spent BSM was replaced at this stagnant growth state (low pH), thus in the second stage, remaining DEHP bound to BB utilized completely (over 99%). Furthermore, A. parasiticus and F. subglutinans also grew well on scrapes of PVC water pipes in BSM. F. subglutinans was as efficient independently as consortium in completely utilizing the DEHP bound to BB, and these fungi offer great potentials for the inexpensive and eco-friendly bioremediation of phthalates in medical and allied PVC wastes on a large scale through a batch process in alleviating the plactics waste management issue. PMID:22858127

  13. Leaching of the plasticizer di(2-ethylhexyl)phthalate (DEHP) from plastic containers and the question of human exposure.

    PubMed

    Erythropel, Hanno C; Maric, Milan; Nicell, Jim A; Leask, Richard L; Yargeau, Viviane

    2014-12-01

    Di(2-ethylhexyl)phthalate (DEHP) is a widely used plasticizer to render poly(vinyl chloride) (PVC) soft and malleable. Plasticized PVC is used in hospital equipment, food wrapping, and numerous other commercial and industrial products. Unfortunately, plasticizers can migrate within the material and leach out of it over time, ending up in the environment and, frequently, the human body. DEHP has come under increased scrutiny as its breakdown products are believed to be endocrine disruptors and more toxic than DEHP itself. DEHP and its breakdown products have been identified as ubiquitous environmental contaminants, and daily human exposure is estimated to be in the microgram per kilogram level. The objective of this review is to summarize and comment on published sources of DEHP exposure and to give an overview of its environmental fate. Exposure through bottled water was examined specifically, as this concern is raised frequently, yet only little exposure to DEHP occurs through bottled water, and DEHP exposure is unlikely to stem from the packaging material itself. Packaged food was also examined and showed higher levels of DEHP contamination compared to bottled water. Exposure to DEHP also occurs in hospital environments, where DEHP leaches directly into liquids that passed through PVC/DEHP tubing and equipment. The latter exposure is at considerably higher levels compared to food and bottled water, specifically putting patients with chronic illnesses at risk. Overall, levels of DEHP in food and bottled water were below current tolerable daily intake (TDI) values. However, our understanding of the risks of DEHP exposure is still evolving. Given the prevalence of DEHP in our atmosphere and environment, and the uncertainty revolving around it, the precautionary principle would suggest its phaseout and replacement. Increased efforts to develop viable replacement compounds, which necessarily includes rigorous leaching, toxicity, and impact assessment studies, are

  14. Exposure to di-2-ethylhexyl phthalate, di-n-butyl phthalate and bisphenol A through infant formulas.

    PubMed

    Cirillo, Teresa; Latini, Giuseppe; Castaldi, Maria Antonietta; Dipaola, Lucia; Fasano, Evelina; Esposito, Francesco; Scognamiglio, Gelsomina; Francesco, Fabio Di; Cobellis, Luigi

    2015-04-01

    Phthalates and bisphenol A (BPA) are ubiquitous contaminants identified as endocrine disruptors. Phthalates are worldwide used as plasticizers, in particular to improve the mechanical properties of polymers such as polyvinyl chloride. Because they are not chemically bound to the polymer, they tend to leach out with time and use. Di-2-ethylhexyl phthalate (DEHP) and di-n-butyl phthalate (DnBP) are the two most common phthalates. BPA is an estrogenic compound used to manufacture polycarbonate containers for food and drink, including baby bottles. It can migrate from container into foods, especially at elevated temperatures. Diet is a predominant source of exposure for phthalates and BPA, especially for infants. The aim of this study was to test the presence of DEHP, DnBP, and BPA in infant formulas. DEHP, DnBP, and BPA concentrations were measured in 22 liquid and 28 powder milks by gas chromatography with flame ionization detection and high performance liquid chromatography with fluorimetric detection, respectively. DEHP concentrations in our samples were between 0.005 and 5.088 μg/g (median 0.906 μg/g), DnBP concentrations were between 0.008 and 1.297 μg/g (median 0.053 μg/g), and BPA concentrations were between 0.003 and 0.375 μg/g (median 0.015 μg/g). Concentrations of the investigated contaminants in liquid and powder milks were not significantly different, even though samples were packed in different types of containers. These data point out potential hazards for infants fed with baby formulas. Contamination seems more related to the production of formulas than to a release from containers. PMID:25730646

  15. Relative sensitivity of developmental and immune parameters in juvenile versus adult male rats after exposure to di(2-ethylhexyl) phthalate

    SciTech Connect

    Tonk, Elisa C.M.; Verhoef, Aart; Gremmer, Eric R.; Loveren, Henk van; Piersma, Aldert H.

    2012-04-01

    The developing immune system displays a relatively high sensitivity as compared to both general toxicity parameters and to the adult immune system. In this study we have performed such comparisons using di(2-ethylhexyl) phthalate (DEHP) as a model compound. DEHP is the most abundant phthalate in the environment and perinatal exposure to DEHP has been shown to disrupt male sexual differentiation. In addition, phthalate exposure has been associated with immune dysfunction as evidenced by effects on the expression of allergy. Male wistar rats were dosed with corn oil or DEHP by gavage from postnatal day (PND) 10–50 or PND 50–90 at doses between 1 and 1000 mg/kg/day. Androgen-dependent organ weights showed effects at lower dose levels in juvenile versus adult animals. Immune parameters affected included TDAR parameters in both age groups, NK activity in juvenile animals and TNF-α production by adherent splenocytes in adult animals. Immune parameters were affected at lower dose levels compared to developmental parameters. Overall, more immune parameters were affected in juvenile animals compared to adult animals and effects were observed at lower dose levels. The results of this study show a relatively higher sensitivity of juvenile versus adult rats. Furthermore, they illustrate the relative sensitivity of the developing immune system in juvenile animals as compared to general toxicity and developmental parameters. This study therefore provides further argumentation for performing dedicated developmental immune toxicity testing as a default in regulatory toxicology. -- Highlights: ► In this study we evaluate the relative sensitivities for DEHP induced effects. ► Results of this study demonstrate the age-dependency of DEHP toxicity. ► Functional immune parameters were more sensitive than structural immune parameters. ► Immune parameters were affected at lower dose levels than developmental parameters. ► Findings demonstrate the susceptibility of the

  16. Di(2-ethylhexyl) phthalate inhibits antral follicle growth, induces atresia, and inhibits steroid hormone production in cultured mouse antral follicles.

    PubMed

    Hannon, Patrick R; Brannick, Katherine E; Wang, Wei; Gupta, Rupesh K; Flaws, Jodi A

    2015-04-01

    Di(2-ethylhexyl) phthalate (DEHP) is a ubiquitous environmental toxicant found in consumer products that causes ovarian toxicity. Antral follicles are the functional ovarian units and must undergo growth, survival from atresia, and proper regulation of steroidogenesis to ovulate and produce hormones. Previous studies have determined that DEHP inhibits antral follicle growth and decreases estradiol levels in vitro; however, the mechanism by which DEHP elicits these effects is unknown. The present study tested the hypothesis that DEHP directly alters regulators of the cell cycle, apoptosis, and steroidogenesis to inhibit antral follicle functionality. Antral follicles from adult CD-1 mice were cultured with vehicle control or DEHP (1-100 μg/ml) for 24-96 h to establish the temporal effects of DEHP on the follicle. Following 24-96 h of culture, antral follicles were subjected to gene expression analysis, and media were subjected to measurements of hormone levels. DEHP increased the mRNA levels of cyclin D2, cyclin dependent kinase 4, cyclin E1, cyclin A2, and cyclin B1 and decreased the levels of cyclin-dependent kinase inhibitor 1A prior to growth inhibition. Additionally, DEHP increased the mRNA levels of BCL2-associated agonist of cell death, BCL2-associated X protein, BCL2-related ovarian killer protein, B-cell leukemia/lymphoma 2, and Bcl2-like 10, leading to an increase in atresia. Further, DEHP decreased the levels of progesterone, androstenedione, and testosterone prior to the decrease in estradiol levels, with decreased mRNA levels of side-chain cleavage, 17α-hydroxylase-17,20-desmolase, 17β-hydroxysteroid dehydrogenase, and aromatase. Collectively, DEHP directly alters antral follicle functionality by inhibiting growth, inducing atresia, and inhibiting steroidogenesis. PMID:25701202

  17. The effects of di(2-ethylhexyl) phthalate and/or selenium on trace element levels in different organs of rats.

    PubMed

    Erkekoglu, Pinar; Arnaud, Josiane; Rachidi, Walid; Kocer-Gumusel, Belma; Favier, Alain; Hincal, Filiz

    2015-01-01

    Di(2-ethylhexyl)phthalate (DEHP), a widely used plasticizer for synthetic polymers, is known to have endocrine disruptive potential, reproductive toxicity, and induces hepatic carcinogenesis in rodents. Selenium (Se) is a component of several selenoenzymes which are essential for cellular antioxidant defense and for the functions of mammalian reproductive system. The present study was designed to investigate the effects of DEHP exposure on trace element distribution in liver, testis, and kidney tissues and plasma of Se-deficient and Se-supplemented rats. Se deficiency was produced by feeding 3-week old Sprague-Dawley rats with ≤0.05mg Se/kg diet for 5 weeks, and supplementation group were on 1mg Se/kg diet. DEHP treated groups received 1000mg/kg dose by gavage during the last 10 days of feeding period. Se, zinc (Zn), copper (Cu), iron (Fe) and manganese (Mn) levels were measured by inductively coupled plasma mass spectrometry (ICP-MS). Se supplementation caused significant increases in hepatic, renal, and testicular Se levels. With DEHP exposure, plasma Se and Zn, kidney Se, Cu and Mn levels were significantly decreased. Besides, liver Fe decreased markedly in all the DEHP-treated groups. Liver and kidney Mn levels decreased significantly in DEHP/SeD group compared to both DEHP and SeD groups. These results showed the potential of DEHP exposure and/or different Se status to modify the distribution pattern of essential trace elements in various tissues, the importance of which needs to be further evaluated. PMID:25193691

  18. Desensitization of ovalbumin-sensitized mice by repeated co-administrations of di-(2-ethylhexyl) phthalate and ovalbumin

    PubMed Central

    Larsen, Søren T; Nielsen, Gunnar D

    2009-01-01

    Background The plasticizer di-(2-ethylhexyl) phthalate (DEHP) has been shown to stimulate a non-allergy related immune response with increased levels of IgG1 and IgG2a, but not IgE, after co-administration with the model allergen ovalbumin (OVA) in mice. In mice, decreased IgG1 and increased IgG2a have been associated with the development of mucosal tolerance towards inhaled allergens. As DEHP selectively promote formations of IgG1 and IgG2a without stimulating the IgE response, it was hypothesized that DEHP may suppress an established IgE mediated allergic response. Mice pre-sensitised to OVA were repeatedly co-exposed to DEHP and OVA and the effects were evaluated on the levels of OVA-specific antibodies, ex vivo cytokine levels and the degree of lung inflammation after challenge with an OVA aerosol. Findings Compared to the OVA-sensitised control mice, multiple co-exposures to DEHP+OVA reduced the IgG1 level and reduced the IgE/IgG2a ratio. This suggests that DEHP may attenuate allergic sensitisation, as the IgE/IgG2a ratio has been shown to correlate with the degree of anaphylaxis. Nevertheless, no effect of DEHP exposures was seen on inflammatory cells in bronchoalveolar lavage fluid and on cytokine levels in spleen cell culture. Conclusion Data from humane and murine studies suggest that DEHP may attenuate the allergic response. More studies are necessary in order to assess the size of this effect and to rule out the underlying mechanism. PMID:19900263

  19. Diffusion and accumulation in cultivated vegetable plants of di-(2-ethylhexyl) phthalate (DEHP) from a plastic production factory.

    PubMed

    Du, Q Z; Wang, J W; Fu, X W; Xia, H L

    2010-08-01

    Di-(2-ethylhexyl) phthalate (DEHP) concentrations in the atmosphere and in four vegetable crops including Brassica chinensis L. (bok choy), Brassica campestris L. (field mustard), Vigna unguiculata Walp. (cowpea), and Solanum melongena L. (eggplant) cultivated on land surrounding a plastic production factory were determined. The air DEHP concentrations (means) at the sites 0.2, 0.4, 0.8, and 1.6 km away from the plastic production building were about 9.4-12.8, 5.8-9.6, 1.6-5.0, and 0.04-0.27 microg m(-3) dry weight (DW), respectively. Wind direction is a key factor influencing the measurable DEHP concentration of the air, which was highest in the downwind direction and lowest in the upwind direction, and thus the vegetables accumulated the highest DEHP contents in the downwind direction and the lowest quantities in the upwind direction. The highest DEHP accumulations content of bok choy, field mustard, eggplant, and cowpea were 52.0 +/- 3.1, 43.1 +/- 2.2, 36.2 +/- 2.8, and 19.4 +/- 0.47 mg kg(-1) DW, respectively. Safety estimation on the basis of the daily intake limit referenced by the US Environmental Protection Agency (USEPA) led to the conclusion that eating vegetables cultivated 0.2 km away from the plastic production building is not a food safety problem under normal conditions. A strong positive linear correlation between atmospheric DEHP concentration and DEHP content of the vegetable crops was found. The limits for air DEHP concentration for safe vegetable cultivation are 24.0, 34.8, 40.8, and 82.8 microg m(-3) for bok choy, field mustard, cowpea, and eggplant, respectively, by calculating from the equation of linear regression between air DEHP concentration and vegetable DEHP content. PMID:20496185

  20. Extraction of alkaline earth and actinide cations by mixtures of Di(2-ethylhexyl)alkylenediphosphonic acids and neutral synergists.

    SciTech Connect

    McAlister, D. R.; Chiarizia, R.; Dietz, M. L.; Herlinger, A. W.; Zalupski, P. R.; Chemistry; Loyola Univ.

    2002-09-18

    The synergistic extraction of alkaline earth (Ca{sup 2+}, Sr{sup 2+}, Ba{sup 2+} and Ra{sup 2+}) and actinide (Am{sup 3+}, UO{sub 2}{sup 2+} and Th{sup 4+}) cations from aqueous nitric acid solutions by mixtures of P,P'-di(2-ethylhexyl) methylene-(H{sub 2}DEH[MDP]), ethylene-(H{sub 2}DEH[EDP]), and butylene-(H{sub 2}DEH[BuDP]) diphosphonic acids and neutral extractants in o-xylene has been investigated. The cis-syn-cis and cis-anti-cis stereoisomers of dicyclohexano-18-crown-6 (DCH18C6), the unsubstituted 21-crown-7 (21C7) and dicyclohexano-21-crown-7 (DCH21C7) were used as neutral synergists of the crown ether type. For Am(III) synergistic effects were also investigated using neutral organophosphorus esters, such as, tri-n-butylphosphate (TBP), diamyl amylphosphonate (DA[AP]) and tri-n-octylphosphine oxide (TOPO) as co-extractants. In all systems investigated, no synergistic extraction enhancement was observed for actinide ions. For the alkaline earth cations, synergistic effects were only observed when mixtures of H{sub 2}DEH[EDP] or H{sub 2}DEH-[BuDP] with DCH18C6 were used to extract Sr{sup 2+}, Ba{sup 2+} and Ra{sup 2+}. No synergistic effects were observed for the extraction of alkaline earth cations by H{sub 2}DEH[MDP] or for the extraction of Ca{sup 2+} by any of the diphosphonic acids studied. The synergistic effects obtained with DCH18C6 were significantly higher for the cis-syn-cis than for the cis-anti-cis stereoisomer.

  1. Electromembrane extraction of polar basic drugs from plasma with pure bis(2-ethylhexyl) phosphite as supported liquid membrane.

    PubMed

    Huang, Chuixiu; Seip, Knut Fredrik; Gjelstad, Astrid; Pedersen-Bjergaard, Stig

    2016-08-31

    Electromembrane extraction (EME) of polar basic drugs from human plasma was investigated for the first time using pure bis(2-ethylhexyl) phosphite (DEHPi) as the supported liquid membrane (SLM). The polar basic drugs metaraminol, benzamidine, sotalol, phenylpropanolamine, ephedrine, and trimethoprim were selected as model analytes, and were extracted from 300 μL of human plasma, through 10 μL of DEHPi as SLM, and into 100 μL of 10 mM formic acid as acceptor solution. The extraction potential across the SLM was 100 V, and extractions were performed for 20 min. After EME, the acceptor solutions were analyzed by high-performance liquid chromatography-ultraviolet detection (HPLC-UV). In contrast to other SLMs reported for polar basic drugs in the literature, the SLM of DEHPi was highly stable in contact with plasma, and the system-current across the SLM was easily kept below 50 μA. Thus, electrolysis in the sample and acceptor solution was kept at an acceptable level with no detrimental consequences. For the polar model analytes, representing a log P range from -0.40 to 1.32, recoveries in the range 25-91% were obtained from human plasma. Strong hydrogen bonding and dipole interactions were probably responsible for efficient transfer of the model analytes into the SLM, and this is the first report on efficient EME of highly polar analytes without using any ionic carrier in the SLM. PMID:27506347

  2. Di(2-ethylhexyl) phthalate inhibits antral follicle growth, induces atresia, and inhibits steroid hormone production in cultured mouse antral follicles

    SciTech Connect

    Hannon, Patrick R. Brannick, Katherine E. Wang, Wei Gupta, Rupesh K. Flaws, Jodi A.

    2015-04-01

    Di(2-ethylhexyl) phthalate (DEHP) is a ubiquitous environmental toxicant found in consumer products that causes ovarian toxicity. Antral follicles are the functional ovarian units and must undergo growth, survival from atresia, and proper regulation of steroidogenesis to ovulate and produce hormones. Previous studies have determined that DEHP inhibits antral follicle growth and decreases estradiol levels in vitro; however, the mechanism by which DEHP elicits these effects is unknown. The present study tested the hypothesis that DEHP directly alters regulators of the cell cycle, apoptosis, and steroidogenesis to inhibit antral follicle functionality. Antral follicles from adult CD-1 mice were cultured with vehicle control or DEHP (1–100 μg/ml) for 24–96 h to establish the temporal effects of DEHP on the follicle. Following 24–96 h of culture, antral follicles were subjected to gene expression analysis, and media were subjected to measurements of hormone levels. DEHP increased the mRNA levels of cyclin D2, cyclin dependent kinase 4, cyclin E1, cyclin A2, and cyclin B1 and decreased the levels of cyclin-dependent kinase inhibitor 1A prior to growth inhibition. Additionally, DEHP increased the mRNA levels of BCL2-associated agonist of cell death, BCL2-associated X protein, BCL2-related ovarian killer protein, B-cell leukemia/lymphoma 2, and Bcl2-like 10, leading to an increase in atresia. Further, DEHP decreased the levels of progesterone, androstenedione, and testosterone prior to the decrease in estradiol levels, with decreased mRNA levels of side-chain cleavage, 17α-hydroxylase-17,20-desmolase, 17β-hydroxysteroid dehydrogenase, and aromatase. Collectively, DEHP directly alters antral follicle functionality by inhibiting growth, inducing atresia, and inhibiting steroidogenesis. - Highlights: • DEHP inhibits antral follicle growth by dysregulating cell cycle regulators. • DEHP induces antral follicle atresia by dysregulating apoptosis regulators. • DEHP

  3. Maternal in utero exposure to the endocrine disruptor di-(2-ethylhexyl) phthalate affects the blood pressure of adult male offspring

    SciTech Connect

    Martinez–Arguelles, D.B.; McIntosh, M.; Rohlicek, C.V.; Culty, M.; Zirkin, B.R.; Papadopoulos, V.

    2013-01-01

    Di-(2-ethylhexyl) phthalate (DEHP) is used industrially to add flexibility to polyvinyl chloride (PVC) polymers and is ubiquitously found in the environment, with evidence of prenatal, perinatal and early infant exposure in humans. In utero exposure to DEHP decreases circulating testosterone levels in the adult rat. In addition, DEHP reduces the expression of the angiotensin II receptors in the adrenal gland, resulting in decreased circulating aldosterone levels. The latter may have important effects on water and electrolyte balance as well as systemic arterial blood pressure. Therefore, we determined the effects of in utero exposure to DEHP on systemic arterial blood pressure in the young (2 month-old) and older (6.5 month-old) adult rats. Sprague-Dawley pregnant dams were exposed from gestational day 14 until birth to 300 mg DEHP/kg/day. Blood pressure, heart rate, and activity data were collected using an intra-aortal transmitter in the male offspring at postnatal day (PND) 60 and PND200. A low (0.01%) and high-salt (8%) diet was used to challenge the animals at PND200. In utero exposure to DEHP resulted in reduced activity at PND60. At PND200, systolic and diastolic systemic arterial pressures as well as activity were reduced in response to DEHP exposure. This is the first evidence showing that in utero exposure to DEHP has cardiovascular and behavioral effects in the adult male offspring. Highlights: ► In utero exposure to 300 mg DEHP/kg/day decreases activity at postnatal day 60. ► In utero exposure to DEHP decreases aldosterone levels at postnatal day 200. ► In utero exposure to DEHP decreases systolic blood pressure at postnatal day 200. ► An 8% salt diet recovers the decreased blood pressure at postnatal day 200.

  4. Magnetic resonance studies of a redox probe in a reverse sodium bis(2-ethylhexyl)sulfosuccinate/octane/water microemulsion.

    PubMed

    Binks, Daniel A; Spencer, Neil; Wilkie, John; Britton, Melanie M

    2010-10-01

    The location and dynamics of the [Ru(bpy)(3)](2+) complex inside sodium bis(2-ethylhexyl)sulfosuccinate (AOT)/octane/water microemulsions were studied, over a range of droplet sizes, using magnetic resonance spectroscopy, dynamic light scattering, and molecular modeling. The T(1) magnetic resonance relaxation times of water inside the AOT reverse micelles (RMs) were measured in both the presence and the absence of the [Ru(bpy)(3)](2+) complex. Large size droplet RMs (ω(0) > 20) were found to be sensitive to the presence of the [Ru(bpy)(3)](2+) complex, which was detected through a decrease in the T(1) relaxation time of the water inside the RM core, as compared to RMs containing no [Ru(bpy)(3)](2+). However, no difference in T(1) relaxation time was observed for water in small RMs (ω(0) < 20). Two-dimensional (1)H-(1)H NOESY spectroscopy was performed to probe the location of the [Ru(bpy)(3)](2+) complex in both small (ω(0) = 9.2) and large droplets (ω(0) = 34.9). Cross-peaks between protons in the AOT tail groups and bipyridyl ligands were observed, showing that the [Ru(bpy)(3)](2+) complex resided in the RM interface. Finally, molecular modeling simulations were performed to probe the location of the [Ru(bpy)(3)](2+) complex and the structure of the RM. Molecular dynamics simulations confirmed the location of the [Ru(bpy)(3)](2+) complex in the RM interface and detected differences in the surfactant layer and the amount of water penetration into this layer with changing droplet size. PMID:20831183

  5. Effect of mono-(2-ethylhexyl) phthalate on human and mouse fetal testis: In vitro and in vivo approaches

    SciTech Connect

    Muczynski, V.; Cravedi, J.P.; Lehraiki, A.; Levacher, C.; Moison, D.; Lecureuil, C.; Messiaen, S.; Perdu, E.; Frydman, R.; Habert, R.; and others

    2012-05-15

    The present study was conducted to determine whether exposure to the mono-(2-ethylhexyl) phthalate (MEHP) represents a genuine threat to male human reproductive function. To this aim, we investigated the effects on human male fetal germ cells of a 10{sup −5} M exposure. This dose is slightly above the mean concentrations found in human fetal cord blood samples by biomonitoring studies. The in vitro experimental approach was further validated for phthalate toxicity assessment by comparing the effects of in vitro and in vivo exposure in mouse testes. Human fetal testes were recovered during the first trimester (7–12 weeks) of gestation and cultured in the presence or not of 10{sup −5} M MEHP for three days. Apoptosis was quantified by measuring the percentage of Caspase-3 positive germ cells. The concentration of phthalate reaching the fetal gonads was determined by radioactivity measurements, after incubations with {sup 14}C-MEHP. A 10{sup −5} M exposure significantly increased the rate of apoptosis in human male fetal germ cells. The intratesticular MEHP concentration measured corresponded to the concentration added in vitro to the culture medium. Furthermore, a comparable effect on germ cell apoptosis in mouse fetal testes was induced both in vitro and in vivo. This study suggests that this 10{sup −5} M exposure is sufficient to induce changes to the in vivo development of the human fetal male germ cells. -- Highlights: ► 10{sup −5} M of MEHP impairs germ cell development in the human fetal testis. ► Organotypic culture is a suitable approach to investigate phthalate effects in human. ► MEHP is not metabolized in the human fetal testis. ► In mice, MEHP triggers similar effects both in vivo and in vitro.

  6. Di(2-ethylhexyl) phthalate inhibits antral follicle growth, induces atresia, and inhibits steroid hormone production in cultured mouse antral follicles

    PubMed Central

    Hannon, Patrick R.; Brannick, Katherine E.; Wang, Wei; Gupta, Rupesh K.; Flaws, Jodi A.

    2015-01-01

    Di(2-ethylhexyl) phthalate (DEHP) is a ubiquitous environmental toxicant found in consumer products that causes ovarian toxicity. Antral follicles are the functional ovarian units and must undergo growth, survival from atresia, and proper regulation of steroidogenesis to ovulate and produce hormones. Previous studies have determined that DEHP inhibits antral follicle growth and decreases estradiol levels in vitro; however, the mechanism by which DEHP elicits these effects is unknown. The present study tested the hypothesis that DEHP directly alters regulators of the cell cycle, apoptosis, and steroidogenesis to inhibit antral follicle functionality. Antral follicles from adult CD-1 mice were cultured with vehicle control or DEHP (1-100μg/ml) for 24-96 hr to establish the temporal effects of DEHP on the follicle. Following 24-96 hr of culture, antral follicles were subjected to gene expression analysis, and media were subjected to measurements of hormone levels. DEHP increased the mRNA levels of cyclin D2, cyclin dependent kinase 4, cyclin E1, cyclin A2, and cyclin B1 and decreased the levels of cyclin-dependent kinase inhibitor 1A prior to growth inhibition. Additionally, DEHP increased the mRNA levels of BCL2-associated agonist of cell death, BCL2-associated X protein, BCL2-related ovarian killer protein, B-cell leukemia/lymphoma 2, and Bcl2-like 10, leading to an increase in atresia. Further, DEHP decreased the levels of progesterone, androstenedione, and testosterone prior to the decrease in estradiol levels, with decreased mRNA levels of side-chain cleavage, 17α-hydorxylase-17,20-desmolase, 17β-hydroxysteroid dehydrogenase, and aromatase. Collectively, DEHP directly alters antral follicle functionality by inhibiting growth, inducing atresia, and inhibiting steroidogenesis. PMID:25701202

  7. Disruption of reproductive development in male rat offspring following gestational and lactational exposure to di-(2-ethylhexyl) phthalate and genistein.

    PubMed

    Zhang, Lian-Dong; Deng, Qian; Wang, Zi-Ming; Gao, Ming; Wang, Lei; Chong, Tie; Li, He-Cheng

    2013-01-01

    Studies of developmental effects of mixtures of endocrine disrupters on the male reproductive system are of great concern. In this study, the reproductive effects of the co-administration of di-2-(ethylhexyl) phthalate (DEHP) and genistein (GEN) during pregnancy and lactation were studied in male rat offspring. Pregnant Sprague-Dawley rats were gavaged from gestation day 3 to postnatal day 21 with vehicle control, DEHP 250 mg/kg body weight (bwyday, GEN 50 mg/kg bwday, GEN 400 mg/kg bwday, and two combinations of the two compounds (DEHP 250 mg/kg bwday + GEN 50 mg/kg bwday, DEHP 250 mg/kg bwday + GEN 400 mg/kg bwday). The outcomes studied were general morphometry (weight, AGD), testicular histology, testosterone levels, and expression at the mRNA level of genes involved in steroidogenesis. Organ coefficient, AGD / body weight1/3 י, serum testosterone concentration and genes involved in steroidogenic pathway expression when exposed to DEHP (250mg/kg bwday), GEN(50mg/kg bwday) or GEN(400mg/kg bwday) alone were not significantly different from the control group. When exposed to (DEHP 250mg/kg bwday +GEN 50mg/kg bwday) together during pregnancy and lactation, serum testosterone concentration, epididymis coefficient and Cypal17a1,Scarb1 m RNA expression significantly decreased compared to the control and GEN(50mg/kg bwday). When exposed to (DEHP 250mg/kg bwday +GEN 400mg/kg bwday) together during pregnancy and lactation, AGD / body weight1/3 י, serum testosterone concentration, testis and epididymis coefficient and Star, Cypal17a1 mRNA expression appeared significantly decreased compared to the control and DEHP/GEN single exposure, together with developmental impairment of seminiferous tubules and seminiferous epithelium. Overall, co-administration of DEHP and GEN during gestation and lactation seem to acts in a cumulative manner to induce the most significant alterations in the neonate, especially with GEN at high dose, although the effect of the DEHP-GEN mixture on

  8. Di-(2-ethylhexyl)-phthalate disrupts pituitary and testicular hormonal functions to reduce sperm quality in mature goldfish.

    PubMed

    Golshan, Mahdi; Hatef, Azadeh; Socha, Magdalena; Milla, Sylvain; Butts, Ian A E; Carnevali, Oliana; Rodina, Marek; Sokołowska-Mikołajczyk, Mirosława; Fontaine, Pascal; Linhart, Otomar; Alavi, Sayyed Mohammad Hadi

    2015-06-01

    Di-(2-ethylhexyl) phthalate (DEHP) interferes with male reproductive endocrine system in mammals, however its effects on fish reproduction are largely unknown. We evaluated sperm quality and investigated reproductive endocrine system in mature goldfish (Carassius auratus) exposed to nominal 1, 10, and 100μg/L DEHP. To examine DEHP estrogenic activity, one group of goldfish was exposed to 17β-estradiol (5μg/L E2) for comparison. Following 30d of exposure, sperm production was decreased and suppressed in DEHP and E2 treated goldfish, respectively. Sperm motility and velocity were decreased in goldfish exposed to 100 and 10μg/L DEHP at 15s post-sperm activation, respectively. Compared to control, 11-ketotestosterone (11-KT) levels were decreased at 10 and 1μg/L DEHP at day 15 and 30, respectively. In E2 treated goldfish, 11-KT levels were decreased compared to control during the period of exposure. E2 levels were increased in goldfish exposed to E2, but remained unchanged in DEHP treated goldfish during the period of exposure. StAR mRNA levels encoding regulator of cholesterol transfer to steroidogenesis were decreased in DEHP and E2 treated goldfish following 15 and 30d of exposure, respectively. Luteinizing hormone (LH) levels were decreased in DEHP and E2 treated goldfish following 15 and 30d of exposure, respectively. In DEHP treated goldfish, gnrh3, kiss1 and its receptor (gpr54) mRNA levels did not change during the experimental period. In E2 treated goldfish, gnrh3 mRNA levels were decreased at day 7, but kiss1 and gpr54 mRNA levels were increased at day 30 of exposure. The mRNA levels of genes encoding testicular LH and androgen receptors remained unchanged in DEHP and E2 treated goldfish. In contrast to E2 treated goldfish, vitellogenin production was not induced in DEHP treated goldfish and mRNA levels of genes with products mediating estrogenic effects remained unchanged or decreased. In conclusion, DEHP interferes with testis and pituitary hormonal

  9. The role of adsorption of sodium bis(2-ethylhexyl) sulfosuccinate in wetting of glass and poly(methyl methacrylate) surface

    NASA Astrophysics Data System (ADS)

    Harkot, Joanna; Jańczuk, Bronisław

    2008-02-01

    Advancing contact angles, θ, for aqueous solutions of the anionic surfactant, sodium bis(2-ethylhexyl) sulfosuccinate (AOT) were measured on glass and poly(methyl methacrylate) (PMMA) surface. Using the obtained results we determined the properties of aqueous AOT solutions in wetting of these surfaces. It occurs that the wettability of glass and PMMA by these solutions depends on the concentration of AOT in solution. There is almost linear dependence between the contact angle ( θ) and concentration of AOT (log C) in the range from 5 × 10 -4 to 2.5 × 10 -3 M/dm 3 (value of the critical micelle concentration of AOT—CMC) both for glass and PMMA surface. For calculations of AOT adsorption at solid (glass, PMMA)-solution drop-air system interfaces the relationship between the adhesion tension ( γLV cos θ) and surface tension ( γLV) and the Gibbs and Young equations were taken into account. From the measurement and calculation results the slope of the γLV cos θ - γ LV curve was found to be constant and equal 0.7 for glass and -0.1 for PMMA over the whole range of AOT concentration in solution. From this fact it can be concluded that if ΓSV is equal zero then ΓSL > 0 for the PMMA-solution and ΓSL < 0 for glass-solution systems. It means that surfactant concentration excess at PMMA-solution interface is considerably lower than at solution-air interface, but this excess of AOT concentration at glass-solution interface is lower than in the bulk phase. By extrapolating the linear dependence between the adhesion and surface tension the value of the critical surface tension ( γc) of wetting for glass and PMMA was also determined, that equaled 25.9 and 25.6 mN/m for glass and PMMA, respectively. Using the value of the glass and PMMA surface tension as well as the measured surface tension of aqueous AOT solutions in Young equation, the solid-liquid interface tension ( γSL) was found. There was a linear dependence between the γSL and γLV both for glass and PMMA

  10. High static pressure alters water-pool properties in reversed micelles formed by aerosol OT (sodium bis(2-ethylhexyl)sulfosuccinate): A high pressure ESR study

    NASA Astrophysics Data System (ADS)

    Sueishi, Yoshimi; Yoshioka, Daisuke; Negi, Mieko; Kotake, Yashige

    2005-11-01

    ESR spectra of Fremy's salt in sodium bis(2-ethylhexyl)sulfosuccinate (AOT) reversed micelles were recorded at high pressures in order to monitor dynamic properties of water molecules inside water pools. Rotational correlation times of Fremy's salt in large AOT water pools slightly decreased with increasing pressure, conversely those in small water pools increased with pressure: Δ V‡ for the rotational motion = -1.05 and 9.19 cm 3 mol -1 at ω0 = 20 and 2, respectively. These results demonstrate that most water molecules in small water pools are bound to AOT head groups and show very different physical properties from bulk water.

  11. Is peroxisome proliferation an obligatory precursor step in the carcinogenicity of di(2-ethylhexyl)phthalate (DEHP)?

    PubMed Central

    Melnick, R L

    2001-01-01

    Di(2-ethylhexyl)phthalate (DEHP), a peroxisome proliferator, has been listed by the International Agency for Research on Cancer (IARC) and by the National Toxicology Program as a possible or reasonably anticipated human carcinogen because it induces dose-related increases in liver tumors in both sexes of rats and mice. Recently, the suggestion has been advanced that DEHP should be considered unlikely to be a human carcinogen because it is claimed that the carcinogenic effects of this agent in rodents are due to peroxisome proliferation and that humans are nonresponsive to this process. An IARC working group recently downgraded DEHP to "not classifiable as to its carcinogenicity to humans" because they concluded that DEHP produces liver tumors in rats and mice by a mechanism involving peroxisome proliferation, which they considered to be not relevant to humans. The literature review presented in this commentary reveals that, although our knowledge of the mechanism of peroxisome proliferation has advanced greatly over the past 10 years, our understanding of the mechanism(s) of carcinogenicty of peroxisome proliferators remains incomplete. Most important is that published studies have not established peroxisome proliferation per se as an obligatory pathway in the carcinogenicity of DEHP. No epidemiologic studies have been reported on the potential carcinogenicity of DEHP, and cancer epidemiologic studies of hypolipidemic fibrate drugs (peroxisome proliferators) are inconclusive. Most of the pleiotropic effects of peroxisome proliferators are mediated by the peroxisome proliferator activated receptor (PPAR), a ligand-activated transcription factor that is expressed at lower levels in humans than in rats and mice. In spite of this species difference in PPAR expression, hypolipidemic fibrates have been shown to induce hypolipidemia in humans and to modulate gene expression (e.g., genes regulating lipid homeostasis) in human hepatocytes by PPAR activation. Thus, humans

  12. Time- and Dose-Related Effects of Di-(2-ethylhexyl) Phthalate and Its Main Metabolites on the Function of the Rat Fetal Testis in Vitro

    PubMed Central

    Chauvigné, François; Menuet, Arnaud; Lesné, Laurianne; Chagnon, Marie-Christine; Chevrier, Cécile; Regnier, Jean-François; Angerer, Jürgen; Jégou, Bernard

    2009-01-01

    Background Endocrine-disrupting effects of phthalates are understood primarily from in utero exposures within the fetal rat testis. Nevertheless, their path of action, dose–response character, and cellular target(s) within the fetal testis are not known. Objectives In this study we investigated the effects of di-(2-ethylhexyl) phthalate (DEHP), mono-(2-ethylhexyl) phthalate (MEHP), and several of their metabolites on the development of organo-cultured testes from rat fetus. Methods We removed testes from 14.5-day-old rat fetuses and cultured them for 1–3 days with or without DEHP, MEHP, and the metabolites. Results DEHP (10−5 M) produced a proandrogenic effect after 3 days of culture, whereas MEHP disrupted testis morphology and function. Leydig cells were the first affected by MEHP, with a number of them being inappropriately located within some seminiferous tubules. Additionally, we found a time- and dose-dependent reduction of testosterone. By 48 hr, gonocyte proliferation had decreased, whereas apoptosis increased. Sertoli cell number was unaffected, although some cells appeared vacuolated, and production of anti-Müllerian hormone decreased in a time- and dose-dependent manner. The derived metabolite mono-(2-ethyl-5-hydroxyhexyl) phthalate was the only one to cause deleterious effects to the rat fetal testis in vitro. Conclusion We hope that this in vitro method will facilitate the study of different phthalate esters and other endocrine disruptors for direct testicular effects. PMID:19440488

  13. Genotoxicity evaluation of benzene, di(2-ethylhexyl) phthalate, and trisodium ethylenediamine tetraacetic acid monohydrate using a combined rat comet/micronucleus assays.

    PubMed

    Kitamoto, Sachiko; Matsuyama, Ryoko; Uematsu, Yasuaki; Ogata, Keiko; Ota, Mika; Yamada, Toru; Miyata, Kaori; Kimura, Juki; Funabashi, Hitoshi; Saito, Koichi

    2015-07-01

    As a part of the Japanese Center for the Validation of Alternative Methods (JaCVAM)-initiative international validation study of the in vivo alkaline comet assay (comet assay), we examined DNA damage in the liver, stomach, and bone marrow of rats dosed orally three times with up to 2000 mg/kg of benzene, di(2-ethylhexyl) phthalate, and trisodium ethylenediamine tetraacetic acid monohydrate. All three compounds gave negative results in the liver and stomach. In addition, a bone marrow comet and micronucleus analysis revealed that benzene, but not di(2-ethylhexyl) phthalate or trisodium ethylenediamine tetraacetic acid monohydrate induced a significant increase in the median % tail DNA and micronucleated polychromatic erythrocytes, compared with the respective concurrent vehicle control. These results were in good agreement with the previously reported genotoxicity findings for each compound. The present study has shown that combining the micronucleus test with the comet assay and carrying out these analyses simultaneously is effective in clarifying the mechanism of action of genotoxic compounds such as benzene. PMID:26212304

  14. Rates of dissolution and biodegradation of water-insoluble organic compounds.

    PubMed Central

    Thomas, J M; Yordy, J R; Amador, J A; Alexander, M

    1986-01-01

    We conducted a study of the relationship between the dissolution rates of organic compounds that are sparingly soluble in water and the biodegradation of these compounds by mixed cultures of bacteria. The rates of dissolution of naphthalene and 4-chlorobiphenyl were directly related to their surface areas. The bacteria caused a decline in the concentration of the soluble substrate. The rate of bacterial growth fell abruptly when 4-chlorobiphenyl or naphthalene was no longer detectable in solution. The population continued to increase in media with different surface areas of insoluble 4-chlorobiphenyl, but the final counts were higher in media in which the surface areas of the substrate were larger. The rates of dissolution of palmitic acid, octadecane, di(2-ethylhexyl) phthalate, and 1-naphthyl N-methylcarbamate were determined in the absence of microorganisms. A mixed culture of microorganisms mineralized palmitic acid, di(2-ethylhexyl) phthalate, and Sevin (1-naphthyl N-methylcarbamate) at a logarithmic rate, but octadecane mineralization was linear. The rates of mineralization at the end of the active phase of the biodegradation were lower than the rate of dissolution of palmitic acid but higher than the rate of dissolution of octadecane in the uninoculated medium. We suggest that spontaneous dissolution rates are only one of the factors that govern the rates of biodegradation. PMID:3092736

  15. Acute pulmonary pathology and sudden death in rats following the intravenous administration of the plasticizer, DI (2-ethylhexyl) phthalate, solubilized with Tween surfactants. [pathology of vinyl plastics poisoning

    NASA Technical Reports Server (NTRS)

    Schulz, C. O.; Rubin, R. J.; Hutchins, G. M.

    1975-01-01

    Intravenous administration of 200-300 mg/kg of di(2-ethylhexyl)phthalate (DEHP) solubilized in aqueous solutions of several Tween surfactants caused respiratory distress in rats. There was a dose-dependent lethality with death generally occurring within 90 minutes after injection. The lungs from DEHP:Tween treated animals were enlarged, generally darkened, and in some cases showed hemorrhagic congestion. Neither the overt symptoms nor the morphologic alterations resulting from DEHP:Tween administration could be reproduced by intravenous administration of aqueous Tween solutions alone. The absence of pulmonary abnormalities following the intravenous administration of DEHP as an aqueous emulsion given either alone or even as soon as 2 minutes after pretreatment with Tween 80, suggests that the specific in vivo interaction between DEHP and Tween surfactants depends on the prior formation of water-soluble micelles of DEHP.

  16. Extraction of uranium(VI) by N,N-di-(2-ethylhexyl)isobutyramide (DEHIBA): from the batch experimental data to the countercurrent process

    SciTech Connect

    Miguirditchian, M.; Sorel, C.; Cames, B.; Bisel, I.; Baron, P.

    2008-07-01

    The selective separation of uranium(VI) in the first cycle of the GANEX process is operated by a hydrometallurgical process using a monoamide extractant DEHiBA (N,N-di-(2-ethylhexyl)isobutyramide). Distribution ratios of uranium(VI) and nitric acid in 1 M DEHiBA/HTP were determined with macro-concentrations of uranium, and the experimental data were modelled by taking into account the activity coefficients of the constituents in aqueous phases. A flowsheet was designed and tested in a countercurrent process in laboratory-scale mixer-settlers on a surrogate U(VI)/HNO 3 feed. More than 99.999% of the uranium was recovered. (authors)

  17. Kinetics of the oxidation of iodide ion by persulfate ion in the critical water/bis(2-ethylhexyl) sodium sulfosuccinate/n-decane microemulsions.

    PubMed

    Yin, Handi; Du, Zhongyu; Zhao, Jihua; Shen, Weiguo

    2014-11-13

    In this work, we studied the kinetics of the oxidation of iodide ion by persulfate ion in the critical water/bis(2-ethylhexyl) sodium sulfosuccinate (AOT)/n-decane microemulsions with the molar ratios of water to AOT being 35.0 and 40.8 via the microcalorimetry at various temperatures. It was found that the Arrhenius equation was valid for correlating experimental measurements in the noncritical region, but the slowing down effect existed significantly in the near critical region. We determined the values of the critical slowing down exponent and found it to be 0.187 ± 0.023 and 0.193 ± 0.032, respectively, which agreed well with the theoretical value of 0.207 predicted by the Griffiths-Wheeler rule for the singularity of the dimer/monomer droplet equilibrium in the critical AOT/water/n-decane microemulsions. PMID:25348218

  18. CROSS-DISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY: Synthesis and photoluminescence properties of Nd2O3 nanoparticles modified by sodium bis(2-ethylhexyl) sulfosuccinate

    NASA Astrophysics Data System (ADS)

    Ren, Jian-Hua; Zhao, Tong-Gang; Liu, Jian-Hua; Kong, Juan; He, Jia-Xin; Guo, Lin

    2008-12-01

    This paper reports that Nd2O3 nanoparticles modified by AOT(sodium bis(2-ethylhexyl) sulfosuccinate) were prepared using microemulsion method in the system of water and propanol/AOT/toluene. Transmission electron microscopy shows that the Nd2O3 nanoparticles take the shape of sphere with 18 nm and 31 nm with different preparation. The organic sol of Nd2O3 nanoparticles is very stable at room temperature. X-ray diffraction results show that the product has hexagonal phase structure. Two ultraviolet emission band at 344 nm and 361 nm corresponding to the transition of 4D3/2 → 4 I9/2 and 2P3 /2 →4 I11/2 or 4D3/2 → 4 I13/2 were observed.

  19. Optical Studies of Poly(9,9-di-(2-ethylhexyl)-9H-fluorene-2,7-vinylene) and its Nanocomposites

    NASA Astrophysics Data System (ADS)

    Layek, S.; Ghosh, M.; Reddy, K. Siddarth; Senapati, S.; Maiti, P.; Sinha, S.

    2015-11-01

    Steady state and time-resolved spectroscopic measurements are carried out to understand the fluorescent optical properties of the conjugated polymer poly(9,9-di-(2-ethylhexyl)-9H-fluorene-2,7-vinylene) (PFV) in liquid phase and solid phase. Quite significant color tuning is observed in the fluorescence emission of PFV in the blue side of the spectra in the solid phase, especially in powder form, when the polymer is doped with 30B nanoclay (organically modified Montmorillonite) and graphene nanoparticles. Interestingly, the average fluorescence lifetime of PFVgraphene nanocomposite in thin film is found to be much higher (8.1 ns) compared to that for PFV only in thin film (3 ns). These novel nanocomposites may have potential applications in polymer optoelectronics industry.

  20. Association between maternal exposure to di(2-ethylhexyl) phthalate and reproductive hormone levels in fetal blood: the Hokkaido study on environment and children's health.

    PubMed

    Araki, Atsuko; Mitsui, Takahiko; Miyashita, Chihiro; Nakajima, Tamie; Naito, Hisao; Ito, Sachiko; Sasaki, Seiko; Cho, Kazutoshi; Ikeno, Tamiko; Nonomura, Katsuya; Kishi, Reiko

    2014-01-01

    Prenatal di(2-ethylhexyl) phthalate (DEHP) exposure can produce reproductive toxicity in animal models. Only limited data exist from human studies on maternal DEHP exposure and its effects on infants. We aimed to examine the associations between DEHP exposure in utero and reproductive hormone levels in cord blood. Between 2002 and 2005, 514 pregnant women agreed to participate in the Hokkaido Study Sapporo Cohort. Maternal blood samples were taken from 23-35 weeks of gestation and the concentration of the primary metabolite of DEHP, mono(2-ethylhexyl) phthalate (MEHP), was measured. Concentrations of infant reproductive hormones including estradiol (E2), total testosterone (T), and progesterone (P4), inhibin B, insulin-like factor 3 (INSL3), steroid hormone binding globulin, follicle-stimulating hormone, and luteinizing hormone were measured from cord blood. Two hundred and two samples with both MEHP and hormones' data were included in statistical analysis. The participants completed a self-administered questionnaire regarding information on maternal characteristics. Gestational age, birth weight and infant sex were obtained from birth records. In an adjusted linear regression analysis fit to all study participants, maternal MEHP levels were found to be associated with reduced levels of T/E2, P4, and inhibin B. For the stratified analyses for sex, inverse associations between maternal MEHP levels T/E2, P4, inhibin B, and INSL3 were statistically significant for males only. In addition, the MEHP quartile model showed a significant p-value trend for P4, inhibin B, and INSL3 decrease in males. Since inhibin B and INSL3 are major secretory products of Sertoli and Leydig cell, respectively, the results of this study suggest that DEHP exposure in utero may have adverse effects on both Sertoli and Leydig cell development in males, which agrees with the results obtained from animal studies. Comprehensive studies investigating phthalates' exposure in humans, as well as

  1. Preventive effect of D-psicose, one of rare ketohexoses, on di-(2-ethylhexyl) phthalate (DEHP)-induced testicular injury in rat.

    PubMed

    Suna, Shigeru; Yamaguchi, Fuminori; Kimura, Shoji; Tokuda, Masaaki; Jitsunari, Fumihiko

    2007-09-10

    To investigate the preventive effects of d-psicose, one of rare ketohexoses, on di-(2-ethylhexyl) phthalate (DEHP)-induced testicular injury, prepubertal male Sprague-Dawley rats were exposed to DEHP via their diet or orally, while under treatment with d-psicose. The rats given a diet-containing 1% DEHP alone for 7-14 days showed severe testicular atrophy accompanied by aspermatogenesis. On the other hand, those given the diet plus 2% but not 1% d-psicose-supplemented water for 14 days did not develop testicular atrophy, and exhibited an almost complete spermatogenesis. There was no significant difference in plasma mono-(2-ethylhexyl) phthalate (MEHP) levels between the d-psicose-free and d-psicose-treated groups. The testicular malondialdehyde (MDA) level after a single oral administration of 2g/kg of DEHP showed a similar pattern of increase to the plasma MEHP level and peaked in 24h suggesting a close and dose-dependent relation between plasma MEHP and testicular reactive oxygen species (ROS) levels. Pretreatment with d-psicose at a concentration of 2% and 4% resulted in an almost complete but not absolute suppression of testicular MDA production among rats administered 2g/kg of DEHP. The microarray analysis showed the induction of oxidative stress related genes including the thioredoxin, glutathione peroxidase 1 and 2, glutaredoixn 1 after 24h of the DEHP treatment in the testis. These results show that d-psicose prevents DEHP-induced testicular injury by suppressing the generation of ROS in the rat testis. This effect may be due to the direct scavenging by d-psicose of ROS generated in the testis. PMID:17698303

  2. Estimating the contribution of inhalation exposure to di-2-ethylhexyl phthalate (DEHP) for PVC production workers, using personal air sampling and urinary metabolite monitoring.

    PubMed

    Fong, Jer-Pei; Lee, Fang-Jin; Lu, I-Syuan; Uang, Shi-Nian; Lee, Ching-Chang

    2014-01-01

    Because of troubling reports of high urinary metabolite levels and adverse reproductive health effects in workers exposed to di(2-ethylhexyl)phthalate (DEHP) in occupational settings, concern about exposure to DEHP in occupational settings is increasing. However, the contributions of different routes of exposure to DEHP are unclear. We used personal air sampling and biomonitoring to determine the contribution of inhalation exposure to the body burden of DEHP in the workplace. Eighty-nine workers (high-exposure group: 66 raw-materials workers; low-exposure group: 23 administrative workers) were recruited from three polyvinyl chloride (PVC) factories. Urinary levels of mono(2-ethylhexyl) phthalate (MEHP), (mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), and mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) were measured in pre-shift and post-shift samples. The geometric means of airborne concentrations of DEHP were 5.3 μg/m3 (low-exposure group) and 32.7 μg/m3 (high-exposure group) (P<0.01). Correlation analysis showed a consistently significant association between airborne DEHP concentration and urinary DEHP metabolite levels in the high-exposure group. Calculating daily DEHP intake based on total urinary metabolite levels showed that the geometric means of total daily urinary metabolite levels of DEHP were 9.2 μg/kg/day (low-exposure group) and 15.5 μg/kg/day (high-exposure group) (P<0.01). A quartile analysis of all workers showed a significant trend toward an association between the individual contribution of inhalation exposure to DEHP and urinary DEHP metabolite levels, for which the mean inhalation contribution was 46.7% in the highest quartile. We conclude that inhalation-absorbed airborne DEHP significantly increased the total body burden of DEHP in these occupationally exposed workers. PMID:23665067

  3. Mono(2-ethylhexyl) phthalate induces apoptosis in p53-silenced L02 cells via activation of both mitochondrial and death receptor pathways.

    PubMed

    Yang, Guangtao; Zhang, Wenjuan; Qin, Qizhi; Wang, Jing; Zheng, Hongyan; Xiong, Wei; Yuan, Jing

    2015-09-01

    Mono(2-ethylhexyl) phthalate (MEHP) is one of the main metabolites of di(2-ethylhexyl) phthalate. The evidence shows that DEHP may exert its toxic effects primarily via MEHP, which is 10-fold more potent than its parent compound in toxicity in vitro. MEHP-induced apoptosis is mediated by either p53-dependent or -independent pathway. However, the detailed mechanism of its toxicity remains unclear. In this study, immortalized normal human liver cell line L02 was chosen, as an in vitro model of nonmalignant liver, to elucidate the role of p53 in MEHP-induced apoptosis. The cells were treated with MEHP (6.25, 12.50, 25.00, 50.00, and 100.00 μM) for 24 and 36 h, then small interfering RNA (siRNA) was used to specifically silence p53 gene of L02 cells. The results indicated that MEHP caused oxidative DNA damage and apoptosis in L02 cells were associated with the p53 signaling pathway. Further study found that MEHP (50.00 and 100.00 μM) induced apoptosis in p53-silenced L02 cells, along with the up-regulations of Fas and FasL proteins as well as increased the Bax/Bcl-2 ratio and Caspase 3, 8, and 9 activities. Additionally, both FasL inhibitor (AF-016) and Caspase inhibitor N-benzyloxycarbonyl-Val-Ala-Asp- fluoromethylketone (Z-VAD-FMK) could prevent the cell apoptosis induced by MEHP. The findings suggested that MEHP-induced apoptosis in L02 cells involving a Caspases-mediated mitochondrial signaling pathway and/or death receptor pathway. p53 was not absolutely necessary for MEHP-induced L02 cell apoptosis. PMID:24706461

  4. Mono(2-ethyl-5-hydroxyhexyl) phthalate and mono-(2-ethyl-5-oxohexyl) phthalate as biomarkers for human exposure assessment to di-(2-ethylhexyl) phthalate.

    PubMed Central

    Kato, Kayoko; Silva, Manori J; Reidy, John A; Hurtz, Donald; Malek, Nicole A; Needham, Larry L; Nakazawa, Hiroyuki; Barr, Dana B; Calafat, Antonia M

    2004-01-01

    Exposure to di-(2-ethylhexyl) phthalate (DEHP) is prevalent based on the measurement of its hydrolytic metabolite mono-(2-ethylhexyl) phthalate (MEHP) in the urine of 78% of the general U.S. population studied in the 1999-2000 National Health and Nutrition Examination Survey (NHANES). However, despite the high level of production and use of DEHP, the urinary MEHP levels in the NHANES samples were lower than the monoester metabolites of phthalates less commonly used than DEHP, suggesting metabolic differences between phthalates. We measured MEHP and two oxidative DEHP metabolites, mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP) and mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) to verify whether these other metabolites account for a greater proportion of DEHP metabolic products in 127 paired human urine and serum samples. We found that the urinary levels of MEHHP and MEOHP were 10-fold higher than levels of MEHP; concentrations of urinary MEOHP and MEHHP were strongly correlated (r = 0.928). We also found that the serum levels of MEOHP and MEHHP were comparatively lower than those in urine. Furthermore, the glucuronide-bound conjugates of the oxidative metabolites were the predominant form in both urine and serum. MEOHP and MEHHP cannot be formed by serum enzymes from the hydrolysis of any contamination from DEHP potentially introduced during blood collection and storage. Therefore, concentrations of MEHHP and MEOHP in serum may be a more selective measure of DEHP exposure than is MEHP. However, additional data on the absorption, distribution, metabolism, and elimination of these oxidative metabolites are needed to completely understand the extent of DEHP exposure from the serum concentrations of oxidative DEHP metabolites. PMID:14998748

  5. Oxidation and biodegradation of polyethylene films containing pro-oxidantadditives: Synergistic effects of sunlight exposure, thermal aging and fungal biodegradation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Synergistic effects of sunlight exposure, thermal aging and fungal biodegradation on the oxidation and biodegradation of linear low density poly (ethylene) PE-LLD films containing pro-oxidant were examined. To achieve oxidation and degradation, films were first exposed to the sunlight for 93 days du...

  6. Homogeneous liquid-liquid extraction of metal ions with non-fluorinated bis(2-ethylhexyl)phosphate ionic liquids having a lower critical solution temperature in combination with water.

    PubMed

    Depuydt, Daphne; Liu, Liwang; Glorieux, Christ; Dehaen, Wim; Binnemans, Koen

    2015-09-28

    Ionic liquids with an ether-functionalised cation and the bis(2-ethylhexyl)phosphate anion show thermomorphic behaviour in water, with a lower critical solution temperature. These ionic liquids are useful for homogeneous liquid-liquid extraction of first-row (3d) transition metals. PMID:26255754

  7. Effects of route of administration and repetitive dosing on the disposition kinetics of di(2-ethylhexyl) phthalate and its mono-de-esterified metabolite in rats.

    PubMed

    Pollack, G M; Li, R C; Ermer, J C; Shen, D D

    1985-06-30

    The disposition kinetics of the plasticizer di(2-ethylhexyl) phthalate (DEHP) and its biologically active metabolite mono(2-ethylhexyl) phthalate (MEHP) were studied in rats following single or multiple administration of DEHP by various routes. Following a single intraarterial (ia) injection, a large apparent volume of distribution (5390 ml/kg) and a high rate of clearance (21.5 ml/min/kg) were observed for DEHP. The systemic availability of DEHP was low following both single po (13.6%) and ip (5.2%) administration. A marked route-dependency in the formation of MEHP from DEHP was observed. The circulating concentrations of MEHP were substantially higher than those of DEHP (i.e., area under the blood concentration-time curve (AUC) ratio of approximately 7) after po administration, whereas concentrations of the mono-de-esterified metabolite were much lower relative to the parent diester concentration after ia or ip administration (i.e., AUC ratio less than 0.4). Pharmacokinetic calculations revealed that approximately 80% of a po dose of DEHP undergoes mono-de-esterification, as compared to only about 1% of the dose following either ia or ip administration. Hence, the low po systemic availability of DEHP may be largely attributed to presystemic hydrolysis of DEHP to MEHP in the gut, whereas slow and/or incomplete absorption is the likely cause of the poor bioavailability of DEHP after ip administration. No significant accumulation in the circulating concentrations of DEHP or derived MEHP were observed following 7 days of repetitive administration of DEHP. However, multiple ip injections resulted in an apparent decrease in the rate and/or extent of DEHP absorption from the peritoneal cavity, while no significant change in the po absorption of the diester was observed. The striking difference in the MEHP to DEHP AUC ratio between po and ip routes was still evident after multiple dosing. These data suggest that previously reported differences in the biologic effects of

  8. Combining octyl(phenyl)-N,N-diisobutyl-carbamoylmethylphosphine oxide and bis-(2-ethylhexyl)phosphoric acid extractants for recovering transuranic elements from irradiated nuclear fuel

    SciTech Connect

    Lumetta, Gregg J.; Carter, Jennifer C.; Gelis, Artem V.; Vandegrift, George F.

    2009-10-14

    Advanced concepts for closing the nuclear fuel cycle include separating Am and Cm from other fuel components. Separating these elements from the lanthanide elements at an industrial scale remains a significant technical challenge. We describe here a chemical system in which a neutral extractant--octyl(phenyl)-N,N-diisobutyl-carbamoylmethyl-phosphine oxide (CMPO)--is combined with an acidic extractant--bis-(2-ethylhexyl)phosphoric acid (HDEHP)--to form a single process solvent (with dodecane as the diluent) for separating Am and Cm from the other components of irradiated nuclear fuel. Continuous variation experiments in which the relative CMPO and HDEHP concentrations are varied indicate a synergistic relationship between the two extractants in the extraction of Am from buffered diethylenetriaminepentaacetic acid (DTPA) solutions. A solvent mixture consisting or 0.1 M CMPO + 1 M HDEHP in dodecane offers acceptable extraction efficiency for the trivalent lanthanides and actinides from 1 M HNO3 while maintaining good lanthanide/actinide separation factors in the stripping regime (buffered DTPA solutions with pH 3.5 to 4). Using citrate buffer instead of lactate buffer results in improved lanthanide/actinide separation factors.

  9. Di(2-Ethylhexyl) Phthalate Exposure In Utero Damages Sertoli Cell Differentiation Via Disturbance of Sex Determination Pathway in Fetal and Postnatal Mice.

    PubMed

    Wang, Yongan; Yang, Qing; Liu, Wei; Yu, Mingxi; Zhang, Zhou; Cui, Xiaoyu

    2016-07-01

    Mice may share similar mechanism with human underlying reproductive toxicity induced by di(2-ethylhexyl) phthalate (DEHP), which is not supposed to be associated with decreased testicular testosterone. Pregnant mice were exposed to DEHP by gavage, with the dosage regime beginning at human relevant exposure level. After in utero DEHP exposure, loss of Sertoli cells and germ cells were observed in the male pups at postnatal days 21. And SRY-related HMG box 9 (SOX9), Fibroblast growth factor-9 (FGF9), and Double-sex and Mab-3 related transcripttion factor 1 (DMRT1) proteins were significantly downregulated by DEHP at 2 mg/kg/d and above, suggesting the depression of Sertoli cell differentiation. The repression of Sox9 genes expression was supported by whole-mount in situ hybridization and real-time real-time-quantitative PCR. The expressions of Cyp11α1 and Star were not significantly affected by in utero DEHP exposure, indicating the absence of effects on testosterone biosynthesis. Furthermore, the testosterone-independent pathway regulating Sertoli cells differentiation was disturbed in fetus by DEHP at 2 mg/kg/d and above during the critical time window of sex determination, involving Gadd45g → Gata4/Fog2 → Sry → Sox9 → Fgf9 The results suggest that in utero DEHP exposure damaged Sertoli cells in the postnatal life of mice offspring via disturbance of the differentiation regulating pathway, potentially inducing declines in spermatogenesis. PMID:27060630

  10. Prenatal Exposures of Male Rats to the Environmental Chemicals Bisphenol A and Di(2-Ethylhexyl) Phthalate Impact the Sexual Differentiation Process.

    PubMed

    Abdel-Maksoud, Fatma M; Leasor, Khrystyna R; Butzen, Kate; Braden, Timothy D; Akingbemi, Benson T

    2015-12-01

    The increasing incidence of reproductive anomalies, described as testicular dysgenesis syndrome, is thought to be related to the exposure of the population to chemicals in the environment. Bisphenol A (BPA) and di(2-ethylhexyl)phthalate (DEHP), which have hormonal and antihormonal activity, have attracted public attention due to their presence in consumer products. The present study investigated the effects of BPA and DEHP on reproductive development. Timed-pregnant female rats were exposed to BPA and DEHP by gavage from gestational days 12 to 21. Results showed that prenatal exposures to test chemicals exerted variable effects on steroidogenic factor 1 and GATA binding protein 4 protein expression and increased (P < .05) sex-determining region Y-box 9 and antimüllerian hormone protein in the infantile rat testis compared with levels in the control unexposed animals. Pituitary LHβ and FSHβ subunit protein expression was increased (P < .05) in BPA- and DEHP-exposed prepubertal male rats but were decreased (P < .05) in adult animals relative to control. Exposure to both BPA and DEHP in utero inhibited (P < .05) global DNA hydroxymethylation in the adult testis in association with altered DNA methyltransferase protein expression. Together the present data suggest that altered developmental programming in the testes associated with chemical exposures are related to the disruption of sexual differentiation events and DNA methylation patterns. The chemical-induced effects impact the development of steroidogenic capacity in the adult testis. PMID:26372177

  11. Complete degradation of the endocrine disruptor di-(2-ethylhexyl) phthalate by a novel Agromyces sp. MT-O strain and its application to bioremediation of contaminated soil.

    PubMed

    Zhao, Hai-Ming; Du, Huan; Lin, Jing; Chen, Xue-Bin; Li, Yan-Wen; Li, Hui; Cai, Quan-Ying; Mo, Ce-Hui; Qin, Hua-Ming; Wong, Ming-Hung

    2016-08-15

    A newly isolated strain Agromyces sp. MT-O could utilize various phthalates and efficiently degraded di-(2-ethylhexyl) phthalate (DEHP). Response surface methodology was successfully employed for the optimization of culture conditions including pH (7.2), temperature (29.6), and inoculum size (OD600 of 0.2), resulting in almost complete degradation of DEHP (200mgL(-1)) within 7days. At different initial concentrations (50-1000mgL(-1)), DEHP degradation curves were fitted well with the first-order kinetic model, and the half-life of DEHP degradation ranged from 0.83 to 2.92days. Meanwhile, the substrate inhibition model was used to describe the special degradation rate with qmax, Ks, and Ki of 0.6298day(-1), 86.78mgL(-1), and 714.3mgL(-1), respectively. The GC-MS analysis indicated that DEHP was degraded into mono-ethylhexyl phthalate and phthalate acid before its complete mineralization. Bioaugmentation of DEHP-contaminated soils with strain MT-O has greatly enhanced DEHP disappearance rate in soils, providing great potential for efficiently remediating DEHP-contaminated environment. PMID:27099998

  12. Di-(2-ethylhexyl) phthalate exposure is negatively correlated with trait anxiety in girls but not with trait anxiety in boys or anxiety-like behavior in male mice.

    PubMed

    Park, Subin; Cheong, Jae Hoon; Cho, Soo-Churl; Kim, Jae-Won; Shin, Min-Sup; Yoo, Hee Jeong; Han, Doug Hyun; Kim, Bung-Nyun

    2015-01-01

    The authors aimed to study the effects of postnatal exposure to phthalate on anxiety-like behavior in mice and anxiety proneness in children. Male Imprinting Control Region (ICR) mice aged 4 weeks were administered 20 to 540 mg/kg of di-(2-ethylhexyl) phthalate (DEHP) or vehicle and assessed in the Open Field Test. A group of 277 children aged 8-11 years (150 males) was recruited from South Korea. A cross-sectional examination of urinary DEHP and dibutylphthalate metabolite concentrations was conducted, and the children were scored on the Trait Anxiety Inventory for Children (TAIC). DEHP metabolite concentrations in the urine were significantly and negatively correlated with TAIC scores in the female population but not in the male population. There were no significant group differences in the percentage of distance moved or time spent in the central area in male mice treated with DEHP or vehicle. Our results suggest a sex-dependent effect of DEHP on anxiety proneness in childhood. PMID:24762863

  13. Integrating Biomonitoring Exposure Data into the Risk Assessment Process: Phthalates [Diethyl Phthalate and Di(2-ethylhexyl) Phthalate] as a Case Study

    PubMed Central

    Calafat, Antonia M.; McKee, Richard H.

    2006-01-01

    The probability of nonoccupational exposure to phthalates is high given their use in a vast range of consumables, including personal care products (e.g., perfumes, lotions, cosmetics), paints, industrial plastics, and certain medical devices and pharmaceuticals. Phthalates are of high interest because of their potential for human exposure and because animal toxicity studies suggest that some phthalates affect male reproductive development apparently via inhibition of androgen biosynthesis. In humans, phthalates are rapidly metabolized to their monoesters, which can be further transformed to oxidative products, conjugated, and eliminated. Phthalate metabolites have been used as biomarkers of exposure. Using urinary phthalate metabolite concentrations allows accurate assessments of human exposure because these concentrations represent an integrative measure of exposure to phthalates from multiple sources and routes. However, the health significance of this exposure is unknown. To link biomarker measurements to exposure, internal dose, or health outcome, additional information (e.g., toxicokinetics, inter- and intraindividual differences) is needed. We present a case study using diethyl phthalate and di(2-ethylhexyl) phthalate as examples to illustrate scientific approaches and their limitations, identify data gaps, and outline research needs for using biomonitoring data in the context of human health risk assessment, with an emphasis on exposure and dose. Although the vast and growing literature on phthalates research could not be covered comprehensively in this article, we made every attempt to include the most relevant publications as of the end of 2005. PMID:17107868

  14. Identification of hot spots of DNA methylation in the adult male adrenal in response to in utero exposure to the ubiquitous endocrine disruptor plasticizer di-(2-ethylhexyl) phthalate.

    PubMed

    Martinez-Arguelles, D B; Papadopoulos, V

    2015-01-01

    Exposure to environmental toxicants during fetal development alters gene expression and promotes disease later in life. Di-(2-ethylhexyl) phthalate (DEHP) is a plasticizer widely used for the manufacturing of consumer products. Exposure to DEHP has been associated with obesity, asthma, and low T levels. In utero exposure of pregnant dams to DEHP from gestational day 14 until birth resulted in reduced levels of serum T and aldosterone in the adult male offspring. Because DEHP is rapidly cleared from the body, the effects observed in the adult are likely epigenetic in origin. Under the same experimental conditions, we used reduced-representation bisulfite sequencing to assess changes in DNA methylation. We identified hot spots of DNA methylation changes primarily within CpG islands followed by shelf regions of the genome known to control regional gene expression. We also identified epigenomic areas responsive to exposure to environmental levels of DEHP and found the chromosomal region that houses genes controlling immune responsiveness to be a primary target of DEHP. These data suggest that DEHP phthalate exposure early in life induces epigenetic changes that may be linked to altered gene expression and function in the adult. PMID:25330100

  15. Binding of bis-(2-ethylhexyl) phthalate at the surface of hydrozincite nanocrystals: An example of organic molecules absorption onto nanocrystalline minerals.

    PubMed

    Sanna, Roberta; Medas, Daniela; Podda, Francesca; Meneghini, Carlo; Casu, Mariano; Lattanzi, Pierfranco; Scorciapino, Mariano Andrea; Floris, Costantino; Cannas, Carla; De Giudici, Giovanni

    2015-11-01

    As a contribution to understand the interactions between mineral surfaces and organic molecules, this study reports an accurate characterization of the bis-(2-ethylhexyl) phthalate (DEHP)-Hydrozincite (DEHP-HY), that has been conduced combining the following techniques: FTIR, NMR, XAS spectroscopies and XRD. XRD patterns indicate that the HY is made of nanocrystals whose size is not influenced by the presence of DEHP. The (1)H NMR analysis of DEHP-HY samples points out the presence of interactions of DEHP with HY. CPMAS NMR analysis suggests that the interaction is operated by ester carbonyl groups while the aliphatic chain, as expected, is not involved. MAS and CPMAS NMR measurements, performed on (13)C ester carbonyl enriched DEHP, allow to demonstrate that there are two ester carbonyl linkage sites interacting at the HY surface: an acid site with a strong link and a second one with weak chemical interactions. Zn K-edge XAS spectroscopy demonstrates that the local atomic structure around Zn in DEHP-HY sample remains essentially unchanged with respect to that of HY. Such a weak structural effect suggests that HY interaction with DEHP is limited to the nanoparticle surface. PMID:26196713

  16. In utero exposure to the endocrine disruptor di(2-ethylhexyl) phthalate targets ovarian theca cells and steroidogenesis in the adult female rat.

    PubMed

    Meltzer, Deborah; Martinez-Arguelles, Daniel B; Campioli, Enrico; Lee, Sunghoon; Papadopoulos, Vassilios

    2015-01-01

    Di-2-ethylhexyl phthalate (DEHP) is an endocrine disruptor used in industry as an additive to polyvinyl chloride-based products. Pregnant dams were gavaged with oil, 1, 20, 50, or 300mg of DEHP/kg/day from gestational day 14 until birth in order to characterize the effects of DEHP in the adult female offspring. In utero exposure to DEHP resulted in reduced estrogen levels at proestrus. Theca cell layer thickness was decreased starting at 50mg DEHP/kg/day dose. Follicle-stimulating hormone levels were significantly increased at proestrus and estrus. F1 reproduction using a known breeder was not affected. F3 generation showed a decreased pregnancy rate and weight, and increased litter size in the animals exposed to 20mg DEHP/kg/day. The data presented herein suggest that in utero exposure to DEHP targets the theca cell layer and decreases the estrus cycle steroid surge, but despite these effects, does not cause infertility. PMID:25530038

  17. Thymic Stromal Lymphopoietin Neutralization Inhibits the Immune Adjuvant Effect of Di-(2-Ethylhexyl) Phthalate in Balb/c Mouse Asthma Model

    PubMed Central

    Wei, Chenxi; Chen, Shaohui; Mao, Lin; Zhang, Zhenye; Yang, Xu

    2016-01-01

    Di-(2-ethylhexyl) phthalate (DEHP), a commonly used plasticizer, has an adjuvant effect in combination with ovalbumin (OVA). The adjuvant effect of DEHP has already been verified in our previous studies. In this study, to further investigate whether thymic stromal lymphopoietin (TSLP) was involved in the DEHP-adjuvant effect, DEHP was administered through a daily gavage exposure route. Mice were sensitized with ovalbumin (OVA) to trigger allergic responses, and an anti-TSLP monoclonal antibody was used to neutralize the effect of TSLP. Biomarkers including cytokines in bronchoalveolar lavage fluid (BALF), serum total IgE and TSLP content in the lung were detected. In addition, airway hyperreactivity and lung sections were examined. Collectively, these data indicated a salient Th2 response which was characterized by the upregulation of Th2-type cytokines, such as interleukin 4 (IL-4), IL-5 and IL-13. Moreover, the eosinophil number in BALF and the eosinophil cationic protein (ECP) in the lung were seen to have increased significantly. However, neutralization of TSLP with an anti-TSLP mAb reversed the adjuvant effect of DEHP on airway inflammation, structural alterations in the airway wall and increased airway hyperresponsiveness (AHR) to methacholine induced by the OVA allergen, suggesting that TSLP was an effective target site for suppressing the adjuvant effect of DEHP co-exposure. PMID:27467143

  18. Study of the photochemical transformation of 2-ethylhexyl 4-(dimethylamino)benzoate (OD-PABA) under conditions relevant to surface waters.

    PubMed

    Calza, P; Vione, D; Galli, F; Fabbri, D; Dal Bello, F; Medana, C

    2016-01-01

    We studied the aquatic environmental fate of 2-ethylhexyl 4-(dimethylamino)benzoate (OD-PABA), a widespread sunscreen, to assess its environmental persistence and photoinduced transformation. Direct photolysis is shown to play a key role in phototransformation, and this fast process is expected to be the main attenuation route of OD-PABA in sunlit surface waters. The generation of transformation products (TPs) was followed via HPLC/HRMS. Five (or four) TPs were detected in the samples exposed to UVB (or UVA) radiation, respectively. The main detected TPs of OD-PABA, at least as far as HPLC-HRMS peak areas are concerned, would involve a dealkylation or hydroxylation/oxidation process in both direct photolysis and indirect phototransformation. The latter was simulated by using TiO2-based heterogeneous photocatalysis, involving the formation of nine additional TPs. Most of them resulted from the further degradation of the primary TPs that can also be formed by direct photolysis. Therefore, these secondary TPs might also occur as later transformation intermediates in natural aquatic systems. PMID:26512801

  19. The influence of humidity on the emission of di-(2-ethylhexyl) phthalate (DEHP) from vinyl flooring in the emission cell "FLEC"

    NASA Astrophysics Data System (ADS)

    Clausen, Per Axel; Xu, Ying; Kofoed-Sørensen, Vivi; Little, John C.; Wolkoff, Peder

    Asthma in children appears to be associated with both phthalate esters and dampness in buildings. An important question is whether the concentrations of phthalate esters correlate with dampness (expressed as relative humidity—RH) in indoor air. The objective was to study the influence of RH on the specific emission rate (SER) of di-(2-ethylhexyl)phthalate (DEHP) from one type of vinyl flooring in the well characterized Field and Laboratory Emission Cell (FLEC). The vinyl flooring with ca. 17% (w/w) DEHP as plasticizer was tested in 6 FLECs at 22 °C. The RH in the 6 FLECs was 10%, 30%, 50% (in triplicate) and 70%. The RH was changed after 248 d in 2 of the 50%-FLECs to 10% and 70%, and to 50% in the 10%-and 70%-FLECs. The data show that the SER of DEHP from vinyl flooring in FLECs during a 1 yr period is independent of the RH. A new physically based emission model for semivolatile organic compounds was found to be consistent with the experimental data and independent of the RH. The model helps to explain the RH results, because it appears that RH does not significantly influence any of the identified controlling mechanisms.

  20. Emission of di-2-ethylhexyl phthalate from PVC flooring into air and uptake in dust: emission and sorption experiments in FLEC and CLIMPAQ.

    PubMed

    Clausen, Per Axel; Hansen, Vivi; Gunnarsen, Lars; Afshari, Alireza; Wolkoff, Peder

    2004-05-01

    The emission of di-2-ethylhexyl phthalate (DEHP) from a PVC flooring was studied for up to 472 days in both the FLEC (Field and Laboratory Emission Cell) and the CLIMPAQ (Chamberfor Laboratory Investigations of Materials, Pollution, and Air Quality). The loading of the CLIMPAQs was varied but was constant in the FLECs. The sorption properties of FLEC and CLIMPAQ were investigated using different methods. In addition, the uptake of DEHP by office floor dust on the PVC flooring was studied in CLIMPAQ experiments. The concentration versus time curves in both FLECs and CLIMPAQs increased slowly over about 150 days and reached a quasi-static equilibrium at 1 microg m(-3). The main conclusions were that (i) the emission rate of DEHP was limited by gas-phase mass transport and (ii) the dust layer increased the emission rate by increasing the external concentration gradient above the surface of the PVC. These conclusions were based on the facts that the specific emission rate was inversely proportional to the loading and that the dust had sorbed about four times as much DEHP over a 68-day period as emitted in the gas-phase experiments. About one-half of the emitted DEHP was deposited on the internal surfaces of both the FLEC and the CLIMPAQ. PMID:15180047

  1. Di-(2-Ethylhexyl) Phthalate Metabolites in Urine Show Age-Related Changes and Associations with Adiposity and Parameters of Insulin Sensitivity in Childhood

    PubMed Central

    Smerieri, Arianna; Testa, Chiara; Lazzeroni, Pietro; Nuti, Francesca; Grossi, Enzo; Cesari, Silvia; Montanini, Luisa; Latini, Giuseppe; Bernasconi, Sergio; Papini, Anna Maria; Street, Maria E.

    2015-01-01

    Objectives Phthalates might be implicated with obesity and insulin sensitivity. We evaluated the levels of primary and secondary metabolites of Di-(2-ethylhexyl) phthalate (DEHP) in urine in obese and normal-weight subjects both before and during puberty, and investigated their relationships with auxological parameters and indexes of insulin sensitivity. Design and Methods DEHP metabolites (MEHP, 6-OH-MEHP, 5-oxo-MEHP, 5-OH-MEHP, and 5-CX-MEHP), were measured in urine by RP-HPLC-ESI-MS. Traditional statistical analysis and a data mining analysis using the Auto-CM analysis were able to offer an insight into the complex biological connections between the studied variables. Results The data showed changes in DEHP metabolites in urine related with obesity, puberty, and presence of insulin resistance. Changes in urine metabolites were related with age, height and weight, waist circumference and waist to height ratio, thus to fat distribution. In addition, clear relationships in both obese and normal-weight subjects were detected among MEHP, its products of oxidation and measurements of insulin sensitivity. Conclusion It remains to be elucidated whether exposure to phthalates per se is actually the risk factor or if the ability of the body to metabolize phthalates is actually the key point. Further studies that span from conception to elderly subjects besides further understanding of DEHP metabolism are warranted to clarify these aspects. PMID:25706863

  2. Structure of adsorption layer of silver nanoparticles in sodium bis(2-ethylhexyl) sulfosuccinate solutions in n-decane as observed by photon-correlation spectroscopy and nonaqueous electrophoresis.

    PubMed

    Bulavchenko, Alexander I; Popovetskiy, Pavel S

    2014-11-01

    Photon correlation spectroscopy, nonaqueous electrophoresis, and transmission electron microscopy were used to study the structure of silver nanoparticles (NPs) in n-decane, as a dependence of the concentration of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) and temperature. If the concentration of AOT is lower than the critical micelle concentration (CMC), a silver NP is covered with a monolayer of AOT and reveals no electrophoretic mobility. At average concentrations (from CMC to 0.1 M) the hydrodynamic diameter of a NP does not change, but the ζ-potential increases from 0 to 110 mV. When the concentration of AOT increases from 0.1 to 1 M, ζ potential drops to 13 mV, and the hydrodynamic diameter increases to 90 nm. An increase in temperature to 70 °C leads to a reversible decrease in diameter to 40 nm. The hypothesis of clustering (polylayer adsorption) of "empty" micelles on silver NPs is proposed for the qualitative interpretation of the experimental data. PMID:25290335

  3. A small angle x-ray scattering study of the droplet-cylinder transition in oil-rich sodium bis(2-ethylhexyl) sulfosuccinate microemulsions

    NASA Astrophysics Data System (ADS)

    Svergun, D. I.; Konarev, P. V.; Volkov, V. V.; Koch, M. H. J.; Sager, W. F. C.; Smeets, J.; Blokhuis, E. M.

    2000-07-01

    A method for nonlinear fitting of x-ray scattering data from polydisperse mixtures was developed. It was applied to the analysis of the structural changes in the droplet phase of oil-rich water-in-oil (w/o) sodium bis(2-ethylhexyl) sulfosuccinate (AOT) microemulsions with increasing temperature or upon addition of salt. Data were collected at different temperatures (15 to 60 °C) and salt concentrations (up to 0.6% NaCl) within the one-phase region of the L2 phase (w/o microemulsion) for different droplet sizes (water/AOT molar ratio wo=25 to 56) and concentrations (droplet weight fraction cw=2% to 20%). This allowed us to distinguish between contributions from individual scattering particles, e.g., droplets and cylinders to the total scattering intensity. The complete data set containing over 500 scattering curves could be interpreted by fitting the scattering of weighted sums of AOT covered water droplets, long cylinders, and inverse AOT micelles containing bound water only, to the experimental scattering curves. The polydispersity of the droplets and cylinders is described by Schulz distributions and the interactions between the droplets are calculated using a sticky hard-sphere potential in the Percus-Yevick approximation. The volume fractions of the components, their average sizes and polydispersity, and the stickiness of the water/AOT droplets are determined by a nonlinear fit to the experimental data.

  4. Promotion of breast cancer cells MDA-MB-231 invasion by di(2-ethylhexyl)phthalate through matrix metalloproteinase-2/-9 overexpression.

    PubMed

    Zhang, Shuya; Ma, Jiehua; Fu, Ziyi; Zhang, Zhilei; Cao, Jian; Huang, Lei; Li, Wenqu; Xu, Pengfei; Cao, Xin

    2016-05-01

    Di(2-ethylhexyl)phthalate (DEHP) is an estrogenic chemical that is widely used in polyvinyl products. We aimed to determine the mechanisms behind the effects of DEHP on ERα-negative breast cancer cells MDA-MB-231 invasion and matrix metalloproteinases-2/-9 (MMP-2/-9) up-regulation in this study. Transwell assay indicated that DEHP exposure (>50 μg/ml) significantly enhanced the invasion ability of MDA-MB-231 cells. Quantitative real-time PCR (qPCR) and western blotting revealed that MMP-2/-9 is overexpressed in mRNA and protein levels after DEHP treatment. Gelatin zymography consistently demonstrated that DEHP exposure also enhances the activity of MMP-2/-9. Immunofluorescence assay showed that DEHP could accelerate NF-kappaB (NF-κB) subunits-p65 translocation into the nucleus, which is confirmed by western blotting assay, suggesting that the ratio of nuclear/cytosolic level of p65 was significantly increased. Furthermore, the invasion and MMP-2/-9 overexpression of MDA-MB-231 cells after DEHP-treated were reversed by the NF-κB chemical inhibitor JSH-23 via drug inhibition assay. This study suggested that DEHP could promote ERα-negative breast cancer cells MDA-MB-231 invasion through activating NF-κB and MMP-2/-9 overexpression. PMID:26850096

  5. Di-(2-ethylhexyl) phthalate inhibits DNA replication leading to hyperPARylation, SIRT1 attenuation, and mitochondrial dysfunction in the testis

    PubMed Central

    Li, Xiaolin; Fang, Evandro Fei; Scheibye-Knudsen, Morten; Cui, Honghua; Qiu, Lu; Li, Jian; He, Yuping; Huang, Jing; Bohr, Vilhelm A.; Ng, Tzi Bun; Guo, Hongwei

    2014-01-01

    Di-(2-ethylhexyl)-phthalate (DEHP) is a ubiquitously used endocrine disruptor.There is widespread exposure to DEHP in the general population which has raised substantial public concern due to its potential detrimental health effects. It is particularly pertinent to investigate the molecular mechanisms of its testicular toxicity which are largely unknown. By feeding male rats DEHP for 2 weeks, rat spermatogenesis became disrupted, resulting in a decreased number of spermatocytes and spermatids. Since rapidly dividing tissues appeared to be particularly vulnerable to DEHP toxicity we investigated the effect of DEHP on DNA replication. Intriguingly, DEHP appeared to inhibit DNA replication as evidenced by results of fiber tract analysis. This led to induction of the mitochondrial apoptotic pathways and increased ROS production. Furthermore, the toxicity of DEHP led to respiratory chain defects and attenuation of ATP level probably brought about by hyperPARylation and undermined SIRT1 activity. Our findings reveal a previously unknown mitochondrial dysfunction in DEHP-induced testicular toxicity and highlight the importance of SIRT1 in male reproduction. PMID:25242624

  6. Determination of 2-ethylhexyl 4-(dimethylamino) benzoate using membrane-assisted liquid-liquid extraction and gas chromatography-mass spectrometric detection.

    PubMed

    March, J G; Genestar, C; Simonet, B M

    2009-06-01

    A flow-cell for micro-porous membrane liquid-liquid extraction with a sheet membrane was used to extract 2-ethylhexyl 4-(dimethylamino) benzoate (EDB) from urine of solar-cream users and spiked wine samples. The cell enabled the target analyte to be extracted from 7.9 mL of donor solution into 200 microL of acceptor solution (decane). After extraction, the acceptor solution was transferred to a micro-vial for GC-MS analysis without derivation. In this work, variables affecting the enrichment factor were also studied, such as organic solvent, extraction time, recirculation flow of the donor solution through the donor chamber, presence of potassium chloride and ethanol in the donor solution and pH. The method has been evaluated in terms of linearity, sensitivity, precision, limits of detection and quantification and extraction efficiency. Limits of quantification were 1 and 3 microg L(-1) EDB for urine and wine, respectively. Quantitative analysis has been carried out by applying the method of standard additions. Within- and between-day relative standard deviations were lower than 12% and 20%, respectively. EDB was found in the urine of users of cream containing EDB in the concentration interval 1.2-7.2 microg L(-1). Therefore, this provides evidence of EDB dermal absorption and subsequent excretion through the urinary tract. EDB was not found in the analysed wine samples. PMID:19347661

  7. Epigallocatechin-3-O-Gallate Protects Against Hepatic Damage and Testicular Toxicity in Male Mice Exposed to Di-(2-Ethylhexyl) Phthalate.

    PubMed

    Ge, Jian; Han, Baoyu; Hu, Huajun; Liu, Jun; Liu, Yang

    2015-07-01

    The aim of this study was to examine the effects of epigallocatechin-3-O-gallate (EGCG) on hepatic damage and testicular toxicity in male mice exposed to daily oral administration of di-(2-ethylhexyl) phthalate (DEHP). A mouse model was used to assess the effects of daily intraperitoneal EGCG injection on hepatic and testicular damage. Histological and mitochondrial membrane potential results revealed that EGCG treatment significantly arrested the progression of hepatic damage. EGCG treatment resulted in significant suppression of liver injury (i.e., reduced activities of alanine aminotransferase [ALT] and aspartate aminotransferase [AST]). The development of DEHP-induced hepatic and testicular damage altered the testosterone concentration in mouse serum, which could affect the reproductive ability of male mice. Moreover, EGCG treatment markedly attenuated testes lesions, sperm deformity, and spermatogenic cell apoptosis. At the molecular level, hepatic CYP3A4 expression was substantially reduced by EGCG treatment in mice exposed to DEHP compounds, whereas testicular aromatase expression was increased significantly in testes. Thus, these results demonstrate that EGCG administration may protect against liver damage and reproductive toxicity in males exposed to DEHP. PMID:25789634

  8. The adverse effects of low-dose exposure to Di(2-ethylhexyl) phthalate during adolescence on sperm function in adult rats.

    PubMed

    Hsu, Ping-Chi; Kuo, Ya-Ting; Leon Guo, Yueliang; Chen, Jenq-Renn; Tsai, Shinn-Shyong; Chao, How-Ran; Teng, Yen-Ni; Pan, Min-Hsiung

    2016-06-01

    Di(2-ethylhexyl) phthalate (DEHP) is the most crucial phthalate derivative added to polyvinyl chloride as a plasticizer. This study examined the effects of low-dose exposure to DEHP during adolescence on sperm function in adult rats. The male rats were daily gavaged with 30, 100, 300, and 1000 µg kg(-1) of DEHP or corn oil from postnatal day (PND) 42 until PND 105. The selection of DEHP doses ranged from the mean daily intake by the normal-population exposure levels to no-observed-adverse-effect level of DEHP for the endpoints evaluated until adulthood. Significant increases in the percentage of sperm with tail abnormality, tendency for sperm DNA fragmentation index (DFI) and percentage of sperm with DFI were found in those exposed to 100, 300, and 1000 µg kg(-1) (P < 0.05). We observed a significant increase of hydrogen peroxide (H2 O2 ) generation in the sperm of the 1000 µg kg(-1) group compared with the control group (P < 0.05). The excessive production of sperm H2 O2 coincided with an increase in sperm DFI. In this study, the lowest-observed-adverse-effect level for sperm toxicity was considered to be 100 µg DEHP/kg/day in sperm morphology and chromatin DNA damage. Further research is necessary to clarify the mechanisms of DEHP-related sperm ROS generation on sperm DNA damage. © 2014 Wiley Periodicals, Inc. Environ Toxicol 31: 706-712, 2016. PMID:25410017

  9. Effects of exposure of pre-pubertal boars to di(2-ethylhexyl) phthalate on their frozen-thawed sperm viability post-puberty.

    PubMed

    Spjuth, L; Saravia, F; Johannisson, A; Lundeheim, N; Rodríguez-Martínez, H

    2006-10-01

    Late effects of pre-pubertal oral exposure to di(2-ethylhexyl) phthalate (DEHP), a plastic softener used in, for example, polyvinyl chloride-products, on semen quality in young boars have not been clear-cut. The aim of this study was to determine whether stress imposed on spermatozoa would reveal such effects. Semen was collected from post-pubertal boars (8-9 months of age), which had been exposed to 300 mg kg(-1) body weight of DEHP per os three times a week from 3 to 7 weeks of age and from control siblings given placebo (water). The semen was cryopreserved and examined for plasma membrane integrity post-thaw using the short hypo-osmotic swelling test and flow cytometry (propidium iodide /SYBR-14). Sperm motility was assessed by computer-assisted sperm analysis. No significant difference in plasma membrane integrity could be found between the groups. The DEHP-exposed group had a significantly lower percentage of linearly motile spermatozoa at 30 min (P < 0.05) and 120 min (P < 0.001) after thawing, and a larger amplitude of lateral displacement of the head 120 min after thawing (P < 0.05), compared with controls. In summary, spermatozoa from boars pre-pubertally exposed to low doses of DEHP, showed kinematic deviations post-thaw that could be related to DEHP exposure. PMID:16961572

  10. Basic Characteristics of Bis(2-ethylhexyl)phosphate-impregnated Adsorbent Used for Separation of Minor Actinides from FBR-Spent Fuel

    NASA Astrophysics Data System (ADS)

    Oda, Ryohei; Arai, Tsuyoshi; Nagayama, Katsuhisa; Watanabe, Sou; Sano, Yuichi; Myouchin, Munetaka

    FBR-spent nuclear fuel includes a great deal of minor actinides (MA: Am and Cm), which become febrile. Radioactive wastes including MA require a large area of ground for dumping and result in high cost. In Fast Reactor Cycel System Technology Development Project (FaCT) in Japan, we have been investigating extraction chromatography for separation of long-lived MA and specific fission products (FP) from high-level liquid wastes (HLLW). This method is expected to allow us to reduce an organic solvent use and to realize compact equipment. In this work, we have studied the static and dynamic adsorption behavior of representative FP contained in HLLW, Mo(VI), Zr(IV), Nd(III) and EU(III), on a bis(2-ethylhexyl)phosphate (HDEHP)-impregnated adsorbent. Such fundamental data should facilitate the efficient design of efficient MA recovery processes. Column adsorption experiments with the HDEHP-impregnated adsorbent have revealed that an increase in a flow rate results in a short breakthrough time and reduces the adsorption capacity of the column for all the elements tested. These results strongly suggest that a lower flow rate is preferable to enhance the adsorption capacity of the adsorbent.

  11. Adiabatic compressibility of AOT [sodium bis(2-ethylhexyl)sulfosuccinate] reverse micelles: Analysis of a simple model based on micellar size and volumetric measurements

    NASA Astrophysics Data System (ADS)

    Amararene, A.; Gindre, M.; Le Huérou, J.-Y.; Urbach, W.; Valdez, D.; Waks, M.

    2000-01-01

    The self-assembly of amphiphilic molecules into supramolecular aggregates involves a number of complex phenomena and forces. Recent developments of highly sensitive, densimetric and acoustic methods on small volume samples have provided novel sensitive probes to explore the physical properties of these complex fluids. We have investigated, by high precision densimetry and ultrasound velocimetry, reverse micelles of [sodium bis(2-ethylhexyl)sulfosuccinate] in oil (isooctane and decane), at increasing water concentration and at variable micellar volume fractions. The size of these spherical micelles has been determined by small angle x-ray scattering. Using these results, in the framework of the effective medium theory, we have developed a simple model of micellar compressibility, allowing the calculation of physical parameters (aggregation number, volume, and compressibility) of the surfactant monomolecular film as well as that of the micellar waters. In particular, we show that the central aqueous core designated as ``free'' water, located at a distance from the oil-water interacting interface, is twice as compressible as ``bulk'' water. One notable feature of this work is the influence of the nature of the oil on the above parameters.

  12. Microscope measurements for the transient formation of W/O emulsions of sodium bis(2-ethylhexyl) sulfosuccinate in the dodecane/water interfacial region.

    PubMed

    Tsukahara, Satoshi; Shishino, Yuichi; Fujiwara, Terufumi

    2011-06-21

    The present study investigated the transient formation of water-in-oil (W/O) emulsions of sodium bis(2-ethylhexyl) sulfosuccinate (aerosol OT, AOT) in a dodecane/water interfacial region and the anomalous uptake of water in the dodecane phase by in situ bright-field optical microscopy and water concentration measurements in detail. The hydrodynamic radius of the individual W/O emulsions in the dodecane phase was determined to be 0.1-1.2 μm from the analysis of their diffusion behavior; they are much larger than common W/O microemulsions (a few nanometers in radius). At first, they were formed spontaneously in the dodecane/water interfacial region without shaking, and they diffused away into the dodecane phase. Then, almost all of them vanished at the interface by fusion. Their number and the water concentration in the dodecane phase increased first and then decreased gradually. The formation mechanism was discussed with estimated concentration profiles of AOT and water molecules, which suggests that larger W/O emulsions of 0.01-0.44 μm in radius can be formed in the dodecane phase near the interface (within 2 μm) because the concentration of AOT becomes lower than that of water there. PMID:21627084

  13. Gas phase charged aggregates of bis(2-ethylhexyl)sulfosuccinate (AOT) and divalent metal ions: first evidence of AOT solvated aggregates.

    PubMed

    Giorgi, Gianluca; Pini, Ivana; Ceraulo, Leopoldo; Liveri, Vincenzo Turco

    2011-09-01

    Assembling and chelating properties of sodium bis(2-ethylhexyl)sulfosuccinate (AOTNa) towards divalent metal ions have been investigated in the gas phase by electrospray ionization mass spectrometry. A variety of positively charged monometallated and mixed metal aggregates are formed. Interestingly, several ions contain solvent (MeOH, H(2)O) molecules and constitute the most abundant AOT cationic aggregates not containing sodium. These species are the first example of solvated AOT-metal ion aggregates in the gas phase. By increasing the surfactant aggregation number, the abundance of solvated species becomes lower than that of unsolvated ones. Decompositions of ionic species have been studied by tandem mass spectrometry, and their stability has been determined through energy resolved mass spectrometry. In contrast with positively charged AOT-alkaline metal ion aggregates, whose decompositions are dominated by the loss of individual surfactant molecules, AOTNa-divalent ion aggregates mainly dissociate through the cleavage of the AOT H(2)C-O bond followed by further intramolecular fragmentations. This finding, that is consistent with an enhanced chelation of divalent ions with AOT(-) head groups, has been taken as an indication that such aggregates are characterized by a reverse micelle-like organization with a ionic core formed by the metal cations interacting with the negatively charged surfactant polar heads, whereas the surfactant alkyl chains point outside. PMID:21915957

  14. Comparative pharmacokinetics and subacute toxicity of di(2-ethylhexyl) phthalate (DEHP) in rats and marmosets: extrapolation of effects in rodents to man

    SciTech Connect

    Rhodes, C.; Orton, T.C.; Pratt, I.S.; Batten, P.L.; Bratt, H.; Jackson, S.J.; Elcombe, C.R.

    1986-03-01

    Certain phthalate esters and hypolipidemic agents are known to induce morphological and biochemical changes in the liver of rodents, which have been associated with an increased incidence of hepatocellular tumors in these species. There is evidence that hypolipidemic agents do not induce these effects in either subhuman primates or man. The oral and intraperitoneal administration of di(2-ethylhexyl) phthalate (DEHP) to the marmoset monkey at doses up to 5 mmole DEHP/kg body weight/day for 14 days did not induce morphological or biochemical changes in the liver or testis comparable with those obtained in rats given the same amount of DEHP. In the marmoset, the excretion profile of (/sup 14/C)-DEHP following oral, IP, and IV administration and the lower tissue levels of radioactivity demonstrated a considerably reduced absorption in this species compared to the rat. The urinary metabolite pattern in the marmoset was in many respects qualitatively similar to but quantitatively different from that in the rat. The pharmacokinetic differences between these two species indicate that the tissues of the marmoset are exposed to a level of DEHP metabolites equivalent to the complete absorption of a dose of Ca. 0.1 to 0.25 mmole DEHP/kg body weight/day without significant toxicological effects. The evidence suggests that in some nonrodent species the hepatocellular and testicular response to DEHP is considerably less than that in rodents and is dose-dependent.

  15. A molecular dynamics study of structure, stability and fragmentation patterns of sodium bis(2-ethylhexyl)sulfosuccinate positively charged aggregates in vacuo.

    PubMed

    Longhi, Giovanna; Abbate, Sergio; Ceraulo, Leopoldo; Ceselli, Alberto; Fornili, Sandro L; Turco Liveri, Vincenzo

    2011-12-28

    Positively charged supramolecular aggregates formed in vacuo by n AOTNa (sodium bis(2-ethylhexyl)sulfosuccinate) molecules and n(c) additional sodium ions, i.e. [AOT(n)Na(n+n(c))](n(c)), have been investigated by molecular dynamics (MD) simulations for n = 1-20 and n(c) = 0-5. Statistical analysis of physical quantities like gyration radii, atomic B-factors and moment of inertia tensors provides detailed information on their structural and dynamical properties. Even for n(c) = 5, all stable aggregates show a reverse micelle-like structure with an internal solid-like core including sodium counterions and surfactant polar heads surrounded by an external layer consisting of the surfactant alkyl chains. Moreover, the aggregate shapes may be approximated by rather flat and elongated ellipsoids whose longer axis increases with n and n(c). The fragmentation patterns of a number of these aggregates have also been examined and have been found to markedly depend on the aggregate charge state. In one particular case, for which experimental findings are available in the literature, a good agreement is found with the present fragmentation data. PMID:22048331

  16. Gas phase infrared multiple photon dissociation spectra of positively charged sodium bis(2-ethylhexyl)sulfosuccinate reverse micelle-like aggregates.

    PubMed

    Giorgi, Gianluca; Ceraulo, Leopoldo; Berden, Giel; Oomens, Jos; Liveri, Vincenzo Turco

    2011-03-17

    The capability of infrared multiple photon dissociation (IRMPD) spectroscopy to gain structural information on surfactant-based supramolecular aggregates has been exploited to elucidate intermolecular interactions and local organization of positively charged sodium bis(2-ethylhexyl)sulfosuccinate (AOTNa) aggregates in the gas phase. A detailed analysis of the stretching modes of the AOTNa CO and SO(3)(-) head groups allows one to directly probe their interactions with sodium counterions and to gain insight in their organization within the aggregate. Similarities and differences of the IRMPD spectra as compared to the infrared absorption spectrum of micellized AOTNa in CCl(4) have been analyzed. They strongly suggest a reverse micelle-like organization of AOTNa charged aggregates in the gas phase. Apart from low-abundance fragmentation channels of the AOTNa (molecule) itself, the main dissociation pathway of singly charged surfactant aggregates is the loss of neutral surfactant molecules, while doubly charged aggregates dissociate preferentially by charge separation forming singly charged species. In both cases, decomposition leads to the formation of the most energetically stable charged fragments. PMID:21341816

  17. Biodegradable Polydepsipeptides

    PubMed Central

    Feng, Yakai; Guo, Jintang

    2009-01-01

    This paper reviews the synthesis, characterization, biodegradation and usage of bioresorbable polymers based on polydepsipeptides. The ring-opening polymerization of morpholine-2,5-dione derivatives using organic Sn and enzyme lipase is discussed. The dependence of the macroscopic properties of the block copolymers on their structure is also presented. Bioresorbable polymers based on polydepsipeptides could be used as biomaterials in drug controlled release, tissue engineering scaffolding and shape-memory materials. PMID:19333423

  18. Theoretical studies on the AnO2(n+) (An = U, Np; n = 1, 2) complexes with di-(2-ethylhexyl)phosphoric acid.

    PubMed

    Luo, Juan; Wang, Cong-Zhi; Lan, Jian-Hui; Wu, Qun-Yan; Zhao, Yu-Liang; Chai, Zhi-Fang; Nie, Chang-Ming; Shi, Wei-Qun

    2015-02-21

    Actinide separation in spent nuclear fuel reprocessing is essential for the closed nuclear fuel cycle. Organophosphorus reagents have been found to exhibit strong affinities for actinides in experiments. In this work, the extraction complexes of AnO2(n+) (An = U, Np; n = 1, 2) with the traditional organophosphorus ligand HDEHP (di-(2-ethylhexyl)phosphoric acid) have been investigated using density functional theory together with scalar-relativistic effective core potentials (ECPs) for actinide elements. According to our calculations, the HDEHP dimer prefers to act as a bidentate ligand in most of the studied complexes. HDEHP ligands show a higher extraction ability for An(vi) over An(v), and the formation of Np(vi) complexes is slightly more favorable than those of U(vi) analogues, which is mainly attributed to the stronger donor-acceptor interaction in Np(vi) complexes. The intramolecular hydrogen bonds play a significant role in the stability of the 1 : 1 type complexes AnO2(HL)2(NO3)2 (L = DEHP(-)). Moreover, AnO2(HL)2(NO3)2 are the most stable species in nitrate-rich acid solutions, while at low nitric acid concentrations, the complexing reaction of AnO2(H2O)5(2+) + 2(HL)2 → AnO2(HL2)2 + 2H(+) + 5H2O is probably the dominant reaction in the extraction process. Our results can help to understand the speciation of actinyl complexes in real solvent extraction of actinides with HDEHP at the molecular level. PMID:25598207

  19. Identification of toxicological biomarkers of di(2-ethylhexyl) phthalate in proteins secreted by HepG2 cells using proteomic analysis.

    PubMed

    Choi, Seonyoung; Park, So-Young; Jeong, Ji; Cho, Eunkyung; Phark, Sohee; Lee, Min; Kwak, Dongsub; Lim, Ji-Youn; Jung, Woon-Won; Sul, Donggeun

    2010-05-01

    The effects of di(2-ethylhexyl) phthalate (DEHP) on proteins secreted by HepG2 cells were studied using a proteomic approach. HepG2 cells were exposed to various concentrations of DEHP (0, 2.5, 5, 10, 25, 50, 100, and 250 microM) for 24 or 48 h. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and comet assays were then conducted to determine the cytotoxicity and genotoxicity of DEHP, respectively. The MTT assay showed that 10 microM DEHP was the maximum concentration that did not cause cell death. In addition, the DNA damage in HepG2 cells exposed to DEHP was found to increase in a dose- and time-dependent fashion. Proteomic analysis using two different pI ranges (4-7 and 6-9) and large size 2-DE revealed the presence of 2776 protein spots. A total of 35 (19 up- and 16 down-regulated) proteins were identified as biomarkers of DEHP by ESI-MS/MS. Several differentiated protein groups were also found. Proteins involved in apoptosis, transportation, signaling, energy metabolism, and cell structure and motility were found to be up- or down-regulated. Among these, the identities of cystatin C, Rho GDP inhibitor, retinol binding protein 4, gelsolin, DEK protein, Raf kinase inhibitory protein, triose phosphate isomerase, cofilin-1, and haptoglobin-related protein were confirmed by Western blot assay. Therefore, these proteins could be used as potential biomarkers of DEHP and human disease associated with DEHP. PMID:20198640

  20. In utero exposure to di-(2-ethylhexyl) phthalate exerts both short-term and long-lasting suppressive effects on testosterone production in the rat.

    PubMed

    Culty, Martine; Thuillier, Raphael; Li, Wenping; Wang, Yan; Martinez-Arguelles, Daniel B; Benjamin, Carolina Gesteira; Triantafilou, Kostantinos M; Zirkin, Barry R; Papadopoulos, Vassilios

    2008-06-01

    We examined the effects of fetal exposure to a wide range of di-(2-ethylhexyl) phthalate (DEHP) doses on fetal, neonatal, and adult testosterone production. Pregnant rats were administered DEHP from Gestational Day (GD) 14 to the day of parturition (Postnatal Day 0). Exposure to between 234 and 1250 mg/kg/day of DEHP resulted in increases in the absolute volumes of Leydig cells per adult testis. Despite this, adult serum testosterone levels were reduced significantly compared to those of controls at all DEHP doses. Organ cultures of testes from GD20 rats exposed in utero to DEHP showed dose-dependent reductions in basal testosterone production. Surprisingly, however, no significant effect of DEHP was found on hCG-induced testosterone production by GD20 testes, suggesting that the inhibition of basal steroidogenesis resulted from the alteration of molecular events upstream of the steroidogenic enzymes. Reduced fetal and adult testosterone production in response to in utero DEHP exposure appeared to be unrelated to changes in testosterone metabolism. In view of the DEHP-induced reductions in adult testosterone levels, a decrease in the expression of steroidogenesis-related genes was anticipated. Surprisingly, however, significant increases were seen in the expression of Cyp11a1, Cy17a1, Star, and Tspo transcripts, suggesting that decreased testosterone production after birth could not be explained by decreases in steroidogenic enzymes as seen at GD20. These changes may reflect an increased number of Leydig cells in adult testes exposed in utero to DEHP rather than increased gene expression in individual Leydig cells, but this remains uncertain. Taken together, these results demonstrate that in utero DEHP exposure exerts both short-term and long-lasting effects on testicular steroidogenesis that might involve distinct molecular targets in fetal and adult Leydig cells. PMID:18322279

  1. Genotypic variation in the uptake, accumulation, and translocation of di-(2-ethylhexyl) phthalate by twenty cultivars of rice (Oryza sativa L.).

    PubMed

    Cai, Quan-Ying; Xiao, Pei-Yun; Chen, Tong; Lü, Huixiong; Zhao, Hai-Ming; Zeng, Qiao-Yun; Li, Yan-Wen; Li, Hui; Xiang, Lei; Mo, Ce-Hui

    2015-06-01

    Agricultural soil in China contains high levels of di-(2-ethylhexyl) phthalate (DEHP), especially in paddy-field soil of Guangdong province of China, but the accumulation and translocation of DEHP by rice (Oryza sativa L.) remains unknown. In the present study, twenty rice cultivars were cultivated in paddy soil spiked with DEHP, and variations in DEHP accumulation and translocation among various cultivars were investigated. Our results showed that DEHP concentrations in roots and shoots of different rice cultivars at four growth stages (i.e., ripening, tillering, jointing, and flowering stages) varied greatly from 0.26 to 11.8 mg/kg (dry weight, dw) and 0.40 to 7.58 mg/kg (dw), respectively. No obvious change over time was observed. The greatest variation in DEHP concentrations among the rice cultivars occurred at ripening stage, whereas the lowest variation at flowering stage. During ripening stage, the largest variation in DEHP concentrations among cultivars were observed in stems (varying from 0.35 to 13.2 mg/kg), whereas the least one was observed in roots (ranging from 1.01 to 5.72 mg/kg). Significant differences in DEHP concentrations in the roots, stems, leaves and grains of most rice cultivars were found. The translocation factors of DEHP from roots to stems or stems to leaves were higher than those from shoots to grains. Overall, cultivars Tianfengyou 316, Wuyou 308, and Peizataifeng, which contained low levels of DEHP in grains but high levels in shoots, were ideal cultivars for simultaneous production of safe food and phytoremediation of contaminated soil. PMID:25768422

  2. Di(2-ethylhexyl) phthalate inhibits B cell proliferation and reduces the abundance of IgM-secreting cells in cultured immune tissues of the rainbow trout.

    PubMed

    Martins, Kelly; Applegate, Ben; Hagedorn, Birgit; Kennish, John; Zwollo, Patty

    2015-05-01

    Plasticizer di(2-ethylhexyl) phthalate (DEHP) and its active metabolite MEHP have important immunotoxic effects in mammalian species, including inhibition of cell proliferation, inflammation inhibition, lowering of the antibody response, and apoptosis. Virtually nothing is known about the potential detrimental effects of DEHP/MEHP on the teleost immune system, although phthalates are a likely threat to fish health. Here we investigated whether short-term in vitro DEHP exposure would affect B lineage cells in the rainbow trout, using cultured immune tissues. Cell culture conditions, evidence of cellular incorporation of DEHP, and possible effects of DEHP on immune genes were first established using the mouse pre-B cell line PD31 and data confirmed a dose-dependent cellular uptake of DEHP using liquid chromatography-coupled ion trap mass spectrometry. Effects of in vitro DEHP exposure on trout B cell proliferation were tested by flow cytometry. Significant, dose-dependent inhibition was evident in both anterior and posterior kidney cultures after 24 h exposure to ≥4 μM DEHP. DEHP-induced cell death was not significant for the range of DEHP tested. Further, the abundance of IgM-secreting plasmablasts and plasma cells was significantly reduced after in vitro exposure of ≥16 μM DEHP for 2 or 7 days. Finally, in vitro DEHP exposure significantly lowered the levels of secreted HCmu transcripts in a dose-dependent manner. B lineage cells from posterior kidney were more sensitive to effects of in vitro DEHP exposure than those from anterior kidney. Together, the data support a model where DEHP modifies the normal B cell activation pathways in rainbow trout, promoting B cell differentiation while suppressing plasmablast expansion, resulting in fewer IgM-secreting plasma cells. Insufficient production of protective antibody make fish more susceptible to infection, and increases their risk for disease and mortality in polluted waters. PMID:25748607

  3. Di(2-ethylhexyl) phthalate-induced apoptosis in rat INS-1 cells is dependent on activation of endoplasmic reticulum stress and suppression of antioxidant protection.

    PubMed

    Sun, Xia; Lin, Yi; Huang, Qiansheng; Shi, Junpeng; Qiu, Ling; Kang, Mei; Chen, Yajie; Fang, Chao; Ye, Ting; Dong, Sijun

    2015-03-01

    Di(2-ethylhexyl) phthalate (DEHP) is used as plasticizer and is ubiquitously found in the environment. Exposure to DEHP has been linked to an increased incidence of type 2 diabetes. Pancreatic β-cell dysfunction is a hallmark of type 2 diabetes; however, it is unknown whether DEHP exposure contributes to this risk. Here, we aimed to investigate the cytotoxic effects of DEHP on INS-1 cells and to further explore the related underlying mechanisms. INS-1 cells were exposed to 0, 5, 25, 125 or 625 μM DEHP for 24 hrs. Cell viability, glucose-stimulated insulin secretion, reactive oxygen species (ROS) generation, cellular antioxidant response, Ca(2+) homoeostasis and the levels of genes and proteins involved in endoplasmic reticulum (ER) stress were measured. The results showed that DEHP decreased insulin secretion and content and induced apoptosis in INS-1 cells in a dose-dependent manner. Furthermore, ROS generation was increased and Nrf2-dependent antioxidant defence protection was dysregulated in INS-1 cells after DEHP exposure. Most importantly, DEHP effectively depleted ER Ca(2+) and triggered the ER stress response as demonstrated by the elevated transcription and translation of the ER chaperone GRP78 and GRP94, the increased phosphorylation of protein kinase R-like endoplasmic reticulum kinase (PERK) and its downstream substrate eukaryotic translation initiation factor 2α (eIF2α), as well as the increased levels of activating transcription factor 4 (ATF4) and C/EBP homologous protein (CHOP). Taken together, DEHP exerted toxic effects on INS-1 cells by inducing apoptosis, which is dependent on the activation of the PERK-ATF4-CHOP ER stress signalling pathway and the suppression of Nrf2-dependent antioxidant protection. PMID:25418486

  4. Effects of uterine and lactational exposure to di-(2-ethylhexyl) phthalate on spatial memory and NMDA receptor of hippocampus in mice.

    PubMed

    Dai, Yuhua; Yang, Yanling; Xu, Xiaohong; Hu, Yizhong

    2015-05-01

    Di-(2-ethylhexyl) phthalate (DEHP) is an environmental endocrine disrupter. Currently, little is known about neurodevelopmental toxicity of DEHP in wildlife and humans. The present study investigated the effects of DEHP, focusing on the changes in the behavior of offspring mice at the ages of 6 and 12w, respectively, following utero and lactational exposure to DEHP (10, 50, and 200mg/kg/d) from gestation day 7 through postnatal day 21. The results of open field tasks showed that DEHP increased the grooming of males at age 6w and females at age 12w but decreased the frequency of rearing of 6-w-old females and the number of grid crossings of 12-w-old females. In the Morris water maze task, 50 and 200mg/kg/d DEHP significantly prolonged the time of searching the hidden platform in water maze and reduced the time staying in the target quadrant during a probe trial of 6-w-old male mice, but not of 6-w-old females nor 12-w-old mice of both sexes, suggesting an impaired spatial learning and memory among younger males after perinatal exposure to DEHP. Western blot analyses further showed that DEHP at 50 and 200mg/kg/d decreased the levels of the N-methyl-d-aspartic acid (NMDA) receptor subunits NR1 and NR2B in the hippocampus of 6-w-old males. These results suggest that uterine and lactational exposure to low doses of DEHP sex-specifically impacted behaviors, including locomotion activity and spatial memory, via the concomitant inhibition of the NMDA receptor of the hippocampus in offspring mice. PMID:25870019

  5. Adsorption and Fenton regeneration of SBA-15 for di-(2-ethylhexyl) phthalate leached from PVC sheets by Gram-positive strains LHM1 and LHM2

    NASA Astrophysics Data System (ADS)

    Hwang, S.; Latorre, I.; Caban, M.; Soto, B.; Montalvo-Rodríguez, R.; Hernández-Maldonado, A.

    2012-12-01

    Bioleaching of Di-(2-ethylhexyl) phthalate (DEHP) from PVC sheets was studied with newly isolated, Gram-positive strains LHM1 and LHM2 capable of growing on DEHP as the sole carbon source. According to 16S rRNA gene analysis, strains LHM1 and LHM2 were closely related (more than 97% similarity) to Chryseomicrobium imtechense MW 10(T) and Lysinibacillus fusiformis NBRC 15717(T), respectively. The biodeteriorated PVC sheets by the strains LHM1 and LHM2 had thicker biofilm development. Despite their metabolic capability of degrading DEHP as the sole carbon source, the strains LHM1 and LHM2 did not metabolize all DEHP leached out of the PVC sheets. Thermogravimetric analysis (TGA) showed that the biodeterioration by strains LHM1 and LHM2 resulted in less amount of and weakly bonded DEHP present in PVC sheets, in comparison to the virgin PVC sheet. Therefore, PVC biodeterioration by strains LHM1 and LHM2 might play an important role in stability of PVC sheets and fate and effect of leached DEHP on the environmental receptors. In response to this, an advanced adsorption with SBA-15 was assessed as a potential alternative DEHP remediation with arsenic as a co-contaminant. SBA-15 had an excellent arsenic adsorption showing >90% arsenic removal when arsenic was present as a singular contaminant. Adsorption effectiveness was irrelevant to the solid/liquid (S/L) ratio. However, when arsenic was present together with DEHP, arsenic adsorption to bare SBA-15 was reduced by 10 - 40%, with lesser S/L ratio having greater arsenic removal. On the contrary, bare SBA-15 only adsorbed ~30% of DEHP on average. When DEHP was present as a co-solute with arsenic, DEHP adsorption to bare SBA-15 was increased. For SBA-15 regeneration, adsorbed arsenic was recovered with EDTA elution, whereas adsorbed DEHP was destructed with Fenton oxidation.

  6. Study on the influence of temperature, storage time and packaging type on di-n-butylphthalate and di(2-ethylhexyl)phthalate release into packed meals.

    PubMed

    Cirillo, Teresa; Fasano, Evelina; Esposito, Francesco; Del Prete, Ernesto; Cocchieri, Renata Amodio

    2013-01-01

    Ready-to-eat meals packed in polyethylene terephthalate (PET) and aluminium dishes, supplied to patients in two hospitals in the Campania region (Italy), were studied to evaluate the probable migration of di-n-butylphthalate (DBP) and di(2-ethylhexyl)phthalate (DEHP) from the packaging into the food. The influence of temperature, storage time and type of package on the migration process was considered, analysing the meals according to three time ranges, before the packaging (T(0)) and after 60 min (T(1)) and 120 min (T(2)) from packaging during the storage in thermostatic delivery carts. At T(0) in the meals sampled before packaging in PET dishes, mean levels of DBP and DEHP were 0.023 ± 0.002 µg/g and 0.069 ± 0.041 µg/g, respectively; the DBP level increased 230% and that of DEHP increased 208% by time T(0) versus T(2). In the meals sampled before packaging (T(0)) in aluminium dishes, the mean levels of DBP and DEHP were 0.030 ± 0.001 µg/g and 0.057 ± 0.015 µg/g, respectively. The significant increase in contaminant levels over storage times for meals packed in PET dishes demonstrates that from packages made of plastic materials the migration of phthalic acid esters into foods is possible. In meals packed in PET dishes, the highest DBP and DEHP increases were observed in the T(0) to T(1) range, which represented the time interval over which meals were kept hot, and mainly in the first ones, where the highest temperatures have been recorded. PMID:23185971

  7. Effects of di-n-butyl phthalate and di (2-ethylhexyl) phthalate on the growth, photosynthesis, and chlorophyll fluorescence of wheat seedlings.

    PubMed

    Gao, Minling; Qi, Yun; Song, Wenhua; Xu, Haoran

    2016-05-01

    Phthalates are commonly used man-made chemicals that can be released into soil, water, and the atmosphere. The potential toxicity of phthalates on wheat seedlings has not been well studied. To better understand the deleterious effects of di-n-butyl phthalate (DBP) and di (2-ethylhexyl) phthalate (DEHP) on wheat seedlings, their influences on the following were investigated: plant growth, net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), intercellular CO2 concentration (Ci), chlorophyll content, initial fluorescence (F0), maximal photochemical efficiency (Fv/Fm), photochemical quenching (qP), non-photochemical quenching (qN), effective quantum yield of photosystem II (ΦPSII), and photosynthetic electron transport rate (ETR). Compared with the control, the growth indices (plant height, fresh and dry weights of shoots, fresh and dry weights of roots), Pn, Gs, Tr, Ci, chlorophyll content, Fv/Fm, qP, ΦPSII, and ETR decreased in the 5 μg mL(-1) and 10 μg mL(-1) DBP and DEHP treatments, whereas F0 and qN increased. When wheat seedlings were treated with 20 μg mL(-1) of DBP and DEHP, the growth indices, Pn, Gs, Tr, chlorophyll content, Fv/Fm, qP, qN, ΦPSII, and ETR decreased significantly, whereas Ci and F0 increased. A decrease in the Pn of wheat seedlings was mainly caused by stomatal limitation in the 5 μg mL(-1) and 10 μg mL(-1) DBP and DEHP treatments. However, stomatal and non-stomatal limitations may have caused the reduction in Pn in the 20 μg mL(-1) DBP and DEHP treatments. Notably, the noxious effect of DBP on the wheat seedlings was significantly greater than that of DEHP. PMID:26928333

  8. Influence of temperature on the emission of di-(2-ethylhexyl)phthalate (DEHP) from PVC flooring in the emission cell FLEC.

    PubMed

    Clausen, Per Axel; Liu, Zhe; Kofoed-Sørensen, Vivi; Little, John; Wolkoff, Peder

    2012-01-17

    Emissions of di-(2-ethylhexyl) phthalate (DEHP) from one type of polyvinylchloride (PVC) flooring with approximately 13% (w/w) DEHP as plasticizer were measured in the Field and Laboratory Emission Cell (FLEC). The gas-phase concentrations of DEHP versus time were measured at air flow rate of 450 mL·min(-1) and five different temperatures: 23 °C, 35 °C, 47 °C, 55 °C, and 61 °C. The experiments were terminated two weeks to three months after steady-state was reached and the interior surface of the FLECs was rinsed with methanol to determine the surface concentration of DEHP. The most important findings are (1) DEHP steady-state concentrations increased greatly with increasing temperature (0.9 ± 0.1 μg·m(-3), 10 ± 1 μg·m(-3), 38 ± 1 μg·m(-3), 91 ± 4 μg·m(-3), and 198 ± 5 μg·m(-3), respectively), (2) adsorption to the chamber walls decreased greatly with increasing temperature (measured partition coefficient between FLEC air and interior surface are: 640 ± 146 m, 97 ± 20 m, 21 ± 5 m, 11 ± 2 m, and 2 ± 1 m, respectively), (3) gas-phase DEHP concentration in equilibrium with the vinyl flooring surface is close to the vapor pressure of pure DEHP, and (4) with an increase of temperature in a home from 23 to 35 °C, the amount of DEHP in the gas- and particle-phase combined is predicted to increase almost 10-fold. The amount in the gas-phase increases by a factor of 24 with a corresponding decrease in the amount on the airborne particles. PMID:22191658

  9. Plant-originated glycoprotein (24 kDa) has an inhibitory effect on proliferation of BNL CL.2 cells in response to di(2-ethylhexyl)phthalate.

    PubMed

    Lee, Jin; Lim, Kye-Taek

    2011-08-01

    Di(2-ethylhexyl)phthalate (DEHP) is one of the many environmental chemicals that are widely used in polyvinyl chloride products, vinyl flooring, food packaging and infant toys. They cause cell proliferation or dysfunction of human liver. The purpose of this study is to investigate the inhibitory effect of a glycoprotein (24 kDa) isolated from Zanthoxylum piperitum DC (ZPDC) on proliferation of liver cell in the DEHP-induced BNL CL. 2 cells. [³H]-thymidine incorporation, intracellular reactive oxygen species (ROS), intracellular Ca²⁺ mobilization and activity of protein kinase C (PKC) were measured using radioactivity and fluorescence method respectively. The expression of mitogen-activated protein kinases [extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK)], activator protein (AP)-1 (c-Jun and c-Fos), proliferating cell nuclear antigen (PCNA) and cell cycle-related factors (cyclin D1/cyclin-dependent kinase [CDK] 4) were evaluated using Western blotting or electrophoretic mobility shift assay. The results in this study showed that the levels of [³H]-thymidine incorporation, intracellular ROS, intracellular Ca²⁺ mobilization and activity of PKCα were inhibited by ZPDC glycoprotein (100 µg/ml) in the DEHP-induced BNL CL. 2 cells. Also, activities of ERK, JNK and AP-1 were reduced by ZPDC glycoprotein (100 µg/ml). With regard to cell proliferation, activities of PCNA and cyclin D1/CDK4 were significantly suppressed at treatment with ZPDC glycoprotein (100 µg/ml) in the presence of DEHP. Taken together, these findings suggest that ZPDC glycoprotein significantly normalized activities of PCNA and cyclin D1/CDK4, which relate to cell proliferation factors. Thus, ZPDC glycoprotein appears to be one of the compounds derived from natural products that are able to inhibit cell proliferation in the phthalate-induced BNL CL. 2 cells. PMID:21721021

  10. Stereoselectivity and the potential endocrine disrupting activity of di-(2-ethylhexyl)phthalate (DEHP) against human progesterone receptor: a computational perspective.

    PubMed

    Sheikh, Ishfaq Ahmad

    2016-05-01

    Di-(2-ethylhexyl)phthalate (DEHP) is a phthalate plasticizer and is one of the very common endocrine-disrupting chemicals (EDCs) contaminating our ecosystem. It is used for imparting flexibility to plastics and frequently used in personal and industrial products. Clinical and experimental studies have indicated that exposure to DEHP is associated with developmental abnormalities of the reproductive system particularly of male neonates, endometriosis and miscarriage in women, low sperm counts and lower sperm motility and DNA integrity in men, and placental problems with higher rates of low birth weight, premature birth, and fetal loss in laboratory animals. Binding of DEHP to progesterone receptor (PR) represents a potential mechanism of interference in the reproductive functions. DEHP is a chiralmolecule and is available commercially as a racemic mixture of RR, SS and RS stereoisomers. The ability of individual stereoisomers of DEHP to interfere with the reproductive functions of humans and animals is not known and molecular interactions of DEHP stereoisomers with PR are not available. In the present study, in silico approaches were adopted for molecular simulation studies of the three stereoisomers of DEHP with PR. The study suggested that all three stereoisomers of DEHP have the potential to compete with the normal substrate binding of PR. However, the binding of DEHP to PR was stereoselective with RR stereoisomer of DEHP having the best binding characteristics compared with SS, and RS stereoisomers. It has been suggested that stereoselectivity may be employed for improving the safety of the commercial compounds using pure stereoisomers instead of racemic mixtures. PMID:26879776