N-acetylcysteine and zinc sulphate abate di-2-ethylhexyl phthalate-mediated reproductive dysfunction in rats:Focus on oxidative and sex hormone receptors mechanisms

Objective:To investigate the potential of N-acetylcysteine(NAC)and zinc sulphate(ZnSO_(4))in mitigating reproductive dysfunction caused by di-2-ethylhexyl phthalate(DEHP)in rats and to understand the underlying mechanisms,specifically oxidative stress and sex hormone receptor activity.Methods:Thirty-five male Wistar rats were randomly divided into five equal groups(n=7 per group).Group 1 was administered 0.5 mL of distilled water and served as the control group.Group 2 was given only DEHP(750 mg/kg/day),while group 3,4 and 5 were given DEHP(750 mg/kg/day)plus NAC(100 mg/kg/day),DEHP(750 mg/kg/day)plus ZnSO_(4)(0.5 mg/kg/day),and DEHP(750 mg/kg/day)plus NAC(100 mg/kg/day)as well as ZnSO_(4)(0.5 mg/kg/day),respectively.All treatments lasted for 21 days.Samples were obtained after the rats were sacrificed,and hormones levels in the serum and markers of oxidative stress in the testicles were analyzed using the enzyme-linked immunosorbent assay.The amount of androgen receptors in the testicles was determined by immunohistochemistry,and the susceptibility of testosterone and DEHP to bind to androgen receptor and 5α-reductase was determined by molecular docking studies.Results:DEHP decreased reproductive hormones,testicular antioxidant enzymes,increased malondialdehyde levels,and negatively impacted histology of the pituitary and testes.NAC or ZnSO_(4) treatment showed a marked improvement in testicular antioxidant status and hormone levels,as well as a positive effect on the histology of the pituitary and testes.The combination of both treatments appeared to be more effective.The affinity of DEHP to bind to androgen receptors may lead to disruption of androgen receptor signaling,which can further result in dysfunction of hormones related to androgen.However,NAC is more likely to form stronger binding interactions with follicle stimulating hormone and luteinizing hormone receptors,as well as gonadotropin-releasing hormone receptors,when compared to DEHP.Conclusions:The possibility that NAC and ZnSO_(4) could downregulate DEHP-induced sex hormone changes is suggested by their potential to reduce toxicity.

Research Progress on Distribution,Sources and Ecological Effects of Phthalate in Soil

Phthalate esters(PAEs)are widely used as main plasticizers in plastic products,agricultural regulators,toys,and other fields.This paper reviewed the research progress on the distribution,sources,and ecological effects of PAEs.The effects of PAEs on soil microorganisms,animals,plants and soil properties were explored in sequence,providing effective theoretical basis for future research on PAEs.

Recent Advances of Sensitive Electrochemical Sensing Platforms for Rapid Detection of Phthalate Acid Esters

As a kind of plasticizer,phthalic acid esters(PAEs)are often added to plastics to enhance elasticity,transparency,durability and prolong service life.However,it does not chemically bind to plastics and is easy to migrate to the environment.It is difficult to degrade in the environment,and it is also enriched in the human body through the food chain and respiration,which will lead to obvious adverse reactions such as decreased learning and memory function and neurobehavioral disorders.Due to the toxicity,universality and low concentration limitations of PAEs in the environment and food,it is essential to achieve rapid and sensitive detection of PAEs in soil,atmosphere,water and food.Electrochemical(EC)sensors have the advantages of simplicity,fast,low cost,portability,easy operation,high specificity and high sensitivity,so they are applied for the detection of PAEs.Although there are a large number of studies on the detection of PAEs by EC sensors,there is no review on this aspect.In this review,we introduce the detection of PAEs from classical EC sensors,electrochemiluminescence(ECL)sensors and photo-electrochemical(PEC)sensors in the past five years.This review is beneficial to understanding the construction of EC sensors and the detection mechanism of PAEs.We also propose that the development of rapid,accurate and real-time detection methods of PAEs is key to assessing risk and preventing related diseases.

Bis(2-butoxyethyl) Phthalate Delays Puberty Onset by Increasing Oxidative Stress and Apoptosis in Leydig Cells in Rats

Objective This study investigated the effects of bis(2-butoxyethyl) phthalate(BBOP) on the onset of male puberty by affecting Leydig cell development in rats.Methods Thirty 35-day-old male Sprague-Dawley rats were randomly allocated to five groups mg/kg bw per day that were gavaged for 21 days with BBOP at 0, 10, 100, 250, or 500 mg/kg bw per day. The hormone profiles;Leydig cell morphological metrics;mRNA and protein levels;oxidative stress;and AKT,mTOR, ERK1/2, and GSK3β pathways were assessed.Results BBOP at 250 and/or 500 mg/kg bw per day decreased serum testosterone, luteinizing hormone, and follicle-stimulating hormone levels mg/kg bw per day(P < 0.05). BBOP at 500 mg/kg bw per day decreased Leydig cell number mg/kg bw per day and downregulated Cyp11a1, Insl3, Hsd11b1,and Dhh in the testes, and Lhb and Fshb mRNAs in the pituitary gland(P < 0.05). The malondialdehyde content in the testis significantly increased, while Sod1 and Sod2 mRNAs were markedly downregulated, by BBOP treatment at 250–500 mg/kg bw per day(P < 0.05). Furthermore, BBOP at 500mg/kg bw per day decreased AKT1/AKT2, mTOR, and ERK1/2 phosphorylation, and GSK3β and SIRT1levels mg/kg bw per day(P < 0.05). Finally, BBOP at 100 or 500 μmol/L induced ROS and apoptosis in Leydig cells after 24 h of treatment in vitro(P < 0.05).Conclusion BBOP delays puberty onset by increasing oxidative stress and apoptosis in Leydig cells in rats.The graphical abstract is available on the website www.besjournal.com.

Green tea polyphenols alleviate di-(2-ethylhexyl)phthalate-induced liver injury in mice

BACKGROUND Di(2-ethylhexyl)phthalate(DEHP)is a common plasticizer known to cause liver injury.Green tea is reported to exert therapeutic effects on heavy metal exposureinduced organ damage.However,limited studies have examined the therapeutic effects of green tea polyphenols(GTPs)on DEHP-induced liver damage.AIM To evaluate the molecular mechanism underlying the therapeutic effects of GTPs on DEHP-induced liver damage.METHODS C57BL/6J mice were divided into the following five groups:Control,model[DEHP(1500 mg/kg bodyweight)],treatment[DEHP(1500 mg/kg bodyweight)+GTP(70 mg/kg bodyweight),oil,and GTP(70 mg/kg bodyweight)]groups.After 8 wk,the liver function,blood lipid profile,and liver histopathology were examined.Differentially expressed micro RNAs(miRNAs)and mRNAs in the liver tissues were examined using high-throughput sequencing.Additionally,functional enrichment analysis and immune infiltration prediction were performed.The miRNA-mRNA regulatory axis was elucidated using the starBase database.Protein expression was evaluated using immunohistochemistry.RESULTS GTPs alleviated DHEP-induced liver dysfunction,blood lipid dysregulation,fatty liver disease,liver fibrosis,and mitochondrial and endoplasmic reticulum lesions in mice.The infiltration of macrophages,mast cells,and natural killer cells varied between the model and treatment groups.mmu-miR-141-3p(a differentially expressed miRNA),Zcchc24(a differentially expressed mRNA),and Zcchc24(a differentially expressed protein)constituted the miRNA-mRNA-protein regulatory axis involved in mediating the therapeutic effects of GTPs on DEHP-induced liver damage in mice.CONCLUSION This study demonstrated that GTPs mitigate DEHP-induced liver dysfunction,blood lipid dysregulation,fatty liver disease,and partial liver fibrosis,and regulate immune cell infiltration.Additionally,an important miRNAmRNA-protein molecular regulatory axis involved in mediating the therapeutic effects of GTPs on DEHP-induced liver damage was elucidated.

Anodizing of AZ91D magnesium alloy using environmental friendly alkaline borate-biphthalate electrolyte

A kind of environmental friendly anodizing routine for AZ91D magnesium alloy,based on an alkaline borate-potassium acid phthalate（KAP） electrolyte,was studied.The effect of KAP on the properties of the anodized film was investigated by scanning electron microscopy（SEM）,X-ray diffraction（XRD）,energy dispersive spectrometry（EDS）,potentiodynamic polarization and electrochemical impedance spectroscopy（EIS）,respectively.The results showed that the anodizing process,surface morphology,thickness,phase structure and corrosion resistance of the anodized film were strongly dependent on the concentration of KAP.In the presence of adequate KAP,a compact and smooth anodized film with excellent corrosion resistance was obtained.

Determination of phthalate esters in fat-containing foods by packed nanofiber solid-phase extraction column and gas chromatography

A new method for simultaneous determination of four phthalate esters （ PAEs） in commercial fat-containing foods was developed by the combination of a packed nanofibers column based on solid-phase extraction with gas chromatography-flame ionization detector （ GC-FID ）. Conditions for obtaining optimum extraction efficiency such as extraction solvents, morphologies of adsorbent, ion strength and pH were investigated and optimized in detail. Under the optimized conditions, the limits of detection （LODs） found for dibutyl phthalate （DBP） , butyl benzyl phthalate （BBP）, diethyl hexyl phthalate （DEHP） and di-n-octyl phthalate （DNOP） were 50, 25, 50 and 25 ng/g, respectively. Good linearity of four PAEs was achieved in the range of 50 to 4 000 ng/g. The proposed method was applied for analyzing different kinds of fat-containing samples. PAEs in commercial fat-containing samples can be highly extracted by a packed solid-phase extraction column of 5 mg polystyrene （ PS） nanofibers. The satisfactory average recoveries were obtained in the range of 96. 7% to 102. 3% , and the relative standard deviations （RSDs） below 5% were achieved. The proposed method reduces the organic solvent consumption, the complex and tedious procedures for sample pretreatment, and achieves high sensitivity and reproducibility for the investigated PAEs.

Isolation, Identification and Biodegradation Characteristics of a Phthalate Ester Degrading Bacterium

By using plate screening techniques with five phthalate esters （DMP, DEP, DBP, DEHP and DOP） as energy and carbon sources, an active strain was isolated from the sediments of Chaohu Lake, which was identified as Burkholderia pickettil and named B. pickettii.z-1. The biodegradation of five phthalate esters by B. pick- ettii.z-1 strain was in accordance with the pseudo first-order kinetic equation： Ct = C0.e-kt. As the concentration of phthalate esters increased, the degradation rate of phthalate esters was reduced. B. pickettii.z-1 strain exhibited remarkably different degradation effects on various PAEs. Specifically, short-side-chain DMP and DEP were degraded rapidly, while long-side-chain DBP and DEHP were degraded slowly.

Characterization of V_2O_5/MoO_3 composite photocatalysts prepared via electrospinning and their photodegradation activity for dimethyl phthalate

Vanadium pentoxide（V2O5）/molybdenum trioxide（MoO 3） composites with different molar ratios of vanadium（V） to molybdenum（Mo） were synthesized via a simple electrospinning technique. The photocatalytic activity of the composites were evaluated by their ability to photodegrade methylene blue and dimethyl phthalate（DMP） under visible-light irradiation. Compared with pure V2O5 and MoO 3,the V2O5/MoO 3 composites showed enhanced visible-light photocatalytic activity because of a V 3d impurity energy level and the formation of heterostructures at the interface between V2O5 and MoO 3. The optimal molar ratio of V to Mo in the V2O5/MoO 3 composites was found to be around 1/2. Furthermore,high-performance liquid chromatographic monitoring revealed that phthalic acid was the main intermediate in the photocatalytic degradation process of DMP.

An Association of Elevated Serum Prolactin with Phthalate Exposure in Adult Men

Objective To investigate the associations of hormone circulation with phthalate exposure in adult men. Methods Semen and serum samples were collected from 118 men who were suspected of infertility. Phthalate diesters including dibutyl phthalate （DBP） and diethylhexyl phthalate （DEHP） in both semen and serum samples were measured, along with serum levels of follicle stimulating hormone （FSH）, luteinizing hormone （LH）, testosterone （T）, estradiol （E 2 ） and prolactin （PRL）. Results Serum PRL was positively associated with serum DBP and DEHP and semen DEHP in all models of Spearman correlation, linear regression and binary logistic regression. In linear regression models adjusted for potential confounders and excluding subjects with undetectable phthalates, a 10‐fold increase in semen DEHP was associated with a 23% increase in serum PRL, as well as a 26% increase in serum DBP and a 20% increase in serum DEHP. In logistic regression models all subjects demonstrated a dose‐response relationship between above reference value PRL and semen DEHP （odds ratio per tertile adjusted for potential confounders = 1.0, 1.70, 3.50; P for trend = 0.01）, and serum DBP （1.0, 1.10, 2.62; P for trend = 0.04）, and serum DEHP （1.0, 1.46, 4.69; P for trend 0.01）. A positive correlation between serum estradiol and semen DEHP （linear regression）, and an inverse correlation between semen DBP and serum testosterone and T：E 2 ratio （Spearman correlation） were also established. Conclusions Serum PRL is suggested to be positively associated with both DBP and DEHP exposure in adult men.

Cloud point extraction coupled with HPLC-UV for the determination of phthalate esters in environmental water samples

A method based on cloud point extraction was developed to determine phthalate esters including di-ethyl-phthalate （DEP）, di- （2-ethylhexyl）-phthalate （DEHP） and di-cyclohexyl-phthalate （DCP） in environmental water samples using high-performance liquid chromatography separation and ultraviolet detection （HPLC-UV）. The non-ionic surfactant Triton X-114 was chosen as extraction solvent. The parameters affecting extraction efficiency, such as concentrations of Triton X-114 and Na2SO4, equilibration temperature, equilibration time and centrifugation time were evaluated and optimized. Under the optimum conditions, the method can achieve preconcentration factors of 35, 88, 111 and detection of limits of 2.0, 3.8, 1.0 ng/ml for DEP, DEHP and DCP in 10-ml water sample, respectively. The proposed method was successfully applied to the determination of trace amount of phathalate esters in effluent water of the wastewater treatment plant and the lixivium of plastic fragments.

Effects of di-n-butyl phthalate on male rat reproduction following pubertal exposure

Di-n-butyl phthalate （DBP） is an endocrine-disrupting chemical that has the potential to affect male reproduction. However, the reproductive effects of low-dose DBP are still not well known, especially at the molecular level. In the present study, pubertal male Sprague-Dawley rats were orally administered DBP at a wide range of doses （0.1, 1.0, 10, 100 and 500 mg kg^-1 day^-1） for 30 days. The selected end points included reproductive organ weights, testicular histopathology and serum hormonal levels. Additionally, proteomic analysis was performed to identify proteins that are differentially expressed as a result of exposure to DBP at low doses （0.1, 1.0 and 10 mg kg^-1 day^-1）. Toxic effects were observed in the high-dose groups, including anomalous development of testes and epididymides, severe atrophy of seminiferous tubules, loss of spermatogenesis and abnormal levels of serum hormones. Treatment with low doses of DBP seemed to exert a ＇stimulative effect＇ on the serum hormones. Proteomics analysis of rat testes showed 20 differentially expressed proteins. Among these proteins, alterations in the expression of HnRNPA2/B1, vimentin and superoxide dismutase 1 （SOD1） were further confirmed by Western blot and immunohistochemistry. Taken together, we conclude that high doses of DBP led to testicular toxicity, and low doses of DBP led to changes in the expression of proteins involved in spermatogenesis as well as changes in the number and function of Sertoli and Leydig cells, although no obvious morphological changes appeared. The identification of these differentially expressed proteins provides important information about the mechanisms underlying the effects of DBP on male rat reproduction.

Phthalate Exposure and Human Semen Quality in Shanghai:A Cross-sectional Study

Objective To monitor the level of phthalates in human semen samples and to analyze the relationship between phthalate levels and semen parameters. Methods Concentrations of three kinds of commonly used phthalates （di-ethyl phthalate, DEP; di-n-butyl phthalate, DBP; di-2-ethylhexyl phthalate, DEHP） were measured using reversed-phase HPLC. Semen parameters were measured by computer aided sperm analysis （CASA）. Results The three phthalates were detected in most of the biological samples, with median levels of 0.30 mg/L （0.08-1.32 mg/L） in semen specimens. There was a significant positive association between liquefied time of semen and phthalate concentrations of semen. The correlation coefficient was 0.456 for DEP, 0.475 for DBP, and 0.457 for DEHP, respectively. There was no significant difference between phthalate concentrations of semen and sperm density or livability, though the correlation coefficients were negative. Conclusion These results suggest that people who reside in Shanghai are exposed to phthalates, especially to DBP and DEHP. Although the level of phthalates is relatively mild, an association of phthalate levels and reduced quality of human semen has been shown in the present study.

Anoxic biodegradation of dimethyl phthalate (DMP) by activated sludge cultures under nitrate-reducing conditions

Worldwide extensive use of plasticized plastics has resulted in phthalates pollution in different environment. Nitrates from industry and agriculture are also widely disseminated in the soils, natural waters and wastewaters. Dimethyl phthalate （DMP） biodegradation by activated sludge cultures under nitrate-reducing conditions was investigated. Under one optimized condition, DMP was biodegraded from 102.20 mg/L to undetectable level in 56 h under anoxic conditions and its reaction fitted well with the first-order kinetics. Using the high-performance liquid chromatography （HPLC） and liquid chromatography mass spectrometry （LC-MS） analysis, mono-methyl phthalate （MMP） and phthalic acid （PA） were detected as the major intermediates of DMP biodegradation. When combined with the determination of chemical oxygen demand （CODer） removal capacity and pH, DMP was found to be mineralized completely under anoxic conditions. The biodegradation pathway was proposed as DMP → MMP→ PA→…→ CO2 ＋ H2O. The molar ratio of DMP to nitrate consumed was found to be 9.0：1, which agrees well with the theoretical stoichiometric values of DMP biodegradation by nitrate-reducing bacteria. The results of the non-linear simulation showed that the optimum pH and temperature for the degradation were 7.56 and 31.4℃, respectively.

Brief maternal exposure of rats to the xenobiotics dibutyl phthalate or diethylstilbestrol alters adult-type Leydig cell development in male offspring

Maternal exposure to estrogenic xenobiotics or phthalates has been implicated in the distortion of early male reproductive development, referred to in humans as the testicular dysgenesis syndrome. It is not known, however, whether such early gestational and/or lactational exposure can influence the later adult-type Leydig cell phenotype. In this study, Sprague-Dawley rats were exposed to dibutyl phthalate （DBP; from gestational day （GD） 14.5 to postnatal day （PND） 6） or diethylstilbestrol （DES; from GD14o5 to GD16.5） during a short gestationalllactational window, and male offspring subsequently analysed for various postnatal testicular parameters. All offspring remained in good health throughout the study. Maternal xenobiotic treatment appeared to modify specific Leydig cell gene expression in male offspring, particularly during the dynamic phase of mid-puberty, with serum INSL3 concentrations showing that these compounds led to a faster attainment of peak values, and a modest acceleration of the pubertal trajectory. Part of this effect appeared to be due to a treatment-specific impact on Leydig cell proliferation during puberty for both xenobiotics. Taken together, these results support the notion that maternal exposure to certain xenobiotics can also influence the development of the adult-type Leydig cell population, possibly through an effect on the Leydig stem cell population.

Electrochemical incineration of dimethyl phthalate by anodic oxidation with boron-doped diamond electrode

The anodic oxidation of aqueous solutions containing dimethyl phthalate （DMP） up to 125 mg/L with sodium sulfate （Na2SO4） as supporting electrolyte within the pH range 2.0-10.0 was studied using a one-compartment batch reactor employing a boron-doped diamond （BDD） as anode. Electrolyses were carded out at constant current density （1.5-4.5 mA/cm^2）. Complete mineralization was always achieved owing to the great concentration of hydroxyl radical （-OH） generated at the BDD surface. The effects of pH, apparent current density and initial DMP concentration on the degradation rate of DMP, the specific charge required for its total mineralization and mineralization current efficiency were investigated systematically. The mineralization rate of DMP was found to be pH-independent and to increase with increasing applied current density. Results indicated that this electrochemical process was subjected, at least partially, to the mass transfer of organics onto the BDD surface. Kinetic analysis of the temporal change of DMP concentration during electrolysis determined by High Performance Liquid Chromatography （HPLC） revealed that DMP decay under all tested conditions followed a pseudo first-order reaction. Aromatic intermediates and generated carboxylic acids were identified by Gas Chromatography- Mass Spectrometry （GC-MS） and a general pathway for the electrochemical incineration of DMP on BDD was proposed.

Removal of a type of endocrine disruptors—di-n-butyl phthalate from water by ozonation

Ozonation of synthetic water containing a type of endocrine disruptor-di-n-butyl phthalate （DBP） was examined. Key impact factors such as pH, temperature, ionic strength, ozone dosage and initial DBP concentration were investigated. In addition, the activities of radicals on uncatalysed and catalysed ozonation were studied. The degradation intermediate products were followed and the kinetic of the ozonation were assessed as well. Results revealed that ozonation of DBP followed two mechanisms. Firstly, the reaction rate of direct ozonation was slower at lower pH, temperature, and ionic strength. Secondly, when these factors were increased for indirect radical reaction, higher percentage of DBP was removed with the increase of the initial ozone dosage and the decrease of the initial DBP concentration. In addition, tea-butanol, humic substances and Fe（Ⅱ） affected DBP ozonation through the radical pathway. It was determined that ozonation was restrained by adding tea-butanol for its radical inhibition effect. Furthermore, humic substances enhanced the reaction to some extent, but a slight negative effect would be encountered if the optimum dosage was exceeded. As a matter of fact, Mn（Ⅱ） affected the ozonation by ＂active sites＂ mechanism. In the experiment, three different kinds of intermediate products were produced during ozonation, but the amount of products for each one of them decreased as pH, temperature, ionic strength and initial ozone dosage increased. A kinetic equation of the reaction between ozone and DBP was obtained.

Analysis of Phthalate Esters in Air, Soil and Plants in Plastic Film Greenhouse

The phthalate esters such as DMP, DEP, DBP and DEHP in air, soil and plant samples in plastic film greenhouse were clean up with fine silica gel column and determined with HPLC. It was found that the concentrations of PEs in air and soil samples in plastic film greenhouse are much higher than those of contrast samples. But concentrations of PEs in plants in plastic film greenhouse are not remarkably affected by the pollution of air and soil.

Detection of phthalates migration from disposable tablewares to drinking water using hexafluoroisopropanol-induced catanionic surfactant coacervate extraction

Hexafluoroisopropanol(HFIP)-induced sodium dodecyl sulfate/dodecyltrimethylammonium bromide(SDS/DTAB) catanionic surfactant coacervate extraction method coupled with high performance liquid chromatography(HPLC) was used to detect the migration of phthalates from disposable tablewares to drinking water. The concentration factors are larger than 82 and extraction recoveries over 53% for water samples spiked with 100 or 200 ng/m L phthalates. Limit of detection is in the range of 1.0–2.6 ng/m L.Good linearity with correlation coefficients larger than 0.9985 is obtained in the concentration of20–1500 or 40–3000 ng/m L. Relative recoveries are from 82.4% to 123.6% for water samples spiked with30/60, 250/500, and 1500/3000 ng/m L phthalates, respectively. Relative standard deviations(RSDs) are0.4%–7.4% for intraday precision(n = 5) and 0.6%–7.8% for interday precision(n = 3). Four of studied phthalates are found in the drinking water samples prepared from four kinds of tablewares.

Presence of phthalates in gastrointestinal medications: Is there a hidden danger?

Pharmaceutical companies that produce gastrointestinal(GI)medications often utilize phthalates for their ability to localize medication release.Commonly prescribed GI medications that may utilize phthalates are 5-Aminosalicylates,proton pump inhibitors,and pancreatic enzymes.Our understanding of the cumulative health effects of phthalates from medications remains unclear,and there is increasing evidence that phthalates are not harmless.Experimental studies in animals have shown that phthalates,specifically dibutyl phthalate and Di-(2-ethyl-hexyl)phthalate,have the potential to alter and/or inhibit reproductive biology and in utero development.Despite the lack of definitive human data,many cohort and cross-sectional studies demonstrate concerning associations between phthalates and poor health status,specifically developmental problems.Longitudinal studies and studies with larger sample sizes are required to determine whether phthalates actually cause negative health consequences.It is also important that physicians regularly review and discuss with patients the medicinal ingredients in their medications and supplements,specifically in pregnant woman with inflammatory bowel disease.