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Background Di(2-ethylhexyl)phthalate (DEHP) and dibutyl phthalate (DBP) are representative environmental endocrine disruptors of phthalate esters (PAEs). Some studies have shown that PAEs exposure may have an impact on lipid metabolism. Objective To investigate the effects of DEHP and/or DBP on lipid metabolism in rats and their possible mechanisms of action. Methods Thirty-six weaned healthy SD male rats, 3 weeks old, weighing 50-70 g, were divided into four groups, i.e., a corn oil control group, a DEHP (750 mg·kg−1) group, a DBP (500 mg·kg−1) group, and a DEHP+DBP (750 mg·kg−1+500 mg·kg−1) group. The rats were exposed to DEHP and/or DBP by oral gavage for 8 weeks, and weighed once a week. The rats were anesthetized 24 h after the last dose, and blood was taken from the apical part of the heart. Serum high density lipoprotein-cholesterol (HDL-C), low density lipoprotein-cholesterol (LDL-C), total cholesterol (TC), and triglyceride (TG) were detected. Liver tissues and perigenital adipose tissues were collected, weighed, and one portion of the tissues was fixed in 10% neutral formalin for pathomorphological observation, and another portion was used for mRNA detection of lipid metabolism-related genes such as Janus kinase 3 (JAK3), signal transducer and activator of transcription 5b (STAT5b), and peroxisome proliferator-activated receptor γ (PPARγ). Results During the DEHP and/or DBP exposure period, the rats in all groups were free to eat and drink without death or injury observed. Compared with the control group: The body weight gain in the DEHP+DBP group was lower at all time points from the 2nd week onwards (P<0.05); the liver organ coefficients of the DEHP and the DEHP+DBP groups were higher (P<0.05); the serum LDL-C levels in the DEHP and the DBP groups were higher (P<0.05). Compared with the DEHP+DBP group: The body weight gains in the DEHP group at the 2nd, 4th, 5th, and 8th weeks were higher (P<0.05), and the body weight gains in the DBP group were higher at all time points except the 1st week (P<0.05); the liver organ coefficients in the DEHP group and the DBP group were lower (P<0.05); the serum TG level in the DEHP group was higher(P<0.05), and the serum LDL-C levels in the DEHP and the DBP groups were higher (P<0.05). The pathomorphological results of liver tissues showed that the hepatocytes in the DEHP, DBP, and DEHP+DBP groups were disordered with loss of cord-like arrangement, swelling (suggesting change of cell proliferation), and presented bilirubin pigmentation. The pathomorphological results of rat perigenital adipose tissues showed had irregular alignment, sizes, and arrangement of adipocyte in the DEHP, DBP, and DEHP+DBP groups. The results of rat liver lipid metabolism-related gene mRNA levels showed that the liver JAK3, STAT5b, and PPARγ mRNA levels in the DEHP, DBP, and DEHP+DBP groups were lower than those in the control group (P<0.05); the rat liver PPARγ mRNA levels in the DEHP and DBP groups were lower than those in the DEHP+DBP group (P<0.05). Conclusion DEHP and/or DBP can inhibit the increase of body weight to varying degrees, induce inflammatory damage to liver tissues, and cause abnormal lipid metabolism in rats, and the associated mechanism may be related to inhibiting the activation of JAK3/STAT5b/PPARγ signaling pathway in rat liver tissues.
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Objective:Phthalates （PAEs） are common environmental endocrine disruptors. In this study， the effects of oxidative stress on liver and nutrient metabolism were determined in male diabetic rats exposed to di-2-ethylhexyl phthalate （DEHP）， and the mechanism of DEHP toxicity was explored. Methods:Thirty-two SPF male Wistar rats aged five weeks， weighing 150-170 g， were fed adaptively for one week to establish the model of type 2 diabetes. The model was established by intraperitoneal injection of streptozotocin （STZ） （25 mg/kg） after feeding with high sugar and high fat diet for four weeks. Second STZ injection was given two days later. The model was considered to be established successfully when the random blood glucose level was found to be higher than 16.7 mmol/L in two separate tests. Twenty diabetic rats were then randomly divided into four groups， including control group （corn oil）， 100， 300 and 900 mg/kg DEHP groups. The rats were treated with DEHP by gavage （5 mL/kg） once a day for 30 days. They were fed with normal diet during the treatment period. Caudal venous blood was collected on the 1st， 14th， and 28th days to measure the random blood glucose level. The changes of glucose tolerance were determined by oral glucose tolerance test on the 29th day. Fasting blood glucose （FPG） was measured on the next day of the last exposure. After the rats were anesthetized with pentobarbital and killed， the liver was weighed， the liver coefficient was calculated and the liver pathological section was made. Blood was taken from the abdominal aorta. The levels of aspartate aminotransferase （AST）， alanine aminotransferase （ALT）， alkaline phosphatase （ALP）， triacylglycerol （TG） and albumin （ALB） in serum were measured by spectrophotometry， and the levels of insulin， glutathione （GSH）， H2O2， malondialdehyde （MDA） and superoxide dismutase （SOD） in fasting serum were measured by radioimmunoassay. Results:There was no significant difference in body weight and random blood glucose in the type 2 diabetic rats exposed to different concentrations of DEHP （all P>0.05）. At each time point of the glucose tolerance curve， the blood glucose value of the exposure groups was higher than that of the control group. A "false plateau period" appeared after the blood glucose value reached or exceeded the upper limit at 15 minutes， and the blood glucose level in each group was higher than that of the control group at 120 minutes. The liver organ coefficient of 300 and 900 mg/kg DEHP groups was higher than that of the control group （both P<0.01）， and the liver organ coefficient was positively correlated with the exposure concentration of DEHP （r=0.80，P<0.000 1）. Under the microscope， the liver cells in diabetic rats were swollen， the cytoplasm was light stained， and there were vacuoles in the cells. The serum ALP level in diabetic rats of 900 mg/kg DEHP group was significantly higher than that in the control group （P<0.01）. The serum ALP level was positively correlated with the concentration of DEHP （r=0.75， P<0.01）. The serum MDA level in diabetic rats of 300 mg/kg and 900 mg/kg DEHP groups was significantly higher than that of the control group （both P<0.01）， and the serum MDA level was positively correlated with the concentration of DEHP （r=0.84， P<0.000 1）. The serum SOD level of 900 mg/kg DEHP group was significantly higher than that of control group （P<0.01）. Conclusion:DEHP exposure could lead to liver damage， abnormal glycolipid metabolism， and increase the level of oxidative stress and antioxidant level in male diabetic rats， but did not show a significant effect on insulin resistance.
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Objective@#Di-(2-ethylhexyl) phthalate (DEHP) is a ubiquitous environmental contaminant. As an endocrine disruptor, it seriously threatens human health and ecological environmental safety. This study examines the impact of intervention with soybean isoflavones (SIF) on DEHP-induced toxicity using a metabonomics approach.@*Methods@#Rats were randomly divided into control (H), SIF-treated (A, 86 mg/kg body weight), DEHP-treated (B, 68 mg/kg), and SIF plus DEHP-treated (D) groups. Rats were given SIF and DEHP daily through diet and gavage, respectively. After 30 d of treatment, rat urine was tested using UPLC/MS with multivariate analysis. Metabolic changes were also evaluated using biochemical assays.@*Results@#Metabolomics analyses revealed that p-cresol glucuronide, methyl hippuric acid, N1-methyl-2-pyridone-5-carboxamide, lysophosphatidycholine [18:2 (9Z, 12Z)] {lysoPC [18:2 (9Z, 12Z)]}, lysoPC (16:0), xanthosine, undecanedioic acid, and N6-acetyl-l-lysine were present at significantly different levels in control and treatment groups.@*Conclusion@#SIF supplementation partially protects rats from DEHP-induced metabolic abnormalities by regulating fatty acid metabolism, antioxidant defense system, amino acid metabolism, and is also involved in the protection of mitochondria.
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OBJECTIVE: To investigate the effects of combined exposure to di(2-ethylhexyl) phthalate(DEHP) and bisphenol A(BPA) on glucose metabolism in female rats during gestational and lactation periods, and its possible mechanism. METHODS: Twenty-four specific pathogen free pregnant SD rats were randomly divided into control group, DEHP group, BPA group, and combined exposure group, with 6 rats in each group. From the 5 th day of gestation to the 21 st day after birth of the offspring, the rats in the DEHP group were treated with DEHP 600 mg/kg body weight(bw); rats in BPA group were treated with 80 mg/kg bw BPA, and rats in combined exposure group were treated with 600 mg/kg bw DEHP and 80 mg/kg bw BPA by intragastric perfusion, while the rats in the control group were given the same amount of corn oil, once per day. After exposure, maternal rats were sacrificed immediately. The levels of glucose metabolism related indicators in liver tissues and serum were examined, and the mRNA and protein expression of phosphatidylinositol 3-kinase(PI3 K)/protein kinase B(AKT) signaling pathway related factors in liver tissues were detected by real-time fluorescence quantitative polymerase chain reaction and Western blot. RESULTS: Except for the activity of phosphoenolpyruvate carboxykinase(PEPCK) in BPA group, the levels of liver glycogen and serum high density lipoprotein cholesterol(HDL-C) in rats of the 3 exposure groups decreased(P<0.05), while the activity of serum PEPCK and the level of low density lipoprotein cholesterol(LDL-C) increased(P<0.05) compared with rats in the control group. The levels of liver glycogen and serum HDL-C in the combined exposure group were lower than that in the BPA group(P<0.05), while the level of serum LDL-C were lower than that in DEHP group and BPA group(P<0.05). The levels of serum glycosylated serum protein, total cholesterol and triglyceride in the 4 groups were not statistically different when compared with each other(P>0.05). Except for the PI3 K protein in DEHP group, the mRNA and protein expression of PI3 K, AKT, and glucose transporter 4 in liver tissues of rats in the 3 exposure groups decreased(P<0.05), and the mRNA expression of forkhead box protein 1(Foxo1) decreased(P<0.05), but the protein expression of FOXO1 increased(P<0.05) compared with the control group. CONCLUSION: Exposure to DEHP or BPA during pregnancy and lactation can cause glucose metabolism disorders in rats. The combined exposure of DEHP and BPA has certain synergistic effect. This process may be achieved through the PI3 K/AKT signaling pathway.
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@#Aim: Di-(2-ethylhexyl) phthalate (DEHP) has been identified as an endocrine-disrupting chemical, commonly found in the environment. The aim of this study was to isolate bacteria from municipal solid waste (MSW) leachates in Nigeria and its ability to degrade DEHP. Methodology and results: The DEHP degrading bacterium was isolated and identified. The degradation process was monitored aerobically at varying temperature and pH and the metabolites were determined using High PerformanceLiquid Chromatography and Gas Chromatography-Mass Spectrometry, respectively. Based on the morphology and the 16S rDNA sequence, the bacterial isolate was identified as Bacillus aquimaris. B aquimaris was able to degrade 99% of 200 mg/L DEHP within 12 days. The optimum pH and temperature for its biodegradation were 8 and 25 °C, respectively and the intermediate metabolites were identified as butyl octyl phthalate and phthalic acid. Conclusion, significance and impact of study: This study showed that B. aquimaris could be a useful tool for the biodegradation of DEHP in the environment.
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OBJECTIVE@#To investigate the effects of Shoutai pills (a traditional Chinese medicinal preparation) on immune functions and oxidative stress in pregnant rats exposed to di(2-ethylhexyl) phthalate (DEHP).@*METHODS@#Thirty-six mature female SD rats were randomly divided into 3 groups (=12). After pregnancy was confirmed, the rats were given 10 mL/kg corn oil +10 mL/kg saline (control group), 500 mg/kg DEHP+10 mL/kg saline (model group), and 500 mg/kg DEHP+10 mL/kg Shoutai pills (treatment group). At 19 days of gestation, the rats were sacrificed and the fetal rats were weighed and the numbers of live and stillborn fetal rats were recorded. Serum levels of interleukin-6 (IL-6), interleukin-2 (IL-2), tumor necrosis factor-ɑ (TNF-ɑ), estradiol (E2) and progesterone (P) levels were detected. The appearance, color and quality of the placenta in each group were recorded, and the placental tissues were examined pathologically. The total antioxidant capacity (T-AOC), superoxide dismutase (SOD), glutathione peroxidase (GSH- Px), catalase (CAT), reactive oxygen species (ROS) and malondialdehyde (MDA) in the placental tissues were measured.@*RESULTS@#Compared with the control group, the rats with DEHP exposure showed slow weight gain in the middle and late gestation period and significantly lower fetal weight ( < 0.05) with lowered serum levels of IL-2, IL-6 and TNF-ɑ, increased estradiol level ( < 0.05), decreased placental T-AOC, GSH-Px, SOD and CAT levels, and increased ROS and MDA levels ( < 0.01). Compared with the model group, the rats treated with Shoutai pills had significantly increased weight gain in mid and late pregnancy and greater fetal weight ( < 0.05) with significantly increased serum IL-2 and IL-6 levels, decreased estradiol level ( < 0.05), slightly increased TNF-ɑ expression (> 0.05), increased placenta T-AOC, GSH- Px and CAT levels, decreased MDA level ( < 0.05), and slightly increased SOD and decreased ROS levels (>0.05). No significant difference was found in progesterone levels among the groups (>0.05). HE staining showed that the trophoblast in the placental tissue sponge in the model group was loose and irregular with numerous vacuoles. In the treatment group, the structure of the placenta remained intact with clearly visible labyrinth zone, sponge trophoblast and giant cell trophoblast, and the cell distribution in each layer was better than that in the model group.@*CONCLUSIONS@#Shoutai pills can regulate the immune function of DEHP-exposed pregnant rats possibly by antagonizing the estrogenlike effect of DEHP and regulating serum immune factors; Shoutai pills can also reduce placental tissue damage and improve pregnancy outcome by correcting DEHP-induced imbalance of oxidative stress in the placental tissues.
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Animals , Female , Pregnancy , Rats , Diethylhexyl Phthalate , Oxidative Stress , Phthalic Acids , Rats, Sprague-DawleyABSTRACT
The plasticizer di(2-ethylhexyl) phthalate (DEHP) has been widely used in the manufacture of polyvinyl chloride-containing products such as medical and consumer goods. Humans can easily be exposed to it because DEHP is ubiquitous in the environment. Recent research on the adverse effects of DEHP has focused on reproductive and developmental toxicity in rodents and/or humans. DEHP is a representative of the peroxisome proliferators. Therefore, peroxisome proliferator-activated receptor alpha (PPARα)-dependent pathways are the expected mode of action of several kinds of DEHP-induced toxicities. In this review, we summarize DEHP kinetics and its mechanisms of carcinogenicity and reproductive and developmental toxicity in relation to PPARα. Additionally, we give an overview of the impacts of science policy on exposure sources.
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Animals , Humans , Mice , Rats , Diethylhexyl Phthalate , Toxicity , Environmental Pollutants , Toxicity , Haplorhini , PPAR alpha , Genetics , Metabolism , Plasticizers , ToxicityABSTRACT
OBJECTIVE@#To investigate the transcriptome profile of genital tubercles (GTs) in male SD rats and explore the mechanism of hypospadias induced by Di (2-ethylhexyl) phthalate (DEHP).@*METHODS@#Forty time-pregnant SD rats were randomly divided into 4 equal groups, namely GD16 group and GD19 group (in which the male GTs were collected on gestation day[GD]16 and GD19 for RNA-seq, respectively), control group and DEHP exposure group (with administration of oil and 750 mg/kg DEHP by gavage from GD12 to GD19, respectively).In the control and DEHP exposure groups, the GTs were collected from the male fetuses on GD19.5, and scanning electron microscopy and HE staining were used to observe the morphological changes.The differentially expressed genes (DEGs) in the GTs were screened using lllumina HiSeq 2000 followed by GO and KEGG enrichment analyses to characterize the transcriptome profile.Immunofluorescence assay was performed to verify the DEGs (Mafb) identified by RNA-seq results.Immunofluorescence assay and Western blotting were used to examine the expression levels of Mafb in the penile tissue.@*RESULTS@#A total of 1360 DEGs were detected in the GTs between GD16 group and GD19 group by RNA-seq.Among these genes, 797 were up-regulated and 563 were down-regulated.These DEGs were mainly enriched in the cell adhesion plaque signaling pathway, axon guidance signaling pathway, and extracellular matrix receptor signaling pathway.Compared with that in GD16 group, Mafb was significantly up-regulated in GD19 group, which was consistent with the sequencing results.Mafb and β-catenin were significantly down-regulated in DEHP-exposed group compared with the control group ( < 0.01).@*CONCLUSIONS@#Mafb expression increases progressively with the development of GTs in male SD rats.DEHP exposure causes significant down-regulation of Mafb and β-catenin, suggesting that β-catenin signaling pathway that affects Mafb is related to DEHP-induced hypospadias in SD rats.
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Animals , Female , Humans , Male , Pregnancy , Rats , Diethylhexyl Phthalate , Gene Expression Profiling , Hypospadias , MafB Transcription Factor , Oncogene Proteins , Phthalic Acids , Rats, Sprague-DawleyABSTRACT
Objective: To investigate the effect of di (2-ethylhexyl) phthalate (DEHP) on the uterus tissue of female rats, and to clarify the mechanism of uterine toxicity of DEHP in the female rats. Methods: A total of 48 Wistar female rats were randomly divided into control group (given corn oil), low, middle, and high doses of DEHP groups (given 300, 1 000, and 3 000 mg middot; kg-1 middot; d-1 DEHP; 1/100, 1/30, and 1/10 LD50) (n=12). The rats in various groups were sacrificed during anoestrum, the body weights were recorded and uterine organ coefficients of the rats in various groups were calculated. The pathomorphology of the uterus tissue of the rats in various groups was detected by HE staining. The expression levels of follicle stimulating hormonereceptor (FSHR) and luteinizing hormone receptor (LHR) in uterus tissue of the rats in various groups were detected by immunohistochemistry. Results: Compared with control group, the body weights of the rats in different doses of DEHP groups were decreased (P0. 05). Macroscopically, the morphology of the uterus of rats in control group was normal; in middle and high doses of DEHP groups, the uterus showed distorted and the tube wall became thinner; different degrees of hydrops, congestion and swelling were seen on the serosal surface of the uterus. The microscopic observation results showed that in different doses of DEHP groups the endometrium nuclei appeared pseudostratified phenomenon; the epithelial hyperplasia and endothelial fibrosis were found in the endometrium; the gland number in the lamina propria was decreased, and part of the glands were depauperate. Compared with control group, the expression levels of FSHR in uterus tissue of the rats in different doses of DEHP groups had no significant differences (P>0. 05), and the expression levels of LHR were decreased (P<0. 05); the expression levels of LHR in uterus tissue of the rats in middle and high doses of DEHP groups were significantly lower than that in low dose of DEHP group (P<0. 05). Conclusion: DEHP can lead to the weight loss and the pathological changes in the uterus tissue of the female rats, and has a uterine toxicity effect on the female rats.
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Objective@#To construct 3β-HSD gene shRNA lentivirus interference vecto, then transfect into human MCF-7 cells, and construct cell line with 3β-HSD gene silencing, finally to study the effects of 3β-HSD on apoptosis induced by di- (2-ethylhexyl) phthalate (DEHP) .@*Methods@#According to the mRNA sequence of 3β-HSD gene provided by GenBank, three interference sequences were designed and connected to PLVX-shRNA2-puro after annealing. The recombinant lentivirus vector was transfected into 293FT cells, the virus supernatants were collected and infected with MCF-7 cells. After puromycin screening, MCF-7 cells with 3β-HSD gene silencing were constructed. The cells with 3β-HSD gene silencing were identified by real-time quantitative PCR and western blot. Then the 3β-HSD gene silencing cells and MCF-7 cells were treated at various doses of DEHP for 24 hours to detect the gene expression and protein expression of apoptosis genes including Bax, Caspase-3 and Caspase-8.@*Results@#The interference sequence of 3β-HSD gene inserted into lentivirus vector PLVX-shRNA2-puro is consistent with the designed sequence. 3β-HSD gene expression level in MCF-7 cells with 3β-HSD gene silencing was 77% lower than than that of control MCF-7 cells. 3β-HSD protein level in MCF-7 cells with 3β-HSD gene silencing was 74% lower than that of control MCF-7 cells. After DEHP treatment in MCF-7 cells with 3β-HSD gene silencing and control MCF-7 cells, qRT-PCR results showed that Bax gene expression levels increased by 28%-54%, Caspase-3 gene increased by 13%-49%, Caspase-8 gene increased by 21%-70% in MCF-7 cells when compared with the control group. Additionally, in the 3β-HSD gene silencing cells, Bax gene expression level decreased by 11%-28%, Caspase-3 gene expression decreased by 12%-23%, Caspase-8 gene expression decreased by 11%-34%, compared with the same treatment group of MCF-7 cells. Western blot results showed that Bax protein expression level increased by 28%-61%, Caspase-3 protein expression level increased by 40%-48%, Caspase-8 protein increased by 31%-84% in MCF-7 cells when compared with the control group. In 3β-HSD gene silencing cells, Bax protein expression level increased by 11%-27%, Caspase-3 protein increased by 21%-40%, Caspase-8 protein increased by 12%-25%, compared with the same treatment group of MCF-7 cells.@*Conclusion@#The stable 3β-HSD gene silencing cell line are successfully constructed in this study. DEHP can induce increased expression of apoptotic gene and protein. Silencing of 3β-HSD gene can inhibit the activation of apoptotic gene by DEHP in a certain degree.
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<p><b>Objective</b>To explore the antagonistic effect of vitamin E (VE) on male reproductive toxicity induced by di-2-ethylhexyl phthalate (DEHP) in pubertal SD rats and its underlying mechanisms.</p><p><b>METHODS</b>Thirty 5-week-old male SD rats were randomly divided into five groups of equal number, corn oil control, low-dose (10 mg/kg/d), medium-dose (100 mg/kg/d) and high-dose DEHP exposure (500 mg/kg/d), and VE intervention (high-dose DEHP + VE ［100 mg/kg/d］), and treated respectively for 30 successive days. At 3 days after treatment, the testes of the animals were harvested for determination of the oxidative stress index, serum reproductive hormone levels, cauda epididymal sperm parameters, and expressions of cell apoptosis-related genes and proteins.</p><p><b>RESULTS</b>Compared with the control group, the rats of the medium- and high-dose DEHP groups showed significant decreases in the levels of such serum reproductive hormones as follicle-stimulating hormone (FSH), luteinizing hormone (LH) and testosterone (T), sperm parameters as average path velocity (VAP), straight line velocity (VSL), curvilinear velocity (VCL), straightness (STR), linearity (LIN) and wobble (WOB), and the activities of superoxide dismutase (SOD) and glutathione peroxide (GSH-Px), but significant increases were observed in the latter two groups in the content of malondialdehyde (MDA)(［3.32±0.87］ nmol/mg pro vs ［2.13±0.49］ nmol/ mg pro), mRNA expressions of Bad, Bax, Cytochrome C, Caspase-3 and the Bax/Bcl-2 ratio, and protein expressions of Cytochrome C and Caspase-3. In comparison with the high-dose DEHP group, the VE intervention group exhibited remarkably increased serum LH and T levels, sperm VAP, VSL, VCL, STR and WOB, and activities of SOD and GSH-Px, but markedly decreased mRNA expressions of Bad, Bax, Cytochrome C, Caspase-3 and the Bax/Bcl-2 ratio as well as the protein expressions of Cytochrome C and Caspase-3 in the testis tissue (P<0.05).</p><p><b>CONCLUSIONS</b>Exposure to DEHP induces androgen secretion disorders, causes oxidative damage to the testicular tissue, activates the mitochondrial apoptosis pathway in the testis, and ultimately reduces the quality of epididymal sperm, while VE can protect the rat testis from DEHP-induced reproductive toxicity.</p>
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Animals , Male , Rats , Antioxidants , Pharmacology , Apoptosis , Genetics , Autophagy-Related Protein 5 , Metabolism , Caspase 3 , Metabolism , Diethylhexyl Phthalate , Epididymis , Follicle Stimulating Hormone , Blood , Luteinizing Hormone , Blood , Malondialdehyde , Metabolism , Mitochondria , Oxidative Stress , Oxidoreductases , Metabolism , Random Allocation , Rats, Sprague-Dawley , Reproduction , Spermatozoa , Physiology , Superoxide Dismutase , Metabolism , Testis , Testosterone , Blood , Vitamin E , PharmacologyABSTRACT
The environmental organic pollutant of di-2-ethylhexy phthalate ( DEHP ) was analyzed by extractive electrospray ionization mass spectrometry ( EESI-MS ). Effect of some important experimental conditions were investigated systematically, including the electrospray voltage, temperature of ion-transport tube, sample injection rate and extractant composition. Under the optimal conditions, a method for rapid detection of DEHP in water sample was established. DEHP levels in different samples with complex matrixes were measured, including landfill leachate, urban sewage and lake water. The results showed that DEHP in water samples could be ionized by EESI source and obtained the molecule ion (m/ z 391. 28) at the positive detection mode, and then CID experiment were performed to obtain the secondary fragment ions m/ z 279. 26, 167. 12 and 149. 11. The intensity of characteristic peak m/ z 149. 11 possessed a good linearity with the concentration of DEHP in the range of 5-1000 μg / L with the correlation coefficient of R2 = 0. 9991, and the detection limit (LOD) of 0. 21 μg / L. The recoveries of DEHP at three spiked levels (8, 80, 400 μg / L) were 96. 2％ - 111. 2％ , with RSDs of 5. 6％ - 11. 8％ . With the developed EESI-MS method, the concentrations of DEHP in landfill leachate, urban sewage and Yan lake water were 556. 5, 275. 3 and 37. 8 μg / L, respectively. The EESI-MS method possessed many advantages such as no requirement of sample pretreatment, fast analysis speed ( about 3 min per sample), simple operation and high sensitivity, thus providing a new mass spectrometric method for rapid detection of phthalate esters.
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Objective@#To study the oxidative damage of di- (2-ethylhexyl) phthalate (DEHP) on MCF-7 cells, and to investigate the effects of 3β-hydroxysteroid dehydrogenase (3β-HSD) gene silence or overexpression on DEHP-induced oxidative damage.@*Methods@#MCF-7 cells, 3β-HSD gene silencing cells and 3β-HSD gene overexpression cells were treated with different doses of DEHP (0,0.05,0.1,0.2,0.4,0.8 mmol/L) for 24h, then intracellular oxidative damage index such as MDA, SOD, GSH, GSH-PX were detected, DNA repair gene hOGG1, hMTH1 mRNA expression were tested by Q-PCR, hOGG1, hMTH1 protein expression were detected by western blot.@*Results@#After MCF-7 cells were treated by DEHP, MDA levels increased; SOD activity, GSH content, GSH-PX activity decreased, hOGG1 and hMTH1 mRNA expression levels increased, hOGG1 and hMTH1 protein expression levels increased, the differences were statistically significant when compared with control (P<0.05 or P<0.01) . In 3β-HSD gene silencing cells which were treated by DEHP, when compared with the same dose group of MCF-7 cells, MDA content increased, SOD activity, GSH content, GSH-PX activity decreased, hOGG1 and hMTH1 mRNA expression levels decreased, hOGG1 and hMTH1 protein expression levels decreased, the difference were statistically significant (P<0.05 or P<0.01) . In 3β-HSD gene overexpression cells which were treated by DEHP, when compared with the same dose group of MCF-7 cells, MDA content decreased; SOD activity, GSH content, GSH-PX activity increased, of hOGG1 and hMTH1 mRNA expression levels increased, hOGG1 and hMTH1 protein expression levels increased, the difference were statistically significant (P<0.05 or P<0.01) .@*Conclusion@#DEHP could cause oxidative damage in MCF-7 cells, induce the changes of related genes and proteins, 3β-HSD plays an antioxidant role in the process of DEHP ox-idative damage.
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OBJECTIVE To investigate the proliferation effect of di(2-ethylhexyl) phthalate (DEHP) on prostate in aged rats at the environmental exposure dose and the possible mechanism.METHODS Thirty-two male Sprague-Dawley rats,aged 1.5 years,were randomly divided into 4 groups (8 rats per group) and treated with DEHP (30,90 and 270 μg· kg-1,ig) and vehicle once daily respectively for 4 weeks.All the animals were anesthetized with pentobarbital sodium and sacrificed on the day subsequent to the last treatment.① Abdominal aortic blood samples were collected,and serum estradiol (E2),testosterone (T) and prolactin (PRL) levels were assayed by ELISA.② The prostate tissues were dissected and categorized into different lobes,weighed and measured.The prostate relative mass was calculated.③ The morphological changes were detected by HE staining and prostate epithelial height was analyzed with microscopic image analysis software.RESULTS Compared with vehicle control group,the prostate relative mass,dorsolateral prostate mass,and dorsolateral prostate index in DEHP 270 μg· kg-1 group were significantly higher (P＜0.05).The height of the ventral prostate epithelium in DEHP 30,90 and 270 μg· kg-1 groups was increased significantly (P＜0.01),so was the height of dorsal prostate epithelium in DEHP 270 μg· kg-1 group (P＜0.01).There were no significant changes in levels of E2,PRL or T in DEHP 30,90 and 270 μg· kg-1 groups,but the ratios of E2/T in DEHP 30 and 270 μμg· kg-1 groups were increased significantly (P＜0.05).CONCLUSION Low-dose DEHP could promote the proliferation of prostatic hyperplasia in the aged rats,which might be associated with the relative levels of endogenous hormone.
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Objective@#To investigate the effects of developmental exposure to DEHP on learning and memory of mice.@*Methods@#Male littermates of ICR mice randomly assigned to five experimental groups (n=14 for each condition) on PND4 to receive distilled water, vehicle and 10, 50 and 200 mg/ (kg·d) DEHP from PND5 to PND38 by gavage, weighing and recording body weight of mice. Open field task were conducted on PND 26 and Morris water maze task were begun from PND30 to PND 37 to evaluate spontaneous exploration activity and emotion, spatial learning and memory performance of pubertal mice, respectively. On PND39, all animals were killed and hippocampi were isolated on ice, then total proteins of hippocampus were extracted, followed by determining the expression of PSD95 and synapsin I by western blotting.@*Results@#200 mg/ (kg·d) DEHP significantly reduced the growth of body weight of mice and the time staying in the central area in open field, prolonged the time searching the hidden platform in Morris water maze (P<0.05) . 50 mg/ (kg·d) DEHP didn’t change the growth of body weight and the emotion (P>0.05) , but reduced the percent of time and distance in the target quadrant during the probe trial of mice in Morris water maze (P<0.05) . The results of western blotting showed that DEHP significantly reduced the expression of PSD95 in hippocampus of mice with all dose groups (P<0.01) , but only 200 mg/ (kg·d) DEHP reduced the expression of synapsin I (P<0.05) .@*Conclusion@#Developmental exposure to DEHP can damage the development of synapse in hippocampus, adversely impacting spatial memory performance of mice at a dose that are insufficient to significantly influence the general development and result in anxiety.
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OBJECTIVE: To investigate the effects of di-( 2-ethylhexyl) phthalate( DEHP) on the expression of the key genes involved in glucose and lipid metabolism,and explore the toxicity of DEHP on the glucose and lipid metabolism in HepG2 cells cultured in vitro. METHODS: HepG2 cells in logarithmic growth phase were divided into DEHP exposure group and control group. The exposure group was exposed to DEHP with different final concentrations( 5,10,50,100,500 and1 000 μmol / L),and the control group was exposed to dimethyl sulfoxide of corresponding concentrations. After 24 hours of DEHP exposure,real-time fluorescence quantitative polymerase chain reaction( Q-PCR) was applied to detect the level of mRNA transcription of peroxisome proliferators-activated receptor α( PPARα), which is an endogenous marker indicating the success of DEHP exposure. In addition,the level of mRNA transcription of key genes involved in glucose and lipid metabolism were also measured by Q-PCR,including glucose-6-phosphatase( G-6-Pase),phosphoenolpyruvate carboxykinase( PEPCK),stearoyl-coenzyme A desaturase 1( SCD1),fatty acid synthase,sterol regulatory elementbinding protein 1c and acetyl Co A carboxylase 1. P ≤0. 008 was considered as statistical significance. RESULTS: After DEHP exposure,the mRNA transcription level of PPARα was significantly elevated in all exposure groups( P < 0. 008)except for 5 μmol / L DEHP exposure group,which indicated the successful establishment of DEHP exposure model. The mRNA transcription level of G-6-Pase was significantly increased in 100 and 500 μmol / L DEHP exposure groups( P ≤0. 008) when compared with the controls; the PEPCK mRNA transcription level of showed no significant differences between the 6 DEHP exposure groups and their corresponding control groups( P > 0. 008). The mRNA transcription level of SCD1 was significantly down-regulated in 100 μmol / L DEHP exposure group( P < 0. 008) when compared with its control. The mRNA transcription level of other key genes involved in the lipid metabolism were not significantly altered after DEHP exposure( P > 0. 008). CONCLUSION: The effect of DEHP on glucose metabolism was mainly manifested by promoting G-6-Pase gene expression,which is the rate-limiting enzyme for gluconeogenesis. The effect of DEHP on the lipid metabolism of HepG2 cells was limited.
ABSTRACT
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 occupational exposure limit. Therefore, we suggest management of working environments, with exposure levels below 5 mg/m³ and all workers utilizing local exhaust ventilation and respiratory protection when handling DEHP.
Subject(s)
Humans , Carcinogenicity Tests , Chemical Safety , Clergy , Dataset , Diethylhexyl Phthalate , Employment , Ink , Insecticides , International Agencies , Liver , Liver Neoplasms , Lung , Mass Screening , No-Observed-Adverse-Effect Level , Occupational Exposure , Occupational Health , Plasticizers , Plastics , Risk Assessment , Rodentia , Testis , Toxicity Tests, Acute , VentilationABSTRACT
<p><b>OBJECTIVE</b>To estimate the daily intake of DEHP among workers in flavoring factories.</p><p><b>METHODS</b>71 workers in two flavoring manufacturers, 27 administrators in those factories and 31 laboratory technicians in a research institute were recruited and assigned to exposure group, control group 1 and control group 2 respectively. Their urinary DEHP metabolites, mono(2-ethylhexyl) phthalate (MEHP), mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP), were detected by isotope dilution-ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS). The urinary metabolites concentrations were converted into DEHP intake levels using two pharmacokinetic models: the urine creatinine-excretion (UCE) one and the urine volume (UV) one.</p><p><b>RESULTS</b>No significant differences were found among the three groups. Based on the urinary concentrations of Σ₃MEHP, we got a median daily DEHP intake of 3.22 or 1.85 μg/kg body-weight/day applying the UV or UCE models respectively. Depending on the UV model, three subjects (2.34%) exceeded the RfD value given by US EPA and the P₅₀ of estimate daily DEHP intakes accounted for 16.10% of the RfD value. No subjects exceeded the limitation depending on the UCE model.</p><p><b>CONCLUSION</b>The workers in flavoring factories were not supposed to be the high DEHP exposure ones and their exposure level remained at a low risk.</p>
Subject(s)
Adult , Humans , Young Adult , Diethylhexyl Phthalate , Urine , Flavoring Agents , Occupational ExposureABSTRACT
With the development of modem technology,more and more plastic products are widely used in various fields,while bringing significant convenience to the society,it also leads to more and more environmental estrogen.The influence of plasticizer is increasing,especially on the development of children.Extensive contacting with plasticizer is considered to be closely related with gonadal digenesis,obesity and other problems in children.This review focuses on the latest research results about the basic and clinical experiments of Di (2-ethylhexyl) phthalate (DEHP),which illuminate the effects of DEHP on children's growth and metabolism,and lay foundations for rational clinical intervention and scientific plasticizer's application.
ABSTRACT
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 adult offspring should be observed further.