Cell Line, Tumor ; Cell Movement ; Diethylhexyl Phthalate/toxicity* ; Epithelial-Mesenchymal Transition ; Humans ; Neoplasm Invasiveness ; Phthalic Acids

OBJECTIVE: To investigate the effects of diethylhexyl phthalate (DEHP) exposure on anxiety-like behaviors and learning and memory ability in mice and explore the underlying mechanism. METHODS: Forty male ICR mice were randomized equally into control group (0 mg/kg) and 10, 50 and 100 mg/kg DEHP exposure groups, in which the mice were exposed to DEHP at the indicated doses by gavage for 4 weeks. After the treatments, the mice were assessed for behavioral changes using open filed test, elevated plus-maze and Morris water maze test. Brain tissues were collected from the mice for determination of malondialdehyde (MDA) content, pathologies and expressions of ZO-1 and occludin in the hippocampus. RESULTS: Compared with the control group, the mice with DEHP exposure for 4 weeks exhibited no significant body weight change (P>0.05) but presented with obvious behavioral changes, manifested by reduced movement distance (P < 0.05) and time spent in the center of the open field (P < 0.05), reduced movement distance (P < 0.05) and time spent in the open arm of the elevated maze (P < 0.05), significantly increased latency of searching for the platform (P < 0.05), and decreased frequency of crossing the platform (P < 0.05). HE staining showed obvious vertebral cell death in the hippocampal CA1 to CA3 regions of the mice with DEHP exposure. The exposed mice showed significantly increased MDA content and decreased expressions of ZO-1 and occludin at both the mRNA and protein levels in the hippocampus (P < 0.05 or 0.01). Multivariate linear regression analysis suggested a close correlation between anxiety-like behaviors and learning and memory abilities in DEHP-exposed mice. CONCLUSION DEHP exposure may cause damages of the blood-brain barrier and the pyramidal cells in the hippocampus of mice, thereby inducing anxiety-like behaviors and learning and memory impairment.
Animals ; Anxiety/chemically induced* ; Blood-Brain Barrier/metabolism* ; Diethylhexyl Phthalate/toxicity* ; Male ; Maze Learning ; Mice ; Mice, Inbred ICR ; Occludin/pharmacology*

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.
Animals ; Diethylhexyl Phthalate ; toxicity ; Environmental Pollutants ; toxicity ; Haplorhini ; Humans ; Mice ; PPAR alpha ; genetics ; metabolism ; Plasticizers ; toxicity ; Rats

Animals ; Diethylhexyl Phthalate ; toxicity ; Female ; Ovary ; drug effects ; metabolism ; ultrastructure ; Rats, Sprague-Dawley ; Receptors, LH ; metabolism ; Receptors, LHRH ; metabolism ; Toxicity Tests

OBJECTIVE: Previous studies have indicated that the plasticizer di (2-ethylhexyl) phthalate (DEHP) affects lipid accumulation; however, its underlying mechanism remains unclear. We aim to clarify the effect of DEHP on lipid metabolism and the role of TYK2/STAT1 and autophagy. METHODS: In total, 160 Wistar rats were exposed to DEHP [0, 5, 50, 500 mg/(kg•d)] for 8 weeks. Lipid levels, as well as mRNA and protein levels of TYK2, STAT1, PPARγ, AOX, FAS, LPL, and LC3 were detected. RESULTS: The results indicate that DEHP exposure may lead to increased weight gain and altered serum lipids. We observed that DEHP exposure affected liver parenchyma and increased the volume or number of fat cells. In adipose tissue, decreased TYK2 and STAT1 promoted the expression of PPARγ and FAS. The mRNA and protein expression of LC3 in 50 and 500 mg/(kg•d) groups was increased significantly. In the liver, TYK2 and STAT1 increased compensatorily; however, the expression of FAS and AOX increased, while LPL expression decreased. Joint exposure to both a high-fat diet and DEHP led to complete disorder of lipid metabolism. CONCLUSION It is suggested that DEHP induces lipid metabolism disorder by regulating TYK2/STAT1. Autophagy may play a potential role in this process as well. High-fat diet, in combination with DEHP exposure, may jointly have an effect on lipid metabolism disorder.
Adipose Tissue ; drug effects ; metabolism ; Animals ; Autophagy ; drug effects ; Body Weight ; drug effects ; Diet, High-Fat ; adverse effects ; Diethylhexyl Phthalate ; toxicity ; Endocrine Disruptors ; toxicity ; Female ; Lipid Metabolism ; drug effects ; Lipid Metabolism Disorders ; chemically induced ; Liver ; drug effects ; metabolism ; Male ; Rats, Wistar ; STAT1 Transcription Factor ; metabolism ; TYK2 Kinase ; metabolism

Adiposity ; drug effects ; Animals ; Diethylhexyl Phthalate ; toxicity ; Female ; Gene Expression Regulation, Developmental ; drug effects ; Male ; Maternal Exposure ; Metabolic Diseases ; chemically induced ; PPAR gamma ; genetics ; metabolism ; Pregnancy ; Prenatal Exposure Delayed Effects ; Rats ; Rats, Sprague-Dawley

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.
Carcinogenicity Tests ; Chemical Safety ; Clergy ; Dataset ; Diethylhexyl Phthalate ; Employment ; Humans ; 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 ; Ventilation

OBJECTIVETo investigate the mechanism of di-2-ethylhexyl phthalate (DEHP) and cypermethrin (CYP) inducing gonadal dysgenesis in prepubertal male rats.

METHODSA total of 40 healthy 3-week-old specific pathogen-free male Sprague-Dawley rats were randomly and equally divided into four groups: control group (corn oil), DEHP group (500 mg/kg, dissolved in corn oil), CYP group (80 mg/kg, dissolved in corn oil), and combined exposure group (exposed to 500 mg/kg DEHP and 80 mg/kg CYP, dissolved in corn oil). Rats were treated by gavage administration once a day for 30 days. Twenty-four hours after the last exposure, the animals were sacrificed. The body weight and the wet weight of testis were determined, and the weight coefficient of testis was calculated. Radioimmunoassay was used to determine serum testosterone level. Ultrastructural-level histopathological changes of the testis were examined by transmission electron microscopy. The mRNA and protein expression of follicle stimulating hormone receptor (FSHR), androgen binding protein (ABP), inhibin beta-B (INHBB) and vimentin (VIM) were analyzed by real-time PCR and Western blot, respectively. Factorial design analysis of variance was used to compare differences between groups; interaction diagrams were used to determine the interaction between DEHP and CYP.

RESULTSCompared with those of the control group, the testis weights and testis coefficients of the DEHP, CYP, and combined exposure groups significantly decreased by 39.3-59.2%and 19.7-58.6%, respectively, and all exposure groups showed significant reductions in serum level of testosterone, ranging from 49.1% to 62.7% (P < 0.05 or P < 0.01). And all the exposure groups showed different levels of ultrastructural damages in the testes. Compared with that in the control group, the mRNA expression of FSHR, ABP, INHBB, and VIMin the DEHP group was down-regulated by 1.72, 2.64, 2.83 and 1.79 times, and their protein levels were significantly reduced by 65.2%, 53.7%, 70.1%, and 51.9% (P < 0.05 or P < 0.01). Significant decreases in mRNA expression of ABP (down 1.72 times) and INHBB (down 2.06 times) were observed in the CYP group, and their protein levels decreased by 38.3% and 49.7%, respectively (P < 0.05). The combined exposure to both DEHP and CYP resulted in big decreases in the mRNA levels of FSHR (down 1.62 times), ABP (down 2.00 times), INHBB (down 2.35 times), and VIM (down 1.54 times) and protein levels of FSHR (down 52.1%), INHBB (down 53.9%), and VIM (down 58.8%) (P < 0.05). Factorial design analysis of variance showed that the combination of two substances had an antagonistic effect on the expression of ABP and INHBB (P < 0.05).

CONCLUSIONDEHP and CYP, alone or combined, can lead to gonadal dysgenesis in prepubertal male rats. Both of them can disrupt functional mRNA and protein expression in Sertoli cells to certain levels. The combination of DEHP and CYP shows antagonistic effects, and DEHP has a stronger reproductive toxicity than CYP.

Animals ; Diethylhexyl Phthalate ; toxicity ; Gonadal Dysgenesis ; chemically induced ; Male ; Pyrethrins ; toxicity ; Rats ; Rats, Sprague-Dawley ; Sertoli Cells ; metabolism ; Testis ; cytology ; drug effects

OBJECTIVETo investigate the effects of di-(2-ethylhexyl) phthalate (DEHP) on the expressions of Caspase-3 and Caspase-9 genes in rat Leydig cells and the apoptosis of the cells in vitro.

METHODSLeydig cells were isolated from male SD rats, primarily cultured and treated with DEHP at a low (10 nmol/L), a medium (50 nmol/L) and a high dose (100 nmol/L) for 24 hours. Then the mRNA expressions of Caspase-3 and Caspase-9 genes in the Leydig cells were detected by real time PCR, their protein expressions determined by Western blot, and the apoptosis of the Leydig cells measured by flow cytometry.

RESULTSCompared with the DMSO control group, the low-, medium- and high-dose DEHP groups showed significantly upregulated expressions of Caspase-3 mRNA (1.69 +/- 0.38 vs 3.82 +/- 0.39, 6.91 +/- 0.40 and 15.47 +/- 0.40, P < 0.05), Caspase-3 protein (0.18 +/- 0.0.09 vs 0.32 +/- 0.10, 0.61 +/- 0.08 and 0.89 +/- 0.09, P < 0.05), Caspase-9 mRNA (2.24 +/- 0.41 vs 5.16 +/- 0.43, 9.61 +/- 0.45 and 19.22 +/- 0.43, P < 0.05) and Caspase-9 protein (0.26 +/- 0.07 vs 0.40 +/- 0.08, 0.68 +/- 0.09 and 0.96 +/- 0.08, P < 0.05), as well as increased apoptosis rate of Leydig cells (4.36 +/- 1.11 vs 7.52 +/- 1.09, 12.72 +/- 1.10 and 24.59 +/- 1.11, P < 0.05), all in a dose-dependent manner.

CONCLUSIONDEHP can induce the apoptosis of rat Leydig cells by activating the apoptosis Caspase pathway, and consequently affect the function of Leydig cells.

Animals ; Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Caspase 9 ; metabolism ; Diethylhexyl Phthalate ; toxicity ; Leydig Cells ; drug effects ; metabolism ; Male ; Rats ; Rats, Sprague-Dawley

The aim of this study was to evaluate the effects of low concentrations of DEHP and MEHP on steroidogenesis in a murine Leydig tumor cell line (MLTC-1) in vitro. The result of flow cytometry analysis revealed that the proportion of apoptotic cells was significantly increased after the exposure to DEHP. All three genes (P450scc, P450c17, and 3βHSD) under study showed an increased expression following exposure to DEHP or MEHP, although some insignificant inhibitory effects appeared in the 10 μmol/L treatment group as compared with the controls. It was also found that compared with the controls. It was also found that DEHP or MEHP stimulated INSL3 mRNA and protein especially in the 0.001 μmol/L treatment group. Testosterone secretions were stimulated after the exposure to DEHP or MEHP. Alternations of steroidogenic enzymes and INSL3 in MLTC-1 cells might be involved in the biphasic effects of DEHP/MEHP on androgen production.
Animals ; Apoptosis ; drug effects ; Cell Line, Tumor ; Diethylhexyl Phthalate ; analogs & derivatives ; toxicity ; Leydig Cell Tumor ; metabolism ; pathology ; Mice ; Steroids ; biosynthesis