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

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

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

OBJECTIVETo observe the behavioral changes of rats after subchronic exposure to di-(2-ethyl hexyl) phthalate (DEHP).

METHODSTwenty-four healthy male SD rats were randomized equally into 4 groups, namely the solvent control group (sesame oil) and 3 DEHP groups with daily intragastric administration of DEHP at the doses of 150, 450, and 1350 mg/kg for 28 days. The neurobehavioral changes of rats were evaluated by open-field test (OFT) and elevated plus-maze test (EPM), and the body weight and organ coefficients were measured.

RESULTSThe rats showed no significant differences in the performance in OFT or EPM before DEHP exposure. The body weight of the rats increased with the prolonged DEHP exposure, but no significant differences were found between the treatment groups and the control group (P>0.05). From the third week of exposure, the weekly food consumption and the food utilization rate showed significant differences between the treatment groups and the control group (P<0.05 and PP<0.01), and the liver and testis coefficients, but not the kidney coefficient, also differed significantly (PP<0.01, PP<0.01, and P>0.05). In OFT, the total distance of movement was the longest in high dose treatment group (PP<0.05 vs control group), and the durations of stay in the central area, but not the number of times of entry, differed significantly between the 3 treatment groups and the control group (PP<0.05 and P>0.05). In EPM test, however, the performances of the rats was all similar between the 4 groups (P>0.05).

CONCLUSIONDEHP can affect the locomotor activity and exploratory behavior of rats after short-term exposure, suggesting its possible hazard in human being.

Animals ; Behavior, Animal ; Diethylhexyl Phthalate ; toxicity ; Environmental Exposure ; Exploratory Behavior ; Male ; Motor Activity ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo evaluate the ability of di(2-ethylhexyl) phthalate (DEHP) with inducing damage in sexual development of female offspring rats after maternal exposure.

METHODSOn gestational day (GD) 12, pregnant Wistar rats were weighed, encoded and randomly assigned to 5 groups (10 dams per group). From GD 12 through GD 17 each dam was dosed daily by gavage with either corn oil (vehicle control, 1 mgxkg(-1)xd(-1)) or DEHP (1, 250, 750 and 1000 mgxkg(-1)xd(-1)). Then female offspring were monitored for eye opening on postnatal day (PND) 14-17, organ coefficient on PND 22 and the time to vaginal opening on PND 30 - 38 (if vagina did not open during the period, observation time should extent to adult), as well as body weight, time to first estrus.

RESULTSNo significant changes were observed on eye opening at any dose, which were (15.8 +/- 0.4) d, (16.3 +/- 0.6) d, (16.0 +/- 0.6) d, (15.9 +/- 0.6) d, (15.8 +/- 0.4) d respectively in control, 1, 250, 750 and 1000 mgxkg(-1)xd(-1) (F = 1.363, P = 0.262). However, 62.50% (15/24), 81.25% (26/32) female offspring were permanently absence of vaginal orifice in 750 and 1000 mgxkg(-1)xd(-1) groups respectively, while control, 1 and 250 mgxkg(-1)xd(-1) groups developed normally with vaginal orifices (chi(2) values were 84.92, 132.79, respectively, P < 0.01). The ages of vaginal opening were (32.7 +/- 1.3) d, (33.3 +/- 1.5) d, (32.2 +/- 1.5) d, (33.1 +/- 1.3) d, (33.3 +/- 1.2) d and the body weight were (91.56 +/- 6.65) g, (93.79 +/- 6.28) g, (92.98 +/- 8.48) g, (100.57 +/- 6.47) g, (103.83 +/- 8.24) g in control, 1, 250, 750 and 1000 mgxkg(-1)xd(-1). After covariance adjustment for body weight, which can statistically influenced the age of vaginal opening (F = 40.857, P < 0.05), difference were found at the age of vaginal opening (F = 3.075, P < 0.05), and 250 mgxkg(-1)xd(-1) group was advanced than control (t = -2.056, P < 0.05).

CONCLUSIONExposure to DEHP in utero from GD 12 - 17 can result in abnormalities of sexual development such as the time to vaginal opening and vaginal atresia.

Animals ; Diethylhexyl Phthalate ; toxicity ; Female ; Maternal Exposure ; Pregnancy ; Rats ; Rats, Wistar ; Sexual Development ; drug effects ; Vagina ; abnormalities

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*

OBJECTIVETo evaluate the effect of dibutyl phthalate (DBP) and di-(2-ethylhexyl) phthalate (DEHP) on urine superoxide dismutase (SOD) activity and malondialdehyde (MDA) content in rats.

METHODSAccording to 2×2 factorial analysis, 60 adult male SD rats were randomized into 10 groups (n=6), including a control group (fed with sesame oil), 3 DBP groups (fed with DBP at the doses of 30, 100 and 300 mg/kg), 3 DEHP groups (with DEHP at 50, 150, and 450 mg/kg), and 3 DBP+DEHP groups (with 30 mg/kg DBP+50 mg/kg DEHP, 100 mg/kg DBP+150 mg/kg DEHP, and 300 mg/kg DBP +450 mg/kg DEHP). The agents were administered in a single dose through gavage in a volume of 2 ml. After the treatments, the 24, 48, 72, and 96 h urine samples were collected to determine the SOD activity and MDA content.

RESULTSDBP and DEHP, either alone or in combination, significantly decreased SOD activity and increased MDA content in the urine collected at 24 h but not at the other time points. Such changes were gradually reversed with time.

CONCLUSIONDBP or DEHP treatment alone can result in significant oxidative damage in the kidney of rats, and the toxic effect of the combined exposure is even more obvious.

Animals ; Dibutyl Phthalate ; toxicity ; Diethylhexyl Phthalate ; toxicity ; Environmental Pollutants ; toxicity ; Kidney ; drug effects ; physiopathology ; Male ; Malondialdehyde ; urine ; Oxidative Stress ; drug effects ; Rats ; Rats, Sprague-Dawley ; Superoxide Dismutase ; metabolism ; urine

OBJECTIVETo verify the antagonistic effect of Bushen Tianjing Recipe (BTR) on environmental endocrine disruptors (EEDs) induced gonadal dysgenesis (GD) Sprague-Dawley (SD) male rat model.

METHODSTotally 70 3-week-old male SD rats were randomly divided into seven groups, i.e., the control group (fed with corn oil), the model A group [di-2-ethylhexyl-phthalate (DEHP) 500 mg/kg], the CM A group (fed with DEHP 500 mg/kg + BTR 40 mL/kg), the exposed group B (fed with CYP 80 mg/kg), the CM B group (fed with CYP 80 mg/kg + BTR 40 mL/kg), the model C group [fed with DEHP 500 mg/kg + CYP 80 mL/kg], the CM C group (DEHP 500 mg/kg + CYP 80 mg/kg + BTR 40 mL/kg), respectively, 10 in each group. All were administered with corresponding medication by gastrogavage, once daily, for total 30 days. Rats were killed 24 h after the last administration, and their body weight and wet testis weight were weighed. The coefficient of testis was calculated. The serum testosterone (T) level was measured by chemiluminescent immunoassay. The histopathologic tissue was prepared. The ultrastructural changes of genital cells were observed by electron microscope.

RESULTSCompared with the control group, there was no statistical difference in the body weight increase among all groups (P > 0.05). The time of testicular descent and preputial separation were significantly delayed in each exposed group (P < 0.01). In the exposed group A and the exposed group C, the wet weight of the testes was reduced and serum T level decreased (P < 0.01). The coefficient of testis significantly decreased in the exposed group A (P < 0.01). Compared with corresponding model group, the time of testicular descent and preputial separation were significantly fore-laid in each corresponding CM group (P < 0.01). The weight of the testes, the coefficient of testis, and the serum T level increased in the CM A group (P < 0.01). The serum T level obviously increased in the CM B group (P < 0.05).

CONCLUSIONSThe GD rat model was successfully duplicated by using DEHP. EEDs were proved to have significant anti-androgen activities. BTR was verified to have significant antagonistic to its anti-androgen effect.

Animals ; Diethylhexyl Phthalate ; toxicity ; Drugs, Chinese Herbal ; therapeutic use ; Endocrine Disruptors ; toxicity ; Gonadal Dysgenesis ; chemically induced ; drug therapy ; Male ; Phytotherapy ; Rats ; Rats, Sprague-Dawley ; Testosterone ; blood

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

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