Lycopene Prevents DEHP-Induced Liver Lipid Metabolism Disorder by Inhibiting the HIF-1α-Induced PPARα/PPARγ/FXR/LXR System

Di(2-ethylhexyl) phthalate (DEHP) is a widespread pollutant that badly affects animals and human health. Lycopene (LYC) has been used as a dietary supplement that has effective antioxidant and antiobesity functions. The present goal was to understand the molecular mechanisms of LYC preventing DEHP-induced lipid metabolism of the liver. The mice were intragastrically administered with LYC (5 mg/kg) and/or DEHP (500 mg/kg or 1000 mg/kg). Here, we found that LYC attenuated DEHP-caused hepatic histopathological lesions including steatosis. Hematological and biochemical analyses revealed that LYC ameliorated DEHP-caused liver function and lipid metabolism disorders. DEHP caused lipid metabolism disorders via activating the peroxisome proliferator activated receptor α/γ (PPARα/γ) signal transducer and Farnesoid X receptor (FXR)/liver X receptor (LXR) signaling pathway. As a major regulator of lipid metabolism, hypoxia-inducible factor-1α (HIF-1α) system was elevated with increased fatty degeneration under DEHP exposure. However, LYC could decrease the levels of HIF-1α/PPARα/PPARγ/FXR/LXR signaling pathway-related factors. Our research indicated that LYC could prevent DEHP-induced lipid metabolism disorders via inhibiting the HIF-1α-mediated PPARα/PPARγ/FXR/LXR system. This study may provide a possible molecular mechanism for fatty liver induced by DEHP.

Exposure of patients to di(2-ethylhexy)phthalate (DEHP) and its metabolite MEHP during extracorporeal membrane oxygenation (ECMO) therapy

The plasticizer di(2-ethylhexyl)phthalate (DEHP) is often used for PVC medical devices, that are also largely used for intensive care medical treatments, like extracorporeal membrane oxygenation (ECMO) therapy. Due to the toxicological potential of DEHP, the inner exposure of patients with this plasticizer is a strong matter of concern as many studies have shown a high leaching potential of DEHP into blood. In this study, the inner DEHP exposure of patients undergoing ECMO treatment was investigated. The determined DEHP blood levels of ECMO patients and the patients of the control group ranged from 31.5 to 1009 μg/L (median 156.0 μg/L) and from 19.4 to 75.3 μg/L (median 36.4 μg/L), respectively. MEHP blood levels were determined to range from < LOD to 475 μg/L (median 15.9 μg/L) in ECMO patients and from < LOD to 9.9 μg/L (median 3.7 μg/L) in the control group patients, respectively. Increased DEHP exposure was associated with the number of cannulas and membranes of the ECMO setting, whereas residual diuresis decreased the exposure. Due to the suspected toxicological potential of DEHP, its use in medical devices should be further investigated, in particular for ICU patients with long-term exposure to PVC, like in ECMO therapy.

Rosmarinic acid alleviates di-2-ethylhexyl phthalate (DEHP) -induced thyroid dysfunction via multiple inflammasomes activation

DEHP (di-2-ethylhexyl phthalate), an environmental endocrine disruptor, is widely used in industrial products, particularly as plasticizers and softeners which could disrupt the function of the hypothalamic-pituitary-thyroid (HPT) axis. Rosmarinic acid (RA) possesses potential antioxidant and anti-inflammatory capacities in disease models. Nevertheless, evidence on the association between DEHP-induced thyroid dysfunction and inflammation, as well as the molecular mechanism underlying the protective effects of RA-mitigated DEHP-induced thyroid injury remains inconclusive. Male Sprague Dawley (SD) rats were intragastrically administered DEHP (150 mg/kg, 300 mg/kg, 600 mg/kg) once a day for 90 consecutive days. Also, FRTL-5 cells were treated with a wide range of DEHP concentrations (10-8, 10-7, 10-6, 10-5, 10-4, 10-3, 10-2 M) for 24 hr. Subsequently, RA (50 μM) was administered for 24 hr before 10-4 M DEHP challenge. We found that DEHP induced thyroid damage and inflammatory infiltration in vivo. In addition, we showed that DEHP triggered inflammatory cell death, which is mediated by multiple inflammasomes. Moreover, RA, pyroptosis inhibitor (Ac-YVAD-cmk) and antioxidant inhibitor (NAC) treatment significantly alleviated DEHP-induced thyrocyte death, suppressing pro-inflammatory cytokine production, inhibiting multiple inflammasomes activation and attenuating thyrocyte death, respectively. Collectively, our results reveal that a critical role of inflammasomes activation in DEHP-induced thyroid injury, and suggest that RA confers protection against DEHP-induced thyroid inflammation, and facilitating control of the effects of DEHP after given pyroptosis inhibitor or antioxidant inhibitor. These results indicate that it should be possible to provide novel insights into toxicologically and pharmacologically targeting this molecule to DEHP-induced inflammation.

DEHP induces immunosuppression through disturbing inflammatory factors and CYPs system homeostasis in common carp neutrophils

Di-(2-ethylhexyl) phthalate (DEHP), a common pollutant in the water environment, has been reported to be associated with immune functions, especially aquatic organisms. However, whether DEHP exposure causes neutrophils toxicity in common carp is still unclear. To investigate the toxic effect of DEHP on immune functions, common carp neutrophils were exposed to DEHP (40 μmol/L and 200 μmol/L) for 2 h. The common carp neutrophils exposed to DEHP showed a decrease in neutrophil phagocytosis rate compared with control group. DEHP exposure induced a significant decrease in mRNA expression levels of inflammatory cytokines-related genes (Interleukin-6, Interleukin-8, transforming growth factor, tumor necrosis factor (TNF)-α, TNF-R1, TNF-T1, Interferon (IFN)-2a, IFN-g2b, IFN-g1) in common carp neutrophils, while the expression levels of IL-1β and IL-10 were increased compared with control group (P < 0.05). Furthermore, the detection of cytochrome P450 enzyme related genes showed that the mRNA expression levels of CYP (cytochrome P450 proteins)-1A, CYP-1B1, CYP-C1, CYP-2K were significantly decreased, and the mRNA expression level of CYP-3A was significantly reduced (P < 0.05). The results indicated that DEHP could affect the phagocytic ability of neutrophils by regulating the expression of inflammatory cytokines and disrupting cytochrome P450 homeostasis, which caused the immunosuppression in common carp.

[Content of seminal plasma plasticizer in the patients with idiopathic asthenozoospermia and its impact on male fertility]

OBJECTIVE

To investigate the relationship between di-(2-ethyl hexyl) phthalate (DEHP) and male infertility by detecting the concentration of DEHP in the seminal plasma of the patient with idiopathic asthenozoospermia (IAS).

METHODS

This study included 45 infertile males with diagnosed IAS in the observation group and another 45 men with normal sperm parameters as controls. We obtained the general baseline data on the subjects, determined the concentration of DEHP in the seminal plasma, the ROS level and the sperm DNA fragmentation index (DFI), and compared them between the two groups of males.

RESULTS

There were no statistically significant differences between the two groups of subjects in age, living habits and other general in baseline data (P > 0.05). The IAS patients, in comparison with the normal controls, showed significantly increased DEHP concentration in the seminal plasma (［0.45 ± 0.09］ vs ［0.23 ± 0.05］ μg/ml, P < 0.05), ROS level (［569.4 ± 45.3］ vs ［317.6 ± 27.8］ pmol/106 sperm, P < 0.05) and sperm DFI (［22.1 ± 8.3］% vs ［10.5 ± 6.7］%, P < 0.05). The concentration of DEHP in the seminal plasma was correlated positively with the ROS level (r = 0.77, P < 0.05) and sperm DFI (r = 0.75, P < 0.05) but negatively with the percentage of progressively motile sperm (r = －0.81, P < 0.05).

CONCLUSIONS

The DEHP level is escalated in the seminal plasma of the IAS patient, which may be responsible for the reduced sperm motility and increased DFI of the patient.

Effects of di(2-etilhexil) phthalate on human umbilical artery

Di(2-etilhexil) phthalate (DEHP) is a compound used in plastic materials, which has endocrine disrupting properties. The human DEHP exposure depend on the use of plastics in toys, medical devices and food and beverage containers. The DEHP effects were studied in some physiological systems; nevertheless, the actions in human arteries were never described. We analysed the DEHP effect on endothelium denuded human umbilical artery (HUA), an important artery to ensure gases and nutrients exchange with fetus. We assessed DEHP short-term effects on contractility, occurring few minutes after DEHP is in contact with HUA in the organ bath receptacles. The long-term effects on HUA, observed after 24 h in presence of DEHP, were assessed in the organ bath system, and also through the analysis of receptors expression (5-HT_2A and H₁) and of cellular viability, by using HUA smooth muscle cells. DEHP (1 nM-100 μM) induced a short-term relaxing effect on HUA contracted by 5-HT, histamine or KCl. DEHP long-term exposure of arteries (1 nM, 10 μM and 100 μM) reduced its own relaxant effect on HUA contracted by 5-HT and histamine and, precisely, 24 h exposure to DEHP 1 nM reverted the relaxant effect on 5-HT contractility. Long-term exposure at more than 10 nM of DEHP decreased 5HT_2A receptors expression. In conclusion, DEHP short-term exposition elicit vasodilation of HUA contracted by different agents. DEHP long-term exposition reduced the expression of 5HT_2A receptors. The DEHP long-term exposition decrease the short-term relaxant effect and, at low concentrations can increase the contractile effect of 5-HT.

The Role of Peroxisome Proliferator–Activated Receptor Gamma (PPARγ) in Mono(2-ethylhexyl) Phthalate (MEHP)-Mediated Cytotrophoblast Differentiation

BACKGROUND

Phthalates are environmental contaminants commonly used as plasticizers in polyvinyl chloride (PVC) products. Recently, exposure to phthalates has been associated with preterm birth, low birth weight, and pregnancy loss. There is limited information about the possible mechanisms linking maternal phthalate exposure and placental development, but one such mechanism may be mediated by peroxisome proliferator–activated receptor γ (PPARγ). PPARγ belongs to the nuclear receptor superfamily that regulates, in a ligand-dependent manner, the transcription of target genes. Studies of PPARγ-deficient mice have demonstrated its essential role in lipid metabolism and placental development. In the human placenta, PPARγ is expressed in the villous cytotrophoblast (VCT) and is activated during its differentiation into syncytiotrophoblast.

OBJECTIVES

The goal of this study was to investigate the action of mono(2-ethylhexyl) phthalate (MEHP) on PPARγ activity during in vitro differentiation of VCTs.

METHODS

We combined immunofluorescence, PPARγ activity/hCG assays, western blotting, and lipidomics analyses to characterize the impacts of physiologically relevant concentrations of MEHP (0.1, 1, and 10 μM) on cultured VCTs isolated from human term placentas.

RESULTS

Doses of 0.1 and 1 μM MEHP showed significantly lower PPARγ activity and less VCT differentiation in comparison with controls, whereas, surprisingly, a 10 μM dose had the opposite effect. MEHP exposure inhibited hCG production and significantly altered lipid composition. In addition, MEHP had significant effects on the mitogen-activated protein kinase (MAPK) pathway.

CONCLUSIONS

This study suggests that MEHP has a U-shaped dose–response effect on trophoblast differentiation that is mediated by the PPARγ pathway and acts as an endocrine disruptor in the human placenta. https://doi.org/10.1289/EHP3730.

Association Between Diethylhexyl Phthalate Exposure and Thyroid Function: A Meta-Analysis

BACKGROUND

Diethylhexyl phthalate (DEHP) is widely used in industrial products, particularly as plasticizers and softeners. Because it is used extensively, DEHP has been detected in humans worldwide. Although epidemiological studies suggest that DEHP can disrupt the function of the hypothalamic-pituitary-thyroid (HPT) axis, evidence on the association between DEHP exposure and thyroid function remains inconclusive. Therefore, a comprehensive meta-analysis was performed to investigate the association between DEHP exposure and the HPT axis in humans.

METHODS

A literature search of the MEDLINE, EMBASE, and Web of Science databases was conducted to search for studies in which the correlation coefficient values or regression coefficient values between three major DEHP metabolites (i.e., monoethylhexyl phthalate [MEHP], mono [2-ethyl-5-hydroxyhexyl] phthalate [MEHHP], and mono [2-ethyl-5-oxohexyl] phthalate) and thyrotropin, free thyroxine (T4), or total T4 were determined. The association between DEHPs and thyroid hormone levels were evaluated using Pearson's correlation coefficients.

RESULTS

Thirteen eligible articles were included. Urinary MEHP and MEHHP concentration was negatively correlated with total T4. Pooled correlation coefficients between MEHP/MEHHP and total T4 were -0.02 [confidence interval (CI) -0.05 to 0.00] and -0.03 [CI -0.05 to -0.01], respectively. Urinary mono (2-ethyl-5-oxohexyl) phthalate concentration was positively correlated with thyrotropin, and the pooled correlation coefficient was 0.02 [CI 0.00-0.04].

CONCLUSIONS

The findings of this meta-analysis suggest a significant association between the exposure of DEHP metabolites and the function of the HPT axis.

Lactobacillus plantarum TW1-1 Alleviates Diethylhexylphthalate-Induced Testicular Damage in Mice by Modulating Gut Microbiota and Decreasing Inflammation

Diethylhexylphthalate (DEHP), acting as an endocrine disruptor, disturbed reproductive health. Here, we evaluated the effects of Lactobacillus plantarum TW1-1 (L. plantarum TW1-1) on DEHP-induced testicular damage in adult male mice. Results showed that oral supplementation of L. plantarum TW1-1 significantly increased the serum testosterone concentration, enhanced the semen quality, and attenuated gonad development defects in DEHP-exposed mice. L. plantarum TW1-1 also alleviated DEHP-induced oxidative stress and inflammatory responses by decreasing the mRNA expression and serum protein concentration of different inflammatory factors [tumor necrosis factor-α, interleukin (IL)-1β and IL-6]. Furthermore, L. plantarum TW1-1 significantly reduced DEHP-induced intestinal hyper-permeability and the increase in the serum lipopolysaccharide level. Gut microbiota diversity analysis revealed that L. plantarum TW1-1 shifted the DEHP-disrupted gut microbiota to that of the control mice. At phylum level, L. plantarum TW1-1 reversed DEHP-induced Bacteroidetes increase and Firmicutes decrease, and restored Deferribacteres in DEHP-exposed mice. Spearman's correlation analysis showed that Bacteroidetes, Deferribacteres, and Firmicutes were associated with DEHP-induced testicular damage. In addition, the ratio of Firmicutes to Bacteroidetes (Firm/Bac ratio) significantly decreased from 0.28 (control group) to 0.13 (DEHP-exposed group), which was restored by L. plantarum TW1-1 treatment. Correlation analysis showed that the Firm/Bac ratio was negatively correlated with testicular damage and inflammation. These findings suggest that L. plantarum TW1-1 prevents DEHP-induced testicular damage via modulating gut microbiota and decreasing inflammation.

Modulation of heat-shock response is associated with Di (2-ethylhexyl) phthalate (DEHP)-induced cardiotoxicity in quail (Coturnix japonica)

Di(2-ethylhexyl) phthalate (DEHP) is an omnipresent environmental pollutant with endocrine disrupting properties. As a plasticizer, DEHP can be leach from the plastic to transfer the external environment and thus enters the animal food chain, causing serious damage to the animal organs. The heat-shock response (HSR) comprising heat-shock protein (HSPs) and heat-shock transcription factor (HSFs) plays a pivotal role in various toxic stress conditions. For the sake of investigating the effects of DEHP exposure on cardiac toxicity and the regulation of HSR, male quail were fed the diet with 0, 250, 500 and 750 mg/kg DEHP by gavage administration for 45 days. Histopathological changes including cardiomyocyte swelling and muscle fiber dilatation were observed in the hearts exposed to DEHP. During the DEHP treatment, the mRNA expression of HSP60 and HSP70 were universally reduced, while the expression of other HSPs (HSP10, HSP25, HSP27, HSP40, HSP47, HSP90, HSP110) had different degrees of growth. In addition, the levels of HSF1, HSF2, and HSF3 were significantly increased. Given the facts above, DEHP exposure induced the toxic effects of quail heart. DEHP exposure did great harm to HSR via affecting the synthesis of HSFs to mediate the transcription of the HSPs. Ultimately, this study provided new evidence that DEHP-induced cardiotoxicity in quail was related to activation of HSR and playing a protective role.

Effect of residential air cleaning interventions on risk of cancer associated with indoor semi-volatile organic compounds: a comprehensive simulation study

BACKGROUND

Human exposure to multiphase semi-volatile organic compounds (SVOCs) via multiple routes has been associated with health risks. Residential air cleaning interventions remove SVOCs adsorbed on airborne particles, which subsequently affects indoor concentrations of SVOCs in other phases. We aimed to investigate the effect of residential air cleaning interventions on the overall cancer risk associated with multiphase SVOCs.

METHODS

We simulated concentrations of eight multiphase SVOCs (including seven polycyclic aromatic hydrocarbons [PAHs] and di(2-ethylhexyl) phthalate [DEHP]) using a kinetic partition mass balance model for three exposure scenarios: naturally ventilated residences without intervention (scenario 1), naturally ventilated residences with portable air purifiers (scenario 2), and mechanically ventilated residences with air filtration units (scenario 3). We converted indoor concentrations of the individual PAHs into indoor concentrations of equivalent benzo[a]pyrene (BaP_eq) using the BaP cancer potency equivalent factor for each PAH. We estimated indoor exposure to SVOCs via inhalation, dermal absorption, and ingestion. For each scenario, we calculated the incremental lifetime cancer risk (ILCR) associated with indoor exposure to each SVOC via the three routes and the total ILCR (all three routes combined).

FINDINGS

Mean total ILCRs associated with exposure to BaP_eq were 4·42 × 10^-6 (SD 2·84) for scenario 1, 2·36 × 10^-6 (1·53) for scenario 2, and 4·88 × 10^-6 (4·86) for scenario 3. Mean total ILCRs associated with exposure to DEHP were 3·61 × 10^-6 (3·60) for scenario 1, 7·51 × 10^-7 (5·34) for scenario 2, and 1·48 × 10^-5 (2·02) for scenario 3. Ingestion of settled dust was the most important contributor to the total ILCR for both BaP_eq and DEHP in all the studied scenarios.

INTERPRETATION

The large-scale use of mechanical ventilation systems in urban residences in China needs to be evaluated owing to their potential exacerbation of the cancer risks associated with common indoor SVOCs.

FUNDING

National Key Project of the Ministry of Science and Technology and Natural Science Foundation of China.

Prenatal and postnatal exposure to di-(2-ethylhexyl) phthalate and neurodevelopmental outcomes: A systematic review and meta-analysis

BACKGROUND

Di-(2-ethylhexyl) phthalate (DEHP), the most widely used phthalate, has recently been associated with neurodevelopmental disturbances in children. However, the risk is yet to be quantified. Therefore, a systematic review and meta-analysis focusing on the association between exposure to DEHP and neurodevelopmental outcomes is necessary, with particular attention to study design (longitudinal vs. cross-sectional).

METHODS

We performed a comprehensive literature search for associations between exposure to DEHP and neurodevelopmental outcomes. Among 106 published studies found in public databases, eight longitudinal studies and two cross-sectional studies were included in the meta-analysis.

RESULTS

We observed a statistically significant association between the concentrations of DEHP metabolites and the neurodevelopment outcomes of children among cross-sectional results, and found significant association between DEHP exposure measured in prenatal period and the psychomotor development outcomes measured later in childhood.

CONCLUSIONS

To our knowledge, this is the first meta-analysis of studies investigating the association between DEHP exposure and neurodevelopment in children. A need exists for more researches and a precautionary policy for potential health hazard of DEHP, the most commonly used phthalate, to promote healthier neurodevelopment in children.

[Application and Safety Evaluation of DEHP in PVC Medical Devices]

DEHP is largely used in soft PVC products as the plasticizer, which is also widely applied in medical devices. Due to its potential and widespread toxicity and medical devices' specific use, the safety of DEHP's application in medical devices has received extensive attention. In this paper, a comprehensive review of the application and potential toxicity of DEHP in PVC medical devices is made on the basis of the research results all over the world. Besides, the safety evaluation in medical devices is discussed and some possible coping strategies are explored.

[Research on Experimental Model of Security Assessment of DEHP Migration from PVC-Tubes Medical Devices]

As we all know, DEHP is seriously harmful to human health and consequently has been acquired critical attention. DEHP is able to migrate from PVC medical devices for the non-chemically bound to PVC, thus contact with user and patient. The DEHP migration is influenced by various parameters. In order to assess the security of PVC-tubes medical devices scientifically of DEHP migration, we develop an experimental model by analyzing the parameters comprehensively and systematically, taking into account the clinical practices. For example, assessing the security of DEHP migration from infusion sets by utilizing this model.

Maternal exposure to environmental DEHP exacerbated OVA-induced asthmatic responses in rat offspring

Di (ethylhexyl) phthalate (DEHP) is a commonly used phthalates (PAEs) compound as plasticizer and becomes a severe environmental pollutant worldwide. Studies show that DEHP, as an environmental endocrine disruptor, has potential adverse effects on human. Epidemiologic studies indicate that DEHP is positively correlated to allergic diseases. Maternal exposure to DEHP may contribute to the increasing incidence of allergic diseases in offspring. However, the role of DEHP and its detailed mechanism in allergic disease of the offspring are still unclear. The aim of our study is to investigate whether DEHP maternal exposure could aggravate the allergic responses in offspring and its mechanism. Pregnant Wistar rats were randomly divided into three groups and exposed to different doses of DEHP. Half of the offspring were challenged with OVA after birth. All the pups of each group were sacrificed at postnatal day (PND)14, PND21 and PND28. The number of inflammatory cells in bronchoalveolar lavage was counted, lung pathological changes were observed, Th2 type cytokines expressions were checked, and the expression of TSLP signaling pathway were examined. Our results showed that maternal exposure to DEHP during pregnancy and lactation aggravated the eosinophils accumulation and the pathological inflammatory changes in pups' lung after OVA challenge. And maternal exposure to DEHP during pregnancy and lactation also elevated the levels of typical Th2 cytokines in OVA-challenged rats. What's more, maternal exposure to DEHP during pregnancy and lactation increased the levels of TSLP, TSLPR and IL-7R in the offspring after OVA challenge. Our study suggested that DEHP maternal exposure could aggravate the OVA-induced asthmatic responses in offspring. And this adjuvant effect of DEHP was related with the TSLP/TSLPR/IL-7R and its downstream signal pathways.

Systematic reviews and meta-analyses of human and animal evidence of prenatal diethylhexyl phthalate exposure and changes in male anogenital distance

Male reproductive alterations found in animals and humans following in utero phthalate exposure include decreased anogenital distance (AGD) and other reproductive-tract malformations. The aim of this investigation was to conduct systematic reviews of human and animal evidence of the effect of in utero exposure to diethylhexyl phthalate (DEHP) on anogenital distance (AGD) in males. PubMed, Embase, and Toxline were searched for relevant human and experimental animal studies on August 15, 2016. Search results were screened for relevance, and studies that met the inclusion criteria were evaluated for quality and data extracted for analysis. Confidence in the human and animal bodies of evidence was assessed and hazard conclusions reached by integrating evidence streams. The search yielded 6 relevant human studies and 19 animal studies. Meta-analysis of 5 human observational prospective cohort studies showed that increased maternal urinary concentrations of DEHP metabolites were associated with decreased AGD in boys (-4.07 [CI, -6.49 to -1.66] % decrease per log₁₀ rise in DEHP metabolites). Meta-analysis and meta-regression of the 19 experimental animal studies found reduced AGD with DEHP treatment, with a dose-response gradient, and with heterogeneity explained by species and strain. There is a moderate level of evidence from human investigations and a high level of data from animal studies that in utero exposure to DEHP decreases AGD. Based upon the available human and animal evidence, and consideration of mechanistic data, DEHP is presumed to be a reproductive hazard to humans on the basis of effects on AGD.

Systematic reviews and meta-analyses of human and animal evidence of prenatal diethylhexyl phthalate exposure and changes in male anogenital distance

Male reproductive alterations found in animals and humans following in utero phthalate exposure include decreased anogenital distance (AGD) and other reproductive-tract malformations. The aim of this investigation was to conduct systematic reviews of human and animal evidence of the effect of in utero exposure to diethylhexyl phthalate (DEHP) on anogenital distance (AGD) in males. PubMed, Embase, and Toxline were searched for relevant human and experimental animal studies on August 15, 2016. Search results were screened for relevance, and studies that met the inclusion criteria were evaluated for quality and data extracted for analysis. Confidence in the human and animal bodies of evidence was assessed and hazard conclusions reached by integrating evidence streams. The search yielded 6 relevant human studies and 19 animal studies. Meta-analysis of 5 human observational prospective cohort studies showed that increased maternal urinary concentrations of DEHP metabolites were associated with decreased AGD in boys (-4.07 [CI, -6.49 to -1.66] % decrease per log₁₀ rise in DEHP metabolites). Meta-analysis and meta-regression of the 19 experimental animal studies found reduced AGD with DEHP treatment, with a dose-response gradient, and with heterogeneity explained by species and strain. There is a moderate level of evidence from human investigations and a high level of data from animal studies that in utero exposure to DEHP decreases AGD. Based upon the available human and animal evidence, and consideration of mechanistic data, DEHP is presumed to be a reproductive hazard to humans on the basis of effects on AGD.

Treatment of β-thujaplicin counteracts di(2-ethylhexyl)phthalate (DEHP)-exposed vascular smooth muscle activation, inflammation and atherosclerosis progression

The initiation of atherosclerosis involves up-regulation of molecules such as E-selectin, VCAM-1, and ICAM-1. The progression of atherosclerosis is linked to proliferation and migration of vascular smooth muscle cell via MMP-2 and MMP-9 activities. However, the etiology of atherosclerosis concerning plasticizers is unknown. We evaluated β-thujaplicin in preventing the development of atherosclerosis in a model induced by pro-inflammatory cytokines. Moreover, we established a new atherosclerosis model in vascular smooth muscle cells (VSMC) exposed to a common contact plasticizer, di(2-ethylhexyl)phthalate (DEHP). SEVC4-10 endothelial cells were treated with 50% RAW conditioned medium and A7r5 VSMC was treated with the plasticizer, with/without β-thujaplicin (4 or 12 μM). Production of E-selectin, ICAM-1, and VCAM-1 in SEVC4-10 cells as well as MMP-2/MMP-9 (both expression and activity) in VSMC were monitored. Results showed that the conditioned medium induced E-selectin and ICAM were significantly prevented by β-thujaplicin. However, inhibition on the production of VCAM by β-thujaplicin was only seen in a concentration of 12 μM. Both concentrations of β-thujaplicin also significantly prevented DEHP-induced MMP-2 and MMP-9 expression and activities. Evidence uncovers that β-thujaplicin has additional factors in amelioration of atherosclerosis and corroborates that β-thujaplicin is a strong candidate in preventing the initiation and progression of atherosclerosis.

In vitro cytotoxic effects of DEHP-alternative plasticizers and their primary metabolites on a L929 cell line

Phthalic acid esters have been widely used to improve the plasticity of PVC medical devices. They carry a high exposure risk for both humans and the environment in clinical situations. Our study focuses on the cytotoxicity of alternative plasticizers. Postulated primary metabolites were synthesized, not being commercially available. Cytotoxicity assays were performed on L929 murine cells according to the ISO-EN 10993-5 standard design for the biocompatibility of medical devices. The tested concentrations of plasticizers (0.01, 0.05 and 0.1 mg/ml) covered the range likely to be found in biological fluids coming into direct contact with the medical devices. DEHP, DINP and DINCH were cytotoxic at the highest concentration (0.1 mg/ml) for 7 days of exposure. Their corresponding metabolites were found to be more cytotoxic, for the same concentration. By contrast, TOTM and its corresponding metabolite MOTM were not found to be cytotoxic. DEHA showed no cytotoxicity, but its corresponding monoester (MEHA) produced a cytotoxic effect at 0.05 mg/ml. In clinical situations, medical devices can release plasticizers, which can come into contact with patients. In vivo, the plasticizers are quickly transformed into primary metabolites. It is therefore important to measure the effects of both the plasticizers and their corresponding metabolites. Standard first-line cytotoxicity assays should be performed to ensure biocompatibility.

[Effect of di-(2-ethylhexyl) phthalate exposure on placental development in pregnant mice]

OBJECTIVE

To investigate the effect of di-(2-ethylhexyl) phthalate (DEHP) exposure on the growth and development of placenta, uterine natural killer (uNK) cell number and angiogenesis at the maternal-fetal interface in pregnant mice.

METHODS

From day 1 of pregnancy, pregnant mice were exposed daily to DEHP by oral gavage at 125, 250, or 500 mg/kg for 13 consecutive days. The uterine and placental tissues were then harvested for HE staining and immunohistochemistry to examine the effect of DEHP exposure on the growth and development of the placenta and angiogenesis and uNK cell number at the maternal-fetal interface.

RESULTS

Compared with the control group, the mice exposed to 500 mg/kg DEHP, but not those exposed to 125 and 250 mg/kg, showed significantly reduced number of embryo implantation (P<0.05). DEHP exposure significantly increased the rate of abortion. DEHP exposure at 125, 250, and 500 mg/kg significantly and dose-dependently lowered the placental weight compared with that in the control group (0.0637±0.0133, 0.0587±0.0176, 0.0524±0.0183 g vs 0.0786±0.0143 g, respectively; P<0.01), and significantly reduced the total area of the placenta and area of spongiotrophoblasts. DEHP exposure resulted in a significant reduction in the number of fetal vascular branches, and collapse and atresia of blood vessels. The mice exposed to DEHP at 125, 250, and 500 mg/kg had significantly lowered numbers of uNK cells (83.2±10.3, 60.7±12.4, and 50.4±14.5/HP, respectively) as compared with the control group (105.1±14.2/HP) at the maternal-fetal interface (P<0.01).

CONCLUSION

DEHP exposure significantly affects the growth and development of the placenta in mice possibly by suppressing angiogenesis and reducing uNK cell number at the maternal-fetal interface during pregnancy.

DEHP induces obesity and hypothyroidism through both central and peripheral pathways in C3H/He mice

OBJECTIVE

Di(2-ethylhexyl) phthalate (DEHP) is reported to cause obesity and hypothyroidism in both humans and rodents, but the underlying mechanisms were largely unknown. This study was designed to clarify the effects and the mechanisms of DEHP on the pathogenesis of obesity and hypothyroidism and to discover the relationship between them.

METHODS

Male C3H/He mice were treated with DEHP for 5 weeks, and the body weight, food intake, and body temperature were recorded during the exposure. After exposure, key organs and serum were analyzed by Q-PCR, Western blot, and ELISA.

RESULTS

DEHP induced significant body weight gain and adipogenesis in all exposure groups except for 0.05 mg/kg. Marked hyperphagia and daytime hypothermia were also observed, which were accompanied by disturbed hypothalamic neuropeptide expression and reduced BAT UCP1 expression. In addition, WAT lipid metabolism was significantly deceased at low dose (0.5 mg/kg) and increased at high dose (50 and 200 mg/kg). DEHP also induced hypothyroidism, which was probably attributed to the combined effects of hepatic CAR activation and hypothalamic TRH inhibition induced by hypothalamic leptin resistance.

CONCLUSIONS

Chronic DEHP exposure could induce obesity by interrupting energy homeostasis, which is probably due to the synergistic effects of hypothyroidism and hypothalamic leptin resistance.

Phthalates - widespread occurrence and the effect on male gametes. Part 2. The effects of phthalates on male gametes and on the offspring

The general exposure to endocrine disruptors, including phthalates, is considered as one of the reason diminished sperm count and deteriorated sperm quality, which may lead to infertility and higher incidence of congenital malformations of the genital tract. This article describes the effects of selected phthalates di(2-ethylhexyl)phthalate (DEHP), dibutyl phthalate (DBP); butylbenzyl phthalate (BBP), diethyl phthalate (DEP), di-isononyl phthalate (DINP) on the male gametes, reproduction and the offspring of exposed animals. Results of several papers in vitro showed that above mentioned phthalates are weakly estrogenic, whereas in vivo studies showed that they have rather antiandrogenic abilities. Review of papers regarding to laboratory animals confirmed that phthalates cause diminished sperm count, increased frequency of abnormal spermatozoa and DNA damage in germ cells, especially after chronic exposure and in case exposure of immature animals. Phthalates may induce in male gametes mutations leading to increased pre- and postnatal mortality of the offspring and to incidence of congenital malformations, growth retardation, delay in sexual development, shortening of anogenital distance in males, disturbances in sex ratio and diminished quality of semen in F1 generation. The sensitivity on mammalian life stages on phthalates seems to be as follows: fetal > peripubertal > adult. The human studies provided limited evidence of an association between phthalate exposure and semen quality. Concentration of phthalates in semen of men at the level from 0.08 to 1.32 mg/kg was related to declined semen quality and infertility. Majority of human data showed the connection of increased level of phthalates in urine and sperm quality, however on the basis results of other studies, the impact of environmental exposure on sperm parameters seems to be rather small.

KEY WORDS

phthalates, sperm count and quality, pre- and perinatal exposure, mammalian and human effects.

Phthalates - widespread occurrence and the effect on male gametes. Part 1. General characteristics, sources and human exposure

Phthalates are widely present in human environment. Widespead exposure to those agents, which are compounds of numerous daily use products, is unavoidable. In the current paper following phthalates benzylbutyl phthalate (BBP), di- n-butyl phthalate (DBP), di(2-ethylhexyl)phthalate (DEHP), diethyl phthalate (DEP), di-isononyl phthalate (DINP) are described. Phthalates mainly enter to the composition of plastic goods, like boxes and containers for storage of foods, toys, medical devices, and also cosmetics, personal care products, as well as paints, vanishes, printing inks. This paper describes the occurence of individual phthalates in the environment (water, air) and in different products. During production, transportation, manufacturing of goods and improper disposal, phthalates released into soil, water and air. For example indoor air included 13 mg/m3 phthalates, where 72 % of all constitutes DEP (2.29 mg/m(3)), BBP (3.97 mg/m(3)) and DEHP (2.43 mg/m(3)). Exposure to phthalates take place mainly by ingestion or inhalation air or through the skin. Presence of phthalates were observed in numerous food products and is connected with migration of those compounds from food storage containers to preserved food. They could mirgate to salivia during sucking and chewing of toys and this way increased exposure to of children. The results of studies regarding to concentration of phthalates in human tissues and excretions are also described. The level of phthalates were measured in numerous of human biological samples. For example, DEHP, DEP and DBP were detected at levels of 5.71 mg/L in blood serum, of 0.30 mg/L in semen and of 0.72 mg/kg in fat samples.

Urinary phthalate metabolite concentrations in relation to history of infertility and use of assisted reproductive technology

OBJECTIVE

To examine urinary phthalate metabolite concentrations in pregnant women with planned pregnancies in relation to history of infertility and use of assisted reproductive technology (ART).

DESIGN

Phthalate metabolite concentrations were measured in first-trimester urine samples collected from women participating in a prospective pregnancy cohort study.

SETTING

Prenatal clinics.

PATIENT(S)

A total of 750 women, of whom 86 had a history of infertility. Forty-one women used ART to conceive.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Primary outcomes were concentrations of four metabolites of diethylhexyl phthalate (DEHP) and their molar sum (∑DEHP). Multivariable analyses compared phthalate metabolite levels in [1] women reporting a history of infertility vs. those who did not (comparison group); and [2] those who used ART to conceive the index pregnancy vs. women with a history of infertility who did not use ART.

RESULT(S)

Among women with a history of infertility, ∑DEHP was significantly lower in women who conceived after ART compared with those who did not (geometric mean ratio: 0.83; 95% confidence interval 0.71-0.98). Similar significant associations were observed for all of the individual DEHP metabolites. There were no differences in DEHP metabolite concentrations between women with a history of infertility and the comparison group.

CONCLUSION(S)

Women who used ART to conceive had lower first-trimester phthalate metabolite concentrations than women with a history of infertility who did not use ART. Further research is needed to explore whether those pursuing fertility treatments take precautions to avoid exposure to environmental toxins, to improve treatment outcomes.

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

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

[The effects of DEHP on morphology and function of progenitor Leydig cell in rat]

OBJECTIVE

To investigate the effects and mechanisms of diethylhexylphthalate (DEHP) on morphology and function of progenitor Leydig cells (PLC) in rats.

METHODS

Twenty pregnant SD rats were randomly divided into 4 groups ( n = 5): normal control group, DEHP low dose group , middle dose group, and high dose group, which were treated from postnatal day (PND) 1 to PND 21 of the pubs with DEHP at the doses of 0, 10, 100, 750 mg/(kg · d) in 0.5 ml of corn oil by gavage respectively. At the end of the treatment, the male pups were killed and blood samples were collected for determination of serum testosterone concentration by chemiluminescence method. The body weight, testis weight and anogenital distance (AGD) were measured. The morphology of PLC was observed by light and transmission electron microscopy. The protein expression of steroidogenic acute regulatory protein(StAR) in PLC was determined by immunohistochemistry. The mRNA expression of insulin-like growth factor-I (IGF-I) in the testis was assayed by real-time PCR.

RESULTS

Compared with normal control group, the serum testosterone and AGD of male pubs from the middle and high dose groups were declined significantly (P < 0.01), the testis weight and body weight from high dose group were decreased significantly (P < 0.01), while the testis weight increased in the low dose group (P < 0.05). Under light microscope, PLC showed hyperplasia and cluster aggregation in the low dose group and focal hyperplasia in the middle and high dose group. The spermatogenic cells in seminiferous tubules showed decrease, apoptosis and unfix in the high dose group. Under transmission electron microscope, the PLC showed decreased lipid droplets, smooth endoplasmic reticulum and mitochondriae in the treated group. The mRNA expression of IGF-I increased in the low dose group, and the protein expression of StAR decreased in the middle and high dose group.

CONCLUSION

Lactating exposure to DEHP may interfere with the synthesis of testosterone of PLC in male pubs, the decrease of StAR and the damage of PLC may be involved in it.

Phthalate esters affect maturation and function of primate testis tissue ectopically grafted in mice

Di-n-Butyl (DBP) and Di-(2-EthylHexyl) (DEHP) phthalates can leach from daily-use products resulting in environmental exposure. In male rodents, phthalate exposure results in reproductive effects. To evaluate effects on the immature primate testis, testis fragments from 6-month-old rhesus macaques were grafted subcutaneously to immune-deficient mice, which were exposed to 0, 10, or 500 mg/kg of DBP or DEHP for 14 weeks or 28 weeks (DBP only). DBP exposure reduced the expression of key steroidogenic genes, indicating that Leydig cell function was compromised. Exposure to 500 mg/kg impaired tubule formation and germ cell differentiation and reduced numbers of spermatogonia. Exposure to 10 mg/kg did not affect development, but reduced Sertoli cell number and resulted in increased expression of inhibin B. Exposure to DEHP for 14 week also affected steroidogenic genes expression. Therefore, long-term exposure to phthalate esters affected development and function of the primate testis in a time and dosage dependent manner.

[Correlation between di-2-ethylhexyl phthalate and idiopathic oligoasthenospermia]

OBJECTIVE

To investigate the relationship between the level of di-2-ethylhexyl phthalate (DEHP) and idiopathic oligoasthenospermia by measuring the content of DEHP in the semen samples of different subjects.

METHODS

We obtained semen samples from 100 infertile men with idiopathic oligoasthenospermia, 50 working all the year round in the plastic greenhouse (group A) and the other 50 constantly dining from plastic meal boxes (group B). We also enrolled 50 normal male volunteers as controls (group C). We conducted semen analyses using a computer-assisted sperm analyzer, measured the DEHP concentration by reversed-phase high-pressure liquid chromatography, and subjected the data to statistic processing by t-test and correlation analysis.

RESULTS

The mean concentrations of DEHP in the seminal plasma were (0.72 +/- 0.48), (0.71 +/- 0.49) and (0.21 +/- 0.18) mg/L in groups A, B and C, respectively, significantly higher in A and B than in C (both P < 0.05). The DEHP concentration was negatively correlated with sperm motility (P < 0.05).

CONCLUSION

The DEHP level in the seminal plasma is higher in infertile men frequently exposed to plastic products than in normal males and excessive DEHP may be one of the important factors of idiopathic male infertility.

Adipogenic effects of a combination of the endocrine-disrupting compounds bisphenol A, diethylhexylphthalate, and tributyltin

OBJECTIVE

The food contaminants bisphenol A (BPA), diethylhexylphthalate (DEHP), and tributyltin (TBT) are potent endocrine-disrupting compounds (EDC) known to interfere with adipogenesis. EDC usually act in mixtures and not as single compounds. The aim of this study was to investigate the effects of a simultaneous exposure of BPA, DEHP, and TBT on mesenchymal stem cell differentiation into adipocytes.

METHODS

Multipotent murine mesenchymal stem cells (C3H10T1/2) were exposed to EDC mixtures in high concentrations, i.e. MIX-high (10 µmol/l BPA, 100 µmol/l DEHP, 100 nmol/l TBT), and in environmentally relevant concentrations, i.e. MIX-low (10 nmol/l BPA, 100 nmol/l DEHP, 1 nmol/l TBT). The exposure was performed either for the entire culture time (0-12 days) or at distinct stages of adipogenic differentiation. At day 12 of cell culture, the amount of adipocytes, triglyceride content (TG), and adipogenic marker gene expression were analyzed.

RESULTS

MIX-high increased the development of adipocytes and the expression of adipogenic marker genes independently of the exposure window. The total TG amount was not increased. The low-concentrated EDC mixture had no obvious impact on adipogenesis.

CONCLUSION

In EDC mixtures, the adipogenic effect of TBT and DEHP predominates single effects of BPA. Mixture effects of EDC are not deducible from single compound experiments.

[Safety assessment of DEHP from PVC medical devices]

OBJECTIVE

To Investigate necessity of safety evaluation, research ideas, evaluation methods of DEHP in PVC medical devices.

METHODS

The ideas of The United States, Japan and the European Union on safety evaluation of DEHP in PVC medical devices was reviewed and sorted, regarding to currently requirements for PVC medical devices in our country, the research ideas and methods of DEHP in PVC medical devices was explored.

RESULTS

DEHP released from High-risk PVC medical devices may exceed human tolerance intake values and thus potentially be harmful to human health. So it is necessary for production enterprise to assess safety of DEHP in PVC medical device. The assessment can be done by material control and detecting release of DEHP from PVC medical devices.

CONCLUSION

In order to assess safety of DEHP in PVC medical device, production enterprise can firstly assess materials according to national standard. Secondly, production enterprise can detect release of DEHP from PVC medical devices simulating clinical application. By comparing release of DEHP from PVC medical devices and TI, safety of DEHP in PVC medical device can be evaluated.

Molecular link(s) between hepatoblastoma pathogenesis and exposure to di-(2-ethylhexyl)phthalate: a hypothesis

Hepatoblastoma (HB) is the most important primary liver cancer in children, accounting for up to 1% of all paediatric malignancies. It affects mostly infants and young children between the age of 6 months and 3 years. Predisposing genetic factors for HB have been identified and scientific evidence clearly points out HB as a multi-factorial condition based on both genetic and environmental factors. Nevertheless, a clear understanding of the pathogenesis is yet lacking. The present review will focus on the impact of exposure to environmental chemicals, such as di-(2-ethylhexyl)phthalate (DEHP), and recognized risk factors, such as intrauterine growth retardation (IUGR), on HB establishment via altered signalling pathways (Wnt and IGF). The hypothesis linking the impairment of IGF2 foetal/adult switching and exposure to DEHP is discussed as a way forward to support HB prevention and early diagnosis.

Phthalate labelling of medical devices

In the European Union, the use of Di(2-ethylhexyl)phthalate (DEHP) in medical devices has been under serious pressure. A proposed ban on its use was avoided and changed into a labelling requirement. This article reports the dramatic political developments that resulted in this requirement and highlights some new alternative plasticisers that can be used if poly(vinyl chloride) devices without DEHP are required in the future.

Metabolism of phthalates in humans

Phthalates are synthetic compounds widely used as plasticisers, solvents and additives in many consumer products. Several animal studies have shown that some phthalates possess endocrine disrupting effects. Some of the effects of phthalates seen in rats are due to testosterone lowering effects on the foetal testis and they are similar to those seen in humans with testicular dysgenesis syndrome. Therefore, exposure of the human foetus and infants to phthalates via maternal exposure is a matter of concern. The metabolic pathways of phthalate metabolites excreted in human urine are partly known for some phthalates, but our knowledge about metabolic distribution in the body and other biological fluids, including breast milk, is limited. Compared to urine, human breast milk contains relatively more of the hydrophobic phthalates, such as di-n-butyl phthalate and the longer-branched, di(2-ethylhexyl) phthalate (DEHP) and di-iso-nonyl phthalate (DiNP); and their monoester metabolites. Urine, however, contains relatively more of the secondary metabolites of DEHP and DiNP, as well as the monoester phthalates of the more short-branched phthalates. This differential distribution is of special concern as, in particular, the hydrophobic phthalates and their metabolites are shown to have adverse effects following in utero and lactational exposures in animal studies.

Di-(2-ethylhexyl)phthalate and deep venous thrombosis in children: a clinical and experimental analysis

BACKGROUND

Five children with catheter-related deep venous thrombosis were encountered in our PICU. Three types of polyvinyl chloride tubing for the administration of intravenous solutions were in use (Terumo, Codan, and Perfusend). All were di-(2-ethylhexyl)phthalate plasticized. We suspected problems with the Codan tubing.

METHODS

Different types of tubing at different time intervals in vitro were investigated. Tubing segments were assessed on structural alterations by surface electron microscopy. High-performance liquid chromatography-diode array detection and liquid chromatography-mass spectrometry-diode array detection were performed to identify and to quantify di-(2-ethylhexyl)phthalate. The hospital's minimal clinical data set (coded with the International Classification of Diseases, Ninth Revision, Clinical Modification) was investigated on catheter-related deep venous thrombosis between 2000 and 2004.

RESULTS

Surface electron microscopy demonstrated that the Codan tubing's inner surface was severely altered, showing large particles (34.5 +/- 6.1 microm). High-performance liquid chromatography documented that all Codan samples showed a peak at the di-(2-ethylhexyl)phthalate retention time. The analysis of the minimal clinical data set for total catheter-related deep venous thrombosis showed an unusual high incidence in 2001 (52) compared with the expected 36 per year.

CONCLUSIONS

Such occurrence of catheter-related deep venous thrombosis led to the assumption that disintegration of intravenous tubing resulted in intravenous administration of debris. Our data suggested that the particles derived from the tubing are of such size that they might induce catheter-related deep venous thrombosis. The absence of catheter-related deep venous thrombosis caused by the introduction of submicron inline filters outlines the important pathophysiological role of di-(2-ethylhexyl)phthalate-plasticized particles in the onset of catheter-related deep venous thrombosis. Our data indicate that a considerable number of patients might have been exposed to di-(2-ethylhexyl)phthalate, and a major concern is whether this jeopardized the health of the patients at that time.

Altered semen quality in relation to urinary concentrations of phthalate monoester and oxidative metabolites

BACKGROUND

Phthalates are multifunctional chemicals used in a variety of consumer, medical, and personal care products. Previously, we reported dose-response associations of decreased semen quality with urinary concentrations of monobutyl phthalate (MBP) and monobenzyl (MBzP) phthalate, which are metabolites of dibutyl phthalate and butylbenzyl phthalate, respectively. The present study extends our work in a larger sample of men and includes measurements of di(2-ethylhexyl) phthalate (DEHP) oxidative metabolites.

METHODS

Between January 2000 and May 2004, we recruited 463 male partners of subfertile couples who presented for semen analysis to the Massachusetts General Hospital. Semen parameters were dichotomized based on World Health Organization reference values for sperm concentration (<20 million/mL) and motility (<50% motile) and the Tygerberg Kruger Strict criteria for morphology (<4% normal). The comparison group was men with all 3 semen parameters above the reference values. In a single spot urine sample from each man, phthalate metabolites were measured using solid-phase extraction coupled to high-performance liquid chromatography isotope-dilution tandem mass spectrometry.

RESULTS

There were dose-response relationships of MBP with low sperm concentration (odds ratio per quartile adjusted for age, abstinence time, and smoking status = 1.00, 3.1, 2.5, 3.3; P for trend = 0.04) and motility (1.0, 1.5, 1.5, 1.8; P for trend = 0.04). There was suggestive evidence of an association between the highest MBzP quartile and low sperm concentration (1.00, 1.1, 1.1, 1.9; P for trend = 0.13). There were no relationships of monoethyl phthalate, monomethyl phthalate, and the DEHP metabolites with these semen parameters.

CONCLUSION

The present study confirms previous results on the relationship of altered semen quality with exposure to MBP at general population levels. We did not find associations between semen parameters and 3 DEHP metabolites.

Promoting environmentally responsible health care

Dioxins, polyvinyl chloride and di(2-ethylhexyl) phthalate are the three main toxins interfering with the goal to maintain a healthy environment, according to the international organization Health Care Without Harm (2004). Exposure to these chemicals has been linked to cancer, as well as reproductive, cardiac, hepatic and developmental disorders (Tickner, Schettler, Guidotti, McCally, and Rossi, 2001). Health-care clients are potentially exposed to these toxins every day: polyvinyl chloride equipment, such as i.v. bags and tubing, is widely used in hospitals, and medical incineration practices emit dioxins into the air (Chlorine Chemistry Council, 2006). Nurses are uniquely positioned to play an active role in environmentally responsible health care through education, advocacy and the implementation of measures to reduce medical wastage and exposure to these chemical toxins (Canadian Nurses Association, 2005).

Dietary di(2-ethylhexyl)phthalate-impaired glucose metabolism in experimental animals

The effects of chronic intake of di(2-ethylhexyl)phthalate (DEHP) on the main intermediate glycolytic metabolites in liver and gastrocnemius muscle were investigated in experimental animals. Male Wistar rats (90-100 g) were fed for 21 days either with a standard chow or the same diet supplemented with 2% (w/w) of DEHP. The DEHP-fed rats had an altered in vivo glucose tolerance associated with abnormal glucose intermediate metabolite contents in liver and skeletal muscle. In these rats, the hepatic content of glucose-6-phosphate (G-6-P), fructose-6-phosphate, pyruvate, lactate, glucose-1-phosphate and glycogen decreased. At the same time, the G-6-P content decreased while the pyruvate and lactate levels increased in skeletal muscle. These data, along with the high plasma glucose concentration and the normal lactate blood levels of this group, could indicate that DEHP-fed rats could present a deficiency in muscle glucose and lactate transport, a reduction of the flux through muscle hexokinase and hepatic glucokinase, and a reduction in glycogen synth-

Clinical waste generation from renal units: implications and solutions

The treatment of end-stage renal disease (ESRD) makes extensive use of presterilized disposable items which, after use, are contaminated by blood. The preferred route of disposal of such items is by incineration. Disposal costs have risen and this increase in costs has not been matched by waste management programs in renal units. Many of the waste items generated also contain polyvinyl chloride (PVC) whose incineration is environmentally sensitive. Furthermore blood tubing sets contain plasticizers such as di(2-ethylhexyl) phthalate (DEHP), which is known to pose health risks to specific groups of patients. The generation of clinical waste in a dialysis unit is analyzed, issues associated with disposal are discussed, and approaches toward a cost-effective, environmentally sustainable clinical waste management program are reviewed.

Evaluation of endocrine disrupting activity of plasticizers in polyvinyl chloride tubes by estrogen receptor alpha binding assay

Polyvinyl chloride (PVC) tubing is an indispensable medical material for extracorporeal circulation therapy. However, di(2-ethylhexyl)phthalate (DEHP), a suspected endocrine disruptor, can be eluted from PVC, suggesting that an alternative material that does not contain DEHP is needed for clinical applications. First, we evaluated the endocrine disrupting risks of the plasticizers contained in PVC tubes by investigating their binding affinities for the human estrogen receptor alpha (ERalpha). Our results revealed that, while DEHP has some binding affinity for ERalpha, neither epoxidized soybean oil nor tris(2-ethylhexyl)trimellitate (an alternative to DEHP) has any affinity for ERalpha. Second, we evaluated the endocrine disrupting risks of a tube made of newly developed plasticizer-free (PF) materials. We confirmed the presence of DEHP and detected several unidentified substances in plasma stored within the PVC tube. This plasma's competitive binding affinity for ERalpha was significantly higher than that of control plasma (P < 0.01). In contrast, the profile of plasma stored in the PF tube was similar to that of the control, both in terms of high-performance liquid chromatography chromatograms and competitive binding capacity for ERalpha, suggesting that the PF tube is biocompatible and is useful for reducing the elution of substances capable of binding to ERalpha.

Nurses: taking precautionary action on a pediatric environmental exposure: DEHP

Di(2-ethylhexyl) phthalate, or DEHP, is a chemical used to soften rigid polyvinyl chloride (PVC) plastic. Medical devices made of flexible PVC, such as intravenous (IV) bags and tubing, contain DEHP to make them pliable and soft. Animal studies show that exposure to DEHP can damage the liver, kidneys, lungs, and reproductive system, particularly the developing testes of prenatal and neonatal males. Because of this, the U.S. Food and Drug Administration (FDA) has issued a Public Health Notification on PVC devices containing DEHP, urging health care providers to use DEHP-free devices for certain vulnerable patients. Many hospitals and health systems have successfully transitioned away from use of DEHP, particularly in neonatal intensive care units (NICUs).

Microbial production and vaporization of mono-(2-ethylhexyl) phthalate from di-(2-ethylhexyl) phthalate by microorganisms inside houses

Laboratory workers were bothered by an irritation that caused coughing during the cultivation of microorganisms that degraded di-(2-ethylhexyl) phthalate (DEHP). The authors found that mono-(2-ethylhexyl) phthalate (MEHP), a known cause of asthma, was released during the degradation of DEHP. At its highest production and vaporization rate, the amount was almost equal to that of the DEHP starting material. It appeared that transport into the atmosphere depended on its adsorption on dust particles. The authors attempted to cultivate several microorganisms from house materials, especially those composed of rotting polyvinyl chloride. And microorganisms produced MEHP in the culture medium. In addition, MEHP was produced from DEHP by several stock microorganisms. Thus, MEHP could easily be produced from DEHP by microorganisms in the environment. In Japan, there are many cases of asthma with unknown causes. If MEHP is one of causes, then preventive measures against some cases of asthma could be taken.

Delayed effects on plasma concentration of testosterone and testicular morphology by intramuscular low-dose di(2-ethylhexyl)phthalate or oestradiol benzoate in the prepubertal boar

The immediate and delayed effects of prepubertal exposure to di(2-ethylhexyl)phthalate (DEHP) or oestradiol benzoate on the plasma concentrations of testosterone, oestradiol and LH, as well as testicular morphology were examined in prepubertal boars. In a split litter design experiment, prepubertal boars were intramuscularly exposed to DEHP, oestradiol or vehicle during five weeks, starting at six weeks of age. The dose of DEHP was 50mg/kg of bodyweight twice weekly, which is in the same range as recently used oral doses in rodents. Oestradiol-benzoate was administered at 0.25mg/kg of bodyweight twice weekly. One set of animals was examined immediately after the exposure, and the other set was examined at an age of 7.5 months. During the exposure period concentrations of LH in plasma were lower (p=0.02) in the oestradiol-treated animals than in the control group. In the group exposed to oestradiol, the relative to the body weight of the testicles tended to be lower (p=0.07) than control immediately after five weeks of exposure, and the relative to the body weight of the seminal vesicles tended to be lower (p=0.05) than control at 7.5 months of age. In the DEHP-exposed group an elevated (p=0.005) concentration of testosterone and increased (p=0.04) area of the Leydig cells in the testicles compared to the control group were seen at 7.5 months of age. These data suggest that DEHP early in life causes delayed effects on the reproductive system in the adult.

Avoiding carcinogen exposure with intraperitoneal paclitaxel

PURPOSE/OBJECTIVES

Diethylhexylphthalate (DEHP) is a lipid-soluble plasticizer commonly used in the manufacture of polyvinyl chloride- (PVC-) based plastics. Previous studies have documented the leaching of DEHP from PVC-based containers and extension sets during the IV administration of paclitaxel.

DESIGN

Study of the leaching of DEHP from infusion bags and peritoneal dialysis solution transfer sets and clinical study of DEHP was proposed.

SETTING

The experiments were performed in a laboratory with plastic ware normally used for intraperitoneal chemotherapy delivery.

SAMPLE

Samples were taken from fluids that had been in contact with the plastic ware. Also, blood, peritoneal fluid, and urine were collected from a patient.

METHODS

In a controlled laboratory environment, the authors used an established high-performance liquid chromatography assay to determine the rate and extent of DEHP leaching from infusion bags and in the solution transfer set used for early postoperative intraperitoneal chemotherapy (EPIC) administration of paclitaxel. Paclitaxel was tested at a concentration of 40 mg/L to simulate the median dose used for EPIC. In a single patient receiving 34 mg paclitaxel in 1 liter of 1.5% dextrose peritoneal dialysis solution (Dianeal), the presence and concentration of DEHP in samples of peritoneal fluid and urine were determined during the first 24-hour EPIC administration.

MAIN RESEARCH VARIABLES

DEHP levels in fluids exposed to plastic ware and in the patients blood, peritoneal fluid, and urine were determined.

FINDINGS

The in vitro studies showed that a solution of 40 mg paclitaxel dissolved in a 1 liter bag of Dianeal resulted in the extraction of approximately 26 mg DEHP over 24 hours. Approximately 2 mg DEHP was leached during the first hour and approximately 1 mg per hour over the following 23 hours. Equivalent results were obtained when 20 mg paclitaxel was dissolved in a 500 ml bag of 6% hetastarch (Hespan) with a leaching of approximately 13 mg DEHP in 24 hours. Using the same paclitaxel concentration, the chronic ambulatory peritoneal dialysis solution transfer tubing with a total capacity of 10 ml produced approximately 2 mg DEHP over 24 hours, of which approximately 0.5 mg was produced during the first four hours. Samples from a single patient showed that immediately prior to administration, a 1 liter bag of Dianeal containing 34 mg paclitaxel had about 3.3 mg DEHP. Approximately 3% (110 mcg) of unchanged DEHP was recovered from the peritoneal fluid at 24 hours. Total DEHP excreted in urine over the 24-hour period was approximately 900 mcg (27%).

CONCLUSION

This study showed that the carcinogen DEHP is leached after preparation of paclitaxel from PVC-based containers and DEHP constantly accumulates in the solution transfer tubing.

IMPLICATIONS FOR NURSING

Unless precautionary steps are taken, DEHP can be transferred to patients receiving intraperitoneal paclitaxel. Steps to minimize patient exposure to DEHP during EPIC with paclitaxel are necessary. In the ideal situation, no DEHP-containing plastic should be used for chemotherapy delivery. If that is not possible, (a) paclitaxel solution should be administered as soon as possible after preparation by the pharmacy, (b) infusion should proceed as rapidly as possible via the Tenckhoff catheter, and (c) the Tenckhoff catheter and extension tubing should be cleared by draining ascites fluid through these tubes prior to subsequent intraperitoneal infusions.

Evaluation of childhood exposure to di(2-ethylhexyl) phthalate from perfusion kits during long-term parenteral nutrition

Leachability of the plasticizer di(2-ethylhexyl) phthalate (DEHP) from administration sets into intravenous parenteral emulsions containing fat was investigated. DEHP is added to polyvinyl chloride (PVC) to impart flexibility. However, DEHP is a lipid-soluble suspected carcinogen that is hepatotoxic and teratogenic in rodents, and has been shown to leach from PVC products containing lipophilic mixtures. Consequently, total parenteral nutrition (TPN) mixtures containing fat emulsions should be stored in ethylvinyl acetate (EVA) bags rather than PVC packs. However, while TPN bags are made of EVA, they contain PVC-DEHP residues and the lines used between TPN bags and venous catheters are made of PVC-DEHP. The present study quantified the amount of DEHP leached from bags and tubing that could potentially contaminate patients during home TPN. Four types of emulsions containing fat were studied. Levels of DEHP in the bag and at the outlet tubing were measured by high-performance liquid chromatography (HPLC). This was measured during simulated TPN at different times after starting perfusion, 1 day after reconstitution of solutions in the bags, and 1 week later after storage at 4 degrees C. Detectable and stable amounts of DEHP were found to leach from bags (0.2 +/- 0.008 mg to 0.7 +/- 0.02 mg) and DEHP content increased in the outlet tubing (0.8 +/- 0.09 mg to 2 +/- 0.07 mg) during simulated infusions. The same phenomenon was observed after 1 week of storage at 4 degrees C. DEHP extraction by TPN depends on the lipid content of each TPN preparation and the flow rate. These results suggest that children treated with prolonged TPN are regularly exposed to significant amounts of DEHP.