DEHP Research Articles

The effect of low-level phthalate mixture on the prevalence of type 2 diabetes mellitus among adults in the US

ABSTRACT Type 2 diabetes mellitus (T2DM) is an important public health issue owing to its rising global prevalence. Phthalates cause various health problems and are currently regulated in developed countries. However, studies on the impacts of low-level phthalate exposure under these regulations on T2DM are limited. This study investigated the impacts of combined and single exposures to phthalates and their alternatives on the prevalence of T2DM in 3,005 adults in the United States. The results indicated a positive joint effect of phthalate mixtures on the prevalence of T2DM. The joint effect was primarily attributed to Di-2-ethylhexyl phthalate (DEHP) metabolites, whereas the contributions of others were limited. This study suggests that, despite the stringent regulations on phthalates, low levels of phthalates, including DEHP, still have joint effects on T2DM. The findings highlight the importance of regulating hazardous phthalates and the need for safer alternatives to reduce public health risks.

Effects of D-allulose on di (2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DBP)-induced toxicity in rats

Background: Oral exposure to high concentrations of DEHP and DBP causes testicular and hepatotoxicity in rodents. Phthalate metabolites such as mono (2-ethylhexyl) phthalate (MEHP) and mono-n-butyl phthalate (MBP) stimulate peroxisome proliferator-activated receptors and disrupts carbohydrate and lipid metabolism. The oxidative stress generated may be closely related to these toxicities. Method: To clarify the effects of the rare sugar D-allulose, a potent free radical scavenger, on testicular and hepatotoxicity induced by DEHP and DBP, rats were fed DEHP or DBP containing diet and D-allulose water. Result: Dietary exposure to DEHP and DBP induced a significant decrease in testicular weight and significant increase in liver weight. D-allulose treatment significantly inhibited the testicular weight loss. But D-allulose treatment did not significantly suppress the increase in liver weight. Plasma glucose levels were significantly lower in the DEHP- or DBP-only treated groups compared to controls, but were improved by D-allulose treatment. This suggests that D-allulose blocks DEHP- and DBP-induced glycemic suppression. Plasma lipid-related markers such as total cholesterol, high-density lipoprotein cholesterol, and triglycerides were lower than controls in all treatment groups on the DEHP and DBP diets, but showed a slight trend toward improvement with D-allulose. Conclusion: D-allulose reduced DEHP- and DBP-induced testicular toxicity and blood glucose suppression in rats, but did not improve liver hypertrophy. This effect may be due to the strong oxidant scavenging ability of D-allulose.

Dust phase and window film phase phthalates in dormitories: profile characteristics, source screening, and estimated gas-phase concentration and dermal exposure comparison.

Recently, phthalate exposure has become a major public health concern. However, gaps still remain in our understanding of phthalate profile characteristics, source screening, and gas-phase estimation. This study measured phthalate concentrations in dust and window films in 101 dormitories at 13 universities in Beijing, China, from October to December 2019. Based on the phthalate concentrations in the dust and window films, we estimated the gas-phase phthalate concentrations using steady-state and instantaneous equilibrium models, respectively, and male and female students' dermal exposure using the Monte Carlo simulation. Commonly used materials and supplies were screened for phthalate sources and evaluated using the positive matrix factorization (PMF) model. The results showed that the detection frequency of ten phthalates ranged from 79.2 to 100% in dust and from 84.2 to 100% in window films. Dicyclohexyl phthalate (DCHP), di-(2-ethylhexyl) phthalate (DEHP), and dibutyl phthalate (DBP) were the most abundant phthalates in both indoor media and were also predominant in the indoor materials and supplies. The PMF results indicated that the potential sources of phthalates in dust and window films had both similarities and differences. Indoor door seals, paint, coatings, cables, air-conditioning rubber cable ties, wallpaper, and window seals were highly probable sources of phthalates. The gas-phase phthalate concentrations estimated using the two methods differed, especially for phthalates with high octanol-air partition coefficients (Koa), varying by 1-2 orders of magnitude. Moreover, compared with related studies, the gas-phase concentrations were significantly underestimated for phthalates with high Koa values, while the estimated gas-phase concentrations of phthalates with low Koa values were closer to the measured values. The estimated dermal exposure using the two methodologies also considerably differed. Such findings suggest that more attention should be focused on the exposure risk from the dust phase and window film phase phthalates.

Sex-Specific Associations between Prenatal Exposure to Di(2-ethylhexyl) Phthalate, Epigenetic Age Acceleration, and Susceptibility to Early Childhood Upper Respiratory Infections.

Di(2-ethylhexyl) phthalate (DEHP) is a common plasticizer that can affect immune system development and susceptibility to infection. Aging processes (measured as epigenetic age acceleration (EAA)) may mediate the immune-related effects of prenatal exposure to DEHP. This study's objective was to examine associations between prenatal DEHP exposure, EAA at three months of age, and the number of upper respiratory infections (URIs) from 12 to 18 months of age using a sample of 69 maternal-child pairs from a Canadian pregnancy cohort. Blood DNA methylation data were generated using the Infinium HumanMethylation450 BeadChip; EAA was estimated using Horvath's pan-tissue clock. Robust regressions examined overall and sex-specific associations. Higher prenatal DEHP exposure (B = 6.52, 95% CI = 1.22, 11.81) and increased EAA (B = 2.98, 95% CI = 1.64, 4.32) independently predicted more URIs. In sex-specific analyses, some similar effects were noted for boys, and EAA mediated the association between prenatal DEHP exposure and URIs. In girls, higher prenatal DEHP exposure was associated with decreased EAA, and no mediation was noted. Higher prenatal DEHP exposure may be associated with increased susceptibility to early childhood URIs, particularly in boys, and aging biomarkers such as EAA may be a biological mechanism. Larger cohort studies examining the potential developmental immunotoxicity of phthalates are needed.

Role of sleep in asthenospermia induced by di (2-ethyl-hexyl) phthalate.

Di (2-ethyl-hexyl) phthalate (DEHP) mainly enters the human body through the digestive tract, respiratory tract, and skin. At the same time, it has reproductive and developmental toxicity, neurotoxicity, and so on, which can cause the decrease of sperm motility. Asthenospermia is also known as low sperm motility, and the semen quality of men in some areas of China is declining year by year. Interestingly, previous studies have shown that sleep disorders can also lead to asthenospermia. However, the relationship between sleep, DEHP, and asthenospermia is still unclear. Analysis of the National Health and Nutrition Examination Survey (NHANES) population database showed that DEHP was associated with sleep disorders, and subsequent experiments in mice and Drosophila indicated that DEHP exposure had certain effects on sleep and asthenospermia. Furthermore, we analyzed the Comparative Toxicogenomics Database (CTD) to find out the common signaling pathway among the three: hypoxia-inducible factor 1(HIF-1). Then Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) was used to screen out the proteins that DEHP affected the HIF-1 pathway: glyceraldehyde-3-phosphate dehydrogenase (GAPDH), serine/threonine-protein kinase (AKT1), epidermal growth factor receptor (EGFR), and finally Western blot analysis was used to detect the expression levels of the three proteins. Compared with the control group, DEHP decreased the protein expression levels of GAPDH and AKT1 in the HIF-1 pathway, and caused sleep disorders and decreased sperm motility. This study provides preliminary evidence for exploring the mechanism among DEHP, sleep disorders, and asthenospermia.

Study on determination of PAEs in water samples by using solid phase extraction combined with gas chromatography-mass spectrometry

Phthalic acid diesters (PAEs) are industrial chemicals used as plasticizers in a variety of commercial products. Due to wide usage, PAEs have been found in various environments and their human exposure risks have also attracted a lot of concerns. However, little information about the distributions of PAEs in the water samples collected from Vietnam was reported. In this study, the method for the determination of nine typical PAEs in water samples by using the solid phase extraction (SPE) combined with gas chromatography-mass spectrometry (GC-MS) technique was optimized. The method detection limits (MDLs) and method quantitation limits (MQLs) of PAEs in water samples were in ranges of 0.2–0.4 ng/L and (0.6-1.2) ng/L, respectively. The recoveries of surrogate compounds in blank and real samples ranged from (74.8 to 93.9) %, with RSD < 9.2 %. The calibration curve for all standards was linear over a concentration range of (1.0-1,000) ng/mL (with R2 ≥ 0.998). The total concentrations of PAEs measured in bottled water of six brands were ranged from 10.0 ng/L to 6,690 ng/L. Among the studied PAEs, di-(2-ethylhexyl) phthalate (DEHP) was found at the highest frequencies and concentrations. Overall, the distribution of PAEs in plastic bottled water is significantly lower than the permitted regulations (only with DEHP) in drinking water by the Ministry of Health of Vietnam in 2011. ® 2023 Journal of Science and Technology - NTTU

MXene-Enhanced Bi2S3/CdIn2S4 Heterojunction Photosensitive Gate for DEHP Detection in a Signal-On OPECT Aptamer Biosensor.

Organic electrochemical transistors with signal amplification and good stability are expected to play a more important role in the detection of environmental pollutants. However, the bias voltage at the gate may have an effect on the activity of vulnerable biomolecules. In this work, a novel organic photoelectrochemical transistor (OPECT) aptamer biosensor was developed for di(2-ethylhexyl) phthalate (DEHP) detection by combining photoelectrochemical analysis with an organic electrochemical transistor, where MXene/Bi2S3/CdIn2S4 was employed as a photoactive material, target-dependent DNA hybridization chain reaction was used as a signal amplification unit, and Ru(NH3)63+ was selected as a signal enhancement molecule. The poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)-based OPECT biosensor modulated by the MXene/Bi2S3/CdIn2S4 photosensitive material achieved a high current gain of nearly a thousand times at zero bias voltage. The developed signal-on OPECT sensing platform realized sensitive and specific detection of DEHP, with a detection range of 1-200 pM and a minimum detection limit of 0.24 pM under optimized experimental conditions, and its application to real water samples was also evaluated with satisfactory results. Hence, the construction of this OPECT biosensing platform not only provides a promising tool for the detection of DEHP but also reveals the great potential of the OPECT application for the detection of other environmental toxins.

Phthalate esters pollution in the leachate, soil, and water around a landfill near the sea, Iran

This investigation aimed to scrutinize the level of phthalate esters (PEs) in the landfill leachate of a coastal city in the north of the Persian Gulf and the sensitive ecosystem (soil and water) around it. Soil (two depths) and water samples were prepared from 5 stations in wet and dry seasons. The studied landfill leachate contained 114–303 μg/L of phthalates. The highest concentration of phthalates was related to bis (2-ethylhexyl) phthalate (3257 ng/g) in the wet season at surface soil (0–5 cm) in the landfill site, while the lowest one (6 ng/g) belonged to dimethyl phthalate at sub-surface soil at 700 m from the landfill in the dry season. A significant change in the level of Σ6PEs in the dry (303 μg/L) and wet (114 μg/L) seasons (P ≤ 0.05) was observed for water samples. The PE concentrations in wet times were higher in all soil depths than in dry times. With increasing depth, the content of phthalates decreased in all studied environments. A direct relationship was observed between the phthalates concentration and the pH value of leachate/water and soil. The PEs concentration was linked to electrical conductivity (leachate: R2 = 0.65, P < 0.01 and surface soil: R2 = 0.77, P < 0.05) and the soil organic content. The ecological risk of di-n-butyl phthalate, benzyl butyl phthalate, bis (2-ethylhexyl) phthalate, and di-n-octyl phthalate in the wet season was greater than one. The results showed that significant levels of phthalate esters are released from landfills to the surrounding environment, which requires adequate measures to maintain the health of the ecosystem and nearby residents.

Migration of plasticizers from flexible PVC: Monitoring the concentration profiles by confocal Raman microspectroscopy

This study introduces and validates an effective approach for monitoring the plasticizer amount and its concentration profile in polyvinyl chloride (PVC) formulations. The method combines gravimetric measurements with confocal Raman depth profiling analysis. Several flexible PVC (pPVC) formulations were compared in this study, including: pPVC@DEHP, using the monomeric plasticizer di(2-ethylhexyl) phthalate (DEHP); pPVC@PBA, using the polymeric plasticizer poly(butylene adipate) (PBA); and crosslinked pPVC (cPVC@DEHP), where isophorone diamine (IPDA) served as the crosslinker. Migration tests were performed according to UNI EN ISO 177 standard. Spectroscopic findings were correlated with gravimetric data, highlighting strong differences in the migration behavior among the formulations. The results demonstrate the effectiveness of the proposed method in quantifying plasticizer leaching and obtaining detailed concentration profiles at fine scale.

Simultaneous targeted and non-targeted analysis of plastic-related contaminants in e-waste impacted soil in Agbogbloshie, Ghana

An LC-MS based analytical method was developed and validated for the simultaneous targeted analysis and suspect screening of plastic-related contaminants in e-waste impacted soils. Satisfactory recoveries (97 ± 13 %) were achieved using ultrasound-assisted extraction for 14/15 of the targeted analytes (7 bisphenols and 8 plasticizers) in a range of agricultural and non-agricultural soils. The method was applied to 53 soil samples collected in May 2015 in the region of Agbogbloshie (Ghana) at e-waste facilities (incl. Dump, trade, and burn sites), neighboring non-agricultural (incl. upstream, downstream, and community) and agricultural fields, and at two control agricultural sites away from e-waste recycling facilities. Bisphenol A (BPA) and bis(2-ethylhexyl) phthalate (DEHP) were the two dominant contaminants in e-waste soil (with concentrations up to 48.7 and 184 μg g−1, respectively), especially at the trade site, where e-waste was sorted and dismantled. The non-targeted workflow was successfully applied to identify additional plastic-related contaminants previously unreported in e-waste impacted soils, including bis(2-propylheptyl) phthalate, diisononyl phthalate, trioctyl trimellitate, 4-dodecylbenzenesulfonic acid, perfluorooctanesulfonic acid, perfluorobutanesulfonic acid, diphenyl phosphate, and triethylene glycol monobutyl ether. The agricultural soils surrounding the e-waste sites were also contaminated by plastic-related chemicals (especially DEHP), highlighting the impact of e-waste activities on the surrounding agricultural system.

Distribution and ecological risk assessment of priority water pollutants in surface river sediments with emphasis on industrially affected areas

Priority water pollutants comprising six plasticizers, 18 volatile organic compounds (VOCs), total petroleum hydrocarbon (TPH), 1,4-dioxane, epichlorohydrin, formaldehyde, acrylamide, and cyanides were determined in surface river sediments to assess their distribution patterns and ecological risks. Among these, di (2-ethylhexyl) phthalate (DEHP), toluene, TPH, and acrylamide were frequently found in sediments. The industrial sites had higher concentrations of ∑plasticizers (median 628 ng/g dry weight (dw)), ∑VOCs (median 3.35 ng/g dw), acrylamide (median 0.966 ng/g dw), and TPH (median 152 μg/g dw) in sediments than the mixed and non-industrial areas. The other pollutants did not show the significant differences in levels according to site types because of their relatively low detection frequencies. Volatile and soluble substances as well as hydrophobic pollutants were predominantly detected in surface sediments from industrial areas. Sediment contamination patterns were affected by the size and composition of the industrial zones around the sampling sites. The ecological risks determined using the sediment quality guidelines (DEHP, VOCs, and TPH) and the mean probable effect level quotients (DEHP) were mostly acceptable. However, the two most representative industrial regions (the largest industrial area and the first industrial city) showed risks of concern for DEHP and TPH.

Legacy and Emerging Plasticizers and Stabilizers in PVC Floorings and Implications for Recycling.

Hazardous chemicals in building and construction plastics can lead to health risks due to indoor exposure and may contaminate recycled materials. We systematically sampled new polyvinyl chloride floorings on the Swiss market (n = 151). We performed elemental analysis by X-ray fluorescence, targeted and suspect gas chromatography-mass spectrometry analysis of ortho-phthalates and alternative plasticizers, and bioassay tests for cytotoxicity and oxidative stress, and endocrine, mutagenic, and genotoxic activities (for selected samples). Surprisingly, 16% of the samples contained regulated chemicals above 0.1 wt %, mainly lead and bis(2-ethylhexyl) phthalate (DEHP). Their presence is likely related to the use of recycled PVC in new flooring, highlighting that uncontrolled recycling can delay the phase-out of hazardous chemicals. Besides DEHP, 29% of the samples contained other ortho-phthalates (mainly diisononyl and diisodecyl phthalates, DiNP and DiDP) above 0.1 wt %, and 17% of the samples indicated a potential to cause biological effects. Considering some overlap between these groups, they together make up an additional 35% of the samples of potential concern. Moreover, both suspect screening and bioassay results indicate the presence of additional potentially hazardous substances. Overall, our study highlights the urgent need to accelerate the phase-out of hazardous substances, increase the transparency of chemical compositions in plastics to protect human and ecosystem health, and enable the transition to a safe and sustainable circular economy.

Regulation of BTB (POZ) Structural Domain 6b by MicroRNA-222b in Zebrafish Embryos after Exposure to Di(2-ethylhexyl)phthalate at Low Concentrations.

Di-(2-ethylhexyl) phthalate (DEHP) is a sort of endocrine disruptor that induces abnormal physiological and biochemical activities such as epigenetic alterations, apoptosis, and oxidative stress. MicroRNAs (miRNAs) are a class of short noncoding RNAs that may regulate the expression of many protein-coding genes when organisms are exposed to environmental chemicals. miR-222b is a differentially expressed miRNA after DEHP exposure. miRNA-mRNA prediction suggested that BTB (POZ) structural domain 6b (BTBD6B) might be a target mRNA of miR-222b, and DEHP exposure altered its expression. However, the correlation between miR-222b and BTBD6B has not been experimentally confirmed. The aim of this study was to investigate the regulation of BTBD6B by miR-222b in zebrafish embryos under the effect of low concentration of DEHP. Dual fluorescent protein assays and dual luciferase reporter gene assays confirmed the interaction between miR-222b and the 3'-untranslated region (3'-UTR) of BTBD6B. Ectopic expression assays showed that miR-222b could negatively regulate BTBD6B in ZF4 cells. However, the relative expression of miR-222b and BTBD6B was significantly higher at both transcriptional and post-transcriptional levels in zebrafish embryos exposed to low concentrations of DEHP. The results of this study improved our understanding of the molecular mechanism of DEHP exposure toxicity. It identified that the aberrant expression of miR-222b/BTBD6B may be one of the mechanisms of DEHP toxicity, which can provide a theoretical reference and scientific basis for environmental management and biological health risk assessment.

Phytochemical analysis, antimicrobial, antioxidant, and cytotoxicity activities of Schinus molle (L.) extracts

AbstractSchinus molle seeds and leaves are frequently employed in traditional medicine to treat a range of diseases. This study aims to explore the potential of Schinus mole (L.) seed and leaf extracts in terms of their phytochemical constituents and antimicrobial, antioxidant, and cytotoxic activities. The study utilized GC-MS spectroscopy, antimicrobials, antioxidants, and cytotoxicity techniques to evaluate the extracts. The result of phytochemical analysis revealed that Schinus molle seed extract contains seven peaks with a major compound, bis (2-ethylhexyl) phthalate (59.11%), followed by n-hexadecanoic acid (10.84), while Schinus molle leaf extract exhibits sixteen peaks with a main compound, squalene (16.87%), followed by azulene (14.88%) and lupeol (12.4%). The Schinus molle seeds and leaf exhibited the high antimicrobial activity with inhibition zones ranging from 15 ± 0.57 to 27.33 ± 0.88 mm against tested microorganisms. In addition, it was investigated that the minimum inhibitory concentrations (MICs) of different extracts against microbial strains, including Bacillus cereus, Klebsiella pneumoniae ATCC 13883, and Cryptococcus neoformans, were found to be 62.5 μg/ml, while Staphylococcus aureus (MRSA) has a MIC of 125 μg/ml with seed extract and 250 μg/ml with leaf extract. The other strains, including Escherichia coli, Salmonella typhimurium, and Pseudomonas aeruginosa, have a MIC of 500 μg/ml in both seed and leaf extracts. Schinus molle seeds and leaf exhibited considerable antioxidant action compared with ascorbic acid. Moreover, significant variation in the effects on Allium cepa root tips was observed upon treatment with Schinus molle seed and leaf extracts. The mitotic index in the group receiving Schinus molle seed and leaf extract showed a significant decrease when compared to the control cells. This decrease was based on the duration and dosage of exposure. On the other hand, there was a clear increase in the occurrence of chromosomal abnormalities. Finally, the findings showed that Schinus molle seed and leaf extract exhibit antibacterial, antioxidant, and anticytotoxic activities and revealed that they are a significant source of bioactive compounds with the possibility of use in biomedical applications.

Genistein prevents the production of hypospadias induced by Di-(2-ethylhexyl) phthalate through androgen signaling and antioxidant response in rats

Environmental estrogen exposure has increased dramatically over the past 50 years. In particular, prenatal exposure to estrogen causes many congenital diseases, among which reproductive system development disorders are extremely serious. In this study, the molecular mechanism of hypospadias and the therapeutic effect of genistein (GEN) were investigated through in vivo models prepared by Di-(2-ethylhexyl) phthalate (DEHP) exposure between 12 and 19 days of gestation. With increased DEHP concentrations, the incidence of hypospadias increased gradually. DEHP inhibited the key enzymes involved in steroid synthesis, resulting in decreasing testosterone synthesis. At the same time, DEHP increased reactive oxygen species (ROS) and produced inflammatory factors via NADPH oxidase-1 (NOX1) and NADPH oxidase-4 (NOX4) pathways. It also inhibited Steroid 5 α Reductase 2 (Srd5α2) and decreased dihydrotestosterone (DHT) synthesis. Additionally, DEHP inhibited the androgen receptor (AR), resulting in reduced DHT binding to the AR that ultimately retarded the development of the external reproductive system. GEN, a phytoestrogen, competes with DEHP for binding to estrogen receptor β (ERβ). This competition, along with GEN's antiestrogen and antioxidant properties, could potentially reverse impairments. The findings of this study provide valuable insights into the role of phytoestrogens in alleviating environmental estrogen-induced congenital diseases.

Fabrication of NiTi-MMO supported on in-situ generated TiO2 for dioctyl phthalate hydrogenation: A strategy for improving the utilization efficiency of Ni

In this work, a NiTi-MMO/TiO2-R catalyst was prepared by in-situ generation of a TiO2 support during hydrothermal synthesis of the hydrotalcite precursor for NiTi-MMO. The formation of NiTi-MMO can reduce the size of metallic Ni particles, which can significantly improve the catalyst's activity, and the in-situ generated TiO2 support can enhance the dispersion of NiTi-MMO and the utilization efficiency of the active nickel species. The NiTi-MMO/TiO2-R catalyst showed high activity for the hydrogenation of dioctyl phthalate to dioctyl-1,2-cyclohexanedicarboxylate. The catalyst also exhibited good stability, maintaining the yield over 90 % after 6 cycles. Characterization results showed that a strong metal-support interaction was formed between the in-situ generated TiO2 support and the metallic Ni particles produced by the reduction of NiTi-MMO. The strong metal-support interactions formed between metallic Ni particles and the in-situ generated TiO2 played a crucial role in stabilizing the nickel species and preventing their aggregation, resulting in superior catalytic performance.

Enhancing SERS Sensitivity in N‐Graphene Hydrangea by Synergistic Charge‐Transfer and Excitation Light Absorption

Surface‐enhanced Raman scattering (SERS) is a versatile spectroscopic technique, which plays a crucial role in enhancing analytical sensitivity, investigating interfacial reaction mechanisms, enabling biosensing, and fostering efficient catalysis. Currently, the common SERS substrates are primarily metal nanostructures, which entail high manufacturing costs, complex processes, and the metal surface undergo change over time and with environmental conditions. These issues limit the development of SERS technology. In this work, a nitrogen‐doped graphene (N‐graphene) hydrangea was synthesized on a silicon (Si) substrate using plasma‐assisted chemical vapor deposition (PACVD), forming an N‐graphene hydrangea/Si hybrid structure as a SERS substrate. This substrate offers the advantages of high stability, ultra‐sensitivity, and reusability. The three‐dimensional nano‐cavity structure of graphene can increase the interaction between light and graphene, resulting in an increased localized electric field. Combining theoretical simulation analysis, the introduction of nitrogen (N) elements adjusts the Fermi level of graphene, promoting efficient charge transfer. In practical scenarios, Di(2‐ethylhexyl) phthalate (DEHP), a commonly used plasticizer, has raised concerns due to its potential as an endocrine disruptor and carcinogen. The as‐prepared SERS substrate achieves a remarkable detection limit of as low as 10−8 m for DEHP, providing significant support for environmental conservation and human health.

A novel and efficient strategy for the biodegradation of di(2-ethylhexyl) phthalate by Fusarium culmorum.

Di(2-ethylhexyl) phthalate (DEHP) is a plasticizer that is used worldwide and raises concerns because of its prevalence in the environment and potential toxicity. Herein, the capability of Fusarium culmorum to degrade a high concentration (3 g/L) of DEHP as the sole carbon and energy source in solid-state fermentation (SSF) was studied. Cultures grown on glucose were used as controls. The biodegradation of DEHP by F. culmorum reached 96.9% within 312 h. This fungus produced a 3-fold higher esterase activity in DEHP-supplemented cultures than in control cultures (1288.9 and 443.2 U/L, respectively). In DEHP-supplemented cultures, nine bands with esterase activity (24.6, 31.2, 34.2, 39.5, 42.8, 62.1, 74.5, 134.5, and 214.5 kDa) were observed by zymography, which were different from those in control cultures and from those previously reported for cultures grown in submerged fermentation. This is the first study to report the DEHP biodegradation pathway by a microorganism grown in SSF. The study findings uncovered a novel biodegradation strategy by which high concentrations of DEHP could be biodegraded using two alternative pathways simultaneously. F. culmorum has an outstanding capability to efficiently degrade DEHP by inducing esterase production, representing an ecologically promising alternative for the development of environmental biotechnologies, which might help mitigate the negative impacts of environmental contamination by this phthalate. KEY POINTS: •F. culmorum has potential to tolerate and remove di(2-ethylhexyl) phthalate (DEHP) •Solid-state fermentation is an efficient system for DEHP degradation by F. culmorum •High concentrations of DEHP induce high levels of esterase production by F. culmorum.

Long-term exposure to the mixture of phthalates induced male reproductive toxicity in rats and the alleviative effects of quercetin

Phthalates (PEs), such as di(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP) and butyl benzyl phthalate (BBP) could cause reproductive and developmental toxicities, while human beings are increasingly exposed to them at low-doses. Phytochemical quercetin (Que) is a flavonoid that has estrogenic effect, anti-inflammatory and anti-oxidant effects. This study was conducted to assess the alleviative effect of Que. on male reproductive toxicity induced by the mixture of three commonly used PEs (MPEs) at low-dose in rats, and explore the underlying mechanism. Male rats were treated with MPEs (16 mg/kg/day) and/or Que. (50 mg/kg/d) for 91 days. The results showed that MPEs exposure caused male reproductive injuries, such as decreased serum sex hormones levels, abnormal testicular pathological structure, increased abnormal sperm rate and changed expressions of PIWIL1 and PIWIL2. Furthermore, MPEs also changed the expression of steroidogenic proteins in steroid hormone metabolism, including StAR, CYP11A1, CYP17A1, 17β-HSD, CYP19A1. However, the alterations of these parameters were reversed by Que. MPEs caused male reproductive injuries in rats; Que. inhibited MPEs' male reproductive toxicity, which might relate to the improvement of testosterone biosynthesis.

Uptake and accumulation of di(2-ethylhexyl) phthalate (DEHP) in a soil-ginseng system and toxicological mechanisms on ginseng (Panax ginseng C.A. Meyer)

Di(2-ethylhexyl) phthalate (DEHP) is regarded as a priority environmental pollutant. This study explored the adsorption and accumulation of DEHP within the ginseng-soil system and the mechanism of DEHP toxicity to ginseng (Panax ginseng C.A. Meyer). Under exposure to 22.10 mg/kg DEHP in soil, DEHP mainly accumulated in ginseng leaves (20.28 mg/kg), stems (4.84 mg/kg) and roots (2.00 mg/kg) after 42 days. The oxidative damage, metabolism, protein express of ginseng were comprehensively measured and analyzed. The results revealed that MDA presented an activation trend in ginseng stems and leaves after 42 days of DEHP exposure, while the opposite trend was observed for POD. Levels of ginsenoside metabolites Rg2, Rg3, Rg5, Rd, Rf and CK decreased in the ginseng rhizosphere exudates under DEHP stress. Further investigations revealed that DEHP disrupts ginsenoside synthesis by inducing glycosyltransferase (GS) and squalene synthase (SS) protein interactions. Molecular docking indicated that DEHP could stably bind to GS and SS by intermolecular forces. These findings provide new information on the ecotoxicological effect of DEHP on ginseng root.