Role of formyl peptide receptor 2 in steatosis of L02 cells exposed to Mono-(2-ethylhexyl) phthalate.

Mono-(2-ethylhexyl) phthalate (MEHP) can accumulate in the liver and then lead to hepatic steatosis, while the underlying mechanism remains unclear. Inflammation plays an important role in the disorder of hepatic lipid metabolism. This study aims to clarify the role of the inflammatory response mediated by formyl peptide receptor 2 (FPR2) in steatosis of L02 cells exposed to MEHP. L02 cells were exposed to MEHP of different concentrations and different time. A steatosis model of L02 cells was induced with oleic acid and the cells were exposed to MEHP simultaneously. In addition, L02 cells were incubated with FPR2 antagonist and then exposed to MEHP. Lipid accumulation was determined by oil red O staining and extraction assay. The indicators related to lipid metabolism and inflammatory response were measured with appropriate kits. The relative expression levels of FPR2 and its ligand were determined by Western blot, and the interaction of them was detected by co-immunoprecipitation. As a result, MEHP exposure could promote the occurrence and progression of steatosis and the secretion of chemokines and inflammatory factors in L02 cells. MEHP could also affect the expression and activation of FPR2 and the secretion of FPR2 ligands. In addition, the promotion effect of MEHP on the secretion of total cholesterol and interleukin 1ß in L02 cells could be significantly inhibited by the FPR2 antagonist. We concluded that FPR2 might affect the promotion effect of MEHP on steatosis of L02 cells by mediating inflammatory response.

Exposure to the phthalate metabolite MEHP impacts survival and growth of human ovarian follicles in vitro.

Phthalates are found in everyday items like plastics and personal care products. There is an increasing concern that continuous exposure can adversely affect female fertility. However, experimental data are lacking to establish causal links between exposure and disease in humans. To address this gap, we tested the effects of a common phthalate metabolite, mono-(2-ethylhexyl) phthalate (MEHP), on adult human ovaries in vitro using an epidemiologically determined human-relevant concentration range (2.05 nM - 20.51 mM). Histomorphological assessments, steroid and cytokine measurements were performed on human ovarian tissue exposed to MEHP for 7 days in vitro. Cell viability and gene expression profile were investigated following 7 days of MEHP exposure using the human granulosa cancer cell lines KGN, and COV434, the germline tumor cell line PA-1, and human ovarian primary cells. Selected differentially expressed genes (DEGs) were validated by RT-qPCR and immunofluorescence in human ovarian tissue. MEHP exposure reduced follicular growth (20.51 nM) and increased follicular degeneration (20.51 mM) in ovarian tissue, while not affecting steroid and cytokine production. Out of the 691 unique DEGs identified across all the cell types and concentrations, CSRP2 involved in cytoskeleton organization and YWHAE as well as CTNNB1 involved in the Hippo pathway, were chosen for further validation. CSRP2 was upregulated and CTNNB1 downregulated in both ovarian tissue and cells, whereas YWHAE was downregulated in cells only. In summary, one-week MEHP exposure of human ovarian tissue can perturb the development and survival of human follicles through mechanisms likely involving dysregulation of cytoskeleton organization and Hippo pathway.

Essential oil composition, morphological characterization, phenolic content and antioxidant activity of Iranian populations of Hymenocrater longiflorus Benth. (Lamiaceae).

The study focused on the morphological and chemical characteristics of 200 Hymenocrater longiflorus Benth. genotypes found in natural habitats of eight regions in west of Iran. The primary objective of the study was to assess the morphological and phytochemical variability within populations grown in their natural habitats, with the aim of identifying their potential for domestication and utilization in pre-breeding programs. The plant height (PH) ranged from 50.32 to 69.65 cm, with the highest observed in population P8. The internode distances ranged from 4.7 to 6.47 cm, with the maximum distance found in P4. Flower lengths varied from 1.95 to 2.45 cm, with the minimum and maximum values observed in P4 and P3, respectively. The highest leaf length (5.20 cm) and width (3.87 cm) were recorded in P2. The aerial parts of the plant were utilized to extraction and determine the essential oil (EO) content and composition, which ranged from 0.40 to 0.78% (v/w). The analysis of EO by gas chromatography (GC) and gas chromatography mass spectrometry (GC/MS) identified 26 compounds, constituting 99-99.5% of the EOs. The main compounds in the EO and their percentage range (v/w DW) were tau-cadinol (0.62-55.56), mono (2-ethylhexyl) phthalate (8.10-94.70), elemol (0.21-19.11), ß-spathulenol (0.08-14.39), 4-terpineol (0.23-10.19), and ß-eudesmol (0.21-9.94). The main chemical groups found in EOs included oxygenated sesquiterpenes (1.12-68.43), and phthalates (9.73-94.72). Cluster analysis revealed three distinct chemotypes: chemotype I (populations 1 and 2) with major components of mono (2-ethylhexyl) phthalate, tau-cadinol, and α-elemol; chemotype II (population 5) rich in mono (2-ethylhexyl) phthalate; and chemotype III (populations 3, 4, 6-8) containing tau-cadinol, ß-eudesmol, and 4-terpineol. The study also evaluated total phenolic, total flavonoid, and DPPH free radical scavenging activity in the fifty percent inhibitory concentration (IC50) in leaf and flower samples of the genotypes, along with estimating total anthocyanin content in the flower samples. The total phenolic content (TPC) in leaf and flower samples ranged from 7.89 to 107.18 mg GAE/g DW and 39.98 to 86.62 mg gallic acid equivalent (GAE)/g DW, respectively. Total flavonoid content (TFC) ranged from 81.04 to 143.46 mg QUE/g DW in leaf samples and from 94.82 to 133.26 mg quercetin equivalent (QUE)/g DW in flower samples. DPPHsc IC50 (µg/mL) ranged from 0.65 to 78.74 in leaf samples and from 4.38 to 7.71 in flower samples. Anthocyanin content ranged from 1.89 to 3.75 mg cyanidin-3-glucoside equivalent (C3GE)/g DW among populations. Canonical correspondence analysis and simple correlation demonstrated a strong association and correlations among the studied attributes. The negative correlations between leaf DPPH (DPPH L) IC50 and TFC (- 0.73), TPC (- 0.63), Elemol (- 0.90), and EO (- 0.85) indicate that these compounds have a significant impact on the antioxidant activity of the leaves. Furthermore, Fruit DPPH (DPPH F) IC50 showed a negative correlation with TPC (- 0.79) and TFC (- 0.78), but a positive correlation with flower anthocyanins (0.51), (Z)-ß-Farnesene (0.66), and 4-Terpineol (0.57). Circular cluster analysis categorized the genotypes of all individuals in the eight studied populations into three main categories based on all the studied traits, indicating significant variation in phytochemical and morphological traits among populations, surpassing the within-populations variation.

Exposure to MEHP during Pregnancy and Lactation Impairs Offspring Growth and Development by Disrupting Thyroid Hormone Homeostasis.

Mono(2-ethylhexyl) phthalate (MEHP), as a highly toxic and biologically active phthalate metabolite, poses considerable risks to the environment and humans. Despite the existence of in vitro studies, there is a lack of in vivo experiments assessing its toxicity, particularly thyroid toxicity. Herein, we investigated the thyroid-disrupting effects of MEHP and the effects on growth and development of maternal exposure to MEHP during pregnancy and lactation on the offspring modeled by SD rats. We found that thyroid hormone (TH) homeostasis was disrupted in the offspring, showing a decrease in total TH levels, combined with an increase in free TH levels. Nonhomeostasis ultimately leads to weight loss in female offspring, longer anogenital distance in male offspring, prolonged eye-opening times, and fewer offspring. Our findings indicate that maternal exposure to MEHP during pregnancy and lactation indirectly influences the synthesis, transport, transformation, and metabolism of THs in the offspring. Meanwhile, MEHP disrupted the morphology and ultrastructure of the thyroid gland, leading to TH disruption. This hormonal disruption might ultimately affect the growth and development of the offspring. This study provides a novel perspective on the thyroid toxicity mechanisms of phthalate metabolites, emphasizing the health risks to newborns indirectly exposed to phthalates and their metabolites.

Responses of peritubular macrophages and the testis transcriptome profiles of peripubertal and adult rodents exposed to an acute dose of MEHP.

Exposure of rodents to mono-(2-ethylhexyl) phthalate (MEHP) is known to disrupt the blood-testis barrier and cause testicular germ cell apoptosis. Peritubular macrophages (PTMφ) are a newly identified type of testicular macrophage that aggregates near the spermatogonial stem cell niche. We have previously reported that MEHP exposure increased the numbers of PTMφs by 6-fold within the testis of peripubertal rats. The underlying mechanism(s) accounting for this change in PTMφs and its biological significance is unknown. This study investigates if MEHP-induced alterations in PTMφs occur in rodents (PND 75 adult rats and PND 26 peripubertal mice) that are known to be less sensitive to MEHP-induced testicular toxicity. Results show that adult rats have a 2-fold higher basal level of PTMφ numbers than species-matched peripubertal animals, but there was no significant increase in PTMφ numbers after MEHP exposure. Peripubertal mice have a 5-fold higher basal level of PTMφ compared with peripubertal rats but did not exhibit increases in number after MEHP exposure. Further, the interrogation of the testis transcriptome was profiled from both the MEHP-responsive peripubertal rats and the less sensitive rodents via 3' Tag sequencing. Significant changes in gene expression were observed in peripubertal rats after MEHP exposure. However, adult rats showed lesser changes in gene expression, and peripubertal mice showed only minor changes. Collectively, the data show that PTMφ numbers are associated with the sensitivity of rodents to MEHP in an age- and species-dependent manner.

Association of mono-2-ethylhexyl phthalate with adverse outcomes in chronic hemodialysis patients.

Phthalate exposure is widespread and has a global impact. Growing evidence shows that mono-2-ethylhexyl phthalate (MEHP) exposure has a negative impact on human health. However, whether MEHP exposure is associated with mortality and other adverse outcomes in hemodialysis patients remains unknown. This study prospectively enrolled 217 patients on maintenance hemodialysis from June 30, 2021, to August 16, 2022. Baseline serum MEHP, di-2-ethylhexyl phthalate (DEHP), and indoxyl sulfate (IS) concentrations were measured. Primary endpoints were all-cause mortality or composite adverse outcomes, including all-cause death plus hospitalization due to cardiovascular disease, heart failure, stroke, infection, or cancer. Serum MEHP concentrations were positively associated with DEHP but not indoxyl sulfate concentrations in hemodialysis patients. Additionally, serum MEHP concentrations were significantly and independently associated with all-cause mortality and composite adverse outcomes (adjusted hazard ratios [HRs], 1.04 and 1.03 per ng/mL, 95% confidence intervals [CIs], 1.01-1.07 and 1.00-1.05; p = 0.016 and 0.015, respectively). We found a cutoff value of MEHP for predicting both endpoints. Patients with serum MEHP concentrations of ≥ 41.8 ng/mL had much higher risks for all-cause mortality and composite adverse outcomes (adjusted HRs, 39.2 and 13; 95% CIs, 2.44-65.7 and 2.74-61.4; p = 0.011 and 0.001, respectively). MEHP exposure is significantly associated with higher risks for all-cause mortality and composite adverse outcomes. Hemodialysis patients with serum MEHP concentrations above 41.8 ng/mL had much poorer prognoses regarding both outcomes.

Precocious puberty in patients with Pompe disease.

Introduction: The life expectancy of Pompe disease patients has increased due to improved neonatal screening and enzyme replacement therapy. Nevertheless, the potential effect of frequent medical device exposure on pubertal development in these patients is not well understood, so further investigation is warranted. Methods: In this cross-sectional study, we assessed the growth and puberty of nine Pompe disease patients. In addition, to determine the effects of frequent plastic medical device exposure in these patients, we measured urinary phthalate metabolites before and one day after enzyme replacement therapy. Results: Five out of nine patients (55%) with Pompe disease on enzyme replacement therapy had precocious puberty. Patients with precocious puberty had significantly shorter predicted adult heights compared to those with normal puberty (p = 0.014). The levels of mono-2-ethylhexyl phthalate (MEHP) and mono(2-ethyl-5-carboxypentyl) phthalate (MECPP) increased after enzyme replacement therapy, but the average levels of phthalate metabolites did not significantly differ between patients with normal and precocious puberty. Conclusion: Pompe disease patients on enzyme replacement therapy tend to have precocious puberty, which may reduce their adult height. There are no significant differences in urinary phthalate metabolites between normal and precocious puberty patients. Regular follow-up of growth and puberty in Pompe disease patients is important to improve their health outcomes.

Mono-(2-ethylhexyl)-phthalate potentiates methylglyoxal-induced blood-brain barrier damage via mitochondria-derived oxidative stress and bioenergetic perturbation.

Phthalates in contaminated foods and personal care products are one of the most frequently exposed chemicals with a public health concern. Phthalate exposure is related to cardiovascular diseases, including diabetic vascular complications and cerebrovascular diseases, yet the mechanism is still unclear. The blood-brain barrier (BBB) integrity disruption is strongly associated with cardiovascular and neurological disease exacerbation. We investigated BBB damage by di-(2-ethylhexyl) phthalate (DEHP) or its metabolite mono-(2-ethylhexyl) phthalate (MEHP) using brain endothelial cells and rat models. BBB damage by the subthreshold level of MEHP, but not a DEHP, significantly increased by the presence of methylglyoxal (MG), a reactive dicarbonyl compound whose levels increase in the blood in hyperglycemic conditions in diabetic patients. Significant potentiation in apoptosis and autophagy activation, mitochondria-derived reactive oxygen species (ROS) production, and mitochondrial metabolic disturbance were observed in brain ECs by co-exposure to MG and MEHP. N-acetyl cysteine (NAC) restored autophagy activation as well as tight junction protein impairment induced by co-exposure to MG and MEHP. Intraperitoneal administration of MG and MEHP significantly altered mitochondrial membrane potential and tight junction integrity in rat brain endothelium. This study may provide novel insights into enhancing phthalate toxicity in susceptible populations, such as diabetic patients.

Mono-(2-ethylhexyl) Phthalate (MEHP)-Induced Telomere Structure and Function Disorder Mediates Cell Cycle Dysregulation and Apoptosis via c-Myc and Its Upstream Transcription Factors in a Mouse Spermatogonia-Derived (GC-1) Cell Line.

As a typical environmental endocrine disrupting chemical (EDC), di-(2-ethylhexyl) phthalate (DEHP) is thought to be related to reproductive disorders, especially in males. Growing evidence suggests that various EDCs may result in an impaired telomere structure and function, which is associated with male infertility. However, the adverse effect of DEHP on telomeres in male reproductive cells has rarely been studied, and the related mechanisms remain unclear. In this study, we tested the effects of mono-(2-ethylhexyl) phthalate (MEHP), the primary metabolite of DEHP, on telomere dysfunction in mouse spermatogonia-derived cells (GC-1) and the potential role of TERT and c-Myc in MEHP-induced spermatogenic cell damage. Results showed that MEHP induced cell viability inhibition, G0/G1 phase cell cycle arrest, and apoptosis in GC-1 cells in a dose-dependent manner. Shortened telomeres, reduced telomerase activity, and decreased expression of TERT, c-Myc, and upstream transcription factors of c-Myc were also observed in the MEHP-treated cells. In conclusion, it can be concluded that TERT-mediated telomere dysfunction may contribute to MEHP-induced G0/G1 phase cell cycle arrest and apoptosis in GC-1 cells through the impairment of c-Myc and its upstream transcription factors.

The role of angiotensin I-converting enzyme gene polymorphism and global DNA methylation in the negative associations between urine di-(2-ethylhexyl) phthalate metabolites and serum adiponectin in a young Taiwanese population.

BACKGROUND: Adiponectin is a key protein produced in adipose tissue, with crucial involvement in multiple metabolic processes. Di-(2-ethylhexyl) phthalate (DEHP), one of the phthalate compounds used as a plasticizer, has been shown to decrease adiponectin levels in vitro and in vivo studies. However, the role of angiotensin I-converting enzyme (ACE) gene polymorphism and epigenetic changes in the relationship between DEHP exposure and adiponectin levels is not well understood. METHODS: This study examined the correlation between urine levels of DEHP metabolite, epigenetic marker 5mdC/dG, ACE gene phenotypes, and adiponectin levels in a sample of 699 individuals aged 12-30 from Taiwan. RESULTS: Results showed a positive relationship between mono-2-ethylhexyl phthalate (MEHP) and 5mdC/dG, and a negative association between both MEHP and 5mdC/dG with adiponectin. The study found that the inverse relationship between MEHP and adiponectin was stronger when levels of 5mdC/dG were above the median. This was supported by differential unstandardized regression coefficients (- 0.095 vs. - 0.049, P value for interaction = 0.038)). Subgroup analysis also showed a negative correlation between MEHP and adiponectin in individuals with the I/I ACE genotype, but not in those with other genotypes, although the P value for interaction was borderline significant (0.06). The structural equation model analysis indicated that MEHP has a direct inverse effect on adiponectin and an indirect effect via 5mdC/dG. CONCLUSIONS: In this young Taiwanese population, our findings suggest that urine MEHP levels are negatively correlated with serum adiponectin levels, and epigenetic modifications may play a role in this association. Further study is needed to validate these results and determine causality.

Di-(2-ethylhexyl) phthalate (DEHP) promoted hepatic lipid accumulation by activating Notch signaling pathway.

Di-(2-ethylhexyl) phthalate (DEHP) and mono-2-ethylhexyl phthalate (MEHP) can induce hepatic lipid metabolism disorders, while the molecular mechanism still remain unknown. We aim to explore the underlying mechanism of Notch signaling pathway on hepatic lipid accumulation induced by DEHP/MEHP. A total of 40 male wistar rats were exposed to DEHP (0, 5, 50, and 500 mg/kg/d) for 8 weeks, BRL-3A hepatocytes were exposed to MEHP (0, 10, 50, 100, and 200 µM) for 24 h. About 50 µM DAPT and 100 µg/mL Aspirin were used to inhibit Notch pathway and prevent inflammation, respectively. Real-Time PCR was performed to detect the mRNA expression, western blot and immunofluorescence were used to detect the protein expression. Lipids and inflammatory factors levels were determined by commercial kits. The results showed that DEHP/MEHP promoted the expression of Notch pathway molecules and lipids accumulation in rat livers/BRL-3A cells. The up-regulated Notch receptors were correlated with the TG levels in the rat liver. MEHP increased the levels of IL-8 and IL-1ß. The lipids levels were reduced after anti-inflammation. The inhibition of Notch pathway reversed the elevation of inflammation and lipid accumulation caused by MEHP. In conclusion, this study demonstrated that DEHP/MEHP led to lipid accumulation in hepatocytes by up-regulating Notch pathway and the inflammation might play a key role in the process.

Dose-response mapping of MEHP exposure with metabolic changes of trophoblast cell and determination of sensitive markers.

Mono(2-ethylhexyl) phthalate (MEHP) is a metabolite of DEHP which is one of phthalic acid esters (PAEs) widely used in daily necessities. Moreover, MEHP has been proven to have stronger biological toxicity comparing to DEHP. In particular, several recent population-based studies have reported that intrauterine exposure to MEHP results in adverse pregnancy outcomes. To explore the mechanisms and metabolic biomarkers of MEHP exposure, we examined the metabolic status of HTR-8/Svneo cell lines exposed to different doses of MEHP (0, 1.25, 5.0, 20 µM). Global and dose-response metabolomics tools were used to identify metabolic perturbations and sensitive markers associated with MEHP. Only 22 metabolic features (accounted for <1 %) were significantly changed when exposed to 1.25 µM. However, when the exposure dose was increased to 5 or 20 µM, the number of significantly changed metabolic features exceeded 300 (approximately 10 %). In particular, amino acid metabolism, pyrimidine metabolism and glutathione metabolism were widely affected according to the enrich analysis of those significant altered metabolites, which has and have previously been reported to be closely related to fetal development. Moreover, 5'-UMP and N-acetylputrescine with the lowest effective concentrations (EC-10 = 0.1 µM and EC+10 = 0.11 µM, respectively) were identified as sensitive endogenous biomarkers of MEHP exposure.

Alteration of the N6-methyladenosine epitranscriptomic profile in synthetic phthalate-treated human induced pluripotent stem cell-derived endothelial cells.

Background: This study aimed to characterize the N6-methyladenosine epitranscriptomic profile induced by mono(2-ethylhexyl) phthalate (MEHP) exposure using a human-induced pluripotent stem cell-derived endothelial cell model. Methods: A multiomic approach was employed by performing RNA sequencing in parallel with an N6-methyladenosine-specific microarray to identify mRNAs, lncRNAs, and miRNAs affected by MEHP exposure. Results: An integrative multiomic analysis identified relevant biological features affected by MEHP, while functional assays provided a phenotypic characterization of these effects. Transcripts regulated by the epitranscriptome were validated with quantitative PCR and methylated RNA immunoprecipitation. Conclusion: The authors' profiling of the epitranscriptome expands the scope of toxicological insights into known environmental toxins to under surveyed cellular contexts and emerging domains of regulation and is, therefore, a valuable resource to human health.

Synthetic phthalates, such as mono(2-ethyhexyl) phthalate, have long been recognized as environmental toxins. What effect these compounds have on endothelial cells remains poorly understood. To address this, the authors utilized a human-induced pluripotent stem cell-derived endothelial cell model to screen for an environmental toxin. They then obtained a profile of the epitranscriptomic changes involving the N⁶-methyladensosine modification and performed biochemical and functional assays. Overall, this study demonstrated how stem cell-based approaches can be used for toxicological screening and provided a valuable resource that profiles the epitranscriptomic response, which was complemented with RNA sequencing and functional and biochemical assays. This study provides relevant toxicological insights into the context of human health.

10-7 M genistein partially alleviates 10-7 M MEHP unfavorable effects in a new modified fetal rat testis culture system.

Background: Recent studies revealed that some common endocrine-disrupting chemicals (EDCs) including phthalates and phytoestrogens may exhibit low-dose effects properties. However, how low dose of these EDCs and their mixture would affect fetal rat testis development still needs further investigation. Moreover, testis organ culture system also needs further modification to provide an effective tool for ex vivo EDCs study. Methods: We firstly modified the agarose organ culture system, in which fetal rat testes were cultured for 4 days (d1 to d4) on agarose gels held by Millicell inserts. Then we used the modified agarose culture system to study the combined effects of multiple EDCs exposure. 15.5 dpc fetal rat testes were isolated and treated with vehicle, MEHP (0.1 µmol/L), GEN (0.1 µmol/L) or MEHP (0.1 µmol/L) + GEN (0.1 µmol/L). Parameters concerning testicular cell development and function were evaluated, trying to gain insight into the early molecular events after multiple EDCs exposure. Results: The development of somatic, germ cells and seminiferous tubule in 15.5 dpc fetal rat testis was better sustained in the modified agarose culture system. Based on the modified system, we found that MEHP at 0.1 µmol/L induced alterations in gonocyte markers, antioxidative enzyme activity as well as transient reduction of testosterone production, accompanied by mitochondria swelling in gonocytes and Sertoli cells. No obvious morphological and histological alterations were observed in all treated groups. However, coadministration of genistein at 0.1 µmol/L partially alleviated MEHP-induced fetal testis damage ex vivo through enhancement of antioxidative action. MEHP at low dose still showed weak endocrine disrupting properties but did not exhibit typical low-dose effects. Conclusion: Our findings indicated that the modified agarose culture system could better mimic testicular microenvironment without obvious hypoxic cell damage. Furthermore, low dose of MEHP induced mild disruption to fetal testis development, cotreatment of genistein at low dose attenuated MEHP induced fetal testis injuries in part by balancing redox state, indicating that low dose of genistein may partially protect fetal testis from phthalates induced injury.

Risk Assessment of Phthalates and Their Metabolites in Hospitalized Patients: A Focus on Di- and Mono-(2-ethylhexyl) Phthalates Exposure from Intravenous Plastic Bags.

Phthalate esters (PAEs) are plasticizers associated with multiple toxicities; however, no strict regulations have been implemented to restrict their use in medical applications in Lebanon. Our study aimed at assessing the potential risks correlated with phthalate exposure from IV bags manufactured in Lebanon. GC-MS analysis showed that di-(2-ethylhexyl) phthalate (DEHP) is the predominant phthalate found in almost all samples tested with values ranging from 32.8 to 39.7% w/w of plastic. DEHP concentrations in the IV solutions reached up to 148 µg/L, as measured by SPME-GC-MS/MS, thus resulting in hazard quotients greater than 1, specifically in neonates. The toxicity of DEHP is mainly attributed to its metabolites, most importantly mono-(2-ethylhexyl) phthalate (MEHP). The IV bag solution with the highest content in DEHP was therefore used to extrapolate the amounts of urinary MEHP. The highest concentrations were found in neonates having the lowest body weight, which is concerning, knowing the adverse effects of MEHP in infants. Our study suggests that the use of IV bags manufactured in Lebanon could pose a significant risk in hospitalized patients, especially infants in neonatal care. Therefore, Lebanon, as well as other countries, should start imposing laws that restrict the use of phthalates in medical IV bags and substitute them with less toxic plasticizers.

Di-(2-ethylhexyl) Phthalate Promotes Allergic Lung Inflammation by Modulating CD8α+ Dendritic Cell Differentiation via Metabolite MEHP-PPARγ Axis.

Di-(2-ethylhexyl) phthalate (DEHP), a common plasticizer, is a ubiquitous environmental pollutant that can disrupt endocrine function. Epidemiological studies suggest that chronic exposure to DEHP in the environment is associated with the prevalence of childhood allergic diseases; however, the underlying causal relationship and immunological mechanism remain unclear. This study explored the immunomodulatory effect of DEHP on allergic lung inflammation, while particularly focusing on the impact of DEHP and its metabolite on dendritic cell differentiation and activity of peroxisome proliferator-activated receptor gamma (PPARγ). The results showed that exposure to DEHP at a human tolerable daily intake dose exacerbated allergic lung inflammation in mice. Ex vivo flow cytometric analysis revealed that DEHP-exposed mice displayed a significantly decreased number of CD8α+ dendritic cells (DCs) in spleens and DC progenitors in the bone marrow, as well as, less interleukin-12 production in splenic DCs and increased T helper 2 polarization. Pharmacological experiments showed that mono-(2-ethylhexyl) phthalate (MEHP), the main metabolite of DEHP, significantly hampered the differentiation of CD8α+ DCs from Fms-like tyrosine kinase 3 ligand-differentiated bone marrow culture, by modulating PPARγ activity. These results suggested that chronic exposure to DEHP at environmentally relevant levels, promotes allergic lung inflammation, at least in part, by altering DC differentiation through the MEHP-PPARγ axis. This study has crucial implications for the interaction(s) between environmental pollutants and innate immunity, with respect to the development of allergic asthma.

Distinct Role of Mono-2-ethylhexyl Phthalate in Neuronal Transmission in Rat CA3 Hippocampal Neurons: Involvement of Ion Channels.

Mono-(2-ethylhexyl) phthalate (MEHP) is one of the main active metabolites of di-(2-ethylhexyl) phthalate (DEHP). In our previous works, by using rat and Drosophila models, we showed a disruption of neural function due to DEHP. However, the exact neural effects of MEHP are still unclear. To explore the effects of MEHP on the central nervous system, the electrophysiological properties of spontaneous action potential (sAP), mini-excitatory postsynaptic currents (mEPSCs), ion channels, including Na+, Ca2+, and K+ channels from rat CA3 hippocampal neurons area were assessed. Our data showed that MEHP (at the concentrations of 100 or 300 µM) decreased the amplitude of sAP and the frequency of mEPSCs. Additionally, MEHP (100 or 300 µM) significantly reduced the peak current density of Ca2+ channels, whereas only the concentration of 300 µM decreased the peak current density of Na+ and K+ channels. Therefore, our results indicate that exposure to MEHP could affect the neuronal excitability and synaptic plasticity of rat CA3 hippocampal neurons by inhibiting ion channels' activity, implying the distinct role of MEHP in neural transmission.

Mono(2-ethylhexyl) phthalate modulates lipid accumulation and reproductive signaling in Daphnia magna.

Mono(2-ethylhexyl) phthalate (MEHP) is a primary metabolite of di(2-ethylhexyl) phthalate (DEHP), which is widely used in industry as a plasticizer. Both DEHP and MEHP have been identified as endocrine disruptors affecting reproduction systems in natural aquatic environments. However, the effects of MEHP exposure on aquatic invertebrates such as Daphnia magna are still poorly understood. In the present study, lipid alterations caused by MEHP in D. magna were identified by analyzing lipid accumulation and nontarget metabolomics. In addition, reproductive endpoints were investigated. MEHP exposure under any conditions upto 2 mg/L was not associated with mortality of D. magna; yet, the number of lipid droplets and the adult female daphnids reproduction rates increased after 96 h of exposure and 21 days of exposure, respectively. MEHP also enhanced lipid metabolism, as evident from 283 potential lipid metabolites, including glycerolipids, glycerophospholipids, and sphingolipids, identified following 48 h of exposure. The MEHP-treated group exhibited significantly higher ecdysone receptor (EcR) and vitellogenin 2 (Vtg2) expression levels at 6 and 24 h. At 48 h, EcR and Vtg2 expression levels were downregulated in the 1 and 2 mg/L MEHP exposure groups. Our data reveal that the EcR pathway changes over MEHP exposure could be associated with lipid accumulation, owing to increased lipid levels and the subsequent increase in the reproduction of MEHP-exposed D. magna.

Assessment of Exposure to Di-(2-ethylhexyl) Phthalate (DEHP) Metabolites and Bisphenol A (BPA) and Its Importance for the Prevention of Cardiometabolic Diseases.

Exposomics analyses have highlighted the importance of biomonitoring of human exposure to pollutants, even non-persistent, for the prevention of non-communicable diseases such as obesity, diabetes, non-alcoholic fatty liver disease, atherosclerosis, and cardiovascular diseases. Phthalates and bisphenol A (BPA) are endocrine disrupting chemicals (EDCs) widely used in industry and in a large range of daily life products that increase the risk of endocrine and cardiometabolic diseases especially if the exposure starts during childhood. Thus, biomonitoring of exposure to these compounds is important not only in adulthood but also in childhood. This was the goal of the LIFE-PERSUADED project that measured the exposure to phthalates (DEHP metabolites, MEHP, MEHHP, MEOHP) and BPA in Italian mother-children couples of different ages. In this paper we describe the method that was set up for the LIFE PERSUADED project and validated during the proficiency test (ICI/EQUAS) showing that accurate determination of urinary phthalates and BPA can be achieved starting from small sample size (0.5 mL) using two MS techniques applied in cascade on the same deconjugated matrix.

MEHP promotes liver fibrosis by down-regulating STAT5A in BRL-3A hepatocytes.

OBJECTIVE: As an environmental endocrine disruptor, mono-2-ethylhexyl phthalate (MEHP) can interfere with liver metabolism and lead to liver diseases. We aimed to investigate the role of MEHP in liver fibrosis and its molecular mechanism. METHODS: BRL-3A hepatocytes were exposed to MEHP (0, 10, 50, 100 and 200 µM) for 24 h. STAT5A gene was overexpressed by lentivirus transfection. The reactive oxygen species (ROS) was tested by the flow cytometer. The malondialdehyde (MDA), glutathione peroxidase (GSH-PX), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were detected by commercial kits. Real-Time PCR and Western blot were performed to test the relative mRNA and proteins levels, respectively. RESULTS: MEHP exposure significantly induced oxidative damage in BRL-3A cells, which inhibited the expression of STAT5A and promoted the expression of fibrosis related proteins MMP2, MMP9, TIMP2 and CTGF. After over-expression of STAT5A gene in BRL-3A cells, the elevated expression levels of CTGF, MMP2, MMP9 and TIMP2 induced by MEHP exposure were significantly reversed. CONCLUSION: This study demonstrated that MEHP exposure inhibited the expression of STAT5A by causing oxidative damage in BRL-3A hepatocytes, thus accelerating the expression of key molecules in fibrosis and promoting the occurrence of liver fibrosis.