Phthalate exposure and risk of metabolic syndrome components: A systematic review

Role of ferroptosis mediated by abnormal membrane structure in DEHP-induced reproductive injury

Di-(2-ethylhexyl) phthalate (DEHP), a commonly used plasticizer, has been demonstrated to possess reproductive toxicity; however, the precise mechanisms underlying this effect have yet to be fully elucidated. This study aimed to investigate the potential mechanisms by which prepubertal DEHP exposure impairs testicular development and to provide possible therapeutic targets. We exposed BALB/c male mice from postnatal days 22-35 to different doses of DEHP (0, 250, and 500 mg/kg/day) and utilized lipid metabolomics and other methods to elucidate the reproductive damage caused by DEHP from a multidimensional tissue-cell-molecule perspective. Our findings indicate that DEHP exposure induces ferroptosis in testicular tissue by remodeling membrane lipid structure, in which the imbalance of phospholipid-polyunsaturated fatty acids (PL-PUFA) and phospholipid-monounsaturated fatty acids (PL-MUFA) playing a crucial role. DEHP exposure altered the expression of ACSL4 and MBOAT2 via HIPPO and androgen receptor pathways, thereby impacting PL-PUFA/PL-MUFA synthesis. In conclusion, this study highlights a link between DEHP-induced reproductive damage and lipid metabolism reprogramming, suggesting new targets for preventing DEHP-induced reproductive toxicity.

[Association between sociodemographic variables, healthy habits and stress with metabolic syndrome. A descriptive, cross-sectional study]

INTRODUCTION

Metabolic syndrome (MS) is a pathological condition that encompasses various cardiometabolic risk factors, such as obesity, dyslipidemia, hyperglycemia, and elevated blood pressure levels. It is considered a multifactorial pathological condition. The aim of this study is to assess how variables such as age, sex, socioeconomic status, tobacco and alcohol consumption, physical activity, adherence to the Mediterranean diet, and stress are associated with the prevalence of MS, determined using two different criteria.

MATERIALS AND METHODS

This is a descriptive, cross-sectional study conducted on 24,224 Spanish workers, evaluating the association between sociodemographic variables, health habits, and stress with MS, determined using two criteria: the National Cholesterol Education Program, Adult Treatment Panel III (NCEP ATP-III), and the International Diabetes Federation (IDF).

RESULTS

All the variables analyzed showed an association with the presence of MS when applying both criteria. Among them, the variables with the strongest association were age: odds ratio 5.55 (95% CI: 4.80-6.30) for MS using the NCEP ATP-III criteria and 6.71 (95% CI: 5.30-8.13) for IDF criteria; and type of job: odds ratio 3.42 (95% CI: 2.95-3.90) for NCEP ATP-III and 3.57 (95% CI: 3.12-4.03) for IDF.

CONCLUSIONS

The profile of an individual at higher risk of developing MS under both criteria would be an older male, manual laborer, smoker, habitual alcohol consumer, sedentary, with low adherence to the Mediterranean diet, and experiencing high levels of stress.

Neurodevelopmental toxicity and mechanism of action of monoethylhexyl phthalate (MEHP) in the developing zebrafish (Danio rerio)

Monoethylhexyl phthalate (MEHP) is the primary metabolite of di(2-ethylhexyl) phthalate (DEHP), the most prevalent phthalate plasticiser globally. It has been demonstrated that MEHP exerts more potent toxic effects than DEHP. Nevertheless, the full extent of the toxicity of MEHP to neurodevelopmental organisms remains unclear. Accordingly, the present study was designed to investigate the neurodevelopmental toxicity of MEHP exposure and the underlying molecular mechanisms. Zebrafish juveniles were exposed to different concentrations of MEHP (7.42, 14.84, 29.68 and 74.2 μg/L) for a period of four weeks. Immunohistological evidence indicated that MEHP exposure resulted in oxidative stress and apoptosis in the developing zebrafish brain. Subsequently, the neurobehaviour of zebrafish larvae was evaluated, and it was determined that MEHP significantly disrupted their locomotor capacity, motor vigor, and social conduct. Furthermore, HE staining revealed damage to brain neurons, which may be linked to impaired synthesis and conduction of inter-synaptic neurotransmitters. Transcriptomic analyses indicated that MEHP may affect the expression levels of genes in the P53 signalling pathway and signalling pathways related to the development of the nervous system. This results in impaired functions, including nerve conduction and neuronal development. Additionally, it induces oxidative stress, which leads to significant brain cell apoptosis and, ultimately, neurotoxicity in developing zebrafish.

Endocrine Disruptors in Child Obesity and Related Disorders: Early Critical Windows of Exposure

PURPOSE OF REVIEW

Endocrine disruptors (EDs) can mimic or interfere with hormones in the body, leading to non-communicable diseases, such as obesity, diabetes, and metabolic syndrome. Susceptibility to EDs increases during prenatal and postnatal life, a critical time window. This review aims to summarize the latest evidence on the relation of early life exposure to some EDs with obesity and the other metabolic disorders.  RECENT FINDINGS: There is increasing evidence that early life exposure to EDs may impair adipogenesis by increasing the number and size of adipocytes, thereby increasing susceptibility to obesity in childhood. It is stated that exposure to EDs during the prenatal and postnatal period may raise the risk of type 2 diabetes in adulthood by disrupting glucose, lipid, and insulin homeostasis in the offspring. They can also accelerate the development of type 1 diabetes through various mechanisms, like immunomodulation, gut microbiota, and vitamin D pathways. There is a growing understanding that ED exposure during critical stages of life could play an important role in the development of obesity and metabolic disorders. We suggest setting national goals, global standards, and policies to reduce environmental exposure to pregnant and lactating women, and babies, considered sensitive populations.

Association between phthalates exposure and all-cause mortality among diabetic cases: A prospective study

The aim of this study was to explore the association between phthalates (PAEs) exposure and all-cause mortality among diabetic cases, and potential molecular mechanisms of the effect. We followed 2806 diabetes cases from 2008 to the end of 2018 based on the Dongfeng-Tongji study, of which 446 cases died. We measured serum levels of six PAEs (DMP, DEP, DiBP, DnBP, BBP, and DEHP). Cox models were used to investigate the associations between PAEs and all-cause mortality. Genes related to PAEs are obtained from the Comparative Toxicogenomics Database. We constructed polygenic scores for sex hormone-binding globulin (SHBG) and testosterone, and functional SNPs for IL-6, PPARG, and GPX1 from genotyping data, and further analyzed the environment-gene interactions. The positive associations of PAEs (DMP, DiBP, DnBP, DEHP) with mortality were only observed in males but not in females. Comparing with the extreme quartile 1, the HRs (95% CI) for quartile 4 were 1.63 (0.17, 2.26) for DMP, 1.82 (1.29, 2.56) for DiBP, 1.68 (1.18, 2.40) for DnBP, 1.66 (1.17, 2.36) for DEHP. Enrichment analysis showed that PAEs-related genes were mainly associated with hormones and IL-6-related pathways. Genetic variants of SHBG, testosterone, and IL-6 modified the association between PAEs mixture and all-cause mortality. PAEs exposure are associated with all-cause mortality among diabetic cases, and PAE exposure increases the risk of all-cause mortality only in males. Effects on the hormonal system and IL6-related pathways may be potential mechanisms.

Preparation of novel magnetic ethylene glycol dimethacrylate-based molecularly imprinted polymer for rapid adsorption of phthalate esters from ethanol aqueous solution

Phthalate esters (PAEs), as emerging pollutants, pose a serious threat to human health and have become a major concern in the fields of environmental protection and food safety. Selective adsorption using molecularly imprinted polymer (MIP) is feasible, but most MIPs use the potentially toxic methacrylic acid (MAA) as a functional monomer, along with other crosslinking agents. In this study, MIP adsorbent was prepared using only ethylene glycol dimethacrylate (EGDMA) as both the functional monomer and crosslinking agent, without the inclusion of MAA. The adsorbent was utilized for the adsorption of PAEs from an ethanol aqueous solution. The results showed that EGDMA-based MIP (EMIP) achieved better adsorption performance of PAEs than MAA-based MIP (MMIP) due to more interactions of EGDMA with PAEs than MAA with them. For the adsorption of dibutyl phthalate (DBP) using EMIP, 95% of the equilibrium adsorption capacity was achieved within the first 15 min. In the isotherm analysis, the theoretical maximum adsorption capacity of EMIP was obtained as high as 159.24 mg/g at 20 °C in an ethanol (10 v%) aqueous solution. Furthermore, the adsorption of EMIP was not affected by the pH of the solution. The adsorption process of EMIP followed the pseudo-second-order kinetic and Freundlich isotherm model. Ethanol had a significant impact on the adsorption of DBP, and the results of molecular simulation could validate this. In addition, the regeneration experiments indicated that EMIP could be recycled 5 times without significant performance change and had a high recovery efficiency of 94.55%.

Oxidative stress as a potential mechanism linking gestational phthalates exposure to cognitive development in infancy

BACKGROUND

Gestational exposure to phthalates, endocrine disrupting chemicals widely used in consumer products, has been associated with poor recognition memory in infancy. Oxidative stress may represent one pathway linking this association. Hence, we examined whether exposure to phthalates was associated with elevated oxidative stress during pregnancy, and whether oxidative stress mediates the relationship between phthalate exposure and recognition memory.

METHODS

Our analysis included a subset of mother-child pairs enrolled in the Illinois Kids Development Study (IKIDS, N = 225, recruitment years 2013-2018). Concentrations of 12 phthalate metabolites were quantified in 2nd trimester urine samples. Four oxidative stress biomarkers (8-isoprostane-PGF2α, 2,3-dinor-5,6-dihydro-8-isoPGF2α, 2,3-dinor-8-isoPGF2α, and prostaglandin-F2α) were measured in 2nd and 3rd trimester urine. Recognition memory was evaluated at 7.5 months, with looking times to familiar and novel stimuli recorded via infrared eye-tracking. Novelty preference (proportion of time looking at a novel stimulus when paired with a familiar one) was considered a measure of recognition memory. Linear mixed effect models were used to estimate associations between monoethyl phthalate (MEP), sum of di(2-ethylhexyl) phthalate metabolites (ΣDEHP), sum of di(isononyl) phthalate metabolites (ΣDINP), and sum of anti-androgenic phthalate metabolites (ΣAA) and oxidative stress biomarkers. Mediation analysis was performed to assess whether oxidative stress biomarkers mediated the effect of gestational phthalate exposure on novelty preference.

RESULTS

The average maternal age at delivery was 31 years and approximately 50 % of participants had a graduate degree. A natural log unit increase in ΣAA, ΣDINP, and ΣDEHP was associated with a statistically significant increase in 8-isoPGF2α, 2,3-dinor-5,6-dihydro-8-isoPGF2α, and 2,3-dinor-8-isoPGF2α. The association was greatest in magnitude for ΣAA and 2,3-dinor-5,6-dihydro-8-isoPGF2α (β = 0.45, 95 % confidence interval = 0.14, 0.76). The relationship between ΣAA, ΣDINP, ΣDEHP, and novelty preference was partially mediated by 2,3-dinor-8-isoPGF2α.

CONCLUSIONS

Gestational exposure to some phthalates is positively associated with oxidative stress biomarkers, highlighting one mechanistic pathway through which these chemicals may impair early cognitive development.

Probiotics as Potential Tool to Mitigate Nucleotide Metabolism Alterations Induced by DiNP Dietary Exposure in Danio rerio

Diisononyl phthalate, classified as endocrine disruptor, has been investigate to trigger lipid biosynthesis in both mammalian and teleostean animal models. Despite this, little is known about the effects of DiNP exposure at tolerable daily intake level and the possible mechanisms of its toxicity. Probiotics, on the other hand, were demonstrated to have beneficial effects on the organism's metabolism and recently emerged as a possible tool to mitigate the EDC toxicity. In the present study, using a metabolomic approach, the potential hepatic sex-related toxicity of DiNP was investigated in adult zebrafish together with the mitigating action of the probiotic formulation SLAB51, which has already demonstrated its ability to ameliorate gastrointestinal pathologies in animals including humans. Zebrafish were exposed for 28 days to 50 µg/kg body weight (bw)/day of DiNP (DiNP) through their diet and treated with 109 CFU/g bw of SLAB51 (P) and the combination of DiNP and SLAB51 (DiNP + P), and the results were compared to those of an untreated control group (C). DiNP reduced AMP, IMP, and GMP in the purine metabolism, while such alterations were not observed in the DiNP + P group, for which the phenotype overlapped that of C fish. In addition, in male, DiNP reduced UMP and CMP levels in the pyrimidine metabolism, while the co-administration of probiotic shifted the DiNP + P metabolic phenotype toward that of P male and closed to C male, suggesting the beneficial effects of probiotics also in male fish. Overall, these results provide the first evidence of the disruptive actions of DiNP on hepatic nucleotide metabolism and mitigating action of the probiotic to reduce a DiNP-induced response in a sex-related manner.

Serum Phthalate Concentrations and Biomarkers of Oxidative Stress in Adipose Tissue in a Spanish Adult Cohort

The relationship between phthalates, a group of chemical pollutants classified as endocrine disruptors, and oxidative stress is not fully understood. The aim of the present hospital-based study was to explore the associations between circulating levels of 10 phthalate metabolites and 8 biomarkers of oxidative stress in adipose tissue. The study population (n = 143) was recruited in two hospitals in the province of Granada (Spain). Phthalate metabolite concentrations were analyzed by isotope diluted online-TurboFlow-LC-MS/MS in serum samples, while oxidative stress markers were measured by commercially available kits in adipose tissue collected during routine surgery. Statistical analyses were performed by MM estimators' robust linear regression and weighted quantile sum regression. Mainly, positive associations were observed of monomethyl phthalate (MMP), monoiso-butyl phthalate (MiBP), and mono-n-butyl phthalate (MnBP) (all low molecular weight phthalates) with glutathione peroxidase (GPx) and thiobarbituric acid reactive substances (TBARS), while an inverse association was found between monoiso-nonyl phthalate (MiNP) (high molecular weight phthalate) and the same biomarkers. WQS analyses showed significant effects of the phthalate mixture on GSH (β = -30.089; p-value = 0.025) and GSSG levels (β = -19.591; p-value = 0.030). Despite the limitations inherent to the cross-sectional design, our novel study underlines the potential influence of phthalate exposure on redox homeostasis, which warrants confirmation in further research.