Urinary metabolomic profiling in rats exposed to dietary di(2-ethylhexyl) phthalate (DEHP) using ultra-performance liquid chromatography quadrupole time-of-flight tandem mass spectrometry (UPLC/Q-TOF-MS)

Combined cytotoxicity of phthalate esters on HepG2 cells: A comprehensive analysis of transcriptomics and metabolomics

Phthalate esters (PAEs), widely used as plasticizers, may pose a potential environmental and human hazard. The aim of this study was to compare the cytotoxicity of di(2-ethylhexyl) phthalates (DEHP) and dibutyl phthalate (DBP)) after their exposure to HepG2 cells alone or in combination. HepG2 cells treated with individual/combined DEHP and DBP at a dose of 10-2 M for 24 h were selected for metabolome and transcriptome analysis. The results demonstrated that exposure to the mixtures of DEHP and DBP caused enhanced or reduced toxic effects regarding 8 pathways with 1065 downregulated genes and 643 upregulated genes, in comparison with those of single chemicals. The combined toxicity of mixture revealed both synergistic and antagonistic interactions between DEHP and DBP. Besides, combined exposure to DEHP and DBP promoted TCA cycle, pyrimidine, and purine metabolism, while an antagonistic effect on fatty acid derangement should require further investigation. To summarize, our results suggest that DEHP exposed alone or combined with DBP caused a variety of metabolic disorders, and the type of combination effects varied among metabolic pathways.

Untargeted Metabolomics Analysis Reveals Toxicity Based on the Sex and Sexual Maturity of Single Low-Dose DEHP Exposure

Di-(2-Ethylhexyl) phthalate (DEHP) is a prevalent environmental endocrine disruptor that affects homeostasis, reproduction, and developmental processes. The effects of DEHP have been shown to differ based on sex and sexual maturity. This study examines the metabolic profiles of mature adult rats from both sexes, aged 10 weeks, and adolescent female rats, aged 6 weeks, following a single 5 mg/kg of body weight DEHP oral administration. An untargeted metabolomic analysis was conducted on urine samples collected at multiple times to discern potential sex- and maturity-specific DEHP toxicities. Various multivariate statistical analyses were employed to identify the relevant metabolites. The findings revealed disruptions to the steroid hormone and primary bile acid biosynthesis. Notably, DEHP exposure increased hyocholic, muricholic, and ketodeoxycholic acids in male rats. Moreover, DEHP exposure was linked to heart, liver, and kidney damage, as indicated by increased plasma GOT1 levels when compared to the levels before DEHP exposure. This study provides detailed insights into the unique mechanisms triggered by DEHP exposure concerning sex and sexual maturity, emphasizing significant distinctions in lipid metabolic profiles across the different groups. This study results deepens our understanding of the health risks linked to DEHP, informing future risk assessments and policy decisions.

Gestational and Lactational Co-Exposure to DEHP and BPA Impairs Hepatic Function via PI3K/AKT/FOXO1 Pathway in Offspring

Di-(2-Ethylhexyl) phthalate (DEHP) and bisphenol A (BPA) present significant environmental endocrine-disrupting chemical properties. Although studies have implied reproductive impairment from exposure to BPA and DEHP, no study to date has shown the effect and mechanism of hepatic function after gestational and lactational co-exposure to DEHP and BPA in offspring. A total of 36 perinatal rats were randomly divided into four groups, DEHP (600 mg/kg/day), BPA (80 mg/kg/day), DEHP combined with BPA (600 mg/kg/day + 80 mg/kg/day), and control. Notably, 11 chemical targets were screened after identifying eight substances associated with chemically-induced hepatic damage. Molecular docking simulations revealed a high-scoring combination of eight metabolic components and targets of the PI3K/AKT/FOXO1 signaling pathway. The DEHP and BPA combination disrupted hepatic steatosis, ultimately affecting systemic the glucose and the lipid metabolic homeostasis with significant toxicity. Mechanistically, co-exposure to DEHP and BPA causes liver dysfunction and hepatic insulin resistance via PI3K/AKT/FOXO1 pathway in offspring. This is the first study of the hepatic function and mechanism of co-exposure to DEHP and BPA that combines metabolomics, molecular docking, and traditional toxicity assessment methods.

Identification of serum metabolic signatures of environmental-leveled phthalate in the Taiwanese child population using NMR-based metabolomics

Phthalates have become important environmental pollutants due to their high exposure frequency in daily life; thus, phthalates are prevalent in humans. Although several epidemiologic surveys have linked phthalates with several adverse health effects in humans, the molecular events underlying phthalate exposure have not been fully elucidated. The purpose of this study was to reveal associations between phthalate exposure and the serum metabolome in Taiwanese children using a metabolomic approach. A total of 256 Taiwanese children (8-10 years old) from two cohorts were enrolled in this study. Twelve urinary phthalate metabolites were analyzed by high-performance liquid chromatography/tandem mass spectrometry, while a nuclear magnetic resonance-based metabolomic approach was used to record serum metabolic profiles. The associations between metabolic profiles and phthalate levels were assessed by partial least squares analysis coupled with multiple linear regression analysis. Our results revealed that unique phthalate exposures, such as mono-isobutyl phthalate, mono-n-butyl phthalate, and mono (2-ethyl-5-oxohexyl) phthalate, were associated with distinct serum metabolite profiles. These phthalate-mediated metabolite changes may be associated with perturbed energy mechanisms, increased oxidative stress, and lipid metabolism. In conclusion, this study suggests that metabolomics is a valid approach to examine the effects of environmental-level phthalate on the serum metabolome. This study also highlighted potentially important phthalates and their possible effects on children.

Inhibition of hepatic energy metabolizing enzymes in murine model exposed to diisononyl phthalate

Background and objectives: Diisononyl phthalate (DINP) is a class of phthalates and phthalates are known to be metabolism disrupting chemicals (MDCs). Numerous MDCs, to which humans are exposed, have an effect on every aspect of energy transduction. They affect the liver by impairing insulin secretion in pancreatic cells and altering the liver’s insulin-dependent glucose metabolism. Methods: For this study, eighteen male albino rats weighing 200±20g were randomly assigned to three groups (of six rats each) and followed for a 14-days period. The groups were: group A or control which was given Tween-80 orally, group B or DINP1 group which was given 20 mg/kg b.wt. DINP, and Group C or DINP2 group which received 200 mg/kg b.wt. DINP. The rats were then sacrificed, their livers were removed, and the glycolytic and oxidative phosphorylation enzyme activities were evaluated. Results: Activities of the glycolytic, tricarboxylic acid cycle and electron transport chain enzymes under investigation were significantly down-regulated with severity observed in decreased activities of hepatic oxidative phosphorylation enzymes when compared with control (P<0.05). Hepatic tissue sections of 20 and 200mg/kg DiNP group revealed distorted cytoarchitecture of hepatocytes ranging from histocellular disarrangement to vaocular changes suggestive of loss of liver integrity or fibrosis. Conclusions: Finally, DINP exposure impairs hepatic energy transduction enzymes as evident in down-regulation of the various enzymes of energy metabolism under investigation and this may invariably be a good tool for the diagnosis of hepatic energy impairment as seen in some disease conditions.

A review of environmental metabolism disrupting chemicals and effect biomarkers associating disease risks: Where exposomics meets metabolomics

Humans are exposed to an ever-increasing number of environmental toxicants, some of which have gradually been elucidated to be important risk factors for metabolic diseases, such as diabetes and obesity. These metabolism-sensitive diseases typically occur when key metabolic and signaling pathways were disrupted, which can be influenced by the exposure to contaminants such as endocrine disrupting chemicals (EDCs), along with genetic and lifestyle factors. This promotes the concept and research on environmental metabolism disrupting chemicals (MDCs). In addition, identifying endogenous biochemical markers of effect linked to disease states is becoming an important tool to screen the biological targets following environmental contaminant exposure, as well as to provide an overview of toxicity risk assessment. As such, the current review aims to contribute to the further understanding of exposome and human health and disease by characterizing environmental exposure and effect metabolic biomarkers. We summarized MDC-associated metabolic biomarkers in laboratory animal and human cohort studies using high throughput targeted and nontargeted metabolomics techniques. Contaminants including heavy metals and organohalogen compounds, especially EDCs, have been repetitively associated with metabolic disorders, whereas emerging contaminants such as perfluoroalkyl substances and microplastics have also been found to disrupt metabolism. In addition, we found major limitations in the effective identification of metabolic biomarkers especially in human studies, toxicological research on the mixed effect of environmental exposure has also been insufficient compared to the research on single chemicals. Thus, it is timely to call for research efforts dedicated to the study of combined effect and metabolic alterations for the better assessment of exposomic toxicology and health risks. Moreover, advanced computational and prediction tools, further validation of metabolic biomarkers, as well as systematic and integrative investigations are also needed in order to reliably identify novel biomarkers and elucidate toxicity mechanisms, and to further utilize exposome and metabolome profiling in public health and safety management.

Seasonal modification of the associations of exposure to polycyclic aromatic hydrocarbons or phthalates of cellular aging

Exposure to polycyclic aromatic hydrocarbons (PAHs) and phthalates link to oxidative stress and inflammatory response, which exert cellular aging. However, modification effect of seasonal factor on the association of PAHs or phthalates exposure with relative telomere length (RTL) or mitochondrial DNA copy number (mtDNA-CN) has remained unclear. In this pilot study, 106 subjects were from an urban population (n = 1240) who lived in the two districts in Wuhan city, China. Participants completed physical examinations and provided 191 blood samples for RTL and mtDNA-CN analysis and 627 urine samples for monohydroxylated-PAHs (OH-PAHs) and phthalate metabolites measurements in the winter and summer seasons. We assessed the associations of urinary OH-PAHs or phthalates metabolites with RTL or mtDNA-CN by linear regression analysis and linear mixed-effect models. We found that urinary OH-PAHs were positively associated with mtDNA-CN at lag 2 day and 3-day moving average, but negatively related to RTL at lag 0, lag 1 and lag 2 day and 3-day moving average (p < 0.05). Urinary phthalate metabolites were negatively associated with mtDNA lag 0, lag 1 and lag 2 day and 3-day moving average, but positively related to RTL at lag 0 day (p < 0.05). Seasonal factor modified the association of urinary OH-PAHs with mtDNA-CN as well as urinary phthalate metabolites with RTL. In vitro experiment showed that under certain conditions, benzo[a]pyrene increased mtDNA-CN at 48 h and di (2-ethylhexyl) phthalate did RTL at 24 h in HepG2 cells. Seasonal variations in the metabolisms of PAHs or phthalates in human body may affect the relation of PAHs or phthalates exposure with cellular aging.

Impact of polyvinyl chloride, polystyrene, and polyethylene on the organism of mice

Goods of plastic, due to their durability, universality and economical properties are broadly used in all spheres of life. On the whole, polymers are inert and nontoxic, but in the process of their production, various additives are used, which on contact or introduction into an organism has a negative effect on it. In our study, we determined the impact of some types of plastic (polyvinyl chloride, polysterene and polyethylene) on the organism of laboratory animals according to changes in their body weight, indices of mass of the internal organs, and blood parameters. For the experiment, we formed four groups of white male mice at the age of 3 weeks and average body weight of 50 g. For each group, we used different litter. For group I, the litter was sawdust; and for the other groups we added plastic products in different volumes to the sawdust; for group II finely cut polyvinyl chloride, for group III cut polyethylene, and for group IV granules of polystyrene. Every 3 days, we determined the body weight of the animals, and 32 days later we determined mass of the organs, clinical and biochemical parameters of the blood. Addition of polyvinyl chloride, polyethylene, and polystyrene into the substrate for mice did not have a significant effect on tempi of growth of body weight, and also relative mass of heart and lungs. Polyvinyl chloride and polystyrene have an immune-suppressive effect, and polyvinyl chloride affects both central and peripheral organs, and polystyrene mostly harms the peripheral organs. All used types of plastic cause leukocytopenia, following which neutrophilia of band neutrophils and monocytosis takes place as a result of damage to the biological barriers. We determined the systemic toxic effect of the studied types of plastic on the internal organs, which manifested in increase in their mass (liver, kidneys), steep increase in the activity of liver enzymes (AST, ALT), simultaneous decrease in activity of alkaline phosphatase and content of cholysterol and glucose in the blood serum of the mice. Also polyvinyl chlorine, polyethylene and polystyrene cause degeneration of the epithelium of the uriniferous tubule, which is manifested in reduction of globulins and creatinine in the blood of animals from the experimental groups following increase in relative mass of the kidneys. The results of our research allow us to state that different types of plastic can cause toxic effect on animals, as well as people who are in frequent contact with them.

The Exposome: Molecules to Populations

Derived from the term exposure, the exposome is an omic-scale characterization of the nongenetic drivers of health and disease. With the genome, it defines the phenome of an individual. The measurement of complex environmental factors that exert pressure on our health has not kept pace with genomics and historically has not provided a similar level of resolution. Emerging technologies make it possible to obtain detailed information on drugs, toxicants, pollutants, nutrients, and physical and psychological stressors on an omic scale. These forces can also be assessed at systems and network levels, providing a framework for advances in pharmacology and toxicology. The exposome paradigm can improve the analysis of drug interactions and detection of adverse effects of drugs and toxicants and provide data on biological responses to exposures. The comprehensive model can provide data at the individual level for precision medicine, group level for clinical trials, and population level for public health.

Plasma metabolic profiling analysis of Strychnos nux-vomica Linn. and Tripterygium wilfordii Hook F-induced renal toxicity using metabolomics coupled with UPLC/Q-TOF-MS

Both Strychnos nux-vomica Linn. (SNV) and Tripterygium wilfordii Hook F (TwHF) have received extensive attention due to their excellent clinical efficacies. However, clinical applications of SNV and TwHF have been limited by their narrow therapeutic windows and severe kidney toxicities. In this paper, based on ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF-MS), endogenous metabolites after administration of SNV and TwHF extracts were detected, and biomarkers were screened successfully. Additionally, the levels of Cr and BUN in serum and pathological findings of kidneys were detected and observed. Finally, both biochemical and pathological tests of the SNV group and TwHF group indicated that kidney damage had occurred. After comparison with the normal saline group, 15 nephrotoxic biomarkers were selected from the SNV group, and 17 nephrotoxic biomarkers were selected from the TwHF group. The experimental results showed that there are some differences in the mechanisms of nephrotoxicity induced by SNV and TwHF, which are significant for revealing the mechanisms of renal injury of different medicines.