Urinary pentachlorophenol in general population of central China: reproducibility, predictors, and associations with oxidative stress biomarkers

Pentachlorophenol causes energy deficiency and liver injury in marine medaka (Oryzias melastigma) through damaging mitochondria and inducing oxidative stress

Pentachlorophenol (PCP) is widely distributed in marine environments and poses a threat to the health of marine organisms. Recent studies have demonstrated that PCP induces energy deficiency in marine organisms. However, the underlying toxification mechanism and the resulting adverse outcomes remain unclear. This study analyzed the energy metabolism of marine medaka (Oryzias melastigma) exposed to PCP at environmentally relevant concentrations via proteomic analysis and multiple physiological assessments. The results showed that PCP disrupted mitochondrial morphology, reduced mitochondrial membrane potential (MMP), and decreased adenosine triphosphate (ATP) levels in marine medaka. Proteomic analysis revealed that PCP induced oxidative stress, cytoskeletal disruption, and inhibition of the cytochrome bc1 complex and ATP synthase. These effects culminated in structural and functional impairments to mitochondria, which in turn inhibited ATP synthesis. Chronic PCP exposure led to enhanced glycolytic activity, the accumulation of liver lipids, and reduced liver function. The present study has deepened our understanding of the mechanism of PCP-induced energy production deficiency in marine fish and provides new insights into ecological risk assessment for PCP.

Exposure to organophosphates, pyrethroids, neonicotinoids, and pentachlorophenol: Spatial variations in urinary biomarkers and associations with oxidative stress based on a repeated-measure study

It is important to identify priority regions regarding contaminant exposure, especially for environmental epidemiological studies. Whereas very few studies explored spatial variations in concentrations of multiple insecticide metabolites in the general population, as well as their relationship with oxidative stress biomarkers (OSBs). We determined related target analytes in urine samples (n = 850) from 425 healthy adults in six cities of China during both autumn and winter. Eight organophosphorus metabolites (mOPPs), three pyrethroid metabolites (mPYRs), nine neonicotinoid insecticide metabolites (mNNIs), and pentachlorophenol (PCP) were detected in the urine samples. Additionally, linear mixed-effects model and weighted quantile sum model were used to assess the individual and combined effects of the insecticide exposure on selected OSBs. Altogether, 17 out of the 21 analytes were widely detected (73.1-100%). The median specific gravity (SG)-adjusted concentrations for the mOPPs, mPYRs, mNNIs, and PCP were 1.17-4.85, 0.45-0.79, 0.09-1.07, and 0.38 ng/mL, respectively. The mOPPs in Lanzhou (northwest China), mPYRs and mNNIs in Dalian (northeast China), and PCP in Chengdu (southwest China) had the highest concentrations among the six cities. The concentrations of the mNNIs and PCP in urban areas were significantly higher than those in rural areas, while the concentrations of some mOPPs and mPYRs were higher in rural areas. The concentrations of most analytes were higher in autumn than in winter. Hazard quotient of >1 for chlorpyrifos was observed in 9.2% of the study participants, suggested a potential health risk, while the estimated daily intake values of the other analytes were lower than their chronic reference doses. Many of the insecticide exposure biomarkers were significantly associated with increased OSBs; among them, each interquartile range-fold increase in the insecticide exposure biomarkers was associated with 5.4-19.0%, 4.6-19.4%, and 12.4-83.3% increase in 8-hydroxy-2'-deoxyguanosine, 8-hydroxy guanosine, and 4-hydroxy-2-nonenal-mercapturic acid, respectively. P-Nitrophenol was the main contributor in the association with the increased OSBs. This study found significant variations in insecticide exposure levels among different regions and seasons. The exposure level of chlorpyrifos suggested a potential health risk, and the insecticide mixture exposure was significantly associated with increased OSBs. Further risk assessments are warranted and control measures in the insecticide use are needed to mitigate the potential health risks.

Pentachlorophenol increases diabetes risk by damaging β-cell secretion and disrupting gut microbial-related amino acids and fatty acids biosynthesis

Pentachlorophenol (PCP), a ubiquitous environmental pollutant, has been reported as a possible contributor to diabetes. However, evidence for general population is scarce while related mechanisms are largely unknown. Using a representative population-based case-control study in Beijing (n = 1796), we found a positive association between PCP exposure and diabetes risk with the odds ratio reaching 1.68 (95 % confidence interval: 1.30 to 2.18). A further rat experiment revealed that low-dose PCP mimicking real-world human exposure can significantly impair glycemic homeostasis by inducing pancreatic β-cell dysfunction, with non-linear dose-response relationships. Subsequent multi-omics analysis suggested that low-dose PCP led to notable gut microbiota dysbiosis (especially the species from genus Prevotella, such as intermedia, dentalis, ruminicola, denticola, melaninogenica, and oris), decreased serum amino acids (L-phenylalanine, L-tyrosine, and L-tryptophan) and increased serum fatty acids (oleic and palmitic acid) in rats, while strong correlations were observed among alterations of gut microbes, serum metabolites and glycemic-related biomarkers (e.g., fasting blood glucose and insulin). Collectively, these results imply PCP may increase diabetes risk by disrupting gut microbial-related amino acids and fatty acids biosynthesis. This will help guide future in-depth studies on the roles of PCP in the development of human diabetes.

Post-synthetic modification fluorescence UiO-66-Eu immunochromatography for high-performance detection of sodium pentachlorophenoate

Sodium pentachlorophenate (PCP) is widely used as a herbicide, fungicide, or molluscicide. It is highly toxic, easily soluble in water, making it highly prone to diffusion and causing water and soil pollution. Through the food chain, it enters animal bodies and remains in food, causing toxicity to humans and animals. Therefore, establishing a rapid and simple detection method for PCP is crucial for human health and environmental protection. Herein, lanthanide metal Eu3+ was introduced into UiO-66-(COOH)2 by post-synthesis modification, and the nanomaterials prepared based on this method have the advantages of both UiO-66-(COOH)2 and Eu3+. The rigid skeleton structure of UiO-66-(COOH)2 can protect the activity of antibody, the detection environment pH tolerance range of UiO-66-Eu is 3-11. While Eu3+ has long fluorescence lifetime, high fluorescence intensity, high signal-to-noise ratio, and low photobleaching rate. UiO-66-Eu-based immunochromatography assay was successfully applied in PCP detection with the detection limits of 0.84, 0.98, and 0.37 μg/kg for pork, chicken, and shrimp, respectively, which was up to 10-fold more sensitive than the reported ICAs. The recoveries ranged from 79.7 %-113.1 %, with the coefficient of variation from 6.6 %-17.1 %. Parallel detection of 30 samples by LC-MS/MS showed a good correlation with that of our proposed method (R2 >0.98). This work not only provides a creative attempt for UiO-66-Eu based highly sensitive and strongly tolerant ICAs, but also guarantees human health and environmental protection.

Associations between single and combined exposures to environmental phenols and ulcerative colitis in American adults

OBJECTIVE

The etiology of ulcerative colitis (UC) is complex and involves multiple factors, with exposure to environmental toxins potentially contributing greatly to its pathogenesis. Therefore, this study was carried out with the purpose of delving into the associations between single and combined exposures to environmental phenols and UC among American adults.

METHODS

Survey data from the 2009-2010 National Health and Nutrition Examination Survey were selected for our research. The associations between single and combined exposures to environmental phenols and the prevalence of UC were analyzed using weighted multivariate logistic regression models as well as Bayesian kernel machine regression (BKMR).

RESULTS

A total of 1,422 adults aged 20 years old and above were included in this study, 17 of whom had UC. The correlation matrix showed strong associations between 2,4-dichlorophenol (2,4-DCP) and 2,5-dichlorophenol (2,5-DCP) (R = 0.81), as well as between 2,4,5-trichlorophenol (2,4,5-TCP) and 2,4,6-trichlorophenol (2,4,6-TCP) (R = 0.73). The logistic regression model revealed that, after adjusting for confounders, exposure to environmental phenols was positively associated with the prevalence of UC, with 2,4,6-TCP showing a significant association (OR = 2.37, 95 % CI = 1.10, 5.09, P = 0.037). The BKMR analysis indicated an upward trend in the overall effect of combined exposures to environmental phenols on UC. All five phenols contributed to this effect, with 2,4,6-TCP exhibiting the most pronounced effect. When other compounds were fixed at the 50th percentile, the impact of the five phenols on UC demonstrated a positive association, without any noteworthy interaction among the compounds.

CONCLUSION

Our findings suggested that exposure to environmental phenols may contribute to the occurrence of UC among American adults.

An integrated LC-MS/MS platform for noninvasive urinary nucleus acid adductomics: A pilot study for tobacco exposure

Tobacco smoke exposure significantly increases the level of global nucleoside damage. To evaluate all aspects of nucleic acid (NA) modifications, NA adductomics analyzes DNA, RNA and nucleobase adducts and provides comprehensive data. Liquid chromatography-tandem triple quadrupole mass spectrometry (LC-QQQ-MS/MS) and LC-Zeno-TOF-MS/MS were employed to screen for DNA, RNA and nucleobase adducts, as part of the analytical platform that was designed to combine high sensitivity and high resolution detection. We identified and distinguished urine nucleoside adducts via precursor ion and neutral loss scanning. A total of 245 potential adducts were detected, of which 28 were known adducts. The smoking group had significantly higher concentrations of nucleoside adducts in rat urine than the control group, based on MRM scanning, which was then used to perform relative quantitative analysis of these adducts. Urine nucleoside adducts were further confirmed using LC-Zeno-TOF-MS/MS. This highlights the potential of untargeted detection methods to provide comprehensive data on both known and unknown adducts. These approaches can be used to investigate the interactions among oxidative and alkylation stresses, and epigenetic modifications caused by exposure to tobacco smoke.

Pentachlorophenol-induced hemotoxicity diminishes antioxidant potential and oxidizes proteins, thiols, and lipids in rat blood: An in vivo study

Pentachlorophenol (PCP) is an excessively used wood preservative and pesticide, which has resulted in human exposure raising concerns about its potential toxic effects. This study is designed to evaluate the hemotoxicity of PCP in adult rats. Wistar rats were orally administered PCP (25-150 mg/kg bw) for five days while untreated (control) rats received corn oil. Animals were sacrificed, blood was taken and fractionated into plasma and red blood cells (RBC). PCP administration increased methemoglobin formation but decreased methemoglobin reductase activity. Significantly increased hydrogen peroxide level indicates initiation of oxidative stress condition in blood. PCP increased the oxidation of thiols, proteins and lipids, lowered glutathione levels, and compromised the antioxidant status of RBC in treated rats. Enzymes of the pathways of glucose breakdown, glycolysis and phosphogluconate pathway, were inhibited. Markers of liver damage were increased in the plasma of PCP-treated rats suggesting hepatotoxicity. This was confirmed by histopathological analysis of stained liver sections. Activity of xanthine oxidase, a reactive oxygen species (ROS) generating pro-oxidant enzyme, was increased. These hematological changes could be a result of the increased generation of ROS or direct chemical transformation by transient reaction species. These results show that PCP induces redox imbalance, diminishes antioxidant potential, inhibits metabolic pathways, and oxidizes cellular components in rat blood. This study suggests an elaborated possible molecular mechanism of PCP toxicity, and similar compounds so that methods can be devised to minimize its damaging effect.