Association of co-exposure to polycyclic aromatic hydrocarbons and phthalates with oxidative stress and inflammation

Associations between phthalate metabolites and two novel systemic inflammatory indexes: a cross-sectional analysis of NHANES data

BACKGROUND

The potentially risky effects of metabolites of phthalates (mPAEs) on inflammation and immune function have attracted much attention in recent years. However, direct studies on the relationship between these metabolites and the systemic immune inflammatory index (SII) and systemic inflammatory response index (SIRI) are limited.

METHODS

This cross-sectional study used generalized linear regression models (GLM), restricted cubic splines (RCS), weighted quantile sum (WQS), and Bayesian kernel-machine regression (BKMR) to analyze data from 2,763 U.S. adults aged between 20 and 80 years, obtained from the U.S. National Health and Nutrition Examination Survey (NHANES) conducted between 2013 and 2018. The study aimed to investigate the relationship between urine samples of nine mPAEs and levels of SII/SIRI in a single, nonlinear, and mixed relationship and explored the robustness of the findings under single and mixed effects using two sensitivity analyses for completeness. In addition, the effects of six variables (age, sex, BMI, the percentage of total daily energy intake from ultra-processed foods (UPFs), total vegetable intake, and dietary supplements) on the association results were explored through subgroup analyses to identify potentially important confounders.

RESULTS

In single exposure analyses, mono-n-butyl phthalate (MnBP), mono-ethyl phthalate (MEP), and monobenzyl phthalate (MBzP) were positively associated with SII/SIRI. The findings from the two mixed exposure models demonstrated a positive association between the collective concentrations of mPAEs and levels of SII/SIRI, with MBzP being identified as a significant contributor to the urinary levels of mPAEs. The subgroup analysis results of the effects of single and mixed exposures show that the association between mPAEs and SII/SIRI is more significant in females, overweight/obese populations, young/middle-aged populations, and populations with high levels of intake of UPFs.

CONCLUSION

Positive associations were identified between mPAEs and SII/SIRI. MBzP was determined to have the most significant impact. The association between mPAEs and SII/SIRI is significantly influenced by female groups, young and middle-aged populations, overweight and obese individuals, as well as those with a higher intake of UPFs.

Oxidative stress and cumulative exposure to environmental pollutants in lactating mothers living in the Valencian Region (Spain)

To widen our understanding of internal exposure to multiple chemicals and extract exposure-response associations from human biomonitoring (HBM) studies, the Exposure Load (EL) approach was used on data from the BETTERMILK project. Urinary levels of biomarkers of exposure to several contaminant groups -polycyclic aromatic hydrocarbons (PAHs), pesticides, bisphenols, phthalates, parabens, acrylamide, and metals - were analyzed, together with urinary concentrations of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8OHdG) as a biomarker of oxidative stress-induced DNA damage. Potential determinants of exposure, obtained through questionnaires, were cross-sectionally evaluated in Valencian breastfeeding mothers (year 2015, Spain). The 50th, 70th, 90th and 95th percentiles (P50, P70, P90 and P95, respectively) of each of the 41 selected biomarker groups were used as thresholds for EL calculations for 93 study participants who provided complete data for cumulative exposure assessment. Approximately 20 % of the mothers were exposed to ≥24 of the selected biomarker groups above the P50 and to ≥3 of these biomarkers above the P95 level. Concentrations exceeding health-based guidance values were observed for two phthalates, total As and acrylamide. A multiple linear regression model, with 8OHdG as the dependent variable and adjusted for potential confounders, revealed that an increased vegetable consumption (g·month-1) was associated with reduced urinary 8OHdG concentrations (-0.302; 95 % CI: -0.301, -0.303, p = 0.006). Bivariate analysis showed that PAHs, pesticides, parabens, and Cd were strongly correlated to higher urinary 8OHdG levels. These findings could be a starting point for designing larger longitudinal studies that consider toxicity, chemical residence time in the body, and a broader range of matrices and compound classes to which the target population might be exposed. These studies could further explore cause-effect relationships and inform preventive public health policies.

Association of urinary phthalate metabolite concentrations with inflammatory biomarker levels among pregnant women

BACKGROUND

Few studies have evaluated the associations between phthalate exposures and maternal inflammation.

OBJECTIVES

To examine cross-sectional associations of urinary phthalate metabolites, individually and as a mixture, with serum inflammatory biomarkers during pregnancy.

METHODS

A total of 175 pregnant women enrolled in the Environment and Reproductive Health (EARTH) Study between 2005 and 2017 were included. Concentrations of 11 urinary phthalate metabolites and two serum inflammatory biomarkers, including C-reactive protein (CRP) and interleukin-6 (IL-6), were measured. Urinary concentrations of phthalate metabolites were adjusted for specific gravity (SG) before analysis. Linear regression and Bayesian Kernel Machine Regression models were used to examine the associations for individual phthalates and their mixture, respectively. Stratified analyses by pre-pregnancy body mass index (BMI) were also conducted.

RESULTS

No association for urinary phthalate metabolites, individually or as a mixture, was observed with serum CRP overall among pregnant women. Urinary mono-3-carboxypropyl phthalate and monocarboxyisooctyl phthalate were positively associated with serum IL-6 (β [95 % CI] per 1-SD increase in log-transformed, SG-adjusted concentrations: 0.09 [0.01, 0.16] and 0.09 [0.02, 0.17], respectively). Besides, urinary mono-isobutyl phthalate was positively associated with serum IL-6 among women with a pre-pregnancy BMI ≥25 kg/m2 (β [95 % CI] per 1-SD increase: 0.15 [0.00, 0.30]), but not with lower BMI (-0.03 [-0.12, 0.07]). A suggestive positive association between phthalate mixture and serum IL-6 was observed in the high pre-pregnancy BMI group.

CONCLUSIONS

Our findings suggest that women with a higher pre-pregnancy BMI may be more vulnerable to the effects of certain phthalates on maternal inflammation reflected by IL-6.

Unraveling the connection between endocrine-disrupting chemicals and anxiety: An integrative epidemiological and bioinformatic perspective

BACKGROUND

The evidence linking endocrine-disrupting chemicals (EDCs) to anxiety in adults is currently sparse, while the effects of various categories of EDCs on the risk of anxiety, along with the underlying mechanisms, remain poorly understood.

METHODS

Four EDCs-polycyclic aromatic hydrocarbons (PAHs), phenols, pesticides, and phthalates-were quantified in 3927 adults from the National Health and Nutrition Examination Survey (NHANES) (2007-2012). We employed five statistical models to assess the individual and joint impacts of EDCs on anxiety risk. Causal mediation analysis frameworks were constructed to explore the mediating role of oxidative stress (OS). We identified potential biological mechanisms linking analytes to outcomes using the Comparative Toxicogenomics Database (CTD), MalaCards, and Open Targets, followed by enrichment analyses with Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG).

RESULTS

In individual chemical analyses, nine PAHs were significantly associated with increased anxiety risk (P < 0.05). Mixed-effects analyses showed that co-exposure to EDCs positively correlated with anxiety, primarily due to 2-hydroxyfluorene (2-FLU) and 3-hydroxyfluorene (3-FLU). Bilirubin mediated 5.42 % of the anxiety linked to the PAH mixture. The inflammatory genes TNF and IL-6 were identified as key biological stressors, with enrichment analysis indicating significant involvement in reactive oxygen species metabolic processes and the AGE-RAGE signaling pathway.

CONCLUSION

This study highlights the association between EDCs and anxiety in a representative U.S. population, indicating that exposure to PAHs may elevate anxiety risk through OS, inflammation, and the AGE-RAGE signaling pathway. Further longitudinal study were merited to support our results.

Hypothetical Behavioral Interventions for Mitigating the Cardiovascular Effects of Long-Term Fine Particulate Matter Exposure: Analyses From 2 Prospective Cohorts

BACKGROUND

Whether healthy behaviors can attenuate the adverse association between ambient fine particulate matter (PM2.5) and cardiovascular disease (CVD) is inconclusive.

METHODS AND RESULTS

The parametric g-formula was used to quantify the potential reduction in PM2.5 effect on CVD under different scenarios of hypothetical behavioral interventions (including dietary patterns, physical activity, body mass index, alcohol consumption, smoking, and dietary supplements). Feasible intervention scenarios, defined on the basis of values considered feasible in previous real-world interventions (eg, overweight participants lose 6.69% of their weight). Intensive scenarios, in which all participants are adopting completely healthy behaviors (eg, maintain normal weight). We also estimate the effect of joint interventions that incorporate the above behaviors. Long-term PM2.5 exposure was associated with incident CVD in both cohorts, with the risk difference per 1000 person-years for a 5 μg/m3 increase in PM2.5 being 1.42 (95% CI, 1.04-1.79) in the UKB (UK Biobank) and 2.15 (95% CI, 1.65-2.59) in the Sichuan Cohort (China Multi-Ethnic Cohort, Sichuan Region). In both feasible and intensive scenarios, improving diet, physical activity, and body mass index could significantly reduce the risk difference of PM2.5 on CVD, with the reduced proportion ranging from 4.59% to 37.22%. A feasible joint hypothetical intervention on 6 behaviors would reduce the effect of PM2.5 on CVD by 31.47% (10.13%-57.26%) and 19.75% (10.78%-42.89%) in the low-pollution UK Biobank and high-pollution Sichuan cohort, respectively. A combination of more intensive interventions would reduce risk difference by 57.51% (21.64%-100.69%) and 45.54% (22.66%-106.66%), respectively.

CONCLUSIONS

Healthier behaviors could serve as individual-level complementary strategies to emission control for minimizing the health impact of PM2.5, whether in high- or low-pollution areas.

Deciphering the phenotypic, inflammatory, and endocrine disrupting impacts of e-waste plastic-associated chemicals

As the volume of plastic waste from electrical and electronic equipment (WEEE) continues to rise, a significant portion is disposed of in the environment, with only a small fraction being recycled. Both disposal and recycling pose unknown health risks that require immediate attention. Existing knowledge of WEEE plastic toxicity is limited and mostly relies on epidemiological data and association studies, with few insights into the underlying toxicity mechanisms. Therefore, this study aimed to perform comprehensive chemical screening and mechanistic toxicological assessment of WEEE plastic-associated chemicals. Chemical analysis, utilizing suspect screening based on high-resolution mass spectrometry, along with quantitative target chemical analysis, unveiled numerous hazardous compounds including polyaromatic compounds, organophosphate flame retardants, phthalates, benzotriazoles, etc. Toxicity endpoints included perturbation of morphological phenotypes using the Cell Painting assay, inflammatory response, oxidative stress, and endocrine disruption. Results demonstrated that WEEE plastic chemicals altered the phenotypes of the cytoskeleton, endoplasmic reticulum, and mitochondria in a dose-dependent manner. In addition, WEEE chemicals induced inflammatory responses in resting macrophages and altered inflammatory responses in lipopolysaccharide-primed macrophages. Furthermore, WEEE chemicals activated the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway, indicating oxidative stress, and the aryl hydrocarbon receptor (AhR). Endocrine disruption was also observed through the activation of estrogenic receptor-α (ER-α) and the induction of anti-androgenic activity. The findings show that WEEE plastic-associated chemicals exert effects in multiple subcellular sites, via different receptors and mechanisms. Thus, an integrated approach employing both chemical and toxicological methods is essential for comprehensive assessment of the toxicity mechanisms and cumulative chemical burden of WEEE plastic-associated chemicals.

Metabolomic Analysis of Serum Reveals a Unique Metabolomic Profile in Patients With Myositis and Identified Several Potential Biomarkers in Polymyositis Versus Dermatomyositis Patients

DM and PM were the two major subtypes in myositis; among which, a unique metabolomic and biomarker profile remains lacking. Serum from 36 diagnosed myositis patients (28 DM and 8 PM) and 29 healthy controls was analyzed using HPLC-Q-TOF-MS/MS. PLS-DA was conducted through MetaboAnalyst 5.0 to identify the differential metabolites. The KEGG analysis was utilized to observe the related metabolic pathways. The potential biomarker value was assessed using ROC analysis. The relationship between the clinical characteristics and the levels of identified differential metabolites was analyzed using R language. PLS-DA showed a clear separation between healthy controls and myositis patients, and 131 differential metabolites were identified. KEGG analysis uncovered multiple disturbed metabolic pathways. Besides, nine differential metabolites were identified between PM and DM patients, which were involved in pentose and glucuronate interconversions. ROC curve analysis revealed the AUC of these identified metabolites is above 0.7. Among them, indoxyl sulfate, oleamide, and palmitoylethanolamide presented moderate or strong correlation with clinical characteristics. Metabolomics presents a different spectrum between myositis patients and healthy controls, PM and DM patients. Besides, indoxyl sulfate, oleamide, and palmitoylethanolamide may be potential biomarkers in distinguishing PM from DM.

Exploring the association between exposure to pesticides, polycyclic aromatic hydrocarbons, and phthalates and metabolic syndrome in National Health and Nutrition Examination Survey in the USA, 2007-2012: utilizing a multi-step statistical strategy

BACKGROUND

Pesticides, polycyclic aromatic hydrocarbons (PAHs), and phthalates are recognized as potential contributors to metabolic disorders. Nevertheless, the combined effect of simultaneous exposure to these chemicals on the metabolic syndrome (MetS) remains elusive.

OBJECTIVES

To explore the impacts of simultaneous exposure to pesticides, PAHs and phthalates and identify critical chemicals on MetS.

METHODS

Based on the National Health and Nutrition Examination Survey (NHANES) database from 2007-2012, our study included 4030 non-pregnant individuals aged 20 years or older. We used the weighted linear regression model, variable selection models (including LASSO regression and BMA models), as well as a mixture exposure model (WQS model) to investigate the correlation between chemicals and MetS. Additionally, stratified analyses were performed based on gender and age.

RESULTS

The weighted generalized linear regression model revealed a positive correlation of 2-hydroxyphenanthrene (2-PHEN) with MetS (OR: 1.37, 95% CI: 1.19-1.59, P < 0.001). Both the LASSO regression and BMA models identified 2-PHEN as a significant chemical positively associated with MetS. Additionally, the WQS model showed a positive association between overall exposure to the three chemical categories and MetS, with the highest weighted chemicals being 2-PHEN. Stratified analyses demonstrated a significant correlation between 2-PHEN and MetS between different subgroups. Notably, the WQS regression model revealed a significant association in the subgroup of female (OR = 1.40, 95% CI: 1.08-1.83, P < 0.05), with 2-PHEN, 2,5-dichlorophenol (2,5-DCP), 2-hydroxynaphthalene (2-NAP), and mono-ethyl phthalate (MEP) identified as the primary contributions to MetS.

CONCLUSION

Combined exposure to the three chemical groups was associated with an increased risk of MetS, with the PAHs group exhibiting the most pronounced effect and 2-PHEN emerging as a key chemical, underscoring significant public health concerns regarding the potential health risks of endocrine-disrupting chemicals (EDCs) exposure to metabolic diseases.

Bisphenol A induces apoptosis and disrupts testosterone synthesis in TM3 cells via reactive oxygen species-mediated mitochondrial pathway and autophagic flux inhibition

Bisphenol A (BPA) is a common endocrine disruptor chemical that is widely used in the production of food plastic packaging, and it has been shown to potentially harm the reproductive system. However, the specific mechanism by which BPA induces apoptosis of Leydig cells (LCs) and inhibits testosterone synthesis in these cells is unclear. In the present study, TM3 cells were used as an experimental model in combination with a reactive oxygen species (ROS) scavenger (N-acetylcysteine), Caspase-3 inhibitor (Ac-DEVD-CHO), autophagy activator (Torin2), and autophagy inhibitor (Chloroquine) to investigate the potential mechanisms by which BPA causes TM3 cell damage in vitro. BPA treatment increased ROS production, which led to a marked decrease in antioxidant enzyme activity and the expression levels of antioxidant-related genes and proteins in TM3 cells. Upregulated ROS cause excessive opening of the mitochondrial permeability transition pore and significantly decrease the expression levels of genes related to membrane potential and mitochondrial function in TM3 cells. The release of cytochrome C from damaged mitochondria into the cytoplasm activated a Caspase cascade reaction. In addition, excessive ROS levels impaired autophagic degradation by inhibiting the fusion of autophagosomes with lysosomes. These abnormalities eventually induced apoptosis and inhibited testosterone synthesis in TM3 cells. The collective findings suggest that BPA induces apoptosis and interferes with testosterone synthesis in TM3 cells by upregulating ROS production, thereby activating the mitochondrial apoptotic pathway and inhibiting autophagic flux. These findings provide novel mechanistic insights into male reproductive toxicity caused by BPA exposure.

Associations between phthalate metabolites and body composition in children aged 8-19 years

This study aimed to determine the relationship between individual and combined phthalate metabolites and body composition in children and adolescents using data from the 2015-2018 National Health and Nutrition Examination Survey. Single-exposure analysis indicated that most phthalate metabolites were negatively correlated with areal bone mineral density (aBMD). Quantile g-computation demonstrated a negative relationship between the mixture of phthalate metabolites and aBMD, which was confirmed by the Bayesian kernel machine regression model. Sex-stratified analysis revealed that mono-butyl phthalate (MBP) was negatively correlated with aBMD, and MBP, mono-ethyl phthalate (MEP), and mono-isobutyl phthalate (MiBP) were negatively linked to lean mass in males but not in females. The results did not differ according to developmental stages (childhood vs. adolescence). Our findings indicate that phthalate metabolites may affect the body composition in children and adolescents, particularly aBMD. Certain phthalate metabolites seem to be sex-specific, with males showing higher sensitivity than females.

Thyroid hormones and oxidative stress moderated the association between urinary phthalate metabolites and cardiovascular risk factors

While previous studies suggested that phthalate exposure poses a risk to cardiovascular health, the results are mixed and indicated variability based on population characteristics and health outcomes assessed. Research that simultaneously investigates the association between urinary phthalate metabolites and multiple cardiovascular risk factors within a single study is relatively scarce. This study assessed human exposure to phthalates by determining urinary metabolite concentrations, and applied multiple statistical techniques to systematically evaluate the individual dose-response relationships and joint effects of phthalate exposure on blood lipids, blood pressure, and fasting blood glucose. The results revealed significant negative associations between urinary phthalate metabolites and low-density lipoprotein cholesterol, triglycerides, total cholesterol, diastolic blood pressure, systolic blood pressure, and fasting blood glucose. Significant nonlinear associations were obtained between specific individual metabolites and diastolic blood pressure. The oxidative stress biomarker 8-hydroxydeoxyguanosine levels in urine and thyroid hormone levels in paired serum were measured simultaneously. Then, we examined the indirect roles of thyroid hormones and oxidative stress in the association between urinary phthalate metabolites and cardiovascular risk factors by mediation and moderation analysis. While the mediation effect was not statistically significant, the negative associations of urinary phthalate metabolites with fasting blood glucose, triglyceride, and lipoprotein cholesterol were statistically significant at lower levels of thyroid hormones by moderation analysis. The association was also significant under certain levels of oxidative stress. The results demonstrated that phthalate exposure is associated with several cardiovascular risk factors, and maintaining appropriate oxidative stress levels and ensuring sufficient thyroid hormone levels may attenuate these associations.

Urinary polycyclic aromatic hydrocarbon metabolites in Chinese pregnant women: Concentrations, variability, predictors, and association with oxidative stress biomarkers

Polycyclic aromatic hydrocarbons (PAHs) are a class of pervasive contaminants having adverse health effects. Urinary monohydroxylated PAHs (OH-PAHs) are commonly employed as biomarkers to estimate PAH exposure levels in humans. However, little is understood about the variability in OH-PAHs among pregnant women across trimesters and their relationship with oxidative stress biomarkers (OSBs). Based on a prospective birth cohort study conducted in Wuhan, China, we selected 644 women who donated (spot) urine samples across different trimesters and measured the urinary concentrations of eight OH-PAHs and three selected OSBs (8-OHG, 8-OHdG, and HNEMA) to explore the relationship between the OH-PAHs and OSBs. Pregnant women were found to be ubiquitously exposed to the PAHs, with detection rates of the OH-PAHs ranging from 86.3% to 100%. 2-Hydroxynaphthalene (2-OH-Nap) had the highest urinary concentrations among the OH-PAHs during the three trimesters (specific gravity-adjusted median values for the first, second, and third trimesters: 1.86, 2.39, and 2.20 ng/mL, respectively). However, low reproducibility of the OH-PAHs was observed across the three trimesters with intraclass correlation coefficients ranged between 0.02 and 0.22. Most urinary OH-PAHs had the highest concentrations at the first trimester and the lowest at the third trimester. Some OH-PAH concentrations were higher in pregnant women with lower educational level [2-hydroxyphenanthrene (2-OH-Phen) and 3-hydroxyphenanthrene (3-OH-Phen)], those who were overweight [2-OH-Nap, 2/3-hydroxyfluorene (2/3-OH-Fluo), 2-OH-Phen, and 4-hydroxyphenanthrene (4-OH-Phen)], those who were unemployed during pregnancy [1-hydroxynaphthalene, 1/9-hydroxyphenanthrene, and 4-OH-Phen], and the samples donated in summer (most OH-PAHs, except for 2-OH-Nap). In multivariable linear mixed-effects model analyses, every OH-PAH was found to be significantly associated with increased levels of the three OSBs. For example, each interquartile range-fold increase in 2/3-OH-Fluo concentration was associated with the largest increase in 8-OHdG (65.4%) and 8-OHG (49.1%), while each interquartile range-fold increase in 3-OH-Phen concentration was associated with the largest increase in HNEMA (76.3%). Weighted quantile sum regression models, which were used to examine the joint effect of OH-PAH mixture on the OSBs, revealed positive associations between the OH-PAH mixture exposure and the OSBs. Specifically, 2/3-OH-Fluo and 2-OH-Nap were the major contributors in the association with oxidative damage of nucleic acids (8-OHdG and 8-OHG), while hydroxyphenanthrenes and 1-hydroxypyrene were the major contributors in the association with oxidative damage of lipid (HNEMA). Further work is required to examine the potential mediating role of oxidative stress in the relationship of adverse health outcomes with elevated PAH exposure among pregnant women.

Associations among urinary 1-hydroxypyrene level, oxidative stress, and high blood pressure: A panel study among elderly Koreans

Polycyclic aromatic hydrocarbons (PAHs) are environmental carcinogens. However, there is limited evidence for the relations between PAHs exposure and blood pressure (BP) with the mediating role of oxidative stress. Therefore, in this study, we evaluated relations among PAHs exposure, oxidative stress, and BP in the elderly population. We measured the levels of 1-hydroxypyrene (1-OHP), an indicator of PAHs exposure, and malondialdehyde (MDA), an oxidative stress marker, in urine samples repeatedly collected from 560 elderly persons aged ≥60 years, and then evaluated the relations among 1-OHP level, MDA level, and systolic or diastolic BP (SBP or DBP) measured on the day of urine collection. Urinary 1-OHP level was significantly associated with both MDA level (β = 0.19 and p < 0.0001) and BP (β = 1.72 and p < 0.0001 for SBP; and β = 1.24 and p < 0.0001 for DBP). Furthermore, urinary MDA level was also significantly associated with BP (β = 4.35 and p < 0.0001 for SBP; and β = 2.51 and p < 0.0001 for DBP). The trend for the change of SBP and DBP by 1-OHP quartile was more apparent in the elderly female participants (ptrend<0.0001 for SBP; and ptrend<0.0001 for DBP) compared with the elderly male participants (ptrend = 0.8351 for SBP; and ptrend = 0.3736 for DBP). To explore the mediating role of oxidative stress in the relation between 1-OHP level and SBP or DBP, we repeated these analyses after adjustment for the MDA levels. The increase in BP by 1-OHP exposure was largely mediated by the production of MDA (96.3% for SBP and 94.7% for DBP). These results revealed that PAHs exposure may increase BP through the mediation of oxidative stress.

Kalanchoe tomentosa: Phytochemical Profiling, and Evaluation of Its Biological Activities In Vitro, In Vivo, and In Silico

In this work, the leaves of K. tomentosa were macerated with hexane, chloroform, and methanol, respectively. The phytochemical profiles of hexane and chloroform extracts were unveiled using GC/MS, whereas the chemical composition of the methanol extract was analyzed using UPLC/MS/MS. The antibacterial activity of extracts was determined against gram-positive and gram-negative strains through the minimal inhibitory concentration assay, and in silico studies were implemented to analyze the interaction of phytoconstituents with bacterial peptides. The antioxidant property of extracts was assessed by evaluating their capacity to scavenge DPPH, ABTS, and H2O2 radicals. The toxicity of the extracts was recorded against Artemia salina nauplii and Caenorhabditis elegans nematodes. Results demonstrate that the hexane and chloroform extracts contain phytosterols, triterpenes, and fatty acids, whereas the methanol extract possesses glycosidic derivatives of quercetin and kaempferol together with sesquiterpene lactones. The antibacterial performance of extracts against the cultured strains was appraised as weak due to their MIC90 values (>500 μg/mL). As antioxidants, treatment with extracts executed high and moderate antioxidant activities within the range of 50-300 μg/mL. Extracts did not decrease the viability of A. salina, but they exerted a high toxic effect against C. elegans during exposure to treatment. Through in silico modeling, it was recorded that the flavonoids contained in the methanol extract can hamper the interaction of the NAM/NAG peptide, which is of great interest since it determines the formation of the peptide wall of gram-positive bacteria. This study reports for the first time the biological activities and phytochemical content of extracts from K. tomentosa and proposes a possible antibacterial mechanism of glycosidic derivatives of flavonoids against gram-positive bacteria.

Biomonitoring urinary organophosphorus flame retardant metabolites by liquid-liquid extraction and ultra-high performance liquid chromatography-tandem mass spectrometry and their association with oxidative stress

Organophosphate flame retardants (OPFRs) are widely used as substitutes for traditional brominated flame retardants, necessitating a reliable and sensitive method for biomonitoring their urinary metabolites to assess human exposure. This study conducted biomonitoring of 10 metabolites of OPFRs in 152 adults and assessed their association with oxidative stress biomarkers 8-hydroxydeoxyguanosine and 8-hydroxyguanosine. Urinary metabolites of OPFRs were released via enzymatic deconjugation. The addition of sodium chloride to the urine samples increases the ionic strength, inducing a salting-out effect that reduces the solubility of these compounds, thereby facilitating their extraction with a mixture of ethyl acetate and acetonitrile. Then, the metabolites of OPFRs were quantified by ultra-high performance liquid chromatography-tandem mass spectrometry, and we validated the method for linear range, precision, matrix effect, and method detection limit. The detection limit of the metabolites of OPFRs ranged from 0.01 to 0.2 μg/L, and these metabolites were detected with high frequencies ranging from 25.0 to 98.68% in the urine samples. The concentration of bis (2-chloroethyl) phosphate was significantly higher in males than in females, with the geometric mean concentration of 0.88 μg/L for males and 0.53 μg/L for females, respectively. Spearman correlation analysis revealed weak but statistically significant positive correlations among the urinary metabolites. Bayesian kernel machine regression analysis showed a significant positive association between elevated urinary concentrations of metabolites of OPFRs and increased oxidative stress levels. Di-n-butyl phosphate was identified as the metabolite that significantly contributed to the elevated level of 8-hydroxyguanosine.

Repair Effect of Umbilical Cord Mesenchymal Stem Cells Embedded in Hydrogel on Mouse Insulinoma 6 Cells Injured by Streptozotocin

Umbilical cord mesenchymal stem cells (UC-MSCs) possess the capabilities of differentiation and immune modulation, which endow them with therapeutic potential in the treatment of type 2 diabetes mellitus (T2DM). In this study, to investigate the repair mechanism of UC-MSCs in hydrogel on pancreatic β-cells in diabetes, mouse insulinoma 6 (MIN-6) cells damaged by streptozotocin (STZ) in vitro were used in co-culture with UC-MSCs in hydrogel (UC-MSCs + hydrogel). It was found that UC-MSCs + hydrogel had a significant repair effect on injured MIN-6 cells, which was better than the use of UC-MSCs alone (without hydrogel). After repair, the expression of superoxide dismutase (SOD) and catalase (CAT) as well as the total antioxidant capacity (T-AOC) of the repaired MIN-6 cells were increased, effectively reducing the oxidative stress caused by STZ. In addition, UC-MSCs + hydrogel were able to curb the inflammatory response by promoting the expression of anti-inflammatory factor IL-10 and reducing inflammatory factor IL-1β. In addition, the expression of both nuclear antigen Ki67 for cell proliferation and insulin-related genes such as Pdx1 and MafA was increased in the repaired MIN-6 cells by UC-MSCs + hydrogel, suggesting that the repair effect promotes the proliferation of the injured MIN-6 cells. Compared with the use of UC-MSCs alone, UC-MSCs + hydrogel exhibit superior antioxidant stress resistance against injured MIN-6 cells, better proliferation effects and a longer survival time of UC-MSCs because the porous structure and hydrophilic properties of the hydrogel could affect the growth of cells and slow down their metabolic activities, resulting in a better repair effect on the injured MIN-6 cells.

Biomonitoring urinary pesticide metabolites in preschool children by supported liquid extraction and ultra-high performance liquid chromatography-tandem mass spectrometry and their association with oxidative stress

Investigating pesticide exposure and oxidative stress in preschool children is essential for elucidating the determinants of environmental health in early life, with human biomonitoring of urinary pesticide metabolites serving as a critical strategy for achieving this objective. This study demonstrated biomonitoring of 2 phenoxyacetic acid herbicides, 2 organophosphorus pesticide metabolites, and 4 pyrethroid pesticide metabolites in 159 preschool children and evaluated their association with oxidative stress biomarker 8-hydroxydeoxyguanosine. An enzymatic deconjugation process was used to release urinary pesticide metabolites, which were then extracted and enriched by supported liquid extraction, and quantified by ultra-high performance liquid chromatography-tandem mass spectrometry with internal standard calibration. Dichloromethane: methyl tert‑butyl ether (1:1, v/v) was optimized as the solvent for supported liquid extraction, and we validated the method for linear range, recovery, matrix effect and method detection limit. Method detection limit of the pesticide metabolites ranged from 0.01 μg/L to 0.04 μg/L, with satisfactory recoveries ranging from 70.5 % to 95.5 %. 2,4,5-Trichlorophenoxyacetic acid was not detected, whereas the other seven pesticide metabolites were detected with frequencies ranging from 10.1 % to 100 %. The concentration of urinary pesticide metabolites did not significantly differ between boys and girls, with the median concentrations being 9.39 μg/L for boys and 4.90 μg/L for girls, respectively. Spearman correlation analysis indicated that significant positive correlations among urinary metabolites. Bayesian kernel machine regression revealed a significant positive association between urinary pesticide metabolites and 8-hydroxydeoxyguanosine. Para-nitrophenol was the pesticide metabolite that contributed significantly to the elevated level of oxidative stress.

Humoral immunosuppression of exposure to polycyclic aromatic hydrocarbons and the roles of oxidative stress and inflammation

Previous studies have indicated adverse health effects of exposure to polycyclic aromatic hydrocarbons (PAHs), but evidence on the association between PAH exposure and immunity is scarce and its underlying mechanism is largely unknown. This study assessed human exposure to PAHs by determining the concentrations of PAHs in serum and their metabolites in paired urine. The oxidative stress and inflammation levels were evaluated by urinary DNA damage biomarker 8-hydroxydeoxyguanosine, white blood cell counts and C-reaction protein. We investigated the relationship between PAH exposure and seven immunological components, and explored the indirect roles of oxidative stress and inflammation by mediation and moderation analysis. Multivariate regression analysis revealed that 1-hydroxynaphthalene and 2-hydroxyfluorene were negatively associated with immunoglobulin A, and 3-hydroxyphenanthrene was negatively correlated with complement component 3. Restricted cubic spline analysis demonstrated nonlinear relationships between some individual PAHs or their metabolites with immunological components. Bayesian kernel machine regression and quantile g-computation revealed significant associations of higher PAH exposure with decreased immunoglobulin G and kappa light chain levels. Phenanthrene was the compound that contributed the most to reduced immunoglobulin G. Mediation analysis demonstrated significant indirect effects of 8-hydroxydeoxyguanosine and white blood cell counts on the association between higher PAH exposure and decreased immunological components. Moderation analysis revealed that PAH exposure and decreased immunological components are significantly associated with higher levels of C-reaction protein and white blood cell counts. The results demonstrated significant immunosuppression of PAH exposure and highlighted the indirect roles of oxidative stress and inflammation. Interventions to reduce systemic inflammation may mitigate the adverse immune effects of PAH exposure.