Association of serum bisphenol A levels with incident overweight and obesity risk and the mediating effect of adiponectin

Association of metals and bisphenols exposure with lipid profiles and dyslipidemia in Chinese adults: Independent, combined and interactive effects

BACKGROUND

Although studies have assessed the association of metals and bisphenols with lipid metabolism, the observed results have been controversial, and limited knowledge exists about the combined and interactive effects of metals and bisphenols exposure on lipid metabolism.

METHODS

Plasma metals and serum bisphenols concentrations were evaluated in 888 participants. Multiple linear regression and logistic regression models were conducted to assess individual associations of 18 metals and 3 bisphenols with 5 lipid profiles and dyslipidemia risk, respectively. The dose-response relationships of targeted contaminants with lipid profiles and dyslipidemia risk were captured by applying a restriction cubic spline (RCS) function. The bayesian kernel machine regression (BKMR) model was used to assess the overall effects of metals and bisphenols mixture on lipid profiles and dyslipidemia risk. The interactive effects of targeted contaminants on interested outcomes were explored by constructing an interaction model.

RESULTS

Single-contaminant analyses revealed that exposure to iron (Fe), nickel (Ni), copper (Cu), arsenic (As), selenium (Se), strontium (Sr), and tin (Sn) was associated with elevated lipid levels. Cobalt (Co) showed a negative association with high density lipoprotein cholesterol (HDL-C). Bisphenol A (BPA) and bisphenol AF (BPAF) were associated with decreased HDL-C levels, with nonlinear associations observed. Vanadium (V), lead (Pb), and silver (Ag) displayed U-shaped dose-response relationships with most lipid profiles. Multi-contaminant analyses indicated positive trends between contaminants mixture and total cholesterol (TC), triglycerides (TG), low density lipoprotein cholesterol (LDL-C), and non-high-density lipoprotein cholesterol (non-HDL-C). The interaction analyses showed that Se-Fe exhibited synergistic effects on LDL-C and non-HDL-C, and Se-Sn showed a synergistic effect on HDL-C.

CONCLUSIONS

Our study suggested that exposure to metals and bisphenols was associated with changes in lipid levels, and demonstrated their combined and interactive effects.

Bisphenol F exposure induces depression-like changes: Roles of the kynurenine metabolic pathway along the "liver-brain" axis

Bisphenol F (BPF), one of the major alternatives of Bisphenol A (BPA), is becoming extensively used in industrial production with great harm to human beings and environment. Recent studies have revealed that environmental exposure is crucial to the initiation and development of depression. Thereby, the aim the present study is to ascertain the correlationship between the BPF exposure and depression occurrence. In the current study, BPF strikingly triggered depression-like changes in mice through the sucrose preference test (SPT), tail suspension test (TST) and forced swim test (FST), accompanied by the perturbation of the kynurenine (KYN) metabolic pathway along the "liver-brain" axis. Mechanistically, the neurotransmitters from the tryptophan metabolic pathway were converted to the toxic KYN pathway after BPF treatment. With the ELISA assay, it revealed that the toxic KYN metabolites, including KYN and 3-hydroxykynurenine (3-HK), were strikingly increased in the mouse brains which was ascribed to the enhanced expression of the rate-limiting enzymes Indoleamine 2,3-dioxygenase (IDO1) and Kynurenine 3-monooxygenase (KMO) respectively. Interestingly, the increased brain KYN induced by BPF was also validated partially from the periphery, since the ELISA and western blotting results indicated the significantly increased KYN in the serum and L-type amino acid transporter 1 (LAT1) in the brain, the key transporter responsible for KYN and 3-HK crossing the blood-brain barrier. Intriguingly, the liver-derived KYN metabolic pathway was the important source of the peripheral KYN and 3-HK, as BPF substantially enhanced hepatic IDO1, Tryptophan, 2, 3-dioxygenase (TDO2), and KMO levels indicated by western blotting. This study is the first to delineate previously unrecognized BPF-induced depression by regulating the KYN metabolic pathway along the "liver-brain" axis; therefore, targeting LAT1 or hepatic KYN signaling may provide a potentially unique therapeutic intervention in BPF-induced depression.

Endocrine disrupting chemical Bisphenol A and its association with cancer mortality: a prospective cohort study of NHANES

Introduction

There is evidence suggesting that Bisphenol A (BPA) is associated with increased all-cause mortality in adults. However, the specific nature of the relationship between BPA exposure and cancer mortality remains relatively unexplored.

Methods

The National Health and Nutrition Examination Survey (NHANES) dataset was used to recruit participants. Urinary BPA was assessed using liquid chromatography-mass spectrum (LC-MS). Through the use of multivariable Cox proportional hazard regressions and constrained cubic splines, the relationships between urine BPA and death from all causes and cancer were investigated.

Results

This study has a total of 8,035 participants, and 137 died from cancers after a 7.5-year follow-up. The median level of BPA was 2.0 g/mL. Urinary BPA levels were not independently associated with all-cause mortality. For cancer mortality, the second quartile's multivariable-adjusted hazard ratio was 0.51 (95% confidence interval: 0.30 to 0.86; p = 0.011) compared to the lowest quartile. The restricted cubic splines showed that the association was nonlinear (p for nonlinearity = 0.028) and the inflection point was 1.99 ng/mL.

Conclusion

Urinary BPA exposure was U-shaped associated with the risk of cancer mortality, and a lower level of BPA less than 1.99 ng/mL was associated with a higher risk of cancer mortality.

The Role of Endocrine Disruptors Bisphenols and Phthalates in Obesity: Current Evidence, Perspectives and Controversies

Excess body weight constitutes one of the major health challenges for societies and healthcare systems worldwide. Besides the type of diet, calorie intake and the lack of physical exercise, recent data have highlighted a possible association between endocrine-disrupting chemicals (EDCs), such as bisphenol A, phthalates and their analogs, and obesity. EDCs represent a heterogeneous group of chemicals that may influence the hormonal regulation of body mass and adipose tissue morphology. Based on the available data from mechanistic, animal and epidemiological studies including meta-analyses, the weight of evidence points towards the contribution of EDCs to the development of obesity, associated disorders and obesity-related adipose tissue dysfunction by (1) impacting adipogenesis; (2) modulating epigenetic pathways during development, enhancing susceptibility to obesity; (3) influencing neuroendocrine signals responsible for appetite and satiety; (4) promoting a proinflammatory milieu in adipose tissue and inducing a state of chronic subclinical inflammation; (5) dysregulating gut microbiome and immune homeostasis; and (6) inducing dysfunction in thermogenic adipose tissue. Critical periods of exposure to obesogenic EDCs are the prenatal, neonatal, pubertal and reproductive periods. Interestingly, EDCs even at low doses may promote epigenetic transgenerational inheritance of adult obesity in subsequent generations. The aim of this review is to summarize the available evidence on the role of obesogenic EDCs, specifically BPA and phthalate plasticizers, in the development of obesity, taking into account in vitro, animal and epidemiologic studies; discuss mechanisms linking EDCs to obesity; analyze the effects of EDCs on obesity in critical chronic periods of exposure; and present interesting perspectives, challenges and preventive measures in this research area.

Carnosic acid and rosemary extract reversed the lipid accumulation induced by bisphenol A in the 3T3-L1 preadipocytes and C57BL/6J mice via SIRT1/FoxO1 pathway

Bisphenol A (BPA) is an endocrine-disrupting chemical, widely used to produce polycarbonate plastic. Carnosic acid (CA) is a rosemary diterpene with an anti-obesity effect. In this study, we investigated the anti-adipogenic effect of CA in BPA-treated 3T3-L1 preadipocytes and C57BL/6 J mice. In vitro experiments showed that CA inhibited lipid accumulation by BPA in 3T3-L1 preadipocytes. CA displayed anti-adipogenic effects through the downregulation of differentiation and adipogenesis-related proteins, along with the upregulation of lipolytic protein and SIRT1/FoxO1 pathway. In vivo experiments, mice treated with BPA exhibited an increase in body weight gain and epididymal adipose tissue mass when compared to the control group. CA treatment improved the epididymal adipose tissue mass induced by BPA. CA and rosemary extract (RE) treatment ameliorated dyslipidemia in BPA-treated mice. We further showed that CA and RE exerted anti-adipogenesis effects in liver tissues of BPA-treated mice via increasing SIRT1, FoxO1, and ATGL proteins and decreasing FAS and aP2 proteins. Moreover, SIRT1 inhibitor sirtinol blocked CA to increase SIRT1, FoxO1, FAS, and aP2 proteins, decrease Ac-FoxO1 protein, and reduce lipid accumulation in BPA-treated cells. These findings indicated that CA and RE could reverse BPA-induced lipid accumulation by regulating adipocyte differentiation, adipogenesis, and lipolysis through SIRT1/FoxO1 pathway.

Unraveling the interaction of bisphenol A with collagen and its effect on conformational and thermal stability

Evidence suggests the association of bisphenol A (BPA) with increased collagen (COL) expression in the development of fibrosis. Ultraviolet and fluorescence spectra on collagen-BPA interaction showed that 100 ng/ml of BPA initiated loosening of protein backbone through unfolding with exposure of tyrosine residues resulting in an intermediate "Molten Globule" state, which later aggregated with 1 μg/ml of BPA indicated with an apparent red-shift. Conformational changes with CD and ATR-FTIR showed disappearance of negative band with broadening and shifting of peptide carbonyl groups. Light scattering findings with TEM images presented initial dissolution followed by unordered thick fibrillar bundles with 30 μg/ml BPA. The complex was pH sensitive, with calorimetric thermogram revealing increased thermal stability requiring 83°C to denature. Hydrogen bonds of 2.8 Å with hydrophobic interactions of BPA in all grooves of collagen molecule with same pattern and binding energy (-4.1 to -3.9 kcal/mol) confirmed the intensity of aggregate formation via in-silico docking.