The relationship of obesity with lifestyle and dietary exposure to endocrine-disrupting chemicals

Toxicological Effects of Naturally Occurring Endocrine Disruptors on Various Human Health Targets: A Rapid Review

Endocrine-disrupting compounds are chemicals that alter the normal functioning of the endocrine system of living organisms. They can be natural (N-EDCs) or synthetic compounds (S-EDCs). N-EDCs can belong to different groups, such as phytoestrogens (PEs), including flavonoids, or mycotoxins originating from plants or fungi, and cyanotoxins, derived from bacteria. Humans encounter these substances in their daily lives. The aim of this rapid review (RR) is to provide a fine mapping of N-EDCs and their toxicological effects on human health in terms of various medical conditions or adverse consequences. This work is based on an extensive literature search and follows a rigorous step-by-step approach (search strategy, analysis strategy and data extraction), to select eligible papers published between 2019 and 2023 in the PubMed database, and to define a set of aspects characterizing N-EDCs and the different human target systems. Of the N-EDCs identified in this RR, flavonoids are the most representative class. Male and female reproductive systems were the targets most affected by N-EDCs, followed by the endocrine, nervous, bone and cardiovascular systems. In addition, the perinatal, pubertal and pregnancy periods were found to be particularly susceptible to natural endocrine disruptors. Considering their current daily use, more toxicological research on N-EDCs is required.

Mitigating the impact of bisphenol A exposure on mortality: Is diet the key? A cohort study based on NHANES

Bisphenol A (BPA) is a widespread environmental pollutant linked to detrimental effects on human health and reduced life expectancy following chronic exposure. This prospective cohort study aimed to examine the association between BPA exposure and mortality in American adults and to explore the potential mitigating effects of dietary quality on BPA-related mortality. This study utilized data from 8761 American adults in the 2003-2016 National Health and Nutrition Examination Survey (NHANES). Urinary BPA levels were employed to assess BPA exposure, and dietary quality was evaluated using the Healthy Eating Index-2015 (HEI-2015). All-cause, cardiovascular disease (CVD), and cancer mortality statuses were determined until December 31, 2019, resulting in a cumulative follow-up of 80,564 person-years. The results showed that the highest tertile of urinary BPA levels corresponded to a 36% increase in all-cause mortality and a 62% increase in CVD mortality compared to the lowest tertile. In contrast, the highest tertile of HEI-2015 scores was associated with a 29% reduction in all-cause mortality relative to the lowest tertile. Although no significant interaction was found between HEI-2015 scores and urinary BPA levels concerning mortality, the association between HEI-2015 scores and both all-cause and CVD mortality was statistically significant at low urinary BPA levels. Continuous monitoring of BPA exposure is crucial for evaluating its long-term adverse health effects. Improving dietary quality can lower all-cause mortality and decrease the risk of all-cause and CVD mortality at low BPA exposure levels. However, due to the limited protective effect of dietary quality against BPA exposure, minimizing BPA exposure remains a vital goal.

Enhancing de novo ceramide synthesis induced by bisphenol A exposure aggravates metabolic derangement during obesity

OBJECTIVE

Exposure to bisphenol A (BPA) has been shown to increase the prevalence of obesity and its related insulin resistance (IR). Ceramide is a sphingolipid known to facilitate the production of proinflammatory cytokines and subsequently exacerbate inflammation and IR during the progression of obesity. Here, we investigated the effects of BPA exposure on ceramide de novo synthesis and whether increased ceramides aggravate adipose tissue (AT) inflammation and obesity-related IR.

METHODS

A population-based case-control study was conducted to explore the relationship between BPA exposure and IR and the potential role of ceramide in AT in obesity. Next, we used mice reared on a normal chow diet (NCD) or a high-fat diet (HFD) to verify the results from the population study and then investigated the role of ceramides in low-level BPA exposure with HFD-induced IR and AT inflammation in mice treated with or without myriocin (an inhibitor of the rate-limiting enzyme in de novo ceramide synthesis).

RESULTS

BPA levels are higher in obese individuals and are significantly associated with AT inflammation and IR. Specific subtypes of ceramides mediated the associations between BPA and obesity, obesity-related IR and AT inflammation in the obesity group. In animal experiments, BPA exposure facilitated ceramide accumulation in AT, activated PKCζ, promoted AT inflammation, increased the expression and secretion of proinflammatory cytokines via the JNK/NF-κB pathway, and lowered insulin sensitivity by disrupting IRS1-PI3K-AKT signaling in mice fed a HFD. Myriocin suppressed BPA-induced AT inflammation and IR.

CONCLUSION

These findings indicate that BPA aggravates obesity-induced IR, which is partly via increased de novo synthesis of ceramides and subsequent promotion of AT inflammation. Ceramide synthesis could be a potential target for the prevention of environmental BPA exposure-related metabolic diseases.

Recent progress in epigenetics of obesity

Nowadays, obesity is one of the largest public health problems worldwide. In the last few decades, there has been a marked increase in the obesity epidemic and its related comorbidities. Worldwide, more than 2.2 billion people (33%) are affected by overweight or obesity (712 million, 10%) and its associated metabolic complications. Although a high heritability of obesity has been estimated, the genetic variants conducted from genetic association studies only partially explain the variation of body mass index. This has led to a growing interest in understanding the potential role of epigenetics as a key regulator of gene-environment interactions on the development of obesity and its associated complications. Rapid advances in epigenetic research methods and reduced costs of epigenome-wide association studies have led to a great expansion of population-based studies. The field of epigenetics and metabolic diseases such as obesity has advanced rapidly in a short period of time. The main epigenetic mechanisms include DNA methylation, histone modifications, microRNA (miRNA)-mediated regulation and so on. DNA methylation is the most investigated epigenetic mechanism. Preliminary evidence from animal and human studies supports the effect of epigenetics on obesity. Studies of epigenome-wide association studies and genome-wide histone modifications from different biological specimens such as blood samples (newborn, children, adolescent, youth, woman, man, twin, race, and meta-analysis), adipose tissues, skeletal muscle cells, placenta, and saliva have reported the differential expression status of multiple genes before and after obesity interventions and have identified multiple candidate genes and biological markers. These findings may improve the understanding of the complex etiology of obesity and its related comorbidities, and help to predict an individual's risk of obesity at a young age and open possibilities for introducing targeted prevention and treatment strategies.

Dietary Risk Factors and Eating Behaviors in Peripheral Arterial Disease (PAD)

Dietary risk factors play a fundamental role in the prevention and progression of atherosclerosis and PAD (Peripheral Arterial Disease). The impact of nutrition, however, defined as the process of taking in food and using it for growth, metabolism and repair, remains undefined with regard to PAD. This article describes the interplay between nutrition and the development/progression of PAD. We reviewed 688 articles, including key articles, narrative and systematic reviews, meta-analyses and clinical studies. We analyzed the interaction between nutrition and PAD predictors, and subsequently created four descriptive tables to summarize the relationship between PAD, dietary risk factors and outcomes. We comprehensively reviewed the role of well-studied diets (Mediterranean, vegetarian/vegan, low-carbohydrate ketogenic and intermittent fasting diet) and prevalent eating behaviors (emotional and binge eating, night eating and sleeping disorders, anorexia, bulimia, skipping meals, home cooking and fast/ultra-processed food consumption) on the traditional risk factors of PAD. Moreover, we analyzed the interplay between PAD and nutritional status, nutrients, dietary patterns and eating habits. Dietary patterns and eating disorders affect the development and progression of PAD, as well as its disabling complications including major adverse cardiovascular events (MACE) and major adverse limb events (MALE). Nutrition and dietary risk factor modification are important targets to reduce the risk of PAD as well as the subsequent development of MACE and MALE.

Nanomedicines, an emerging therapeutic regimen for treatment of ischemic cerebral stroke: A review

Owing to its intricate pathophysiology, cerebral stroke is a serious medical condition caused by interruption or obstruction of blood supply (blockage of vasculature) to the brain tissues which results in diminished supply of essential nutrients and oxygen (hypoxia) and ultimate necrosis of neuronal tissues. A prompt risks assessment and immediate rational therapeutic plan with proficient neuroprotection play critically important role in the effective management of this neuronal emergency. Various conventional medications are being used for treatment of acute ischemic cerebral stroke but fibrinolytic agents, alone or in combination with other agents are considered the mainstay. These clot-busting agents effectively restore blood supply (reperfusion) to ischemic regions of the brain; however, their clinical significance is hampered due to various factors such as short plasma half-life, limited distribution to brain tissues due to the presence of highly efficient physiological barrier, blood brain barrier (BBB), and lacking of target-specific delivery to the ischemic brain regions. To alleviate these issues, various types of nanomedicines such as polymeric nanoparticles (NPs), liposomes, nanoemulsion, micelles and dendrimers have been designed and evaluated. The implication of these newer therapies (nanomedicines) have revolutionized the therapeutic outcomes by improving the plasma half-life, permeation across BBB, efficient distribution to ischemic cerebral tissues and neuroprotection. Furthermore, the adaptation of some diverse techniques including PEGylation, tethering of targeting ligands on the surfaces of nanomedicines, and pH responsive features have also been pondered. The implication of these emerging adaptations have shown remarkable potential in maximizing the targeting efficiency of drugs to ischemic brain tissues, simultaneous delivery of drugs and imaging agents (for early prognosis as well as monitoring of therapy), and therapeutic outcomes such as long-term neuroprotection.

Metabolic pathways, alterations in miRNAs expression and effects of genetic polymorphisms of bisphenol a analogues: A systematic review

Bisphenol A (BPA) is one of the most common endocrine disruptors found in the environment and its harmful health effects in humans and wildlife have been extensively reported One of the main aims of this review was to examine the metabolic pathways of BPA and BPA substitutes and the endocrine disrupting properties of their metabolites. According to the available literature, phase I and phase II metabolic reactions play an important role in the detoxification process of bisphenols (BPs), but their metabolism can also lead to the formation of highly reactive metabolites. The second part of this work addresses the associations between exposure to BPA and its analogues with the alterations in miRNAs expression and the effects of single nucleotide polymorphisms (SNPs). Available scientific evidence shows that BPs can dysregulate the expression of several miRNAs, and in turn, these miRNAs could be considered as epigenetic biomarkers to prevent the development of a variety of BP-mediated diseases. Interestingly, genetic polymorphisms are able to modify the relationship of BPA exposure with the risk of adverse health effects, suggesting that interindividual genetic differences modulate the susceptibility to the effects of environmental contaminants.

Plasticizer contamination in the urine and hair of preschool children, airborne particles in kindergartens, and drinking water in Hong Kong

Common plasticizers and their alternatives are environmentally ubiquitous and have become a global problem. In this study, common plasticizers (phthalates and metabolites) and new alternatives [bisphenol analogs, t-butylphenyl diphenyl phosphate (BPDP), and bisphenol A bis(diphenyl phosphate) (BDP)] were quantified in urine and hair samples from children in Hong Kong, drinking water (tap water/bottled water) samples, and airborne particle samples from 17 kindergartens in Hong Kong. The results suggested that locally, children were exposed to various plasticizers and their alternatives. High concentrations of BPDP and BDP were present in urine, hair, tap water, bottled water, and air particulate samples. The geometric mean (GM) concentrations of phthalate metabolites in urine samples (126-2140 ng/L, detection frequencies < 81%) were lower than those detected in Japanese and German children in previous studies. However, a comparison of the estimated daily intake values for phthalates in tap water [median: 10.7-115 ng/kg body weight bw/day] and air particles (median: 1.23-7.39 ng/kg bw/day) with the corresponding reference doses indicated no risk. Bisphenol analogs were detected in 15-64% of urine samples at GM concentrations of 5.26-98.1 ng/L, in 7-74% of hair samples at GM concentrations of 57.5-2390 pg/g, in 59-100% of kindergarten air samples at GM concentrations of 43.1-222 pg/m³, and in 33-100% of tap water samples at GM concentrations of 0.90-3.70 ng/L. A significant correlation was detected between the concentrations of bisphenol F in hair and urine samples (r = 0.489, p < .05). The estimated daily urinary excretion values of bisphenol analogs suggest that exposure among children via tap water intake and airborne particle inhalation in kindergartens cannot be ignored in Hong Kong.

Effects of a Plastic-Free Lifestyle on Urinary Bisphenol A Levels in School-Aged Children of Southern Italy: A Pilot Study

Bisphenol A (BPA) is an endocrine disruptor (ED) frequently used in food packaging. BPA is used as a monomer in the manufacture of some food packaging. This study aimed to evaluate the urinary BPA concentration in an Italian pediatric cohort, testing the levels of this ED over a period of 6 months, evaluating the effects of a diet regimen with a reduction of Plastic Food Packaging (PFP). One hundred thirty Italian children were enrolled and divided into two groups "School Canteen" and "No School Canteen." The first group consumed one meal at school using a plastic-free service for 5 days/weeks, while the other group did not modify their normal meal-time habits. The BPA levels were tested in urine samples at three time points: T0, is the time before the application of the plastic-free regimen diet; T3, 3 months later; and T6, 6 months later. A reduction of urine BPA levels was detected in the "School Canteen" group. In particular, the reduction was significant analyzing both the intra (among the three testing times) group and inter (between "School Canteen" and "No School Canteen") group variability. Our results show the effects of a diet regimen with a reduction of PFP, demonstrating a connection between urinary BPA levels and food packaging.

Emerging paradigms in treating cerebral infarction with nanotheranostics: opportunities and clinical challenges

Interest is increasing in the use of nanotheranostics as diagnosis, imaging and therapeutic tools for stroke management, but movement to the clinic remains challenging.

Oral Bisphenol A Worsens Liver Immune-Metabolic and Mitochondrial Dysfunction Induced by High-Fat Diet in Adult Mice: Cross-Talk between Oxidative Stress and Inflammasome Pathway

Lines of evidence have shown the embryogenic and transgenerational impact of bisphenol A (BPA), an endocrine-disrupting chemical, on immune-metabolic alterations, inflammation, and oxidative stress, while BPA toxic effects in adult obese mice are still overlooked. Here, we evaluate BPA’s worsening effect on several hepatic maladaptive processes associated to high-fat diet (HFD)-induced obesity in mice. After 12 weeks HFD feeding, C57Bl/6J male mice were exposed daily to BPA (50 μg/kg per os) along with HFD for 3 weeks. Glucose tolerance and lipid metabolism were examined in serum and/or liver. Hepatic oxidative damage (reactive oxygen species, malondialdehyde, antioxidant enzymes), and mitochondrial respiratory capacity were evaluated. Moreover, liver damage progression and inflammatory/immune response were determined by histological and molecular analysis. BPA amplified HFD-induced alteration of key factors involved in glucose and lipid metabolism, liver triglycerides accumulation, and worsened mitochondrial dysfunction by increasing oxidative stress and reducing antioxidant defense. The exacerbation by BPA of hepatic immune-metabolic dysfunction induced by HFD was shown by increased toll-like receptor-4 and its downstream pathways (i.e., NF-kB and NLRP3 inflammasome) amplifying inflammatory cytokine transcription and promoting fibrosis progression. This study evidences that BPA exposure represents an additional risk factor for the progression of fatty liver diseases strictly related to the cross-talk between oxidative stress and immune-metabolic impairment due to obesity.