Bisphenol A substitutes and obesity: a review of the epidemiology and pathophysiology.

The prevalence of obesity, a condition associated with increased health risks, has risen significantly over the past several decades. Although obesity develops from energy imbalance, its etiology involves a multitude of other factors. One of these factors are endocrine disruptors, or "obesogens", when in reference to obesity. Bisphenol A (BPA), a known endocrine disruptor used in plastic materials, has recently been described as an environmental obesogen. Although BPA-free products are becoming more common now than in the past, concerns still remain about the obesogenic properties of the compounds that replace it, namely Bisphenol S (BPS), Bisphenol F (BPF), and Bisphenol AF (BPAF). The purpose of this review is to investigate the relationship between BPA substitutes and obesity. Literature on the relationship between BPA substitutes and obesity was identified through PubMed and Google Scholar, utilizing the search terms "BPA substitutes", "bisphenol analogues", "BPS", "BPF", "BPAF", "obesity", "obesogens", "adipogenesis", "PPARγ", and "adipocyte differentiation". Various population-based studies were assessed to gain a better understanding of the epidemiology, which revealed evidence that BPA substitutes may act as obesogens at the pathophysiological level. Additional studies were assessed to explore the potential mechanisms by which these compounds act as obesogens. For BPS, these mechanisms include Peroxisome proliferator-activated receptor gamma (PPARγ) activation, potentiation of high-fat diet induced weight-gain, and stimulation of adipocyte hypertrophy and adipose depot composition. For BPF and BPAF, the evidence is more inconclusive. Given the current understanding of these compounds, there is sufficient concern about exposures. Thus, further research needs to be conducted on the relationship of BPA substitutes to obesity to inform on the potential public health measures that can be implemented to minimize exposures.

Association of Preterm Birth and Exposure to Endocrine Disrupting Chemicals.

Several studies in recent years have shown that endocrine disrupting chemicals (EDCs) can exert deleterious effects within several systems of the human body, such as the immune, neurological, and reproductive systems, among others. This review aims to summarize the investigations into the effect of EDC exposure on reproductive systems, namely preterm birth (PTB), and the efforts that international organizations have made to curb the harmful results of EDC exposure. To gather information, PubMed was initially searched for relevant articles containing the following terms: endocrine disrupting chemicals; preterm birth. PubMed was subsequently used to identify articles discussing the association between preterm birth and specific EDC exposures (BPA; phthalates; organochlorine pesticides; organophosphate pesticides; lead; PBDE; preterm birth). Both searches, limited to articles published within the past 20 years, identified several publications that have examined the association between various EDCs and PTB. While the findings of the studies differed, collectively they revealed sufficient evidence of a potential association between EDC exposure and risk of PTB. Thus, international organizations such as the United Nations Environmental Programme (UNEP) and World Health Organization (WHO) should continue to limit EDC exposure across the globe and monitor levels among individuals of reproductive age.

Endocrine disrupting chemicals (EDCs) and sex steroid receptors.

Sex-steroid receptors (SSRs) are essential mediators of estrogen, progestin, and androgen signaling that are critical in vast aspects of human development and multi-organ homeostasis. Dysregulation of SSR function has been implicated in numerous pathologies including cancers, obesity, Type II diabetes mellitus, neuroendocrine disorders, cardiovascular disease, hyperlipidemia, male and female infertility, and other reproductive disorders. Endocrine disrupting chemicals (EDCs) modulate SSR function in a wide variety of cell and tissues. There exists strong experimental, clinical, and epidemiological evidence that engagement of EDCs with SSRs may disrupt endogenous hormone signaling leading to physiological abnormalities that may manifest in disease. In this chapter, we discuss the molecular mechanisms by which EDCs interact with estrogen, progestin, and androgen receptors and alter SSR functions in target cells. In addition, the pathological consequences of disruption of SSR action in reproductive and other organs by EDCs is described with an emphasis on underlying mechanisms of receptors dysfunction.

Endocrine Disrupting Chemicals, Hormone Receptors, and Acne Vulgaris: A Connecting Hypothesis.

The relationship between endocrine disrupting chemicals (EDCs) and the pathogenesis of acne vulgaris has yet to be explored in the literature. Acne vulgaris is a chronic inflammatory skin disease of the pilosebaceous unit. The pathogenesis of acne involves several hormonal pathways, including androgens, insulin-like growth factor 1(IGF-1), estrogens, and corticosteroids. EDCs influence these pathways primarily through two mechanisms: altering endogenous hormone levels and interfering with hormone receptor function. This review article describes the mechanistic links between EDCs and the development of acne lesions. Highlighted is the contributory role of androgen receptor ligands, such as bisphenol A (BPA) and mono-2-ethylhexyl Phthalate (MEHP), via upregulation of lipogenic genes and resultant exacerbation of cholesterol synthesis. Additionally discussed is the protective role of phytoestrogen EDCs in counteracting androgen-induced sebocyte maturation through attenuation of PPARy transcriptional activity (i.e., resveratrol) and restoration of estrogen-regulated TGF-B expression in skin cells (i.e., genistein). Examination of the relationship between EDCs and acne vulgaris may inform adjunctive avenues of treatment such as limiting environmental exposures, and increasing low-glycemic, plant-rich foods in the diet. With a better understanding of the cumulative role that EDCs play in acne, clinicians can be better equipped to treat and ultimately improve the lives of their patients.