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Environmental Chemicals and Risk of Uterine Leiomyomata
Published in John C. Petrozza, Uterine Fibroids, 2020
BPA exposure has been associated with an increased risk of UL in most [83–85], but not all [47], previous epidemiologic studies. In a 2013 case-control study of Chinese women, mean (+/−SD) urinary BPA concentrations were significantly higher among cases (17.6 +/− 2.3 ng/mL) than controls (11.8 +/− 1.7 ng/mL) [83]. In another 2013 study of Chinese women (unknown study design and method of UL classification) [85], urinary BPA was non-significantly higher in cases (13.9 +/− 12.7 ng/mL) than controls (8.50 +/− 12.2 ng/mL). Another phenol, nonylphenol, was significantly higher in cases than controls [85], a finding that has since been replicated [86]. In a 2011 study of Chinese women, cases were divided into three groups (mild, moderate and severe) according to tumor size. Controls were shown to be free of UL based on transvaginal ultrasound examination. Higher serum BPA levels were found for “moderate/severe UL cases” relative to “mild UL cases/controls.” [84] However, blood is not an optimal matrix for assessing exposure to nonpersistent chemicals such as BPA because of potential for external contamination [50]. Also, serum BPA levels are approximately an order of magnitude lower than those in urine, with serum levels for many people below the limit of detection [87].
Work in progress
Published in Richard Lawson, Jonathon Porritt, Bills of Health, 2018
Richard Lawson, Jonathon Porritt
nonylphenol, a widespread chemical used as an antioxidant in plastics, and in detergents, paints, lubricating oils, toiletries - and as a contraceptive spermicide. About 20 000 tonnes are produced in the UK alone. It persists in the environment and concentrates in animal tissues.
Estrogens, Xenoestrogens, and the Development of Neoplasms
Published in Rajesh K. Naz, Endocrine Disruptors, 2004
No qualitative differences could be found when comparing animal assays and MCF7-based assays. That is, the estrogenic properties of compounds characterized using animal bioassays was also ascertained by measuring cell proliferation or gene induction in cell culture bioassays. From a pharmacokinetic perspective, these in vitro assays measure estrogenicity at the target cellular level under conditions where estrogen concentrations are mostly constant, much like the ones achieved when animals are treated with estrogen-filled silastic implants. This approach is more relevant to chronic environmental exposure than that of measuring acute effects after a single dose. Estrogen-target cells in culture have a limited metabolic repertory. For example, it is likely that the estrogenic activity of nonylphenol diethoxylate, a compound that does not bind to estrogen receptor, results from metabolism to the free phenol.31 Similarly, methoxychlor was believed to be inactive until metabolized to free phenols, presumably in the liver. Methoxychlor tested positive when assayed by the E-SCREEN test. Therefore, even though the putative proestrogens tested so far were estrogenic when assayed by the E-SCREEN test, an added step in the quest for identifying all xenoestrogens may include their metabolic activation by liver microsome extracts prior to their testing by the E-SCREEN assay.
The antagonistic effect of bisphenol A and nonylphenol on liver and kidney injury in rats
Published in Immunopharmacology and Immunotoxicology, 2021
Endocrine-disrupting compounds (EDCs) are widely distributed in the surrounding environment and in food, which can harm public health as contaminants. Exposure to EDCs may disturb normal endocrine function and finally lead to various developmental and reproductive impairments [1]. Bisphenol A [2,2-bis(4-hydroxyphenyl) propane, BPA] is widely used in food packaging materials, food containers, and dental sealants [2]. However, BPA could mimic the effect of endogenous estrogen as it has an estrogen-like structure and even disrupts the homeostasis of the endocrine systems [3,4]. It has been shown in an epidemiological investigation on the occupational exposure of workers that an increase in cumulative BPA exposure is associated with a high risk of male sexual dysfunction [5]. BPA had adverse effects on the reproductive system and exerted a carcinogenic effect in mice at the doses of 25 ng/kg/day and 1 μg/kg/day, respectively [6]. Nonylphenol (NP) is extensively used in daily detergents, plastic protective agents, pesticide emulsifiers, oil-soluble phenolic resin, and preservatives [5]. NP is a xenoestrogenic compound bound to estrogen receptors and competes for natural hormones [7], which can upset the functions of the reproductive, endocrine, immune, and nervous systems [8,9]. Moreover, NP can result in a reduction in testis and ovary weights and an irregularity in the estrous cycle [10–12]. In addition, BPA and NP can be leached from plastic wastes and enter rivers in the form of landfill leachate [13]. Therefore, BPA and NP are typical endocrine disruptors and persistent organic pollutants.
The adverse effects of chronic low-dose exposure to nonylphenol on type 2 diabetes mellitus in high sucrose-high fat diet-treated rats
Published in Islets, 2018
Jie Yu, Jin Yang, Ya Luo, Yang Mengxue, Wenmei Li, Yu Yang, Liting He, Jie Xu
Nonylphenol (NP) is a well-known EDC with weak estrogenic activity, which is widely used in cleaning and industrial processes, and residential and commercial cleaning products.7 Such wide application and use makes NP frequently detected in the environment. Our prior study testified that the concentration for NP measured in Xiangjiang River in Zunyi city of China ranged from 0.174 to 3.411 μg/L with a mean value of 1.73 μg/L, maintaining at a higher level compare to the developed countries and other civil cities8. Exposure to NP is nearly ubiquitous. NP was detectable in human blood serum,9 urine,10 adipose tissue,11 liver and brain.12 There is strong evidence demonstrating greater risk for NP with increasing risk of endocrine,13 reproductive,14 and immune15 as well as nervous16 system diseases in animals and humans. However, the potential impacts of chronic low-dose exposure to NP on the glucose metabolism and pancreatic endocrine function have scarcely been reported. Therefore, in this study, we employed a developmental NP exposure paradigm in rats to test the hypothesis that chronic low-dose exposure to NP caused a predisposition to T2DM. Furthermore, any additive effect of a high-sucrose/high-fat diet on the toxic effects induced by NP was also evaluated.
Ecotoxicological effects of bisphenol A and nonylphenol on the freshwater cladocerans Ceriodaphnia silvestrii and Daphnia similis
Published in Drug and Chemical Toxicology, 2018
Mariângela Spadoto, Ana Paula Erbetta Sueitt, Carlos Alexandre Galinaro, Tiago da Silva Pinto, Caroline Moço Erba Pompei, Clarice Maria Rispoli Botta, Eny Maria Vieira
Nonylphenol (NP) is another EDC present in some household and industrial products, such as detergents, paints, pesticides, and cosmetics (Naylor et al. 1992, Nimrod and Benson 1996, Soares et al. 2008, Careghini et al. 2015). Studies have reported that concentrations of 25 μg L−1 (Comber et al. 1993) and 42 μg L−1 (Baldwin et al. 1997) of NP are enough to change the rates of testosterone elimination, causing metabolic androgenization in Daphnia magna. It was also observed that Brachydanio rerio was affected by the presence of 171 µg g−1 of NP in the diet, showing higher levels of vitellogenin and lower levels of cytochrome P450 activity (Correa-Reyes et al. 2007).