Triclosan elevates estradiol levels in serum and tissues of cycling and peri-implantation female mice

Conceptualizing the Role of the Microbiome as a Mediator and Modifier in Environmental Health Studies: A Scoping Review of Studies of Triclosan and the Microbiome

PURPOSE OF REVIEW

Triclosan is an endocrine-disrupting antimicrobial additive that is suspected of contributing to antibiotic resistance and altering the microbiome. In this scoping review, we summarize what is known about the association between triclosan exposure and the microbiome using evidence from in vivo and epidemiologic studies.

RECENT FINDINGS

Our review includes 11 rodent studies, seven fish studies, and five human studies. Evidence from animal studies suggests that triclosan decreases the diversity of the microbiome, although only one epidemiologic study agreed. Most studies suggest that triclosan alters the microbial community beta diversity, but disagree on which taxa contributed to compositional differences. Taxa in the Bacteroidetes, Firmicutes, and Proteobacteria may be more influenced by triclosan than those in other phyla. Studies on triclosan and the microbiome were scarce and were inconclusive as to the effects of triclosan on the microbiome. Additional research is needed to clarify windows of heightened susceptibility of the microbiome to triclosan. We recommend guidelines for future microbiome research in environmental health to increase comparability across studies.

Triclosan induces earlier puberty onset in female mice via interfering with L-type calcium channels and activating Pik3cd

Triclosan (TCS) is a broad-spectrum antibacterial chemical widely presents in people's daily lives. Epidemiological studies have revealed that TCS exposure may affect female puberty development. However, the developmental toxicity after low-dose TCS continuous exposure remains to be confirmed. In our study, 8-week-old ICR female mice were continuously exposed to TCS (30, 300, 3000 μg/kg/day) or vehicle (corn oil) from 2 weeks before mating to postnatal day 21 (PND 21) of F1 female mice, while F1 female mice were treated with TCS intragastric administration from PND 22 until PND 56. Vaginal opening (VO) observation, hypothalamic-pituitary-ovarian (HPO) axis related hormones and genes detection, and ovarian transcriptome analysis were carried out to investigate the effects of TCS exposure on puberty onset. Meanwhile, human granulosa-like tumor cell lines (KGN cells) were exposed to TCS to further explore the biological mechanism of the ovary in vitro. The results showed that long-term exposure to low-dose TCS led to approximately a 3-day earlier puberty onset in F1 female mice. Moreover, TCS up-regulated the secretion of estradiol (E2) and the expression of ovarian steroidogenesis genes. Notably, ovarian transcriptomes analysis as well as bidirectional validation in KGN cells suggested that L-type calcium channels and Pik3cd were involved in TCS-induced up-regulation of ovarian-related hormones and genes. In conclusion, our study demonstrated that TCS interfered with L-type calcium channels and activated Pik3cd to up-regulate the expression of ovarian steroidogenesis and related genes, thereby inducing the earlier puberty onset in F1 female mice.

Association of triclosan and human infertility: A systematic review

Triclosan (TCS) is a chemical compound, which has antibacterial, antiviral, and antifungal properties. TCS is considered an endocrine-disrupting chemical, which has been shown to interfere with developmental, behavioral, and reproductive outcomes in biological models and cell cultures. However, implications about exposure to TCS and human infertility are rare. Thus, the main of this review is summarize the available evidence of the association between triclosan exposure on human infertility. For this, systematic review was conducted following the recommendations established in Report of Systematic Reviews and Meta-Analyses guide (PRISMA). Initially, an electronic search in MEDLINE (via PubMed) and Science direct was performed. The methodological quality of the included studies was verified through the Joanna Briggs Institute (JBI) checklists. All selection and data extraction processes were carried out independently by two reviewers. The evidence was organized and presented using tables and narrative synthesis. There is lacking evidence about the association between triclosan and human infertility. Overall, no association between triclosan and infertility was found. However, semen quality and ovarian reserve are susceptible to triclosan exposure. Thus, future studies are still needed to better elucidate the associations between triclosan and infertility outcomes.

Comprehensive insight into triclosan-from widespread occurrence to health outcomes

Humans are exposed to the variety of emerging environmental pollutant in everyday life. The special concern is paid to endocrine disrupting chemicals especially to triclosan which could interfere with normal hormonal functions. Triclosan could be found in numerous commercial products such as mouthwashes, toothpastes and disinfectants due to its antibacterial and antifungal effects. Considering the excessive use and disposal, wastewaters are recognized as the main source of triclosan in the aquatic environment. As a result of the incomplete removal, triclosan residues reach surface water and even groundwater. Triclosan has potential to accumulate in sediment and aquatic organisms. Therefore, the detectable concentrations of triclosan in various environmental and biological matrices emerged concerns about the potential toxicity. Triclosan impairs thyroid homeostasis and could be associated with neurodevelopment impairment, metabolic disorders, cardiotoxicity and the increased cancer risk. The growing resistance of the vast groups of bacteria, the evidenced toxicity on different aquatic organisms, its adverse health effects observed in vitro, in vivo as well as the available epidemiological studies suggest that further efforts to monitor triclosan toxicity at environmental levels are necessary. The safety precaution measures and full commitment to proper legislation in compliance with the environmental protection are needed in order to obtain triclosan good ecological status. This paper is an overview of the possible negative triclosan effects on human health. Sources of exposure to triclosan, methods and levels of detection in aquatic environment are also discussed.

The effects of endocrine-disrupting chemicals on ovarian- and ovulation-related fertility outcomes

Exposure to endocrine-disrupting chemicals (EDCs) is unavoidable, which represents a public health concern given the ability of EDCs to target the ovary. However, there is a large gap in the knowledge about the impact of EDCs on ovarian function, including the process of ovulation. Defects in ovulation are the leading cause of infertility in women, and EDC exposures are contributing to the prevalence of infertility. Thus, investigating the effects of EDCs on the ovary and ovulation is an emerging area for research and is the focus of this review. The effects of EDCs on gametogenesis, uterine function, embryonic development, and other aspects of fertility are not addressed to focus on ovarian- and ovulation-related fertility issues. Herein, findings from epidemiological and basic science studies are summarized for several EDCs, including phthalates, bisphenols, per- and poly-fluoroalkyl substances, flame retardants, parabens, and triclosan. Epidemiological literature suggests that exposure is associated with impaired fecundity and in vitro fertilization outcomes (decreased egg yield, pregnancies, and births), while basic science literature reports altered ovarian follicle and corpora lutea numbers, altered hormone levels, and impaired ovulatory processes. Future directions include identification of the mechanisms by which EDCs disrupt ovulation leading to infertility, especially in women.

Involvement of sirtuins (Sirt1 and Sirt3) and aryl hydrocarbon receptor (AhR) in the effects of triclosan (TCS) on production of neurosteroids in primary mouse cortical neurons cultures

Epidemiological studies have shown the presence of triclosan (TCS) in the brain due to its widespread use as an antibacterial ingredient. One of the confirmed mechanisms of its action is the interaction with the aryl hydrocarbon receptor (AhR). In nerve cells, sirtuins (Sirt1 and Sirt3) act as cellular sensors detecting energy availability and modulate metabolic processes. Moreover, it has been found that Sirt1 inhibits the activation of estrogen receptors, regulates the androgen receptor, and may interact with the AhR receptor. It is also known that Sirt3 stimulates the production of estradiol (E₂) via the estradiol receptor β (Erβ). Therefore, the aim of the present study was to evaluate the effect of TCS alone or in combination with synthetic flavonoids on the production of neurosteroids such as progesterone (P₄), testosterone (T), and E₂ in primary neural cortical neurons in vitro. The contribution of Sirt1 and Sirt3 as well as AhR to these TCS-induced effects was investigated as well. The results of the experiments showed that both short and long exposure of neurons to TCS increased the expression of the Sirt1 and Sirt3 proteins in response to AhR stimulation. After an initial increase in the production of all tested neurosteroids, TCS acting for a longer time lowered their levels in the cells. This suggests that TCS activating AhR as well as Sirt1 and Sirt3 in short time intervals stimulates the levels of P₄, T, and E₂ in neurons, and then the amount of neurosteroids decreases despite the activation of AhR and the increase in the expression of the Sirt1 and Sirt3 proteins. The use of both the AhR agonist and antagonist prevented changes in the expression of Sirt1, Sirt3, and AhR and the production of P₄, T, and E₂, which confirmed that this receptor is a key in the mechanism of the TCS action.

Quantification of Urinary Sex Steroids in the Big Brown Bat (Eptesicus fuscus)

AbstractBats (order Chiroptera) are the second largest group of mammals, diverging ~52.5 million years ago. Many species exhibit an unusual reproductive cycle and extreme longevity without reproductive senescence, yet steroid profiles exist for few bats. Big brown bats (Eptesicus fuscus) are temperate insectivores found throughout North America. They mate promiscuously in fall, store sperm during winter hibernation, and have delayed ovulation and fertilization in spring. Here, we report the first urinary steroid profile in bats by quantifying 17β-estradiol (E₂) in captive male and female E. fuscus across their reproductive cycle. Male bats had higher urinary E₂ levels than females, and adults had higher levels than yearlings following creatinine adjustment for hydration. In nonpregnant females, several seasonal differences in creatinine-adjusted and unadjusted urinary E₂ levels were observed. Urinary E₂ was higher in males than females in winter for both conditions and in autumn for creatinine-adjusted levels. We quantified progesterone (P₄) in a subset of females. In nonpregnant females, urinary P₄ was constant across seasons except for unadjusted levels, which were highest in the summer. In pregnant females, urinary E₂ and P₄ levels peaked beginning ~20 d before parturition, with both steroids returning to baseline in the following weeks. Knowing how urinary steroid levels fluctuate with age and sex and across the annual season is key to understanding reproductive cycling in bats. Our research furthers the potential for bats as a model for medical reproductive research. Moreover, it complements previous studies on the potential role of steroids in primer pheromonal effects in bats.

The triclosan-induced shift from aerobic to anaerobic metabolism link to increased steroidogenesis in human ovarian granulosa cells

Triclosan (TCS) is an endocrine-disrupting chemical (EDC), which is used ubiquitously as an antimicrobial ingredient in healthcare products and causes contamination in the environment such as air, water, and biosolid-amended soil. Exposure to TCS may increase the risk of reproduction diseases and health issues. Several groups, including ours, have proved that TCS increased the biosynthesis of steroid hormones in different types of steroidogenic cells. However, the precise mechanism of toxic action of TCS on increased steroidogenesis at a molecular level remains to be elucidated. In this study, we try to address the mode of action that TCS affects energy metabolism with increased steroidogenesis. We evaluated the adverse effects of TCS on energy metabolism and steroidogenesis in human ovarian granulosa cells. The goal is to elucidate how increased steroidogenesis can occur with a shortage of adenosine triphosphate (ATP) whereas mitochondria-based energy metabolism is impaired. Our results demonstrated TCS increased estradiol and progesterone levels with upregulated steroidogenesis gene expression at concentrations ranging from 0 to 10 µM. Besides, glucose consumption, lactate level, and pyruvate kinase transcription were increased. Interestingly, the lactate level was attenuated with increased steroidogenesis, suggesting that pyruvate fate was shifted away from the formation of lactate towards steroidogenesis. Our study is gathering evidence suggesting a mode of action that TCS changes energy metabolism by predominating glucose flow towards the biosynthesis of steroid hormones. To the best of our knowledge, this is the first report that TCS presents such toxic action in disrupting hormone homeostasis.

Associations among urinary triclosan and bisphenol A concentrations and serum sex steroid hormone measures in the Canadian and U.S. Populations

Exposure to triclosan, an antimicrobial agent, and bisphenol A (BPA), the monomer of polycarbonate plastics, is widespread. Endocrine-disrupting impacts of these chemicals have been demonstrated in in vitro studies, rodent toxicology studies, and some human observational studies. Here we compared urinary concentrations of triclosan and BPA in the Canadian and U.S. populations using nationally-representative data from the 2012-2015 Canadian Health Measures Survey (CHMS) and the 2013-2016 National Health and Nutrition Examination Survey (NHANES). We then examined the cross-sectional associations of urinary triclosan or BPA with serum sex steroid hormones, including estradiol (E2), progesterone (P4), and testosterone (T), using multivariable regression. We observed differences in creatinine-standardized chemical concentrations between countries; urinary triclosan was higher in Canadian females aged 12-19 years, while BPA was higher in U.S. females aged 20-49 years. We also found significant associations among urinary chemicals and serum E2 and T, but not P4. Increasing triclosan was associated with higher levels of E2 in 6-11-year-old girls, but with lower levels of E2 and T in adolescent boys aged 12-19 years. Increasing BPA was associated with lower levels of E2 in 6-11-year-old boys and in adolescents aged 12-19 years of either sex. We observed a U-shaped association between urinary triclosan and E2 in male adults aged 50-79 years; no associations between BPA and hormones were detected in adults. These results, in accordance with the in vitro and animal literature, suggest that triclosan and BPA exposures may be cross-sectionally associated with altered reproductive hormone levels, especially in children and adolescents. Further research and prospective studies are necessary to elucidate country-specific differences in chemical exposures and the potential public health significance of these findings.

Seasonal transfer and quantification of urinary estradiol in the big brown bat (Eptesicus fuscus)

Growing evidence shows that sex steroids not only act within the individual whose glands produce them; they can also act on proximate conspecifics. Previous studies show that exogenous 17β-estradiol (E₂) can be absorbed both nasally and percutaneously, arriving in blood, neural, reproductive, and peripheral tissues. When male bats were injected with radiolabeled E₂ (³H-E₂) and housed with females during the mating season, radioactivity was reliably measured in the females' tissues. The present study was designed to compare E₂ transfer from male to female bats at three time points in the annual reproductive cycle: spring (ovulation and fertilization), summer (maternal season), and autumn (mating season). Pairs of mature female bats were housed with a mature ³H-E₂-treated male (50 μCi). Following 48 h of communal housing, radioactivity was measured in the tissues of female bats. Higher levels of radioactivity were present in the uterus and other tissues during the spring and autumn seasons compared to the summer season. We also measured natural levels of bioactive, unconjugated E₂ in the urine of male bats using enzyme immunoassays, and found that it was present in all three seasons but at lower levels during the summer. Male-excreted E₂ could transfer to females within the close confines of a roost, potentially influencing their reproductive physiology and behavior. These results suggest increased E₂ transfer coincides with female reproduction, with urine as a likely vector. We suggest that sex steroid transfer among interacting individuals may explain several mammalian phenomena historically viewed as "pheromonal".

Maternal exposure to triclosan causes fetal development restriction, deregulation of the oestrous cycle, and alters uterine tissue in rat offspring

The aim of the present study was to evaluate the effects of maternal exposure to triclosan (TCS) during pregnancy and lactation on the uterine morphology of rat offspring. For this, 32 Wistar rat dams were distributed into four dose groups (eight mothers per group), and gavage daily, throughout pregnancy and lactation, as follows: Group I-control (GI): corn oil; Group II (GII): TCS diluted in corn oil at a dose of 75 mg/kg/d; Group III (GIII): TCS diluted in corn oil at a dose of 150 mg/kg/d; Group IV (GIV): TCS diluted in corn oil at a dose of 300 mg/kg/d. A female pup of each mother was selected, and at 90 days the pups were euthanized for weighing and collection of the uterus for histomorphometric analysis. The results showed that the mean litter weight was minor in all the groups treated with TCS, when compared with control. The levels thyroid hormones thyroxine (T4) and triiodothyronine (T3) in TCS mother rats were reduced; however the levels of thyroid stimulating hormone (TSH) were increases. The offspring of all groups exposed to TCS presented deregulation of the estrous cycle, compared with control. Analysis of the uterine histological structure demonstrated that all layers of the uterus were affected by the administration of TCS, and the morphometric analysis showed increased uterine layers thickness in the treated groups. We concluded that maternal exposure to TCS during pregnancy and lactation causes intrauterine development restriction, deregulation of the oestrous cycle, and alters uterine tissue in rat offspring.

Triclosan exposure and ovarian reserve

The objective of the current analysis was to investigate the associations of urinary triclosan concentrations with parameters of ovarian reserve. Five hundred eleven female aged 25-39 years who attended the infertility clinic for diagnostic purposes were recruited. Urinary concentrations of triclosan were measured by a validated gas chromatograohy ion-tap mass spectrometry method. Parameters of ovarian reserve were: antral follicle count (AFC), anti-Müllerian hormone (AMH), follicle-stimulating hormone (FSH) and estradiol (E₂) levels. Urinary concentrations of triclosan decrease antral follicle count. There were no statistically significant associations between other parameters of ovarian reserve (estradiol, FSH and AMH levels) and triclosan concentrations. Triclosan exposure may negatively affect antral follicle count, a marker of ovarian reserve. As the data on triclosan exposure and ovarian reserve are scarce additional study is needed to confirm the results.

Thyroid-disrupting chemicals and brain development: an update

This review covers recent findings on the main categories of thyroid hormone-disrupting chemicals and their effects on brain development. We draw mostly on epidemiological and experimental data published in the last decade. For each chemical class considered, we deal with not only the thyroid hormone-disrupting effects but also briefly mention the main mechanisms by which the same chemicals could modify estrogen and/or androgen signalling, thereby exacerbating adverse effects on endocrine-dependent developmental programmes. Further, we emphasize recent data showing how maternal thyroid hormone signalling during early pregnancy affects not only offspring IQ, but also neurodevelopmental disease risk. These recent findings add to established knowledge on the crucial importance of iodine and thyroid hormone for optimal brain development. We propose that prenatal exposure to mixtures of thyroid hormone-disrupting chemicals provides a plausible biological mechanism contributing to current increases in the incidence of neurodevelopmental disease and IQ loss.

Evaluation of subchronic exposure to triclosan on hepatorenal and reproductive toxicities in prepubertal male rats

Triclosan (TCS), a common antimicrobial ingredient, is present in many consumer products, including soaps, shampoos, and toothpaste. Owing to its widespread use, potential adverse effects on animals and humans may arise from lifetime exposure, but data on chronic prepubertal exposure of TCS are still lacking. The aim of the present study was to investigate the influence of subchronic TCS exposure (0.25, 25, 250, or 750 mg/kg) on target organ toxicity in prepubertal male rats. After daily administration of TCS to rats by oral gavage for 60 d, a significant reduction in body weight and relative weights of liver, kidneys, testes, and adrenal glands was observed in the 750-mg/kg (high dose) group. Serum alanine aminotransferase and aspartate aminotransferase activities as well as levels of blood urea nitrogen, and creatinine were significantly increased at 750 mg/kg TCS. Further, TCS (750 mg/kg) elevated the protein expressions of hepatic CYP2B1, RXR/PPAR, and levels of malondialdehyde. High-dose TCS exposure induced histological changes as evidenced by reduction of Bowman's space, occlusion of the tubular lumen, and degeneration of tubular epithelial cells in the kidney. Tubular necrosis was confirmed as evidenced by a rise in expression of high mobility group box 1 renal protein. Daily sperm production was significantly diminished by high doses of TCS with marked inhibition of androgen receptor protein expression. Our results indicated that subchronic exposure to excessively high concentrations of 750 mg/kg TCS induced hepatorenal and reproductive toxicities in prepubertal male rats; however, the biological relevance of these findings is questionable as these drug levels are not encountered in the environment.

A mixture of five endocrine-disrupting chemicals modulates concentrations of bisphenol A and estradiol in mice

Most people in developed countries are exposed to multiple endocrine-disrupting synthetic chemicals. We previously showed that a single dose of triclosan, tetrabromobisphenol A (TBBPA), butyl paraben, propyl paraben, or di(2-ethylhexyl) phthalate elevated concentrations of bisphenol A (BPA) in mice. Here we investigated whether concurrent exposure to lower doses of these five chemicals could modulate concentrations of bisphenol A (BPA) or the natural estrogen, 17β-estradiol (E2). CF1 mice were injected subcutaneously with 0.1 or 0.5 mg of one chemical, or a 0.5 mg mixture containing 0.1 mg of each of all five chemicals, then given dietary 50 μg kg^-114C-BPA. The mixture elevated ¹⁴C-BPA concentrations in the lungs, muscle, uterus, ovaries, kidney, and blood serum of female mice. When administered alone, triclosan and TBBPA elevated ¹⁴C-BPA concentrations in the uterus, ovaries, and blood serum. In another experiment, CF1 mice were injected subcutaneously with the 0.5 mg mixture containing 0.1 mg of all five chemicals, then E2 was measured in urine 2-12 h later. The mixture elevated E2 at 8 h after injection in female mice. No treatments significantly altered concentrations of ¹⁴C-BPA or E2 in male mice. These data show that these endocrine-disrupting chemicals interact in vivo, magnifying one another's effects, consistent with inhibition of enzymes that are critical for estrogen metabolism. These findings highlight the importance of considering exposure to multiple chemicals when assessing health outcomes and determining regulatory exposure limits.

Toxic effects of triclosan on a zebrafish (Danio rerio) liver cell line, ZFL

Triclosan (TCS, 5-chloro-2-(2,4-dichlorophenoxy) phenol) is an antimicrobial agent widely used in personal care products. It has been detected in surface water, soil, aquatic species, and even humans. In this study, we used zebrafish (Danio rerio) as a model to test the hypothesis that TCS exhibits toxic effects by interacting with thyroid hormone receptor β (TRβ) and aryl hydrocarbon receptor (AhR) and by inducing the transcription of thyroid hormone (TH)-associated genes and affecting phase I and phase II enzymes. The median lethal concentrations (LC₅₀) of TCS in zebrafish embryos/larvae and a zebrafish liver cell line (ZFL) were first determined. Hatched larvae were most sensitive to TCS exposure, with LC₅₀ values ranging from 1.26 to 1.46μM for 96h after hatching exposure. The major effect of TCS was delayed hatching which occurred from 1.13μM. The constructed GFP-zfTRβ fusion protein revealed the subcellular location of zfTRβ as the nucleus in both T3-induced and uninduced states, adding to the difficulty of studying TCS action on thyroid hormone receptors in ZFL cells. TCS had neither agonistic nor antagonistic effects on zfTRβLBD or AhR from the reporter gene systems. Ethoxyresorufin-o-deethylase (EROD) assay suggested that TCS is a weak P4501a (Cyp1a) agonist at 5μM and that it inhibits cytochrome Cyp1a activity induced by benzo(a)pyrene (BaP). In time course-based mRNA profiling in ZFL cells, 4-h exposure to TCS caused a significant (up to 37.5-fold) inhibition of Cyp1a at 2.5μM. An overall inhibition of liver phase I and II gene transcription at 4h exposure indicates the possible quick catabolism of TCS. Our findings suggest that TCS is not a TH mimic that affects TH-related gene expression. The impairment of Cyp1a mRNA expression could be due to stimulation by other stressors such as oxidative stress, warranting further investigation into the underlying mechanism in zebrafish.

Influence of Tetrabromobisphenol A, with or without Concurrent Triclosan, upon Bisphenol A and Estradiol Concentrations in Mice

BACKGROUND

Humans are commonly exposed to multiple environmental chemicals, including tetrabromobisphenol A (TBBPA; a flame retardant), triclosan (an antimicrobial agent), and bisphenol A (BPA; polycarbonate plastics). These chemicals are readily absorbed and may interact with each other.

OBJECTIVES

We sought to determine whether TBBPA, given alone or in combination with triclosan, can modulate the concentrations of BPA and 17β-estradiol (E2).

METHODS

Female and male CF-1 mice were each given a subcutaneous injection of 0-27mg TBBPA, with or without concurrent 0.33mg triclosan, followed by dietary administration of 50μg/kg body weight ¹⁴C-BPA. Radioactivity was measured in blood serum and tissues through liquid scintillation counting. In subsequent experiments, female and male CF-1 mice were each given a subcutaneous injection of 0 or 1mg TBBPA and E2 was measured in urine 2-12 h after injection.

RESULTS

Doses as low as 1mg TBBPA significantly elevated ¹⁴C-BPA concentrations in the uterus and ovaries of females; in the testes, epididymides, vesicular-coagulating glands, and preputial glands of males; and in blood serum, heart, lungs, and kidneys of both sexes; urinary E2 concentrations were also elevated. Lower doses of TBBPA or triclosan that had no effects on their own elevated ¹⁴C-BPA concentrations when the two substances were given concurrently.

CONCLUSION

These data indicate that TBBPA, triclosan, and BPA interact in vivo, consistent with evidence that TBBPA and triclosan inhibit enzymes that are critical for BPA and E2 metabolism. https://doi.org/10.1289/EHP1329.

The Florence Statement on Triclosan and Triclocarban

The Florence Statement on Triclosan and Triclocarban documents a consensus of more than 200 scientists and medical professionals on the hazards of and lack of demonstrated benefit from common uses of triclosan and triclocarban. These chemicals may be used in thousands of personal care and consumer products as well as in building materials. Based on extensive peer-reviewed research, this statement concludes that triclosan and triclocarban are environmentally persistent endocrine disruptors that bioaccumulate in and are toxic to aquatic and other organisms. Evidence of other hazards to humans and ecosystems from triclosan and triclocarban is presented along with recommendations intended to prevent future harm from triclosan, triclocarban, and antimicrobial substances with similar properties and effects. Because antimicrobials can have unintended adverse health and environmental impacts, they should only be used when they provide an evidence-based health benefit. Greater transparency is needed in product formulations, and before an antimicrobial is incorporated into a product, the long-term health and ecological impacts should be evaluated. https://doi.org/10.1289/EHP1788.

Urinary triclosan concentrations and diminished ovarian reserve among women undergoing treatment in a fertility clinic

OBJECTIVE

To investigate the association between urinary triclosan concentrations and antral follicle count (AFC), a well-accepted marker of ovarian reserve, among women from a fertility center.

DESIGN

Prospective cohort study.

SETTING

Hospital fertility center.

PATIENT(S)

A total of 109 women.

INTERVENTION(S)

Urinary triclosan concentrations quantified by online solid phase extraction-high performance liquid chromatography-isotope dilution tandem mass spectrometry.

MAIN OUTCOME MEASURE(S)

AFC through transvaginal ultrasonography on the third day of an unstimulated menstrual cycle or on the third day of a progesterone withdrawal bleed.

RESULT(S)

The geometric mean of the specific gravity-adjusted urinary triclosan concentrations for the 225 samples provided by the 109 women was 13.0 μg/L (95% confidence interval [CI], 8.9, 19.1). Women had median (with interquartile range) AFC of 13 (8, 18). The specific gravity-adjusted urinary triclosan concentrations were inversely associated with AFC (-4%; 95% CI, -7%, -1%). Women with triclosan concentrations above the median had lower AFC compared with those whose triclosan concentrations were equal to or below the median, with an adjusted difference of -3.2 (95% CI, -3.9, -1.6) among those with a body mass index <25 kg/m² and -1.8 (95% CI, -3.2, -0.3) among those who were <35 years old.

CONCLUSION(S)

Specific gravity-adjusted urinary triclosan concentrations were inversely associated with AFC in women seeking care at a fertility center. This association was modified by age and body mass index, with the younger and leaner women showing larger decreases in AFC.

Diethylhexyl phthalate magnifies deposition of 14 C-bisphenol A in reproductive tissues of mice

Endocrine disrupting chemicals are found in diverse common products, including cosmetics, food packaging, thermal receipt paper and plastic containers. This exposes most people in developed countries through ingestion, skin absorption and inhalation. Two ubiquitous endocrine disrupting chemicals, bisphenol A (BPA) and diethylhexyl phthalate (DEHP) can interact in disrupting blastocyst implantation in inseminated females. We hypothesized that DEHP might increase the bioavailability of BPA in tissues by competing for metabolic enzymes. We injected 0, 3, 9 or 18 mg DEHP into female and male mice and allowed 30 min for the chemical to circulate before giving them a food supplement containing 50 μg kg^{-1 14} C-BPA. Animals were dissected 1 h following ¹⁴ C-BPA administration and various tissue samples were acquired. Samples were solubilized and radioactivity was measured via liquid scintillation counting. In cycling females, DEHP increased BPA deposition in the muscle, uterus, ovaries and blood serum relative to controls. In peri-implantation females, DEHP increased deposition of BPA in the uterus, ovaries and serum relative to controls. In males, DEHP doses increased BPA deposition in serum and epididymis relative to controls. These results are consistent with the hypothesis that DEHP competes with BPA for conjugating enzymes such as UDP-glucuronosyltransferase, thereby magnifying the presence of BPA in estrogen-binding reproductive tissues. Copyright © 2017 John Wiley & Sons, Ltd.

Pulmonary apoptotic and oxidative damaging effects of Triclosan alone or in combination with Fluoride in Sprague Dawley rats

This study aimed to assess the potential apoptotic and oxidative damaging impacts of Triclosan (TCS) and Sodium Fluoride (NaF) administered separately or in combination, in rats for thirty days. For this purpose, forty immature female Sprague-Dawley rats were equally allocated into five groups. TCS group administered 185mg TCS/kg Bw dissolved in distilled water (DW), while its control group received only DW. NaF group was given 50mg/kg NaF in corn oil BW and its respective control had corn oil alone. The co-treated group was administered TCS and NaF. The oxidative stress biomarkers were evaluated in lung tissue homogenate and apoptotic proteins (BcL-2 and Caspase-3) expression were quantified in lung tissues. The results of TCS or NaF treated groups revealed a prominent depletion of super oxide dismutase (SOD), Catalase (CAT) and Glutathione (GSH) in lung tissue homogenate. On contrary, a marked increase in the tissue levels of Malondialdehyde (MDA) and lactate dehydrogenase (LDH) enzymatic assay levels. The co-exposed group evoked less severity in the oxidative stress biomarkers concentration than individually exposed groups. The apoptotic genes protein expression was significantly higher in TCS or NaF treated rats when compared to the control with intense to moderate immunolabeling of the bronchiolar lining epithelium and surrounding mononuclear inflammatory cells. On the contrary, no significant differences were detected in the expression of the investigated apoptotic biomarkers between the control and the combined exposed group. We concluded that the exposure to either TCS or NaF resulted in significant perturbations in lung tissue after short term oral administration at variable instances but the co-exposure resulted in less severe toxicological consequences.

Concurrent administration of diethylhexyl phthalate reduces the threshold dose at which bisphenol A disrupts blastocyst implantation and cadherins in mice

Many people are repeatedly exposed to both bisphenol A (BPA) and diethylhexyl phthalate (DEHP), but there has been little research concerning their effects in combination. Both can disrupt blastocyst implantation in inseminated females, albeit at high doses. We exposed mice on gestation days (GD) 1-4 to combinations of BPA and DEHP in doses below the threshold necessary to disrupt implantation on their own. On GD 6, there were fewer normally-developed implantation sites and more underdeveloped implantation sites in females given the combined subthreshold doses. Uterine epithelial cadherin (e-cadherin), a protein that assists in blastocyst adhesion to the uterine epithelium, was significantly reduced by these combined doses, but not by the individual doses. A similar trend was seen in integrin αvβ3, another uterine adhesion molecule. Cadherin-11 was disrupted by BPA but not DEHP. These data are consistent with competition of BPA and DEHP for conjugating enzymes.