Organochlorine isotopic pattern-enhanced detection and quantification of triclosan and its metabolites in human serum by ultra-high-performance liquid chromatography/quadrupole time-of-flight/mass spectrometry

Environmental relevant concentrations of triclosan affected developmental toxicity, oxidative stress, and apoptosis in zebrafish embryos

Triclosan (TCS), as a broad-spectrum antibacterial agent, is widely used in various pharmaceutical and personal care products. However, the details of ecological environmental health risks of TCS are not clear. In this study, zebrafish embryos/larval were exposed to environmentally relevant concentrations of TCS to evaluate the developmental toxicity. Four-hour post-fertilization (hpf) zebrafish embryos were exposed to 0, 2, 10, 50, and 250 μg/L TCS until 96 h. The heart beats at 72 hpf were significantly increased in 2 μg/L TCS group, while significantly decreased in 250 μg/L TCS treated group compared with control. The results of acridine orange staining, terminal deoxynucleotide transferase-mediated UTPnick end labeling assay, and detection of mitochondrial membrane potential showed that 50 and 250 μg/L TCS resulted in apoptosis. Meanwhile, reactive oxygen species (ROS) and DNA damage were induced, but SOD activity was significantly decreased in 250 μg/L TCS treated group. In addition, SOD(Mn) and GPx gene mRNA expressions were significantly down-regulated in 50 and 250 μg/L TCS treated groups, while Casp3, Casp9, Puma, Casp8, Apaf1, and Bid genes in 250 μg/L TCS and Mdm2 gene in 50 μg/L treated groups were significantly up-regulated. P53 protein was significantly up-regulated in 250 μg/L TCS treated group. The overall results showed that TCS can cause oxidative stress and result in apoptosis via the involvement of ROS-p53-caspase-dependent apoptotic pathway in zebrafish embryos. The present findings suggest the potential mechanisms of TCS-induced developmental toxicity appears to be the generation of ROS and the consequent triggering of apoptosis genes.

The Presence of Triclosan in Human Hair Samples in Poland-A Pilot Study

Triclosan (TCS) is an organic substance showing antibacterial action, which is commonly used in many branches of industry, including, among others, cosmetics, pharmaceuticals and the food industry. TCS may penetrate into living organisms and negatively affect the health of humans and animals. The majority of previous investigations on TCS biomonitoring in humans have been performed on urine, but currently, studies on hair samples are becoming increasingly important. The aim of this study was to evaluate TCS concentration levels in residents of Olsztyn, a city in northeastern Poland, using a liquid chromatography-mass spectrometry technique. The presence of TCS was observed in 96.7% of samples tested, with concentration levels from 37.9 pg/mg to 3386.5 pg/mg. The mean concentration level of TCS in the present study was 402.6 (±803.6) pg/mg, and the median value was 103.3 pg/mg. Although there were some differences in TCS concentration levels between males and females, humans of various ages and humans with colored and natural hair had no statistically significant differences in TCS concentration levels. The obtained results have clearly indicated that people living in northeastern Poland are exposed to TCS to a large degree, and hair analysis, despite some limitations, is a suitable method for TCS biomonitoring in humans.

Evaluation of Triclosan Effects on Cultured Swine Luteal Cells

Simple Summary

A great concern has been raised against many chemicals, both natural and man-made, that can mimic or interfere with the hormones. Among these, using swine ovarian cells, we were aimed to explore the potential effect of triclosan, an antimicrobial agent widely used in cosmetics and home products. Our results demonstrate that triclosan disrupts cellular function, in particular interfering with hormone production and proliferation, thus suggesting a critical evaluation of its effects.

Abstract

Triclosan is a chlorinated phenolic, used in many personal and home care products for its powerful antimicrobial effect. Several studies have shown triclosan toxicity and the American Food and Drug Administration (FDA) in 2016 has limited its use. It has been recently included in endocrine-disrupting chemicals (EDCs), a list of chemicals known for their ability to interfere with hormonal signaling with particular critical effects on reproduction both in animals and humans. In order to deepen the knowledge in this specific field, the present study was undertaken to explore the effect of different concentrations of triclosan (1, 10, and 50 µM) on cultured luteal cells, isolated from swine ovaries, evaluating effects on growth Bromodeoxyuridine (BrDU) incorporation and Adenosine TriPhosphate (ATP) production, steroidogenesis (progesterone secretion) and redox status (superoxide and nitric oxide production, enzymatic and non-enzymatic scavenging activity). A biphasic effect was exerted by triclosan on P4 production. In fact, the highest concentration inhibited, while the others stimulated P4 production (p < 0.05). Triclosan significantly inhibited cell proliferation, metabolic activity, and enzymatic scavenger activity (p < 0.05). On the contrary, nitric oxide production was significantly increased by triclosan (p < 0.01), while superoxide anion generation and non-enzymatic scavenging activity were unaffected.

A Review on the Fate of Legacy and Alternative Antimicrobials and Their Metabolites during Wastewater and Sludge Treatment

Antimicrobial compounds are used in a broad range of personal care, consumer and healthcare products and are frequently encountered in modern life. The use of these compounds is being reexamined as their safety, effectiveness and necessity are increasingly being questioned by regulators and consumers alike. Wastewater often contains significant amounts of these chemicals, much of which ends up being released into the environment as existing wastewater and sludge treatment processes are simply not designed to treat many of these contaminants. Furthermore, many biotic and abiotic processes during wastewater treatment can generate significant quantities of potentially toxic and persistent antimicrobial metabolites and byproducts, many of which may be even more concerning than their parent antimicrobials. This review article explores the occurrence and fate of two of the most common legacy antimicrobials, triclosan and triclocarban, their metabolites/byproducts during wastewater and sludge treatment and their potential impacts on the environment. This article also explores the fate and transformation of emerging alternative antimicrobials and addresses some of the growing concerns regarding these compounds. This is becoming increasingly important as consumers and regulators alike shift away from legacy antimicrobials to alternative chemicals which may have similar environmental and human health concerns.

Characterization of covalent protein modification by triclosan in vivo and in vitro via three-dimensional liquid chromatography-mass spectrometry: New insight into its adverse effects

Triclosan (TCS), an antimicrobial agent widely used in personal care products and ubiquitously exists in environment, has drawn increasing concern due to its potential to exert multiple adverse effects, ranging from endocrine disruption to carcinogenesis. However, the mechanism of these adverse effects is still not fully elucidated. More and more studies have shown that chemical reactive metabolites (RMs) covalently binding to proteins is a possible reason for these adverse effects, but there is still a lack of appropriate methods to predict or evaluate these adverse effects due to the extremely low abundance of the modified proteins in complex biological samples. In this study, we attempted to address this problem and investigate the possible mechanism of TCS adverse effects by a shotgun proteomics approach based on three-dimensional-liquid chromatography-mass spectrometry (3D-LC-MS). First, the in vitro incubation with model amino acids and protein in microsomes showed that TCS could react with cysteine residue of proteins through 3 types of RMs. Then, a 3D-LC-MS approach was developed to sensitively determine the low abundant modified proteins, which resulted in the identification of 45 TCS-modified proteins, including albumin, haptoglobin and NR1I2, in rats. STRING analysis indicated that these modified proteins mainly were involved in reproductive and development system, endocrine and immune system, and carcinogenesis, which were in accord with the main reported TCS-induced adverse effects and suggested that the covalent modification of TCS RMs for proteins might affect their activities and functions, thus inducing serious adverse effects. This study provided a new insight into the mechanism of TCS adverse effects and may serve as a valuable method to predict or evaluate adverse effects of ubiquitous chemicals.

Formation of dioxins from triclosan with active chlorine: A potential risk assessment

Triclosan, a widely used antimicrobial agent, can increase colitis-associated colon tumorigenesis, and induce liver fibrosis and cancer in mice through mechanisms which may be relevant in humans. In this study, an analytical method using gas chromatography-mass spectrometry (GC-MS) and high resolution gas chromatography-high resolution mass spectrometry (HRGC-HRMS) was developed to measure dioxins and chlorinated derivatives from triclosan in the presence of active chlorine in seawater matrix. Formation yields of dioxins and chlorinated triclosans were assessed at different initial precursor concentrations under dark and UV light irradiation conditions. Results showed that triclosan was rapidly transformed to its chlorinated derivatives, i.e. tetraclosans and pentaclosans, of which the formation yields peaked after 1 h of reaction. UV light was the key factor to promote the formation of dioxins. With the same initial triclosan/active chlorine ratio, the highest yield of dioxins was observed with lower initial concentrations of triclosan under UV irradiation. Five dioxins, including 2,8-DCDD, 1,2,8-TrCDD, 2,3,7-TrCDD, 1,2,3,8-TeCDD, and 2,3,7,8-TeCDD, were identified and quantified. 2,3,7,8-TeCDD, the most toxic dioxin, was firstly reported as the photo-transformation product of triclosan in aquatic solution. Results presented here are useful for a comprehensive understanding of the fate and toxicity of triclosan in contaminated waters.

The effects and possible mechanisms of triclosan on steroidogenesis in primary rat granulosa cells

BACKGROUND

Triclosan (TCS) has been detected in human tissues. It can disrupt steroidogenesis in vivo. The study on the effects of TCS on ovarian granulosa cells was lacking.

METHODS

Primary rat granulosa cells (rGCs) were treated with TCS. Concentrations of estradiol (E₂), progesterone (P₄) in the cell culture supernatants were measured. Microarray was used to measure gene expression profiles. Pathway analysis was performed to identify signaling networks that linked differentially expressed genes (DEGs). Genes related with steroidogenesis were analyzed.

RESULTS

TCS increased E₂ and P₄ production. A total of 2006 DEGs were identified. Pathway analysis revealed that ovarian steroidogenesis pathway was upregulated. Both PCR and Western-blot demonstrated that the expressions of key genes involved in this pathway were significantly increased.

CONCLUSIONS

TCS co-administered with follicle-stimulating hormone (FSH) could increase E₂ and P₄ production in rGCs and up-regulate ovarian steroidogenesis pathway. StAR and aromatase protein were increased by TCS, while P450scc protein wasn't changed significantly.

Degradation of triclosan by environmental microbial consortia and by axenic cultures of microorganisms with concerns to wastewater treatment

Triclosan is an antimicrobial agent, which is widely used in personal care products including toothpaste, soaps, deodorants, plastics, and cosmetics. Widespread use of triclosan has resulted in its release into wastewater, surface water, and soils and has received considerable attention in the recent years. It has been reported that triclosan is detected in various environmental compartments. Toxicity studies have suggested its potential environmental impacts, especially to aquatic ecosystems. To date, removal of triclosan has attracted rising attention and biodegradation of triclosan in different systems, such as axenic cultures of microorganisms, full-scale WWTPs, activated sludge, sludge treatment systems, sludge-amended soils, and sediments has been described. In this study, an extensive literature survey was undertaken, to present the current knowledge of the biodegradation behavior of triclosan and highlights the removal and transformation processes to help understand and predict the environmental fate of triclosan. Experiments at from lab-scale to full-scale field studies are shown and discussed.

Trends in the application of high-resolution mass spectrometry for human biomonitoring: An analytical primer to studying the environmental chemical space of the human exposome

Global profiling of xenobiotics in human matrices in an untargeted mode is gaining attention for studying the environmental chemical space of the human exposome. Defined as the study of a comprehensive inclusion of environmental influences and associated biological responses, human exposome science is currently evolving out of the metabolomics science. In analogy to the latter, the development and applications of high resolution mass spectrometry (HRMS) has shown potential and promise to greatly expand our ability to capture the broad spectrum of environmental chemicals in exposome studies. HRMS can perform both untargeted and targeted analysis because of its capability of full- and/or tandem-mass spectrum acquisition at high mass accuracy with good sensitivity. The collected data from target, suspect and non-target screening can be used not only for the identification of environmental chemical contaminants in human matrices prospectively but also retrospectively. This review covers recent trends and advances in this field. We focus on advances and applications of HRMS in human biomonitoring studies, and data acquisition and mining. The acquired insights provide stepping stones to improve understanding of the human exposome by applying HRMS, and the challenges and prospects for future research.

Chinese population exposure to triclosan and triclocarban as measured via human urine and nails

Triclosan (TCS) and triclocarban (TCC) exposures are highly concerned due to their suspected endocrine-disrupting effects. The present study investigated TCS and TCC exposure levels in the general Chinese population by biomonitoring human urine and nail samples. TCS (69-80 %) and TCC (99-100 %) were frequently detected, which demonstrates that the general Chinese population has extensive exposure to these chemicals. The geometric mean (GM) urinary concentrations were 0.40 μg/g creatinine (creat), 95 % confidence interval (CI) 0.30-0.56, for TCS and 0.40 μg/g creat, 95 % CI 0.29-0.56, for TCC. On the other hand, the GM levels of TCS and TCC were 13.57 (5.67 μg/kg) and 84.66 μg/kg (41.50 μg/kg) in fingernail (toenail) samples, respectively, indicating that the levels in fingernails were approximately twice as high as those in toenails. Pearson's correlation coefficients between the urine and fingernail (toenail) samples were 0.715 (0.614) for TCS and 0.829 (0.812) for TCC. These data suggest that nail samples can be applied to the biomonitoring for TCS and TCC in the general population. We observed that the levels of both chemicals were higher in females than in males for urine and fingernail samples, but no significant differences were found between different genders for either compound in toenails. Nineteen- to 29-year-olds had the highest TCS levels in their nail samples, whereas TCC levels did not differ with regard to age. Region of residence significantly influenced TCS and TCC concentrations in the three biological matrices measured.

Urinary triclosan concentrations are inversely associated with body mass index and waist circumference in the US general population: Experience in NHANES 2003-2010

BACKGROUND

Humans are extensively exposed to triclosan, an antibacterial and antifungal agent. Triclosan's effects on human health, however, have not been carefully investigated.

OBJECTIVE

To examine whether triclosan exposure is associated with obesity traits.

METHODS

This study included 2898 children (6-19 years old) and 5066 adults (20 years or older) who participated in the National Health and Nutrition Examination Surveys (NHANES) 2003-2010 and had a detectable level of urinary triclosan. Multiple linear regression models were used to examine the association between urinary triclosan and both body mass index (BMI) and waist circumference.

RESULTS

Each standard deviation increase in urinary triclosan was associated with a 0.34 (95% confidence interval, CI: 0.05, 0.64) kg/m² lower level of BMI (P=0.02) and 0.92 (95% CI: 0.09, 1.74)cm smaller waist circumference (P=0.03) in boys, and a 0.62 (95% CI: 0.31, 0.94) kg/m² lower level of BMI (P=0.0002) and 1.32 (95% CI: 0.54, 2.09) cm smaller waist circumference in girls (P=0.001); a 0.42 (95% CI: 0.06, 0.77) kg/m² lower level of BMI (P=0.02) and 1.35 (95% CI: 0.48, 2.22) cm smaller waist circumference (P=0.003) in men, and a 0.71 (95% CI: 0.34, 1.07) kg/m² lower level of BMI (P=0.0002) and 1.68 (95% CI: 0.86, 2.50) cm smaller waist circumference (P=0.0001) in women. In both children and adults, there was a consistent trend for lower levels of BMI and smaller waist circumference with increasing levels of urinary triclosan, from the lowest to the highest quartile of urinary triclosan (P ≤ 0.001 in all cases).

CONCLUSION

Triclosan exposure is inversely associated with BMI and waist circumference. The biological mechanisms linking triclosan exposure to obesity await further investigation.