Hydroxydiphenyl Ether Research Articles

Prediction of Base-Catalyzed Hydrolysis Kinetics of Polychlorinated Dibenzo-p-Dioxins by Density Functional Theory Calculations.

Polychlorinated dibenzo-p-dioxins (PCDDs), comprising 75 congeners, have gained considerable attention from the general public and the scientific community owing to their high toxic potential. The base-catalyzed hydrolysis of PCDDs is crucial for the assessment of their environmental persistence. Nonetheless, owing to the substantial number of congeners and low hydrolysis rates of PCDDs, conducting hydrolysis experiments proves to be exceedingly time-consuming and financially burdensome. Herein, density functional theory and transition state theory were employed to predict the base-catalyzed hydrolysis of PCDDs in aquatic environments. Findings reveal that PCDDs undergo base-catalyzed hydrolysis in aquatic environments with two competing pathways: prevailing dioxin ring-opening and reduced reactivity in the hydrolytic dechlorination pathway. The resultant minor products include hydroxylated PCDDs, which exhibit thermodynamic stability surpassing that of the principal product, chlorinated hydroxydiphenyl ethers. The half-lives (ranging from 17.10 to 1.33 × 1010 h at pH = 8) associated with the base-catalyzed hydrolysis of PCDDs dissolved in water were shorter compared to those within the water-sediment environmental system. This observation implies that hydroxide ions can protect aquatic environments from PCDD contamination. Notably, this study represents the first attempt to predict the base-catalyzed hydrolysis of PCDDs by using quantum chemical methods.

Effects of prepubertal to peripubertal exposure of triclosan on the reproductive health of the young male laboratory mice

Over the last few decades, a massive increase in environmental toxicants has played a significant role in causing hindrance in the process of sexual maturity, leading to impaired reproductive health. Several toxicants are existing in the environment because of rapid industrialization, agricultural activities, and urbanization that act as endocrine disrupting chemicals (EDCs). Triclosan (TCS; 2,4,4’-trichloro-2’-hydroxydiphenyl ether) is one of the EDCs, acts as an antimicrobial chemical, and is used widely in personal care products and several commercial preparations as preservatives. It is found to interfere with normal reproduction and sexual maturity. The present study is therefore, aimed to investigate the impact of prepubertal to peripubertal exposure of TCS (300 and 600 mg/kg BW/day from PND 22 to PND 63) to observe the age of the onset of puberty, weights of the reproductive organs, alterations in the levels of testicular cholesterol, serum testosterone, and histopathology of the testis in the young laboratory mice. TCS exposure caused a significant delay in the age of prepuce separation, an indicator of the onset of puberty. Its exposure from PND 22 to PND 63 resulted in significant reductions in the weights of the testis, epididymis, and seminal vesicle, levels of testicular cholesterol, and serum testosterone in the young mice at PND 64. Testicular histology of such mice also showed regressive changes in the seminiferous tubules, indicating the interference of TCS in the process of spermatogenesis. The findings of the present study, therefore, reveal that TCS delays the age of onset of puberty and interferes with the endocrine functions of the testis.

Characterization of triclosan-induced hepatotoxicity and triclocarban-triggered enterotoxicity in mice by multiple omics screening

Triclosan (2,4,4′-trichloro-2′-hydroxydiphenyl ether, TCS) and triclocarban (3,4,4'-trichloro-carbanilide, TCC) are two antimicrobial agents commonly used for personal care products. Previous studies primarily focused on respective harmful effects of TCS and TCC. In terms of their structural similarities and differences, however, the structure-toxicity relationships on health effects of TCS and TCC exposure remain unclear. Herein, global 1H NMR-based metabolomics was employed to screen the changes of metabolic profiling in various biological matrices including liver, serum, urine, feces and intestine of mice exposed to TCS and TCC at chronic and acute dosages. Metagenomics was also applied to analyze the gut microbiota modulation by TCS and TCC exposure. Targeted MS-based metabolites quantification, histopathological examination and biological assays were subsequently conducted to supply confirmatory information on respective toxicity of TCS and TCC. We found that oral administration of TCS mainly induced significant liver injuries accompanied with inflammation and dysfunction, hepatic steatosis fatty acids and bile acids metabolism disorders; while TCC exposure caused marked intestine injuries leading to striking disruption of colonic morphology, inflammatory status and intestinal barrier integrity, intestinal bile acids metabolism and microbial community. These comparative results provide novel insights into structure-dependent mechanisms of TCS-induced hepatotoxicity and TCC-triggered enterotoxicity in mice.

Environmental Exposure to Triclosan and Male Fecundity: A Prospective Study in China.

Triclosan (2,4,4′-trichloro-2′-hydroxy-diphenyl ether, TCS) is widely used in personal care and household products. It is ubiquitous across the ecosystem nowadays. Several in vitro and in vivo studies have suggested the possible adverse effects of TCS on male reproductive health. However, little research has been done on human beings, especially in eastern countries. To assess the effects of TCS exposure on male fecundity, we recruited couples who planned to conceive and went to the preconception care clinics for physical examination in Shanghai, China. TCS was quantified in male urine samples collected at enrollment. For this study, 443 couples were included in the cohort, and 74.7% of couples (n = 331) were prospectively followed 12 months later. The outcomes of interest included the pregnancy status of their wives and time to pregnancy. Elevated male urinary TCS concentrations were found to be associated with diminished fecundability (fecundability odds ratio (FOR) 0.77; 95% CI, 0.62–0.97). The risk of infertility significantly increased (OR = 1.6; 95% CI, 1–2.6) as TCS levels elevated. Besides, we divided TCS concentration into tertiles a priori, and there tended to be a dose-response pattern in both analyses. Our findings suggest that environmental exposure to TCS may have an adverse impact on male fecundity.

Long-term exposure to triclosan increases migration and invasion of human breast epithelial cells in vitro.

Extensive use of triclosan (2,4,4′‐trichloro‐2′‐hydroxydiphenyl ether) as an antimicrobial agent in household and personal care products has resulted in global exposure of the human population. Its presence in human tissues, including milk, and its oestrogen‐disrupting properties raise concerns for an involvement in breast cancer. Because metastatic tumour spread is the main cause of breast cancer mortality, we have investigated the effects of triclosan on cell migration and invasion using three human breast epithelial cell lines and using concentrations comparable with those in human tissues. Long‐term exposure to 10−7 M of triclosan resulted in increased migration and invasion as measured by xCELLigence technology for all three cell lines, for the immortalized but nontransformed MCF‐10F breast epithelial cells (after 28 weeks), the oestrogen‐responsive MCF‐7 breast cancer cells (after 17 weeks) and the oestrogen‐unresponsive MDA‐MB‐231 breast cancer cells (after 20 weeks). The effects were therefore not limited to cancerous cells or to oestrogen‐responsive cells. This was paralleled in the MCF‐10F and MCF‐7 (but not MDA‐MB‐231) cells by a reduction in levels of E‐cadherin mRNA as measured by reverse transcription–polymerase chain reaction (RT‐PCR) and of E‐cadherin protein as measured by western immunoblotting, suggesting a mechanism involving epithelial‐to‐mesenchymal transition. This adds triclosan to the increasing list of ingredients of personal care products that can not only enter human breast tissue and increase cell proliferation but also influence cell motility. If mixtures of components in household and personal care products contribute to increasing cell migration and invasion, then reduction in exposure could offer a strategy for reducing breast cancer spread.

Prediction of the skin sensitization potential of polyhexamethylene guanidine phosphate, oligo(2-(2-ethoxy)ethoxyethyl) guanidinium chloride, triclosan, and mixtures of these compounds with the excipient propylene glycol through the local lymph node assay: BrdU-FCM.

The guanidine family of antimicrobial agents, which includes polyhexamethylene guanidine phosphate (PHMG) and oligo(2-(2-ethoxy)ethoxyethyl) guanidinium chloride (PGH), and chlorophenol biocidal chemicals such as 2,4,4'-trichloro-2'-hydroxydiphenyl ether (triclosan) are used in various occupational and environmental biocidal applications. The excipient propylene glycol (PG) is used to dissolve the active ingredients. The skin sensitization (SS) potential of these substances has not been systemically investigated and is still debated. Moreover, mixtures of PHMG, PGH, or triclosan with PG have not been evaluated for SS potency. An in vivo assay known as the local lymph node assay: 5-bromo-2-deoxyuridine-flow cytometry method (LLNA: BrdU-FCM) was recently adopted as an alternative testing method and was used to address these issues. Via the LLNA: BrdU-FCM, PHMG, PGH, and triclosan were predicted to be sensitizers, while PG was predicted to be a nonsensitizer. In addition, d-limonene, which is used as a flavoring in various consumer products, was also predicted to be a sensitizer, although no unanimous conclusion has been reached regarding its SS potential. Mixtures of PHMG, PGH, triclosan, or d-limonene with PG at ratios of 9:1, 4:1, and 1:4 (w/w) were all positive in terms of SS potential, indicating that the PG excipient does not influence the SS predictions of these chemicals. Since humans can be occupationally and environmentally exposed to mixtures of excipients with active ingredients, the present study may give insight into further investigations of the SS potentials of various chemical mixtures.

Triclosan and Female Reproductive Health: A Preconceptional Cohort Study.

Triclosan (2,4,4'-trichloro-2'-hydroxy-diphenyl ether) is widely used in personal care and household products. Previous in vitro and in vivo studies showed that triclosan may affect female reproductive health. However, evidence from human studies is scarce. To assess the potential effects of triclosan on women's reproductive health. A prospective cohort study recruited 1,182 couples who planned to conceive and presented to preconception care clinics for physical examination in Shanghai, China, between 2013 and 2015. These couples were then prospectively followed every 2 months for 12 months. Triclosan was quantified in preconception urine samples at enrollment. The outcomes of interest included menstruation and fecundity. Normal menstruation was defined as a woman who had normal cycle duration between 21 and 35 days, duration of menstrual bleeding between 3 and 7 days, and self-reported normal amount of menstrual bleeding. A total of 698 women were included in the analysis on the association between triclosan and menstruation. Compared with low triclosan levels, high triclosan levels were associated with increased risks of abnormal menstruation [adjusted odds ratio (OR) = 1.47; 95% confidence interval = 1.05, 2.06] and prolonged menstrual cycle (OR = 2.08; 95% confidence interval = 1.00, 2.31). In the analysis on the association between triclosan and fecundability, 648 women were included. Compared with the lowest tertile of triclosan level (<1.1 ng/mL), the highest level (>4.5 ng/mL) was associated with a 23% of reduction in fecundability and there tended to be a dose-response pattern. Our findings suggest that triclosan may affect menstruation and reduce female fecundity.

Small Colony Variants and Triclosan Resistance in Five International Clones of Methicillin Resistant Staphylococcus aureus

Triclosan (2.4.4’ trichloro-2’-hydroxydiphenyl ether) is a broad-spectrum biocide which is also used to decolonise patients with methicillin resistant Staphylococcus aureus (MRSA). Microbial resistance to biocides has recently been reported, so it is important that new products should be tested for resistance that may arise from continued exposure to such agents. In a previous study 232 strains of MRSA isolated during 1997-2000 in 30 Scottish hospitals were tested for triclosan susceptibility; overall the minimum inhibitory concentrations (MIC) of triclosan for these strains ranged from &lt;=0.015 to 4 mg/L. In the present study, resistance to triclosan was examined in five major international MRSA clones [Clonal Complex (CC22, CC30, CC45, CC8 and CC5)] by growing them in brain heart infusion broth in the presence of increasing concentrations of triclosan (0.03mg/L, 0.06 mg/L, 0.125 mg/L, 0.25 mg/L, and 0.5 mg/L ) for up to 67 days. Different MRSA clones showed different degrees of triclosan tolerance. CC22 (EMRSA–15), CC30 (EMRSA-16) and CC5 triclosan-tolerant derivatives showed a significant increase in triclosan MIC when compared to their parents, principally through the appearance of pinpoint-size small colony variants (SCV), as well as colonies of normal or small size. These MRSA SCVs emerged in different clones and at different times of exposure to triclosan. The triclosan MICs of mutants of all colony sizes rose to 4 mg/L in all clones except MRSA111-29 (CC45) which had an MIC 4-8 mg/L. Triclosan-resistant MRSA strains were also able to grow in the presence of higher triclosan concentrations: 1.25 mg/L (CC22), 10 mg/L (CC30), 25 mg/L (CC45), 5 mg/L (CC8) and 25 mg/L (CC5). In addition, six triclosan resistant derivatives from each MRSA clone, together with their parental clone, were examined by antibiogram, polymerase chain reaction (PCR) ribotyping and detailed susceptibility to triclosan in terms of MIC and kill kinetics. Susceptibility to the aminoglycosides kanamycin, neomycin and tobramycin was decreased in four clones, and tetracycline susceptibility increased in one clone. PCR ribotyping confirmed clonally similar to the mutants. Kill kinetics of both parents and their triclosan resistant mutants showed 5-Logs reduction at 0.5 min and 5 min respectively in all five clones. In conclusion, repeated exposure of MRSA to triclosan may result in resistance to this biocide, and to clinically-relevant antimicrobials.

Ozonation of Common Textile Auxiliaries

The treatability of four different commonly applied textile auxiliary chemicals, namely two tannin formulations (Tannin 1: a condensation product of aryl sulphonate; Tannin 2: natural tannic acid) and two biocidal finishing agents (Biocide 1: 2,4,4’-trichloro-2’- hydroxydiphenyl ether; Biocide 2: a nonionic diphenyl alkane derivative) with ozone was investigated. Increasing the ozone dose yielded higher COD removals for the natural tannin. Optimum ozone doses of 485 and 662 mg/h were obtained at a pH of 3.5 for natural and synthetic tannin carrying textile bath discharges, respectively. When the reaction pH was increased from 3.5 to 7.0, a slight decrease in COD removal was observed for the natural tannin due to ozone selectivity towards its polyaromatic structure. The same increase in ozonation pH enhanced COD removals for the synthetic tannin as a result of enhanced ozone decomposition rendering free radical chain reactions dominant. Optimum ozone doses of 499 and 563 mg/h were established for Biocide 1 and 2, respectively. With the increase of ozonation, pH exhibited a positive influence on COD removals for both textile tannins. A substantial improvement in terms of TOC removals was observed as the reaction pH was increased from 3.5 to 7.0 for the synthetic tannin, and from 7 to 12 for both textile biocides. Higher AOX removals were evident at pH 7 than at pH 12 for Biocide 1 as a result of the higher selectivity of the dehalogenation reaction at neutral pH.

Multifunctional durable properties of textile materials modified by biocidal agents in the sol-gel process

Abstract The studies were conducted on a cotton fabric modified by the mixture of tetraethoxysilane (TEOS) and triclosan (TC)—(2,4,4′-trichloro-2′-hydroxydiphenyl ether) or TEOS and quaternary ammonium salt (QAS) such as the hexadecyltrimethylammonium bromide in order to obtain biocidal (i.e. antifungal) and hydrophobic properties. The modified unwashed and washed fabrics were tested for the action of a mixture of five mould species which most often cause the decomposition of cellulose (Chaetomium sp., Aureobasidium sp., Paecilomyces sp., Aspergillus sp., Penicillium sp.). The hydrophobicity was examined by measuring the contact angle. The fabrics modified by TC-TEOS are characterized by a higher antifungal effectiveness, however, the durability of the modification can be maintained only when they are dry-cleaned. Silanes form a silica layer on the surface of textiles which results in increased hydrophobicity. These multifunctional textiles can find applications as materials for human health, e.g. insoles, wound dressings, protective clothing, filters.

Detection of the Antimicrobial Triclosan in Environmental Samples by Immunoassay.

A sensitive, competitive enzyme-linked immunosorbent assay (ELISA) for the detection of the antimicrobial triclosan (TCS; 2,4,4'-trichloro-2'-hydroxydiphenyl ether) was developed. Novel immunizing haptens were synthesized by derivatizing at the 4-Cl position of the TCS molecule. Compounds derived from substitutions at 4'-Cl and that replaced the 2'-OH with a Cl atom were designed as unique coating antigen haptens. Polyclonal rabbit antisera were screened against the coating antigen library to identify combinations of immunoreagents resulting in the most sensitive assays. The most sensitive assay identified was one utilizing antiserum no. 1155 and a heterologous competitive hapten, where the 2'-OH group was substituted with a Cl atom. An IC50 value and the detection range for TCS in assay buffer were 1.19 and 0.21-6.71 μg/L, respectively. The assay was selective for TCS, providing low cross-reactivity (<5%) to the major metabolites of TCS and to brominated diphenyl ether-47. A second assay utilizing a competitive hapten containing Br instead of Cl substitutions was broadly selective for both brominated and chlorinated diphenylethers. Using the most sensitive assay combination, we measured TCS concentrations in water samples following dilution. Biosolid samples were analyzed following the dilution of a simple solvent extract. The immunoassay results were similar to those determined by LC-MS/MS. This immunoassay can be used as a rapid and convenient tool to screen for human and environmental exposure.

Association of birth outcomes with fetal exposure to parabens, triclosan and triclocarban in an immigrant population in Brooklyn, New York

BackgroundPrior studies suggest associations between fetal exposure to antimicrobial and paraben compounds with adverse reproductive outcomes, mainly in animal models. We have previously reported elevated levels of these compounds for a cohort of mothers and neonates. ObjectiveWe examined the relationship between human exposure to parabens and antimicrobial compounds and birth outcomes including birth weight, body length and head size, and gestational age at birth. MethodsMaternal third trimester urinary and umbilical cord blood plasma concentrations of methylparaben (MePB), ethylparaben (EtPB), propylparaben (PrPB), butylparaben (BuPB), benzylparaben (BePB), triclosan (2,4,4′-trichloro-2′-hydroxydiphenyl ether or TCS) and triclocarban (1-(4-chlorophenyl)-3-(3,4-dichlorophenyl) urea or TCC), were measured in 185 mothers and 34 paired singleton neonates in New York, 2007–2009. ResultsIn regression models adjusting for confounders, adverse exposure-outcome associations observed included increased odds of PTB (BuPB), decreased gestational age at birth (BuPB and TCC) and birth weight (BuPB), decreased body length (PrPB) and protective effects on PTB (BePB) and LBW (3′-Cl-TCC) (p<0.05). No associations were observed for MePB, EtPB, or TCS. ConclusionsThis study provides the first evidence of associations between antimicrobials and potential adverse birth outcomes in neonates. Findings are consistent with animal data suggesting endocrine-disrupting potential resulting in developmental and reproductive toxicity.

Differential gene expression patterns during embryonic development of sea urchin exposed to triclosan.

Triclosan (TCS; 2,4,4'-trichloro-2'-hydroxydiphenyl ether) is a broad-spectrum antibacterial agent used in common industrial, personal care and household products which are eventually rinsed down the drain and discharged with wastewater effluent. It is therefore commonly found in the aquatic environment, leading to the continual exposure of aquatic organisms to TCS and the accumulation of the antimicrobial and its harmful degradation products in their bodies. Toxic effects of TCS on reproductive and developmental progression of some aquatic organisms have been suggested but the underlying molecular mechanisms have not been defined. We investigated the expression patterns of genes involved in the early development of TCS-treated sea urchin Strongylocentrotus nudus using cDNA microarrays. We observed that the predominant consequence of TCS treatment in this model system was the widespread repression of TCS-modulated genes. In particular, empty spiracles homeobox 1 (EMX-1), bone morphogenic protein, and chromosomal binding protein genes showed a significant decrease in expression in response to TCS. These results suggest that TCS can induce abnormal development of sea urchin embryos through the concomitant suppression of a number of genes that are necessary for embryonic differentiation in the blastula stage. Our data provide new insight into the crucial role of genes associated with embryonic development in response to TCS. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 426-433, 2017.

Environmental Exposure to Triclosan and Semen Quality.

Triclosan (2,4,4′-trichloro-2′-hydroxy-diphenyl ether, TCS) is widely used in personal care, household, veterinary and industrial products. It was considered as a potential male reproductive toxicant in previous in vitro and in vivo studies. However, evidence from human studies is scarce. Our study aims to investigate the relationship between TCS exposure and semen quality. We measured urinary TCS concentrations in 471 men recruited from a male reproductive health clinic. TCS was detected in 96.7% of urine samples, with a median concentration of 0.97 ng (mg·creatinine)−1 (interquartile range, 0.41–2.95 ng (mg·creatinine)−1). A multiple linear regression analysis showed a negative association between natural logarithm (Ln) transformed TCS concentration (Ln-TCS) and Ln transformed number of forward moving sperms (adjusted coefficient β = −0.17; 95% confidence interval (CI) (−0.32, −0.02). Furthermore, among those with the lowest tertile of TCS level, Ln-TCS was negatively associated with the number of forward moving sperms (β = −0.35; 95% CI (−0.68, −0.03)), percentage of sperms with normal morphology (β = −1.64; 95% CI (−3.05, −0.23)), as well as number of normal morphological sperms, sperm concentration and count. Our findings suggest that the adverse effect of TCS on semen quality is modest at the environment-relevant dose in humans. Further studies are needed to confirm our findings.

Preserving ignitable liquid residues on soil using Triclosan as an anti-microbial agent

When a fire is suspected to be intentionally set, fire debris samples can be collected and analyzed for ignitable liquid residues (ILRs). In some cases, samples will contain highly organic substrates such as soil or rotting wood. These substrates will contain a high bacterial load, which can result in systematic and irreversible damage to the ILR due to microbial degradation. This paper explores ways to preserve ILR by sterilizing fire debris samples without interfering with their subsequent analysis. There are many methods reported in the literature for sterilizing soil, such as freezing, irradiation, autoclaving, and various chemical fumigation techniques. However, these methods either do not kill all bacterial species, cannot be easily applied in the field or would interfere with the analysis of the ILRs. For this work, various anti-microbial compounds including triclosan (2,4,4′-trichloro-2′-hydroxydiphenyl ether) were tested for their efficacy at killing bacteria present in the soil. Triclosan was highly effective in qualitative growth studies and was therefore used to measure bacterial growth (or lack thereof) by spectroscopic analysis as well as passive headspace analysis. These experiments showed that triclosan was able to sterilize soil samples in less than 60s, maintain their sterility for at least 77h and preserve gasoline residues on a soil matrix for at least 30 days.

Effects of triclosan on reproductive prarmeters and embryonic development of sea urchin, Strongylocentrotus nudus

Triclosan (TCS, 2,4,4′-trichloro-2′-hydroxydiphenyl ether), a broad-spectrum antibacterial agent, is commonly found in the aquatic environment. In this study, we investigated TCS toxicity with pertaining to gamete viability, fertilization, and embryogenesis up to pluteus stage of the sea urchin, (Strongylocentrotus nudus). When the sperm and eggs were exposed to TCS (0–3.0μM), the viability of sperm was significantly decreased at molarities higher than 1μM of TCS. In addition, for exposure of 2.0μM TCS the viability of eggs was not influenced and none of the sperm was viable. Fertilization rate was significantly decreased when sperm were exposed to 0.5 and 1μM of TCS (p<0.001) and no fertilization was observed for the exposure of 1.5μM of TCS. In embryonic development, embryos are treated with higher than 1.0μM levels of TCS displayed arrested development. For TCS, the EC50 and LOECs values were 1.8, 1.49 and 0.99μM and 0.53, 0.62 and 0.39μM for sperm viability, fertilization rate, and larval development to pluteus, respectively. In the recovery test regarding normal development of arrested embryos based upon TCS exposure time, it was observed that embryos exposed to 1μM TCS for 15h were normally recovered for normal development, while embryos with more than 30h exposure were not recovered to normal larvae. Overall, the results of this study strongly suggest that the gametes and embryos of S. nudus can provide the basis for an effective bioassay, with a fast and sensitive means of evaluating TCS contamination in the marine ecosystem.

Study on the Structure-Activity Relations of Brominated Hydroxy Diphenyl Ethers Derivatives with Anilines

Study on the Structure-Activity Relations of Brominated Hydroxy Diphenyl Ethers Derivatives with Anilines

Synthesis and Antibacterial Activities of Halogenated Hydroxy Diphenyl Ether Derivatives

Synthesis and Antibacterial Activities of Halogenated Hydroxy Diphenyl Ether Derivatives

In vitro effects of triclosan and methyl-triclosan on the marine gastropod Haliotis tuberculata

Triclosan (2,4,4′-trichloro-2′-hydroxy-diphenyl ether; TCS) is an antibacterial agent incorporated in a wide variety of household and personal care products. Because of its partial elimination in sewage treatment plants, TCS is commonly detected in natural waters and sediments. Moreover, due to its high hydrophobicity, TCS accumulates in fatty tissues in various aquatic organisms. TCS can be converted into methyl-triclosan (2,4,4′-trichloro-2′-methoxydiphenyl ether; MTCS) after biological methylation. In this study, the acute cytotoxicity of TCS and MTCS in short-term in vitro experiments was assessed on cell cultures from the European abalone Haliotis tuberculata. The results showed that morphology and density of hemocyte are affected from a concentration of 8μM TCS. Using the XTT reduction assay, TCS has been demonstrated to decrease hemocyte metabolism activity in a dose- and time-dependent exposure. The IC50 was evaluated at 6μM for both hemocyte and gill cells after a 24h-incubation with TCS. A significant cytotoxicity of MTCS was also observed from 4μM in 24h-old hemocyte culture. Our results reveal a toxic effect of TCS and MTCS on immune (hemocytes) and/or respiratory cells (gill cells) of the abalone, species living in coastal waters areas and exposed to anthropogenic pollution.

Comparison of in vitro cytotoxicity, estrogenicity and anti‐estrogenicity of triclosan, perfluorooctane sulfonate and perfluorooctanoic acid

Concern with increasing levels of emerging contaminants exists on a global scale. Three commonly observed emerging environmental contaminants: triclosan (2,4,4-trichloro-2'-hydroxydiphenyl ether), a synthetic, broad-spectrum antibacterial agent, and perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), used in stain- and water-resistant treatments, have become distributed ubiquitously across ecosystems and have been detected in wildlife and humans. MCF-7 BOS human breast cancer cells were used to investigate the potential for cytotoxicity, estrogenicity and anti-estrogenicity of these three compounds at environmentally relevant concentrations using the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt assay (MTS) and the E-SCREEN bioassay. The doses used were 0.002-200 µg ml(-1) for triclosan and 0.03-30 µg ml(-1) for PFOS and PFOA. Quantitative results from the MTS assay revealed no significant cytotoxicity at lower concentrations for any of the test compounds; however, both triclosan and PFOA were cytotoxic at the highest concentrations examined (100-200 and 30 µg ml(-1), respectively), while PFOS showed no significant cytotoxicity at any of the concentrations tested. Positive estrogenic responses (P < 0.05) were elicited from the E-SCREEN at all concentrations examined for triclosan and PFOA and at 30 µg ml(-1) for PFOS. Further, significant anti-estrogenic activity (P < 0.05) was detected for all compounds tested at all concentrations when cells were co-exposed with 10(-9) m 17-β estradiol (E(2)). The overall results demonstrated that triclosan, PFOS and PFOA have estrogenic activities and that co-exposure to contaminants and E(2) produced anti-estrogenic effects. Each of these compounds could provide a source of xenoestrogens to humans and wildlife in the environment. Published 2011. This article is a US Government work and is in the public domain in the USA.