Effects Of Triclosan Research Articles

Effect of Triclosan on the Functioning of Liver Mitochondria and Permeability of Erythrocyte Membranes of Marsh Frog (Pelophylax ridibundus (Pallas, 1771)).

The paper examines the effects of the antimicrobial agent triclosan on the functioning of the liver mitochondria of marsh frog (Pelophylax ridibundus (Pallas, 1771)). It was established that triclosan inhibits DNP-stimulated respiration of mitochondria and decreases respiratory control ratio. In addition, triclosan causes the collapse of the mitochondrial membrane potential on both types of substrates. Such an action of triclosan can be mediated by both a protonophore effect and suppression of the activity of complex II and combined activity of complexes II + III (and, to a lesser degree, the combined activity of complexes I + III) of the mitochondrial respiratory chain. It is shown that high concentrations of triclosan enhance the production of hydrogen peroxide during the oxidation of substrates of the complex I by mitochondria, and decrease it in the case of succinate oxidation. It is found that triclosan is able to induce nonspecific permeability of the liver mitochondria of these amphibians, as well as the plasma membrane of erythrocytes. The possible mechanisms of triclosan effect on marsh frog liver mitochondria and red blood cells are discussed.

The risk of sperm demage in men with the combined effect of endocrine disruptors

Background: The most frequent ultrastructural change in sperm cells is nuclear DNA fragmentation. Many authors believe that DNA damage to sperm cells can serve as a diagnostic marker of a negative paternal effect in the pre-implantation period of human development. A number of studies have shown a direct correlation between the high percentage of sperm DNA damage and the frequency of spontaneous abortions. On the other hand, it is known that the damaging effect of endocrine disruptors, for example, triclosan and bisphenol A, is based on their ability to induce oxidative stress, which is considered as one of the factors in cell DNA damage.
 Aims: to assess the risk of sperm DNA fragmentation in men with the combined effect of bisphenol A, triclosan and 4-nonylphenol in seminal fluid.
 Materials and methods: 84 samples of seminal fluid of men with normo-and patozoospermia were studied. The concentration of bisphenol A, triclosan and 4-nonylphenol in gas was determined by gas chromatography with mass spectrometry (GC-MS). The comparison groups were divided according to the degree of DNA fragmentation of spermatozoa into two groups: the 1st group of patients with DNA fragmentation of spermatozoa 15% (n=18) and the 2nd group 15% (n=29). The spermiological study was carried out according to the WHO recommendations (2010) taking into account the assessment of the number of spermatozoa, their motility and morphology, as well as the degree of fragmentation of the sperm DNA.
 Results: Bisphenol A was found in 100% of the ejaculate samples with a median concentration of 0.150 ng/ml. Triclosan and 4-nonylphenol were detected in 84.3 and 98.1% of ejaculate samples with a median concentration of 0.11 and 0.16 ng/ml respectively. Comparison groups were statistically significantly distinguished by the concentration of bisphenol A and triclosan p=0.014; p0.001 respectively. Triclosan with an increase in concentration in seminal fluid by 0.1 ng/ml increased the chance of development of the degree of DNA fragmentation 15% by 2.9 times. The odds ratio of bisphenol A and 4-nonylphenol to DNA damage was not statistically significant. The prognostic model of the joint effect of endocrine disruptors on DNA damage, constructed using multiple logistic regression analysis, was also found to be statistically significant only with respect to the effect of triclosan.
 Conclusions: The risk of damage to sperm DNA in men is primarily associated with the effect of triclosan in seminal fluid. At the same time, it is necessary to assume the absence of a synergistic effect of bisphenol A, triclosan and 4-nonylphenol on the DNA damage of spermatozoa in men.

Assessment of the effect of triclosan on neuronal cells cause neurological disorders

Assessment of the effect of triclosan on neuronal cells cause neurological disorders

Effects of triclosan and triclocarban on denitrification and N2O emissions in paddy soil

Triclosan (TCS) and triclocarban (TCC) are two common antimicrobial compounds, which are widely used as ingredients in pharmaceuticals and personal care products. They occur ubiquitously in soil due to biosolid application as agricultural fertilizers, but their influence on microbially mediated soil biogeochemical processes is poorly understood. We tested the effects of varying concentrations of TCS and TCC applied both individually and together on denitrification and N2O emissions in paddy soil. We also quantified denitrification functional gene abundances by q-PCR to elucidate the microbial mechanisms of TCS and TCC's effects. Our results showed that TCS and TCC exposure both individually and together significantly (p < 0.05) inhibited denitrification (7.0–36.7%) and N2O emissions (15.4–86.4%) except for the 0.01 mg kg−1 TCC treatment in which denitrification was slightly but significantly (p < 0.05) stimulated. The inhibitory effects of TCS and TCC exposure were mainly attributed to their negative net effects on denitrifying bacteria as suggested by the decrease in abundances of 16S rRNA, narG, nirK and clade I nosZ genes in the TCS and TCC treatments. Overall, we found that TCS and TCC exposure in paddy soil could substantially alter nitrogen cycling in rice paddy ecosystems by inhibiting denitrification and N2O emissions. These effects should be taken into consideration when evaluating the environmental impacts of TCS and TCC.

Effect of Triclosan and Chloroxylenol on Bacterial Membranes.

Triclosan and chloroxylenol are broad-spectrum biocides used extensively in healthcare and consumer products. They have been suggested to perturb the structure of bacterial membranes, but studies so far have not considered that most bacterial membranes contain large amounts of branched-chain lipids. Here, molecular dynamics simulation is used to examine the effect of the two biocides on membranes consisting of lipids with methyl-branched chains, cyclopropanated chains, and nonbranched chains. It is shown that triclosan and chloroxylenol induced a phase transition in membranes from a liquid-crystalline to a liquid-ordered phase irrespective of the presence and nature of branching groups. At high concentration, chloroxylenol promoted chain interdigitation. Our results suggest that triclosan and chloroxylenol decrease the degree of fluidity of membranes and that this effect is more pronounced in bacterial membranes. As a result, their biocidal activity could be associated with a change in the function of membrane proteins.

Triclosan Alters Microbial Communities in Freshwater Microcosms

The effect of triclosan on microbial communities that are found in soil and sediments is well documented. However, little is known regarding the possible effects of triclosan on microbial communities that are present in the column of freshwater streams as the antimicrobial is released from sediments or from water sewage outflow. We show that a concentration of triclosan as low as 1 ng/L decreases richness and evenness in freshwater microbial communities growing in the water column while using controlled experimental microcosms. Crucially, the decrease in evenness that was observed in the microbial communities was due to the selection of bacteria commonly associated with human activity, such as Acinetobacter, Pseudomonas, and Rhodobacter, as opposed to an increase in Cyanobacteria, as previously suggested. Finally, our results demonstrate that higher concentrations of triclosan comparable to heavily polluted environments can also impact the overall phylogenetic structure and community composition of microbial communities. Understanding the impact of triclosan on these microbial populations is crucial from a public health perspective as human populations are more often exposed to microbial communities that are present in the water column via recreative use.

Fate and effects of triclosan in subtropical river biofilms

Triclosan (TCS, 5-chloro-2-(2,4-dichlorophenoxy) phenol) is a broad-spectrum antimicrobial compound. Owing to its wide use, TCS has been frequently detected in river systems, especially in the (sub-)tropics. However, little information on its interaction with river biofilm in the (sub)tropics is currently available. In the present study, subtropical river biofilms were chronically exposed to TCS for 14 d at concentrations of 0.1–100 μg/L in artificial river water, which was followed by a 7 d recovery period. The results show that 100 μg/L TCS inhibited the growth of river biofilms and the no-observed-effect concentration (NOEC) of TCS on river biofilms was 10 μg/L. The affected biofilms did not completely recover within the 7 d of recovery period due to the adsorbed TCS which was not removed together with dissolved TCS. Exposure to TCS caused significant changes in prokaryotic species composition of river biofilms but no significant effects on eukaryotic species composition. In particular, the relative abundance of several TCS-tolerant bacterial species (e.g., Pseudoxanthomonas mexicana, Sphingopyxis alaskensis and Sphingomonas wittichii) in river biofilms increased following exposure to 10 and 100 μg/L TCS. River biofilm efficiently removed TCS from the liquid phase and the pH values of the aquatic system significantly affected the removal efficiency of TCS (from 36% at pH 6.5 to 60% at pH 8.5). No degradation products were detected in the liquid phase after 5 days of exposure, possibly due to strong adsorption of the hydrophobic degradation products to river biofilms and through biodegradation by bacteria utilizing TCS and its degradation products as source of carbon and energy for growth, such as Methyloversalitis universalis and Methylobacterium aquaticum.

Effects of triclosan on performance, microbial community and antibiotic resistance genes during partial denitrification in a sequencing moving bed biofilm reactor

Effects of triclosan (TCS) on performance, microbial community and antibiotic resistance genes (ARGs) during partial denitrification (PD) were investigated in a sequencing moving bed biofilm reactor (SMBBR). TCS inhibited nitrite accumulation; inhibition effect was more obvious as TCS concentration increased from 1 to 5 mg/L, but it could recover. Extracellular polymeric substances contents increased with 1 mg/L TCS addition and decreased a lot at 5 mg/L TCS. Community structure in biofilm was different from that in floccular sludge, but it was similar at 5 mg/L TCS. Illumina sequencing showed that Pseudomonas, Aeromonas, Shewanella and Thauera became dominant genera. Abundance of nirS was stable and higher than that of narG and nosZ. High-throughput qPCR showed that mexF, acrA-02, fabK, etc. were screened at 5 mg/L TCS. IntI1 and tnpA-04 were abundant mobile genetic elements. The study furthers understanding of effects of TCS on PD, bacterial communities and ARGs in SMBBR.

Triclosan Impairs Hippocampal Synaptic Plasticity and Spatial Memory in Male Rats.

Triclosan, a widely used industrial and household agent, is present as an antiseptic ingredient in numerous products of everyday use, such as toothpaste, cosmetics, kitchenware, and toys. Previous studies have shown that human brain and animal tissues contain triclosan, which has been found also as a contaminant of water and soil. Triclosan disrupts heart and skeletal muscle Ca2+ signaling, damages liver function, alters gut microbiota, causes colonic inflammation, and promotes apoptosis in cultured neocortical neurons and neural stem cells. Information, however, on the possible effects of triclosan on the function of the hippocampus, a key brain region for spatial learning and memory, is lacking. Here, we report that triclosan addition at low concentrations to hippocampal slices from male rats inhibited long-term potentiation but did not affect basal synaptic transmission or paired-pulse facilitation and modified the content or phosphorylation levels of synaptic plasticity-related proteins. Additionally, incubation of primary hippocampal cultures with triclosan prevented both the dendritic spine remodeling induced by brain-derived neurotrophic factor and the emergence of spontaneous oscillatory Ca2+ signals. Furthermore, intra-hippocampal injection of triclosan significantly disrupted rat navigation in the Oasis maze spatial memory task, an indication that triclosan impairs hippocampus-dependent spatial memory performance. Based on these combined results, we conclude that triclosan exerts highly damaging effects on hippocampal neuronal function in vitro and impairs spatial memory processes in vivo.

Tiered Approach for the Evaluation of Environmental Impacts of Triclosan on Aquatic Ecosystems

The synthetic broad-spectrum antibacterial agent triclosan is one of the most commonly encountered emerging micro-pollutant in the aquatic environment due to the extensive use since 1968 mainly in cosmetics and household cleaning products and the partial elimination from wastewater. Its low water solubility, high sorption coefficient to organic matter, accumulation potential in fatty tissues and its low acute toxicity determined by conventional ecotoxicological tests suggest that its risk is more related to chronic effects requiring risk assessment based on more sensitive ecotoxicological methods. In this paper the short- and midterm ecotoxicological effects of triclosan were investigated using various test systems taking into account ecological complexity and environmental relevance. Acute single-species, simplified microcosm experiments and complex multi-species microcosm experiments were conducted with the determination of sublethal physiological and behavioral endpoints including the Daphnia magna heartbeat rate and feeding activity, the Heterocypris incongruens movement parameters and the Lemna minor chlorophyll content and root length. All physiological and behavioral endpoints indicated sensitively the adverse effect of triclosan in the concentration range of 4–25.6 µg/L. In some cases, responses of selected organisms in single-species laboratory tests did not correspond to those of the higher levels of test systems. Daphnia sensitivity increased with the level of the test system for all chosen endpoints except the heartbeat rate. Considering the varying ecological complexity of the assembled test systems, according to our results the exposure time and the different combinations of exposure routes were the most decisive parameters in terms of triclosan ecotoxicity and endpoint sensitivity.

Associations between Urinary Triclosan and Serum Thyroid Hormone Concentrations

Introduction: Exposure to the antimicrobial agent triclosan is ubiquitous. In animals, triclosan causes decreases in circulating thyroxine concentrations. However, the effects of triclosan on thyro...

Antimicrobial agent triclosan disrupts mitochondrial structure, revealed by super-resolution microscopy, and inhibits mast cell signaling via calcium modulation

The antimicrobial agent triclosan (TCS) is used in products such as toothpaste and surgical soaps and is readily absorbed into oral mucosa and human skin. These and many other tissues contain mast cells, which are involved in numerous physiologies and diseases. Mast cells release chemical mediators through a process termed degranulation, which is inhibited by TCS. Investigation into the underlying mechanisms led to the finding that TCS is a mitochondrial uncoupler at non-cytotoxic, low-micromolar doses in several cell types and live zebrafish. Our aim was to determine the mechanisms underlying TCS disruption of mitochondrial function and of mast cell signaling. We combined super-resolution (fluorescence photoactivation localization) microscopy and multiple fluorescence-based assays to detail triclosan's effects in living mast cells, fibroblasts, and primary human keratinocytes. TCS disrupts mitochondrial nanostructure, causing mitochondria to undergo fission and to form a toroidal, “donut” shape. TCS increases reactive oxygen species production, decreases mitochondrial membrane potential, and disrupts ER and mitochondrial Ca2+ levels, processes that cause mitochondrial fission. TCS is 60 × more potent than the banned uncoupler 2,4-dinitrophenol. TCS inhibits mast cell degranulation by decreasing mitochondrial membrane potential, disrupting microtubule polymerization, and inhibiting mitochondrial translocation, which reduces Ca2+ influx into the cell. Our findings provide mechanisms for both triclosan's inhibition of mast cell signaling and its universal disruption of mitochondria. These mechanisms provide partial explanations for triclosan's adverse effects on human reproduction, immunology, and development. This study is the first to utilize super-resolution microscopy in the field of toxicology.

Effects of triclosan in breast milk on the infant fecal microbiome

Triclosan is frequently used for its antimicrobial properties and has been detected in human serum, urine, and breast milk. Animal and molecular studies have shown that triclosan exerts a wide range of adverse health effects at both high (ppm) and low (ppb) concentrations. Since triclosan is of growing concern to human and environmental health, there is a need to improve extraction procedures and to study additional effects from triclosan exposure. In this study, we have improved triclosan extraction from breast milk by using salt (MgSO4) to reduce emulsion formation and increase water polarity and water (∼80%) to enhance the overall extraction efficiency (∼3.5 fold). This extraction method was applied to breast milk samples collected from donors who i) recorded their use of triclosan-containing personal care products and ii) provided matching infant stool samples. Of the participants who had detectable amounts of triclosan in their breast milk, nine (75%) of them reported daily use of triclosan-containing personal care products. Levels of triclosan in breast milk were compared to the donor's infant's fecal microbiome. We found that the bacterial diversity in the fecal microbiome of the infants exposed to breast milk with detectable triclosan levels differed compared to their peers exposed to milk containing non-detectable amounts. This finding implies that exogenous chemicals are impacting microbiome diversity.

Effects of triclosan on Japanese medaka (Oryzias latipes) during embryo development, early life stage and reproduction.

Triclosan has been shown to have endocrine-disrupting effects in aquatic organisms. In 2016, the US Food and Drug Administration banned the use of triclosan in consumer soaps. Before the ban, triclosan was reported at low concentrations in the aquatic environment, although the effect of triclosan on reproduction in teleost fish species is yet to be clarified. Here we investigated the effects of triclosan on embryo development and reproduction, and during the early life stage, in Japanese medaka (Oryzias latipes) by using Organisation for Economic Co-operation and Development tests 229, 212 and 210, with minor modifications. In adult medaka, exposure to 345.7μg l-1 suppressed fecundity and increased mortality but had no effect on fertility. Exposure to 174.1 or 345.7μg l-1 increased liver vitellogenin concentration in females but decreased liver vitellogenin concentration in males. With triclosan exposure, mortality was increased dose dependently during the embryonic and early larval stages, and a particularly steep increase in mortality was observed soon after hatching. The lowest observed effect concentrations of triclosan in Japanese medaka obtained in the present study (mortality [embryonic and larval stages, 276.3μg l-1 ; early life stage, 134.4μg l-1 ; adult stage, 174.1μg l-1 ], growth [134.4μg l-1 ], vitellogenin [174.1μg l-1 ], fecundity [345.7μg l-1 ] and fertility [>345.7μg l-1 ]) were at least 55 times (compared with the USA) and up to 13 400 times (compared with Germany) greater than the detected triclosan levels in the aquatic environment. These results suggest that triclosan may not be affecting fish populations in the aquatic environment.

Effects of triclosan (TCS) on hormonal balance and genes of hypothalamus-pituitary- gonad axis of juvenile male Yellow River carp (Cyprinus carpio)

Triclosan (TCS) is a broad spectrum antimicrobial agent which has been widely dispersed and determinated in the aquatic environment. However, the effects of TCS on reproductive endocrine in male fish are poorly understood. In this study, male Yellow River carp (Cyprinus carpio) were exposed to 0, 1/5, 1/10 and 1/20 LC50 (96 h LC50 of TCS to carp) TCS under semi-static conditions for 42 d. Vitellogenin (Vtg), 17β-estradiol (E2), testosterone(T), gonadotropin (GtH), and gonadotropin-releasing hormone (GnRH) levels were measured by enzyme-linked immunosorbent assay (ELISA). Meanwhile, we also examined the mRNA expressions of aromatase, GtHs-β, GnRH, estrogen receptor (Er), and androgen receptor (Ar) by quantitative Real-time Polymerase Chain Reaction (qRT-PCR). TCS induced Vtg levels of hepatopancreas, E2 levels of serum, and inhibited Ar and Er mRNA levels, suggesting that the induction of Vtg production by TCS was indirectly caused by non-Er pathways. TCS-induced Vtg levels by interfering with the reproductive axis at plenty of latent loci of male carps: (a) TCS exposure increased the aromatase mRNA expression of hypothalamus and gonad aromatase, consequently increasing serum concentrations of E2 to induce Vtg in hepatopancreas; (b) TCS treatment changed GtH-β and GnRH mRNA expression and secretion, causing the disturbance of reproductive endocrine; (c) TCS exposure decreased Ar mRNA levels, indicating potential Ar-mediated antiandrogen action. These mechanisms showed that TCS may induce Vtg production in male carp by non-Er-mediated pathways.

Effects of triclosan on hormones and reproductive axis in female Yellow River carp (Cyprinus carpio): Potential mechanisms underlying estrogen effect

Triclosan (TCS), a member of the class of compounds called pharmaceutical and personal care products (PPCPs), is a broad antibacterial and antifungal agent found in a lot of consumer products. However, TCS hormone effect mechanism in teleost female fish is not clear. Female Yellow River carp (Cyprinus carpio) were exposed to 1/20, 1/10 and 1/5 LC50 TCS (96h LC50 of TCS to carp) under semi-static conditions for 42days. Vitellogenin (Vtg), 17β-estradiol (E2), testosterone(T), estrogen receptor (Er), gonadotropin (GtH), and gonadotropin-releasing hormone (GnRH) levels were measured by enzyme-linked immunosorbent assay (ELISA). Meanwhile, we also examined the mRNA expressions of aromatase, GtHs-β, GnRH, and Er by quantitative real-time PCR (qRT-PCR). The results indicated that 1/5 LC50 TCS induced Vtg in hepatopancreas of female carps by interference with the hypothalamic–pituitary–gonadal (HPG) axis at multiple potential loci through three mechanisms: (a) TCS exposure enhanced the mRNA expression of hypothalamus and gonadal aromatase which converts androgens into estrogens, subsequently increasing serum concentrations of E2 to induce Vtg in hepatopancreas; (b) TCS treatment increased GnRH and GtH-β mRNA expression and secretion, causing the disturbance of reproductive endocrine and the increase of E2 to induce Vtg in hepatopancreas; (c) TCS exposure enhanced synthesis and secretion of Er, then it bound to Er to active Vtg synthesis. These mechanisms showed that TCS may induce Vtg production in female Yellow River carp by Er-mediated and non-Er-mediated pathways.

Effects of triclosan on gonadal differentiation and development in the frog Pelophylax nigromaculatus

Previous studies have reported that triclosan (TCS) could possess an androgenic activity. We aimed to investigate the effects of TCS on gonadal differentiation and development in the frog Pelophylax nigromaculatus, a sensitive amphibian species to androgenic chemicals. P. nigromaculatus tadpoles at stage 24 were exposed to TCS (3, 30, and 300nmol/L) to stage 46 in a semi-static exposure system. At the end of exposure, gonadal morphology and histology, sex ratio and gonadal expression of sex-biased genes were examined in P. nigromaculatus. In each TCS treatment group, we found several individuals whose gonads exhibited morphological and/or histological abnormalities. Gonadal histological abnormalities were characterized by few oocytes and many somatic cells. Although the percentage of the individuals with abnormal gonads was low (7.8%) among all animals treated with TCS, statistical test revealed the sex ratios in the 3 and 300nmol/L TCS treatment groups were significantly different from the solvent control. In the 30nmol/L TCS treatment group, abnormal gonads were also observed, although the sex ratio was not changed compared with the solvent control, which was possibly due to the smaller sample size in this group. In all the TCS treatment groups, the sex ratios were not obviously male-biased, but the expression levels of some sex-biased genes were significantly altered by TCS. Altogether, our results suggest that TCS, even at environmentally relevant concentrations, could disrupt gonadal differentiation and development in P. nigromaculatus, but we are not sure whether the disrupting effects were associated with masculinization or feminization.

Profound perturbation induced by triclosan exposure in mouse gut microbiome: a less resilient microbial community with elevated antibiotic and metal resistomes

BackgroundEnvironmental chemical-induced perturbations of gut microbiome are associated with a series of adverse health outcomes. The effects of triclosan on human health have been controversial in recent years. The purpose of this study is to investigate the functional impact of triclosan on the mouse gut microbiome and the link between triclosan exposure and resistomes in gut bacteria.MethodsWe combined 16S rRNA gene sequencing and shotgun metagenomics sequencing to examine the compositional and functional impact of triclosan exposure on the gut microbiota of C57BL/6 mice.Results16S rRNA sequencing results revealed that 13-week triclosan exposure in drinking water induced significant perturbations in mouse gut bacterial assemblages with distinct trajectories compared to controls. Metagenomics sequencing results indicated a remarkable enrichment of gut bacterial genes related to triclosan resistance, stress response, antibiotic resistance and heavy metal resistance.ConclusionsTriclosan exposure has a profound impact on the mouse gut microbiome by inducing perturbations at both compositional and functional levels. To our best knowledge, this is the first evidence regarding the functional alterations of gut microbiome induced by triclosan exposure, which may provide novel mechanistic insights into triclosan exposure and associated diseases.

Comparison of methods for calculating the health costs of endocrine disrupters: a case study on triclosan

BackgroundSocioeconomic analysis is currently used in the Europe Union as part of the regulatory process in Regulation Registration, Evaluation and Authorisation of Chemicals (REACH), with the aim of assessing and managing risks from dangerous chemicals. The political impact of the socio-economic analysis is potentially high in the authorisation and restriction procedures, however, current socio-economic analysis dossiers submitted under REACH are very heterogeneous in terms of methodology used and quality. Furthermore, the economic literature is not very helpful for regulatory purposes, as most published calculations of health costs associated with chemical exposures use epidemiological studies as input data, but such studies are rarely available for most substances. The quasi-totality of the data used in the REACH dossiers comes from toxicological studies.MethodsThis paper assesses the use of the integrated probabilistic risk assessment, based on toxicological data, for the calculation of health costs associated with endocrine disrupting effects of triclosan. The results are compared with those obtained using the population attributable fraction, based on epidemiological data.ResultsThe results based on the integrated probabilistic risk assessment indicated that 4894 men could have reproductive deficits based on the decreased vas deferens weights observed in rats, 0 cases of changed T3 levels, and 0 cases of girls with early pubertal development.The results obtained with the Population Attributable Fraction method showed 7,199,228 cases of obesity per year, 281,923 girls per year with early pubertal development and 88,957 to 303,759 cases per year with increased total T3 hormone levels.The economic costs associated with increased BMI due to TCS exposure could be calculated. Direct health costs were estimated at €5.8 billion per year.ConclusionsThe two methods give very different results for the same effects. The choice of a toxicological-based or an epidemiological-based method in the socio-economic analysis will therefore significantly impact the estimated health costs and consequently the political risk management decision. Additional work should be done for understanding the reasons of these significant differences.

The effect of triclosan on posttranslational modification of proteins through citrullination and carbamylation.

The aim of this study was evaluate the effect of triclosan on citrullination and carbamylation, two important protein posttranslational modifications associated with inflammatory conditions such as periodontitis and rheumatoid arthritis. A range of triclosan concentrations were incubated in the presence of appropriate substrates used for the generation of either citrullinated or carbamylated proteins. The effect of triclosan on protein citrullination and carbamylation in macrophages was also assessed. Citrullination and carbamylation were both significantly decreased by triclosan at concentrations six times lower than the 0.3% triclosan approved by the FDA to use in mouthwash and toothpaste. When macrophages were exposed to triclosan, carbamylation was significantly deceased (p=0.01), and while citrullination also decreased, this reduction was not statistically significant (p=0.06). Triclosan reduced the generation of protein citrullination and carbamylation in vitro. Triclosan may be useful as an adjunct therapy in the management of inflammatory periodontal diseases and help to reduce posttranslational protein modification citrullination and carbamylation) in these tissues.