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Triclosan and Triclocarban, preservatives widely used in cosmetics and other consumer products, underwent evaluation using a battery of new-approach methodologies in vitro (NAMs). Specifically, the Microplate Ames Test (MPF™ Test, Xenometrix, Allschwil, Switzerland) was employed to assess mutagenicity, the Comet assay in vitro on the HaCat cell line and the Mammalian Chromosome Aberration Test were utilized to evaluate genotoxicity, and the XenoScreen® YES/YAS assay was applied to investigate endocrine disruption. The chemicals did not exhibit any positive responses for mutagenicity. However, the mammalian chromosome aberration test identified both chemicals as being positive for genotoxicity at 10 µg/mL. In the Comet assay, the percentage of DNA in the tail significantly increased in a concentration-dependent manner (at 5 and 10 µg/mL for Triclosan, at 2.5, 5, and 10 µg/mL for Triclocarban). The positive response depended on the increasing concentration and the duration of exposure. Triclosan, but not Triclocarban in any of the endocrine assays performed, indicated a potential for endocrine activity in the anti-estrogenic and anti-androgenic assays. The positive in vitro results detected were obtained for concentrations relevant to final products. The alarming findings obtained with the use of new-approach methodologies (NAMs) justify the current precautionary regulatory approach, limiting the use of these preservatives. [ABSTRACT FROM AUTHOR]

Growing worldwide efforts to replace (reduce) animal testing and to improve alternative in vitro tests which may be more efficient in terms of both time, cost and scientific validity include also genotoxicity/mutagenicity endpoints. The aim of the review article was to summarize currently available in vitro testing approaches in this field, their regulatory acceptance and recommended combinations for classification of chemicals. A study using the combination of Comet Assay performed on two cell lines and the Chromosomal Aberration test on human peripheral lymphocytes was performed with the aim to predict the genotoxic potential of selected paraben esters, serving as a model chemical group. Parabens are widely used in consumer products as preservatives and have been reported to exhibit inconclusive results in numerous genotoxicity studies. The Comet Assay identified Ethylparaben and Benzylparaben as potentially genotoxic. The Chromosomal Aberration test revealed weak genotoxic potential in case of Ethylparaben and positive genotoxicity in case of Butylparaben, Propylparaben and Isopropylparaben. The main reasons for variability seem to be limited water solubility of parabens, determining their bioavailability at the cellular level, and absence of metabolic activation in the Comet Assay. The results confirmed that the Comet Assay should serve as a screening test and should not be used as a stand-alone method for classification of genotoxicity. The weight of evidence approach in risk assessment should be supported with data generated with the use of human relevant in vitro methods based on cells/tissues of human origin. [ABSTRACT FROM AUTHOR]

Three preservatives used as ingredients in cosmetics and other consumer products (triclosan, triclocarban and resorcinol) were evaluated for their genotoxic/mutagenic potential by means of a set of in vitro alternative methods, namely Ames Test (MPF Test, Xenometrix, OECD TG 471) with strains TA 98, TA 100, TA 1535 and TA 1537, Comet assay on HaCat cell line (non-tumor human keratinocytes) and Mammalian chromosome aberration test (OECD TG 473) using human peripheral lymphocytes. In the chromosome aberration test all three chemicals were positive in the highest tested concentrations. Similarly, in the Comet assay the percentage of DNA in tail was significantly increased in the highest concentrations. Moreover, the genotoxic effects were clearly dependent on the increasing concentration and duration of exposure. The Ames Test revealed positivity only for resorcinol using strain TA 1537, detecting frameshift mutations. The positive results were recorded for extremely high concentrations which under foreseeable conditions could not be present in the human body, however, the results justify the need to regulate and limit the use of these preservatives in final products. [ABSTRACT FROM AUTHOR]