Assessment of the endocrine-disrupting potential of halogenated parabens: An in silico approach.

Parabens are endocrine-disrupting chemicals present in a variety of pharmaceutical and personal care products. Due to their wide-spread use, significant amounts are also released into the aquatic domain of the environment. During water disinfection, parabens give rise to halogenated transformation products. As opposed to parabens, there is considerable lack of knowledge with regard to the endocrine-disrupting potential of their halogenated counterparts, which presents a challenge for regulatory decision making. We aimed to fill this knowledge gap by using the Endocrine Disruptome and VirtualToxLab™ to predict their endocrine-disrupting potential on the basis of calculated affinities for different nuclear receptors. The applied computational approach indicates a high probability of halogenated parabens binding to glucocorticoid, thyroid and aryl hydrocarbon receptors and suggests that disinfection is likely to form transformation products with more pronounced endocrine-disrupting activities than those of parent parabens. The obtained results not only highlight the need for additional in vitro/in vivo investigations of these chemicals as endocrine disruptors but also provide a means of guiding and prioritizing these future studies, in order to assess fully their hazard to human health.