Disruption of Early Pregnancy in the CF-1 Mouse: Impacts of Triclosan Alone and in Combination with Bisphenol-A

Abstract

<p>Triclosan is an antimicrobial additive found in a number of personal care and household products. Widely detected in humans, the compound has been given increasing attention due to reports of its endocrine-disrupting potential. Recent evidence indicates that triclosan is mildly estrogenic. The carefully timed event of blastocyst implantation in mammals is modulated in part by estrogen and can be disrupted by above optimal elevations in estrogenic stimulation. Here, we examined the influences of triclosan administration in inseminated female mice. Doses of 18 and 27 mg/animal/day on gestation days (GD) 1–3 reduced implantation site numbers as observed on GD 6, relative to vehicle controls and females given lower doses. Single doses of 18 or 27 mg reduced implantations when given on GD 3, whereas only 27 mg did so when given on GD 2. Subsequently, we examined the impacts on early pregnancy of triclosan in combination with the xenoestrogen bisphenol-A, which has been previously found to disrupt implantation, at doses that were individually ineffective. A combination of 4 mg BPA and 9 mg triclosan/animal/day administered on GD 1–3 reduced the number of implantations observed on GD 6 and increased the length of gestation, relative to controls and those animals simply given one or the other compound. All of these effects mimicked stronger effects seen in positive controls given 17β-estradiol. These data are consistent with the notion that triclosan has mild estrogenic properties, and show that it can act together with a known xenoestrogen to disrupt implantation.</p>