Triclosan exacerbates the presence of 14C-bisphenol A in tissues of female and male mice.

Current human generations are commonly exposed to both triclosan (TCS), an antimicrobial agent, and bisphenol A (BPA), the monomer of polycarbonate plastics and epoxies. Both are readily absorbed into circulation and found distributed among diverse tissues. Potential interactions between TCS and BPA are largely unstudied. We investigated whether TCS exposure affects the distribution of ingested (14)C-BPA in select tissues. CF-1 mice were each subcutaneously injected with TCS then orally administered 50 μg/kg (14)C-BPA. Females received 0, 0.2, 0.6, 1, 2, or 18 mg TCS (equivalent respectively to 0, 6.3, 16.9, 30.1, 60.5, and 558.9 mg/kg). Males received 0, 0.2, 2, or 18 mg TCS (equivalent respectively to 0, 5.3, 53.4, and 415.0mg/kg). Levels of radioactivity were measured through liquid scintillation counting in blood serum and brain, reproductive, and other tissues. Significantly elevated levels of radioactivity were observed following combined TCS and (14)C-BPA administration, with minimally effective TCS doses being tissue-dependent (Females: lungs, 0.6 mg; uterus, 1mg; heart, muscle, ovaries, and serum, 18 mg. Males: serum, 0.2mg; epididymides, 2mg). Subsequently, we found that 2 or 6 mg TCS increased radioactivity in the ovaries and serum of females orally given only 5 μg/kg (14)C-BPA. These data indicate that TCS can interact with BPA in vivo, magnifying its presence in certain tissues and serum. The data are consistent with evidence that TCS utilizes enzymes that are critical for metabolism and excretion of BPA. Further research should investigate the mechanisms through which these two chemicals interact at environmentally-relevant doses.