Influence of Tetrabromobisphenol A, with or without Concurrent Triclosan, upon Bisphenol A and Estradiol Concentrations in Mice

Abstract

Background:Humans are commonly exposed to multiple environmental chemicals, including tetrabromobisphenol A (TBBPA; a flame retardant), triclosan (an antimicrobial agent), and bisphenol A (BPA; polycarbonate plastics). These chemicals are readily absorbed and may interact with each other.Objectives:We sought to determine whether TBBPA, given alone or in combination with triclosan, can modulate the concentrations of BPA and (E2).Methods:Female and male CF-1 mice were each given a subcutaneous injection of TBBPA, with or without concurrent triclosan, followed by dietary administration of body weight . Radioactivity was measured in blood serum and tissues through liquid scintillation counting. In subsequent experiments, female and male CF-1 mice were each given a subcutaneous injection of 0 or TBBPA and E2 was measured in urine 2–12 h after injection.Results:Doses as low as TBBPA significantly elevated concentrations in the uterus and ovaries of females; in the testes, epididymides, vesicular-coagulating glands, and preputial glands of males; and in blood serum, heart, lungs, and kidneys of both sexes; urinary E2 concentrations were also elevated. Lower doses of TBBPA or triclosan that had no effects on their own elevated concentrations when the two substances were given concurrently.Conclusion:These data indicate that TBBPA, triclosan, and BPA interact in vivo, consistent with evidence that TBBPA and triclosan inhibit enzymes that are critical for BPA and E2 metabolism. https://doi.org/10.1289/EHP1329