In Vitro Biologic Activities of the Antimicrobials Triclocarban, Its Analogs, and Triclosan in Bioassay Screens: Receptor-Based Bioassay Screens

BackgroundConcerns have been raised about the biological and toxicologic effects of the antimicrobials triclocarban (TCC) and triclosan (TCS) in personal care products. Few studies have evaluated their biological activities in mammalian cells to assess their potential for adverse effects.ObjectivesIn this study, we assessed the activity of TCC, its analogs, and TCS in in vitro nuclear-receptor-responsive and calcium signaling bioassays.Materials and methodsWe determined the biological activities of the compounds in in vitro, cell-based, and nuclear-receptor-responsive bioassays for receptors for aryl hydrocarbon (AhR), estrogen (ER), androgen (AR), and ryanodine (RyR1).ResultsSome carbanilide compounds, including TCC (1-10 muM), enhanced estradiol (E(2))-dependent or testosterone-dependent activation of ER- and AR-responsive gene expression up to 2.5-fold but exhibited little or no agonistic activity alone. Some carbanilides and TCS exhibited weak agonistic and/or antagonistic activity in the AhR-responsive bioassay. TCS exhibited antagonistic activity in both ER- and AR-responsive bioassays. TCS (0.1-10 muM) significantly enhanced the binding of [(3)H]ryanodine to RyR1 and caused elevation of resting cytosolic [Ca(2+)] in primary skeletal myotubes, but carbanilides had no effect.ConclusionsCarbanilides, including TCC, enhanced hormone-dependent induction of ER- and AR-dependent gene expression but had little agonist activity, suggesting a new mechanism of action of endocrine-disrupting compounds. TCS, structurally similar to noncoplanar ortho-substituted poly-chlorinated biphenyls, exhibited weak AhR activity but interacted with RyR1 and stimulated Ca(2+) mobilization. These observations have potential implications for human and animal health. Further investigations are needed into the biological and toxicologic effects of TCC, its analogs, and TCS

Spitzer Observations of Bok Globule B335: Isolated Star Formation Efficiency and Cloud Structure

We present infrared and millimeter observations of Barnard 335, the prototypical isolated Bok globule with an embedded protostar. Using Spitzer data we measure the source luminosity accurately; we also constrain the density profile of the innermost globule material near the protostar using the observation of an 8.0 um shadow. HHT observations of 12CO 2 --> 1 confirm the detection of a flattened molecular core with diameter ~10000 AU and the same orientation as the circumstellar disk (~100 to 200 AU in diameter). This structure is probably the same as that generating the 8.0 um shadow and is expected from theoretical simulations of collapsing embedded protostars. We estimate the mass of the protostar to be only ~5% of the mass of the parent globule.Comment: 15 pages, 17 figures, emulateapj format, accepted for publication in Ap

An immunoassay for the detection of triclosan-O-glucuronide, a primary human urinary metabolite of triclosan

Triclosan-O-glucuronide (TCSG) is one of the primary urinary metabolites of the antibacterial compound triclosan or TCS that is found in many personal care products and consumer goods. We have developed a competitive, indirect heterologous ELISA for the detection of the target TCSG in urine. Such an ELISA for TCSG could be developed as a useful tool to measure this important biomarker of human exposure to TCS. Immunogens were prepared by conjugating TCSG to thyroglobulin, via heterobifunctional cross-linkers AEDP or 3-[(2-aminoethyl)dithio] propionic acid•hydrochloride and TFCS or N-[ε-trifluoroacetylcaproyloxy]succinimide ester. The coating antigen was prepared by the direct conjugation of TCSG to bovine serum albumin. Antibodies raised in rabbits 2619, 2621 (immunogen TCSG-AEDP-Thy), and 2623 (immunogen TCSG-TFCS-Thy), and the coating antigen were screened and characterized to determine their optimal concentrations. The optimized ELISA, developed with antibody 2621, gave an IC50 value of 2.85 ng/mL, with the linear range (IC20-IC80) determined to be 2.6-24.8 ng/mL. Selectivity of the assay was assessed by measuring cross-reactivity of antibody 2621 to related congeners such as the aglycone TCS, triclosan-O-sulfate, triclocarban, a polybrominated diphenyl ether derivative, and 3-phenoxybenzyl alcohol glucuronide. There was virtually no recognition by antibody 2621 to any of these cross-reactants. Graphical Abstract Urinary biomarker analysis of triclosan glucuronide

Development of an Immunoassay for the Detection of the Phenylpyrazole Insecticide Fipronil

Phenylpyrazole insecticides such as fipronil have been used as replacements for organophosphates. The wide application of fipronil raises concern about environmental contamination and risk for fish, birds, and other nontargeted beings as well as human health. A sensitive, competitive indirect heterologous enzyme-linked immunosorbent assay (ELISA) was developed. Antibodies with different specificities to fipronil and its metabolites were produced. Two ELISAs having IC50 values of 0.58 ± 0.06 and 2.6 ± 0.4 ng/mL were developed. Design of different haptens and coating antigens resulted in two assays with distinct cross-reactivity patterns for structurally related compounds: 96, 38, and 101% versus 39, 1.4, and 25% for fipronil-sulfide, fipronil-detrifluoromethylsulfonyl, and fipronil-desulfinyl, respectively. Performance of the immunoassays was demonstrated by a recovery study from spiked water and human serum and urine matrices, giving recovery values in the range of 85-111% for different concentrations. The assays demonstrated good correlation in fipronil recovery with conventional LC-MS/MS analysis. The generic assay 2265 has the sensitivity to measure fipronil and its analogs in serum at levels relevant for exposure monitoring. The assays were used to analyze human urine samples obtained from exposure studies and serum samples from rats treated with a fipronil-containing diet