Nano-TiO2 Adsorbed Decabromodiphenyl Ethane and Changed Its Bioavailability, Biotransformation and Biotoxicity in Zebrafish Embryos/Larvae

Abstract

Decabromodiphenyl ethane (DBDPE), a novel brominated flame retardant, may co-exist with other pollutants including nanoparticles (NPs) in aquatic environment. Due to structural similarity with decabromodiphenyl ether, DBDPE has been reported to exhibit thyroid disrupting effects and neurotoxicity. This study further evaluated the behavior of DBDPE in aqueous environments along with the bioavailability and toxicity of DBDPE in aquatic organisms in the presence of TiO2 nanoparticles (n-TiO2). When co-existing in an aqueous environment, DBDPE was adsorbed by n-TiO2, potentially facilitating the sedimentation of DBDPE from the aqueous phase. Co-exposure to DBDPE and n-TiO2 significantly increased the uptake of DBDPE by zebrafish (Danio rerio) embryos and altered the composition of metabolites in zebrafish larvae compared to zebrafish exposed to DBDPE alone. The DBDPE-induced increases in heart rate, tail bending frequency, average speed under dark/light stimulation, and thyroid hormone levels in zebrafish embryos/larvae were further enhanced in the presence of n-TiO2. Overall, the results demonstrate that n-TiO2 affected the behavior of DBDPE in the aqueous phase and increased the bioavailability and biotoxicity of DBDPE in zebrafish embryos/larvae. These results could be helpful for understanding the environmental behavior and toxicity of DBDPE.

Mitochondrial Dysfunction Was Involved in Decabromodiphenyl Ethane-Induced Glucolipid Metabolism Disorders and Neurotoxicity in Zebrafish Larvae

“…In addition, the average free-swimming speed during the dark–light transition period was significantly increased in all light and dark phases upon 400 μg/L DBDPE exposure (Figure A). These observations were consistent with previous studies, which reported excitatory effects in zebrafish larvae upon embryonic exposure to DBDPE. , …”

Multi- and Transgenerational Developmental Impairments Are Induced by Decabromodiphenyl Ethane (DBDPE) in Zebrafish Larvae

“…Meanwhile, the hyperactivity of larvae was observed during both light and dark cycles (Figure B,D). In our recent study, acute exposure to 10 nM DBDPE also caused significantly increased contents of neurotransmitters (GABA, ACh, choline, and NE) and increased locomotor speed in zebrafish larvae . These results suggested that DBDPE exposure may cause multigenerational effects on the homeostasis of neurotransmitters in zebrafish larvae.…”

The metabolism of novel flame retardants and the internal exposure and toxicity of their major metabolites in fauna - a review

“…Fish and marine mammals DBDPE could be rapidly metabolized (39.6-66.6 pmol in 90 min) to phenolic metabolites by marine mammal liver microsomes from arctic areas (polar bear, beluga whale, and ringed seal) [101] . DBDPE debromination (7 unknown compounds) was also confirmed in zebrafish after water-borne exposure [102] . They tentatively assigned them to nona-BDPE, nona-brominated products, octa-BDPE, hepta-BDPE, and other-brominated products [103] .…”