BDE 49 and developmental toxicity in zebrafish

• Published in: Comparative biochemistry and physiology. Toxicology & pharmacology Vol. 155; no. 2; pp. 253 - 258
• Main Authors: McClain, Valerie, Stapleton, Heather M., Tilton, Fred, Gallagher, Evan P.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-03-2012
• Subjects: Animals; BDE 47; carp; Danio rerio; Development; developmental toxicity; dose response; Dose-Response Relationship, Drug; Embryo, Nonmammalian - drug effects; Embryo, Nonmammalian - embryology; Escape Reaction - drug effects; Female; flame retardants; Flame Retardants - toxicity; Freshwater; Halogenated Diphenyl Ethers - chemistry; Halogenated Diphenyl Ethers - toxicity; Heart - drug effects; Heart - embryology; Heart - physiopathology; heart rate; human health; Humans; Larva - drug effects; Larva - physiology; larvae; Male; metabolism; Molecular Structure; neurotoxicity; polybrominated diphenyl ethers; risk; salmon; Salmonidae; survival rate; tail; Tail - drug effects; Tail - embryology; tissues; Toxicity Tests - methods; trout; wildlife; Zebrafish; Development; Zebrafish; BDE 47
• ISSN: 1532-0456; 1878-1659
• DOI: 10.1016/j.cbpc.2011.09.004

The polybrominated diphenyl ethers (PBDEs) are a group of brominated flame retardants. Human health concerns of these agents have largely centered upon their potential to elicit reproductive and developmental effects. Of the various congeners, BDE 49 (2,2′,4,5′-tetrabromodiphenyl ether) has been poorly studied, despite the fact that it is often detected in the tissues of fish and wildlife species. Furthermore, we have previously shown that BDE 49 is a metabolic debromination product of BDE 99 hepatic metabolism in salmon, carp and trout, underscoring the need for a better understanding of biological effects. In the current study, we investigated the developmental toxicity of BDE 49 using the zebrafish (Danio rerio) embryo larval model. Embryo and larval zebrafish were exposed to BDE 49 at either 5 hours post fertilization (hpf) or 24hpf and monitored for developmental and neurotoxicity. Exposure to BDE 49 at concentrations of 4iμ–32μM caused a dose-dependent loss in survivorship at 6days post fertilization (dpf). Morphological impairments were observed prior to the onset of mortality, the most striking of which included severe dorsal curvatures of the tail. The incidence of dorsal tail curvatures was dose and time dependent. Exposure to BDE 49 caused cardiac toxicity as evidenced by a significant reduction in zebrafish heart rates at 6dpf but not earlier, suggesting that cardiac toxicity was non-specific and associated with physiological stress. Neurobehavioral injury from BDE 49 was evidenced by an impairment of touch–escape responses observed at 5dpf. Our results indicate that BDE 49 is a developmental toxicant in larval zebrafish that can cause morphological abnormalities and adversely affect neurobehavior. The observed toxicities from BDE 49 were similar in scope to those previously reported for the more common tetrabrominated congener, BDE 47, and also for other lower brominated PBDEs, suggest that these compounds may share similarities in risk to aquatic species.