Neurological responses of embryo-larval zebrafish to short-term sediment exposure to decabromodiphenylethane

Abstract

Decabromodiphenylethane (DBDPE) has been widely used as an alternative flame retardant due to the restriction or phase-out of traditional polybrominated diphenyl ethers (PBDEs), and is of increasing concern regarding its ubiquity, persistence, and potential adverse effects. In the present study, the toxicological effects of DBDPE were evaluated using zebrafish as an in vivo model. Upon being exposed to DBDPE-polluted sediments for a short term, it was found that the mortality and malformation of zebrafish (including edema, bent notochord, and bent tail) were not affected even at the highest concentration tested (1000.0 µg/kg dry sediment). Regarding behavioral responses, it was found that zebrafish larvae of 48 hours post fertilization (hpf) in all groups escaped successfully with a touch to the dorsal fin. However, when exposed to the highest DBDPE concentration, the larvae of 120 hpf exhibited significantly smaller distances as compared to the control. Moreover, the results of the acetylcholinesterase (AChE) activity, the expression levels of two important nerve-related genes, and the cell apoptosis all indicated that DBDPE posed low neurotoxicity in embryo-larval zebrafish. The results in this study shed some light on the potential risks of DBDPE in the real environment and highlight the application of the sediment exposure route in the future.

An integrative translational framework for chemical induced neurotoxicity – a systematic review

“…These models offer chemical safety reference and are one-step closer to translate the effects on human nervous system. Mostly neurobehavioral assessment (63.6%) have been used as a close proxy to check neurological disturbances or damage (Figure 5) (Dingemans et al 2007;Vitalone et al 2008;Boix et al 2010;Kim and Pessah 2011;Tseng et al 2013;Lee et al 2014;Ma et al 2015;Moser et al 2015;Liu et al 2018;Yang et al 2018;Zhang et al 2018Zhang et al , 2016Zhu et al 2018).…”

“…Neuroscientists conduct basic tests in animals to detect changes in brain morphology which includes phenotypic characters such as organ weight and growth (18.2%) (Malkiewicz et al 2006;Moser et al 2015;Vitalone et al 2008;Yang et al 2018), histopathological study (18.2%) (Ma et al 2015;Liu et al 2018;Yang et al 2018;Zhang et al 2018) and target tissue concentration of chemical (13.6%) (Vitalone et al 2008;Ruan et al 2009;Lee et al 2014). Hormonal activities e.g.…”

“…Unbalances in these hormones level has an impact on brain development, cell number, cell migration and synaptogenesis as studied by Moser et al (2015), Wang et al (2015) and Zhu et al (2018). Cell death research in recent years has led to development of certain gold techniques like TUNEL and other mechanisms for identifying neuronal cell death (9.1%) (Yang and Lein 2010;Zhang et al 2018) (Figure 5).…”

“…Firstly, neurotransmission as an important mechanism how neuron conducts message and the impact on this can be known by measuring neurotransmitters as a biomarker (Boix et al 2010;Dingemans et al 2007;Gee et al 2011;Lei et al 2017;Moser et al 2015;Pham-Lake et al 2017;Wang et al 2015;Zhang et al 2018;Zhu et al 2018). Secondly, neurochannels balance ionic concentration inside and outside of the cell through voltage gated calcium channels and calcium could be a biomarker to study the ion channel mechanism (Mochida 2000;Dingemans et al 2007).…”

“…Also, ROS (13.6%) production due to oxidative stress leads to effect on nervous system (Tseng et al 2013;Ma et al 2015;Wang et al 2015). Lately, advancement is being made in recognizing the patterns of response in genes (transcriptome) (Basha et al 2006;Malkiewicz et al 2006;Tseng et al 2013;Wang et al 2015;Liu et al 2018;Yang et al 2018;Zhang et al 2018;Zhu et al 2018) and proteins (proteomics) (Basha et al 2006;Malkiewicz et al 2006;Dingemans et al 2007;Boix et al 2010;Yang and Lein 2010;Morris et al 2012;Lee et al 2014;Ma et al 2015;Wang et al 2015;Lei et al 2017) that might be predictive of neuronal effects. Study on effect of immune cells (4.5%) on nervous system measuring subsets of T cells from spleen, myelin basic protein level, serum markers and T cells infiltration in brain region has evaluated by Morris et al (2012) (Figure 5).…”