AEO-7 surfactant is “super toxic” and induces severe cardiac, liver and locomotion damage in zebrafish embryos

Abstract

Background Fatty alcohol polyoxyethylene ether-7 (AEO-7), a non-ionic surfactant, has recently been receiving extensive attention from the ocean pipeline industry for its ability to inhibit corrosion. However, the present lack of information concerning the potential environmental toxicity of AEO-7, especially towards aquatic organisms, is a major impediment to its wider application. Here, we assess potential adverse effects of AEO-7 on zebrafish embryos employing a variety of assays, including (i) a mortality/survival assay which allowed the median lethal concentration (LC50) to be calculated; (ii) a teratogenicity assay on the basis of which the no observed effect concentration (NOEC) was determined; and (iii) specific assays of cardiotoxicity, neurotoxicity (based on locomotion), hematopoietic toxicity (the level of hemoglobin as revealed by o-dianisidine staining) and hepatotoxicity (liver steatosis and yolk retention examined by staining with Oil Red O). Results AEO-7 caused mortality with a calculated LC50 of 15.35 μg/L, which, according to the U.S. Fish and Wildlife Service (USFWS) Acute Toxicity Rating scale, should be considered “super toxic”. Although at its NOEC (0.8 μg/L), there were no signs of significant teratogenicity, cardiotoxicity, or hemopoiesis toxicity, 3.2 µg/L AEO-7 exerted dramatic detrimental effects on organ development. Conclusion On the basis of these findings, we recommend that the industrial usage and environmental impact of AEO-7 be re-evaluated and strictly monitored by environmental and public health organizations.

Nonylcyclohexanol ethoxylates, a green alternative of nonylphenol ethoxylate, on the interfacial physiochemical properties aspects

“…The toxicity of NCEO n to zebra fish embryos decreased with the growth of the EO units, which was consistent with the toxicity of polyoxyethylene ether surfactants to aquatic animals (Al‐Asmakh et al, 2020; Mustapha & Bawa‐Allah, 2020). The LC 50 for zebra fish embryos varies from 5.98 to 7.04 mg/L for NCEO n , which were less toxic than NPEO 10 to zebra fish embryos (LC 50 = 4.84 mg/L), which confirmed that NCEO n is safer than NPEO 10 .…”

JC-10 probe as a novel method for analyzing the mitochondrial membrane potential and cell stress in whole zebrafish embryos

“…immotile, opaque, or embryos with undetectable heartbeats) were excluded. Healthy embryos were incubated in six-well plates containing prepared concentrations of AEO-7 (.4, .8, 3.2, 6.4, 12.8, 25 μg/L), PTU-E3 (negative control), and DEAB (10 and 100 μM) (positive control) [10,12]. The survival rate of the embryos was assessed until 4-dpf.…”

“…The median lethal concentration (LC 50 ) was calculated by fitting a sigmoidal curve to the data on mortality using the GraphPad Prism 8 software (version 8.2.1, San Diego, CA, USA), as previously described [21,25,26]. In addition, we used this curve to calculate the LC 10 , LC 20 and LC 50 at a statistical significance of 95% (P < .05) [12,27]. Moreover, we calculated the no observed effect concentration (NOEC), which is the highest concentration that does not cause a significant effect (P < 0.05) relative to the negative control (PTU-E3).…”

“…Zebrafish (Danio rerio) has emerged as a powerful animal model for environmental toxicity studies of vertebrates [9][10][11][12]. It provides an affordable and relatively rapid approach for cytotoxicity screening and probing the mechanism(s) of toxicity.…”

“…We developed this method using wild-type (WT) zebrafish during early embryogenesis. We tested this method using Fatty Alcohol Polyoxyethylene Ether-7 (AEO-7), a nonionic surfactant [12]. In addition, we investigated the effectiveness of JC-10 assay compared to different cellular cytotoxicity assays; acridine orange (AO) and TUNEL assay to detect apoptosis and western blotting of heat shock protein 70 (Hsp70), a general stress marker).…”