A toxicological comparison between two uranium compounds in Artemia salina: Artificial seawater containing CaCO3

Lara Pedroso da Fontoura; Robson Puntel; Simone Pinton; Daiana Silva de Ávila; João Batista Teixeira da Rocha; Diogo Onofre de Souza; Daniel Henrique Roos

doi:10.1016/j.marenvres.2020.105221

A toxicological comparison between two uranium compounds in Artemia salina: Artificial seawater containing CaCO₃

Mar Environ Res. 2021 Jan:163:105221. doi: 10.1016/j.marenvres.2020.105221. Epub 2020 Dec 1.

Authors

Lara Pedroso da Fontoura¹, Robson Puntel¹, Simone Pinton¹, Daiana Silva de Ávila¹, João Batista Teixeira da Rocha², Diogo Onofre de Souza³, Daniel Henrique Roos⁴

Affiliations

¹ Universidade Federal do Pampa, Campus Uruguaiana, BR-472 Km 592, ZIP code: 97500-970, RS, Brazil.
² Universidade Federal de Santa Maria, Departamento de bioquímica e biologia celular/CCNE/UFSM, Laboratório de Bioquímica Toxicológica, Farmacologia e Organocalcogênios, ZIP code: 97105900, Santa Maria, RS, Brazil.
³ Universidade Federal do Rio Grande do Sul, Instituto de Ciências Básicas da Saúde, Departamento de Bioquímica. Rua Ramiro Barcelos, 2.600 - Anexo Laboratorio 28 Santana, ZIP code: 90035003, Porto Alegre, RS, Brazil.
⁴ Universidade Federal do Pampa, Campus Uruguaiana, BR-472 Km 592, ZIP code: 97500-970, RS, Brazil. Electronic address: danielvarzeano@yahoo.com.br.

PMID: 33341237
DOI: 10.1016/j.marenvres.2020.105221

Abstract

Uranium (U) mining is an aquatic environmental concern because most of these harmful compounds are discharged into freshwater, reaching the saline environment as the final destination of this contaminated water. Carbonates are present in ocean waters and are essential for benthic organisms, however they may influence the U-induced toxicity. Thus, the aim of this study was to compare the toxicity of uranium nitrate (UN) and uranium acetate (UA) in Artemia salina (AS), which is one of the leading representatives of the marine biota. The cultures of AS (instar II) maintained in artificial seawater containing CaCO₃ were exposed for 24 h to different concentrations of U compounds. The results showed that AS were more sensitive to UN (LC₅₀ ≈ 15 μM) when compared with UA (LC₅₀ ≈ 245 μM) indicating higher toxicity of this U compound. Calculated U speciation indicated that Ca₂UO₂(CO₃)₃ and (UO₂)2CO₃(OH)₃^- complexes predominated under our experimental conditions. The immobilization/lethality was observed after 9 h of exposure for both U compounds. However, only UN caused a significant decrease (≈40%) in the acetylcholinesterase (AChE) activity when compared with control. In order to observe preliminary toxicity effects, we evaluated oxidative stress parameters, such as catalase (CAT) activity, TBARS formation, radical species (RS) generation and cell membrane injury and/or apoptosis (CMI). In this study, we demonstrate that U compounds caused a significant decrease in CAT activity. Similarly, we also observed that UN increased TBARS levels in AS at concentrations 5 times lower than AU (10 μM and 50 μM, respectively). Furthermore, RS generation and CMI were enhanced only on AS treated with UN. Overall, the effects observed here were remarkably significant in AS exposed to UN when compared with AU. In this study, we showed different profiles of toxicity for both U compounds, contributing significantly to the current and scarce understanding of the aquatic ecotoxicity of this heavy metal.

Keywords: Artemia salina; Marine ecotoxicity; Uranium acetate; Uranium nitrate.

MeSH terms

Animals
Artemia
Fresh Water
Seawater
Uranium Compounds*
Uranium* / analysis
Uranium* / toxicity

Substances

Uranium Compounds
Uranium