title: Interference of single walled carbon nanotubes (SWCNT) in the measurement of lipid peroxidation in aquatic organisms through TBARS assay.
abstract: Nanomaterials (NM) exhibit unique properties due their size and relative area, but the mechanisms and effects in the living organisms are yet to be unfold in their totality. Potential toxicity mechanisms concerning NM as carbon nanotubes include oxidative stress generation. Several fluorimetric and colorimetric methods have been systematically used to measure NM toxicity, and controversial results have been reported. One of the problems can be related to the interference effects induced by NM, leading to artifacts that can lead to misleading conclusions. In present study, it was performed in vitro assays with two aquatic species: the zebrafish Danio rerio and the polychaete Laeonereis acuta to evaluate the potential interference capacity of single-wall carbon nanotubes (SWCNT) in a fluorometric method (TBARS assay) to measure lipid peroxidation. Obtained results indicated that gills and brain of zebrafish presented a lowered fluorescence only at extremely high concentrations (50 and 500mg/L). Determinations in anterior, middle, and posterior body regions of L. acuta showed a quite different pattern: high fluorescence at low SWCNT concentrations (0.5mg/L) and lowering at the highest (500mg/L). To eliminate matrix effect of biological samples, tests employing the standard for TBARS assay, 1,3,3-tetramethoxipropane, were run and the results showed again higher fluorescence values at low concentrations (0.5-5mg SWCNT/L), a technique artifact that could lead to misleading conclusions since higher fluorescence values implicate higher TBARS concentration, implying oxidative stress. Using the colorimetric FOX assay with cumene hydroperoxide as standard presented remarkable better results since no artifacts were observed in the same SWCNT concentration range that employed with the TBARS technique.
authors.affiliation: Instituto de Ciências Biológicas (ICB), Universidade Federal do Rio Grande - FURG, Rio Grande, RS, Brazil; Programa de Pós-Graduação em Ciências Fisiológicas - Fisiologia Animal Comparada - ICB-FURG, Brazil; Instituto Nacional de Ciência e Tecnologia em Nanomateriais de Carbono (CNPq), Brazil; Rede de Nanotoxicologia (MCTI/CNPq), Brazil. Electronic address: monserrat_jm@furg.br.
authors.forename: J M
authors.initials: JM
authors.lastname: Monserrat
authors.affiliation: Programa de Pós-Graduação em Ciências Fisiológicas - Fisiologia Animal Comparada - ICB-FURG, Brazil; Rede de Nanotoxicologia (MCTI/CNPq), Brazil.
authors.forename: A L R
authors.initials: AL
authors.lastname: Seixas
authors.affiliation: Programa de Pós-Graduação em Ciências Fisiológicas - Fisiologia Animal Comparada - ICB-FURG, Brazil; Rede de Nanotoxicologia (MCTI/CNPq), Brazil.
authors.forename: M
authors.initials: M
authors.lastname: Ferreira-Cravo
authors.affiliation: Programa de Pós-Graduação em Ciências Fisiológicas - Fisiologia Animal Comparada - ICB-FURG, Brazil; Rede de Nanotoxicologia (MCTI/CNPq), Brazil.
authors.forename: M
authors.initials: M
authors.lastname: Bürguer-Mendonça
authors.affiliation: Universidade Federal do Rio Grande do Sul (UFRGS), Lab. de Toxicologia, Porto Alegre, RS, Brazil; Programa de Pós-graduação em Ciências Farmacéuticas, UFRGS, Brazil.
authors.forename: S C
authors.initials: SC
authors.lastname: Garcia
authors.affiliation: Departamento de Materiais, Lab. de Materiais Cerámicos, UFRGS, Brazil.
authors.forename: C G
authors.initials: CG
authors.lastname: Kaufmann
authors.affiliation: Instituto de Ciências Biológicas (ICB), Universidade Federal do Rio Grande - FURG, Rio Grande, RS, Brazil; Programa de Pós-Graduação em Ciências Fisiológicas - Fisiologia Animal Comparada - ICB-FURG, Brazil; Instituto Nacional de Ciência e Tecnologia em Nanomateriais de Carbono (CNPq), Brazil; Rede de Nanotoxicologia (MCTI/CNPq), Brazil.
authors.forename: J
authors.initials: J
authors.lastname: Ventura-Lima
mesh_terms: D000818:Animals; D059001:Aquatic Organisms / Q000187:drug effects* / Q000378:metabolism; D016477:Artifacts; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005470:Fluorometry; D005880:Gills / Q000187:drug effects / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects*; D037742:Nanotubes, Carbon / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects; D010316:Particle Size; D011077:Polychaeta / Q000187:drug effects / Q000378:metabolism; D013059:Spectrum Analysis, Raman; D013499:Surface Properties; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D015027:Zebrafish / Q000378:metabolism
chemical_list: D037742:Nanotubes, Carbon; D017392:Thiobarbituric Acid Reactive Substances; D014874:Water Pollutants, Chemical
keywords: Carbon nanotubes; Fluorescence; Interference; Nanotoxicology; TBARS