Co-exposure of iron oxide nanoparticles with glyphosate herbicides in Poecilia reticulata: Fish liver damages is reversible during iron accumulation and elimination period

Abstract

Iron oxide nanoparticles (IONPs) are advanced materials for water remediation technologies. It is therefore relevant to evaluate the cellular and tissue behavior of fishes in response to IONPs and their associations with agrochemicals such as glyphosate (GLY) and glyphosate-based herbicides (GBHs). Iron accumulation, tissue integrity and lipid distribution in the hepatocytes of Poecilia reticulata (guppy) were investigated in a control group and in groups exposed to soluble iron ions, namely IFe (0.3 mgFe/L), IONPs (0.3 mgFe/L), and IONPs, associated with GLY (0.65 mg/L), GBHs 0.65 mgGLY/L (IONPs + GBH1), and 1.30 mgGLY/L (IONPs + GBH2), for 7, 14, and 21 days, followed by an equal period of postexposure in clean reconstituted water. The results showed that the accumulation of iron was greater in the subjects in the IONP treatment group when compared to that in the Ife group. In addition, the subjects in the mixtures with GBHs had a greater accumulation of iron than those in the IONP + GLY treatment group. Tissue integrity assessments demonstrated an intense accumulation of lipids, formation of necrotic zones and leukocyte infiltrates in all the treated groups, with a greater quantity of lipids in the animals treated with IONP + GLY and IFe. During postexposure, the results indicated an elimination of iron in all treated groups, reaching the same level as the control group, throughout the 21 days postexposure. Thus, the damage caused to animal livers by IONP mixtures is reversible, providing promising results for the development of safe environmental remediation practices using nanoparticles.

Keywords: Nanoecotoxicology; Nanomaterials; Nanosafety; Water remediation.