Toxicity Testing of Neurotoxic Pesticides inCaenorhabditis elegans

Abstract

The use of pesticides is ubiquitous worldwide, and these chemicals exert adverse effects on both target and nontarget species. Understanding the modes of action of pesticides, as well as quantifying exposure concentration and duration, is an important goal of clinicians and environmental health scientists. Some chemical exposures result in adverse effects on the nervous system. The nematode Caenorhabditis elegans (C. elegans) is a model lab organism well established for studying neurotoxicity, since the components of its nervous system are mapped and known, and most of its neurotransmitters correspond to human homologs. This review encompasses published studies in which C. elegans nematodes were exposed to pesticides with known neurotoxic actions. Endpoints measured include changes in locomotion, feeding behavior, brood size, growth, life span, and cell death. From data presented, evidence indicates that C. elegans can serve a role in assessing the effects of neurotoxic pesticides at the sublethal cellular level, thereby advancing our understanding of the mechanisms underlying toxicity induced by these chemicals. A proposed toxicity testing scheme for water-soluble chemicals is also included.

Glucose-rich diet aggravates monocrotophos-induced dopaminergic neuronal dysfunction inCaenorhabditis elegans

“…As they are completely transparent, neurons are easily visualized by expressing a green fluorescent protein (GFP). C. elegans are used as a good model system in pesticide toxicology (Meyer and Williams, ; Rajini et al, ; Williams and Dusenbery, ). C. elegans has been shown to be a suitable model organism to study glucose toxicity, in which high glucose conditions decrease lifespan by increasing reactive oxygen species (ROS) formation and advanced glycation end product modification of mitochondrial proteins and by inducing ectopic apoptosis (Choi, ; Schlotterer et al, ).…”

Caenorhabditis elegans as an emerging model system in environmental epigenetics

“…Richard Nass established the use of C. elegans for chemical-induced neurodegeneration (Nass et al, 2001(Nass et al, , 2002. The number of groups doing such work has grown rapidly in recent years, and C. elegans is now a well-characterized model for human and ecological toxicity and genotoxicity studies (Leung et al, 2008;Steinberg et al, 2008;Boyd et al, 2010;Helmcke et al, 2010;Allard et al, 2013;Choi et al, 2014;Meyer and Williams 2014;Ferreira and Allard 2015;Tejeda-Benitez and Olivero-Verbel 2016;Honnen 2017;Hunt 2017;Lenz et al, 2017;Maurer et al, 2017).…”

Assessment of food toxicology

“…More than 50% of human genes have functional orthologs in C. elegans and all 959 somatic cells of the worms have been characterized with respect to lineage [46,150,151]. As for D. melanogaster, a variety of molecular tools provide the availability of a large number of transgenic strains suited for a differential toxicity screening by high-throughput genomic studies [46, Page 21 of 43 A c c e p t e d M a n u s c r i p t [150][151][152]. Since C. elegans is capable of rudimentary learning and many neurotransmitters are well conserved it is also well suited for neurotoxicity testing [151,153,154].…”

“…As for D. melanogaster, a variety of molecular tools provide the availability of a large number of transgenic strains suited for a differential toxicity screening by high-throughput genomic studies [46, Page 21 of 43 A c c e p t e d M a n u s c r i p t [150][151][152]. Since C. elegans is capable of rudimentary learning and many neurotransmitters are well conserved it is also well suited for neurotoxicity testing [151,153,154]. More recently, the zebrafish Danio rerio has been used as a vertebrate model organism for a wide variety of research including drug discovery and toxicology.…”