Zebrafish as a model to assess the neurotoxic potential of propylene glycol ethers

Propylene glycol ethers are increasingly used as organic solvents of choice in domestic products and industrial manufacturing. However, little is known about their potential neurotoxic effects. In the present study, we therefore evaluated the acute toxic and behavioral effects of propylene glycol ethers using zebrafish larvae as a vertebrate model. Studied endpoints included viability, motor behavior, larval photo and locomotor response, and blood-brain barrier permeability (BBB). We observed hyperactivity at lower concentrations and hypoactivity at higher concentrations. Impaired behavioral patterns in exposed larvae suggested an interaction with the nervous system. Mechanistic studies revealed an impact on BBB permeability since a significant increase in extracellular fluorescent tracer permeability into brain parenchyma was observed following exposure. We conclude that the zebrafish model is a predictive screening model to rank organic solvents with respect to their toxic potential. Experiments with ethanol as a reference correlate with literature findings in humans.