Using High-Throughput Screening to Evaluate Perturbations Potentially Linked to Neurobehavioral Outcomes: A Case Study Using Publicly Available Tools on FDA Batch-Certified Synthetic Food Dyes

There
is growing evidence from human and animal studies indicating
an association between exposure to synthetic food dyes and adverse
neurobehavioral outcomes in children. However, data gaps persist for
potential mechanisms by which the synthetic food dyes could elicit
neurobehavioral impacts. We developed an approach to evaluate seven
US FDA-batch-certified food dyes using publicly available high-throughput
screening (HTS) data from the US EPA’s Toxicity Forecaster
to assess potential underlying molecular mechanisms that may be linked
to neurological pathway perturbations. The dyes were screened through
270 assays identified based on whether they had a neurological-related
gene target and/or were mapped to neurodevelopmental processes or
neurobehavioral outcomes, and were conducted in brain tissue, targeted
specific hormone receptors, or targeted oxidative stress and inflammation.
Some results provided support for neurological impacts found in human
and animal studies, while other results showed a lack of correlation
with in vivo findings. The azo dyes had a range of
activity in assays mapped to G-protein-coupled receptors and were
active in assays targeting dopaminergic, serotonergic, and opioid
receptors. Assays mapped to nuclear receptors (androgen, estrogen,
and thyroid hormone) also exhibited activity with the food dyes. Other
molecular targets included the aryl hydrocarbon receptor, acetylcholinesterase,
and monoamine oxidase. The Toxicological Prioritization Index tool
was used to visualize the results of the Novascreen assays. Our results
highlight certain limitations of HTS assays but provide insight into
potential underlying mechanisms of neurobehavioral effects observed
in in vivo animal toxicology studies and human clinical
studies.