Table 2:
in vitro toxicity and toxicokinetic testing
Toxicological and Toxicokinetic Responses |
Assay | Assay Endpoints |
Purpose | Assay outcomes |
Availability/References |
---|---|---|---|---|---|
Developmental Toxicity | Zebrafish embryo assay | Developmental progression | Assess potential teratogenicity | Zebrafish point of departure (POD) and development information | Internal EPA assay doi:10.1016/j.reprotox.2011.10.018 |
Immunotoxicity | Bioseek Diversity Plus | Protein biomarkers across multiple primary cell types | Measure potential disease and immune responses | 148 individual assays which report hitcall and AC50 | Commercial doi:10.1177/1087057109345; doi:10.1038/nbt.2914 |
Developmental Neurotoxicity | Microelectrode array assay (rat primary neurons) | Neuronal electrical activity | Impacts on development of functional neural networks | 17 different parameters measured to culminate in one in vitro POD | Internal EPA assay doi:10.1007/s00204-017-203505 |
Endocrine Disruption | ACEA real-time cell proliferation assay (T47D), plus selected endpoints from Attagene | Estrogen-dependent cell proliferation | Functional measurement of estrogen receptor activity | 2 individual assays which report hitcall and AC50 | Commercial doi:10.1021/tx400117y; doi:10.1016/j.tiv.2005.12.008 |
General Toxicity / Bioactivity | Attagene cis- and trans-Factorial assays | Nuclear receptor and other transcription factor activation in HepG2 cells | Activation of transcription factors involved in critical cell pathways and stress responses | 81 individual assays which report hitcall and AC50 | Commercial doi:10.1038/nmeh.1186; doi:10.1021/tx900325g |
High-throughput transcriptomic assay | Cellular mRNA, 2D HepaRG and U2OS cells | Measures changes in important biological pathways | 1000s of genes which are used to derive an in vitro POD | Internal EPA assay with contract support doi:10.1371/journal.pone.0178302 |
|
High-throughput phenotypic profiling | Nuclear, endoplasmic reticulum, nucleoli, golgi, plasma membrane, cytoskeleton, and mitochondria morphology, U2OS and MCF7 cells | Changes in cellular organelles and general morphology | Cell painting (CP) and cell viability (CV) PODs. 1300 features aggregated into 49 categories which are used to derive the CP POD. | Internal EPA assay doi:10.1177/2472555220928004; doi:10.1016/j.taap.2019.114876; doi:10.1038/nprot.2016.105 |
|
Intrinsic hepatic clearance | Hepatocyte stability assays | Time course metabolism of parent chemical in primary human hepatocytes | Measure metabolic breakdown by the liver | Clearance (Cl) | Commercial and Internal EPA and NTP assay doi:10.1124/dmd.30.8.892 |
Plasma protein binding | Ultra centrifugation assay | Fraction of chemical not bound to plasma protein | Measure amount of free chemical in the blood | Fraction unbound | Commercial and Internal EPA assay doi:10.1002/jps.21317 |