Modelling biphasic hormetic dose responses to predict sub-NOAEL effects using plant biology as an example

Authors: BELZ, REGINA - University Of Mississippi; DUKE, STEPHEN - University Of Mississippi

Submitted to: Current Opinion in Toxicology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/4/2022
Publication Date: 2/9/2022
Citation: Belz, R.G., Duke, S.0. 2022. Modelling biphasic hormetic dose responses to predict sub-NOAEL effects using plant biology as an example. Current Opinion in Toxicology. https://doi.org/10.1016/j.cotox.2022.01.003.
DOI: https://doi.org/10.1016/j.cotox.2022.01.003

Interpretive Summary: Hormesis is the stimulatory effect of a subtoxic exposure to a toxin. Whether or not hormesis occurs and its magnitude if it does occur has implications for risk assessment, alternative uses of toxins, and other aspects of exposure to toxins. This review, based on phytotoxin examples, points out that hormesis is seldom proven or adequately quantified without appropriate mathematical modeling of the phenomenon.

Technical Abstract: Perception of hormesis as a significant dose-response phenomenon is found in many sciences without predicting and/or quantifying this low-dose effect with statistical models. Only a minority of papers published on hormesis in plant biology or other sciences apply available statistical modelling of the dose-response relationships, along with significance testing for hormesis and prediction of sub-NOAEL quantities. The prediction of threshold quantities opens many further evaluation options such as risk assessment, hormesis in mixtures or in risk groups, selective hormesis in populations, or assessment of transgenerational hormesis. Therefore, the clarity and value of hormesis research can benefit significantly from sound modelling of this biphasic phenomenon. This review is meant to raise awareness of scientists to the value of hormesis modelling.