Chapter 5 - Hormesis and Pharmacology

Abstract

This chapter focuses on the hormetic dose–response relationship, which is not only the most fundamental dose–response relationship, but also a basic biological concept with extremely broad evolutionary, biomedical, and toxicological implications. The quantitative features of the hormetic dose–response have remarkable consistency. This is especially the case with respect to the maximum stimulatory response range, which is typically around 30 to 60% greater than the control. Natural selection provides one possible reason the hormetic response is modest. Selection ought to favor organisms that repair damage in a timely or efficient fashion. The statistical analysis of hormetic dose–response relationships is amenable to a variety of strategies depending on the goals of the research team. The vast majority of experimental papers exhibiting hormetic dose–response relationships have utilized analysis of variance methods in attempts to isolate doses that display statistically significant treatment related effects. An important feature in drug development is the initial screening of candidate drugs. The hormetic dose–response can occur as overcompensation to a disruption in homeostasis or as a direct stimulation.