Year-end Sale % OFF 
Abstract
Cellular adaptive mechanisms emerging after exposure to low levels of toxic agents or stressful stimuli comprise an important biological feature that has gained considerable scientific interest. Investigations of low-dose exposures to diverse chemical compounds signify the non-linear mode of action in the exposed cell or organism at such dose levels in contrast to the classic detrimental effects induced at higher ones, a phenomenon usually referred to as hormesis. The resulting phenotype is a beneficial effect that tests our physiology within the limits of our homeostatic adaptations. Therefore, doses below the region of adverse responses are of particular interest and are specified as the hormetic gain zone. The manifestation of redox adaptations aiming to prevent from disturbances of redox homeostasis represent an area of particular interest in hormetic responses, observed after exposure not only to stressors but also to compounds of natural origin, such as phytochemicals. Findings from previous studies on several agents demonstrate the heterogeneity of the specific zone in terms of the molecular events occurring. Major factors deeply involved in these biphasic phenomena are the bioactive compound per se, the dose level, the duration of exposure, the cell, tissue or even organ exposed to and, of course, the biomarker examined. In the end, the molecular fate is a complex toxicological event, based on beneficial and detrimental effects, which, however, are poorly understood to date.
Highlights
For several decades there was a general belief that the effects arising from exposure to diverse doses of xenobiotics follow a linear pattern, resulting in an enormous knowledge gap regarding the low-dose zone responses [1]
The present review summarizes biphasic effects that are detected in various biomarkers and depend on the specific compound, dose levels, duration of exposure, and the biological system examined in a number of studies associated with effects on redox homeostasis
A central finding within the biological sciences, which, is poorly understood, is the fact that essentially all biological models respond to external stress using similar features for their responses that are dynamically altered with the dose, time, component, and the specific biomarker of exposure
Summary
For several decades there was a general belief that the effects arising from exposure to diverse doses of xenobiotics follow a linear pattern, resulting in an enormous knowledge gap regarding the low-dose zone responses [1]. In the recent past, numerous studies have revealed an inverse response to various doses of foreign chemical substances and stressors, and of bioactive compounds, overturning the notion of linearity and the threshold-response models of dose determination [2,3]. This phenomenon has been described in several studies as “biphasic dose response” and has emerged as a critical step in establishing the modality of each compound [4,5,6,7]. Hormesis can be defined as the phenomenon wherein a harmful substance or a stressful condition exerts both stimulating and beneficial effects to living organisms, in those cases where the quantity or the intensity of a harmful substance or stimuli, respectively, is extremely low [12,13]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
