The role of endogenous versus exogenous sources in the exposome of putative genotoxins and consequences for risk assessment

Abstract

The “totality” of the human exposure is conceived to encompass life-associated endogenous and exogenous aggregate exposures. Process-related contaminants (PRCs) are not only formed in foods by heat processing, but also occur endogenously in the organism as physiological components of energy metabolism, potentially also generated by the human microbiome. To arrive at a comprehensive risk assessment, it is necessary to understand the contribution of in vivo background occurrence as compared to the ingestion from exogenous sources. Hence, this review provides an overview of the knowledge on the contribution of endogenous exposure to the overall exposure to putative genotoxic food contaminants, namely ethanol, acetaldehyde, formaldehyde, acrylamide, acrolein, α,β-unsaturated alkenals, glycation compounds, N-nitroso compounds, ethylene oxide, furans, 2- and 3-MCPD, and glycidyl esters. The evidence discussed herein allows to conclude that endogenous formation of some contaminants appears to contribute substantially to the exposome. This is of critical importance for risk assessment in the cases where endogenous exposure is suspected to outweigh the exogenous one (e.g. formaldehyde and acrolein).

Mass Spectrometry Analysis of DNA and Protein Adducts as Biomarkers in Human Exposure to Cigarette Smoking: Acrolein as an Example

“…81 Evidence suggests that endogenous exposure outweighs the exogenous sources for certain chemicals, and acrolein falls into this category. 82 High adduct levels of AdG were detected in people not exposed to substantial exogenous sources of acrolein, e.g., nonsmokers, as shown in Table 1, suggesting the role for endogenous origin of acrolein.…”

“…In cancer risk assessment, it is difficult, and yet critically important, to distinguish the contribution of endogenous versus exogenous exposure of genotoxic chemicals in the exposome . Evidence suggests that endogenous exposure outweighs the exogenous sources for certain chemicals, and acrolein falls into this category . High adduct levels of AdG were detected in people not exposed to substantial exogenous sources of acrolein, e.g., nonsmokers, as shown in Table , suggesting the role for endogenous origin of acrolein.…”

Food-Borne Chemical Carcinogens and the Evidence for Human Cancer Risk

“…Consumer exposure to carcinogens is multifactorial and, in some cases, in addition to exogenous sources might involve endogenous formation of hazardous chemicals as a result of metabolic reactions [ 6 ]. Such endogenous exposures can significantly contribute to total exposures and complicate risk assessment.…”

“…It has long been known that chemicals with carcinogenic activity in rodent models can be found in many commonly consumed foods [ 1 , 2 , 3 , 4 , 5 ] from a variety of sources including plants, microorganisms, contaminations, additive uses and reactions which occur during storage, processing and cooking [ 2 ] ( Table 1 ). In addition, carcinogens can be formed endogenously, from food materials [ 6 , 7 , 8 ]. This review focuses mainly on carcinogens, both rodent and human, present in foods and beverages at low concentrations which are imperceptible, and a few components present at levels associated with adverse effects.…”

Peculiarities of physico-chemical condition of uterine vaginal mucus during estral cycle

“…The study of the physicochemical state of any biological fluid of the human or animal body under the harmful effects of endogenous and exogenous factors requires an objective assessment of the dynamics of the mass parameters of its inorganic (IS) and organic (OS) substances (Duzu, 1980;Bagrov, 1984;Terekhov & Petrov, 1990;Bulychev, 1991;Socha-Banasiak et al, 2021;Cao et al, 2021;Mylostyvyi et al, 2021;Fischer et al, 2021;Rietjens et al, 2022).…”