Evaluation of AFB1-Lisin and AFB1-N7-guanin aducts as biomarkers of human and animal exposure to aflatoxins

Abstract

Aflatoxins are carcinogenic compounds produced by Aspergillus species, which can contaminate foods before and after processing, leading to human health risks and losses in the animal production. The exposure to aflatoxin B1 (AFB1), the metabolite with higher toxicity produced by the fungus, occurs predominantly through the ingestion of contaminated food, mainly corn, peanuts and by-products, which have been frequently reported as AFB1-contaminated products in Brazil. AFB1 is primarily bio-transformed by microssomal enzymes in the liver, originating AFB1-N7-guanine and AFB1-lysin adducts. This thematic project is constituted by 6 sub-projects, which have independent and complementary objectives for generation of knowledge on AFB1 adducts and their application as biomarkers of exposure to aflatoxins in animals and humans. The involvement of AFB1 and its adducts with human hepatocellular carcinoma (HCC) will also be investigated. The themes of the sub-projects are: Synthesis of AFB1-lysine and AFB1-N7-guanine analytical standards (sub-project I), for using in the sub-projects; Establishment of dose-response relationships between the concentration of AFB1-aducts in biological materials and molecular changes in experimental model of HCC (sub-project IV); Establishment of dose-response relationships between the intake AFB1 and concentration of AFB1-adducts in biological materials and molecular changes of CHC in humans (sub-projects II and III); Application of analysis of AFB1-adducts in biological materials, as biomarkers for evaluation of adsorbents in trials with broilers and pigs (sub-projects V and VI). (AU)