Transformación de la aflatoxina B1 de alimentos, en el cancerígeno humano, aducto AFB1-ADN

Abstract

Aflatoxins (AF) are secondary toxic metabolites formed mainly by the molds Aspergillus flavus and A. parasiticus; they are potent mutagens and carcinogens of foods, and human exposure to them is continuous. AF bind to DNA, RNA and proteins forming AFB₁-DNA adducts that accumulate for years and damage from viruses to humans. To identify and quantify the chemical reactions and molecular biology of these adducts is of primary importance because they are long-term biomarkers validated as a source of mutagenicity and risk of cancer in animals and humans. The cytochrome P₄₅₀ activates AF as an unstable molecule called 8,9 AFB₁ epoxide, that binds mainly to the N⁷ of the guanine nucleotide forming adducts that are the active carcinogens themselves and, as biomarkers, an objective measure of human exposure to environmental carcinogens. Adducts represent an integration of exposure, absorption, distribution, metabolism, DNA repair, and cell turnover. The different issues presented here are the formation of AFB₁-DNA adducts, in vitro and in vivo studies, dietary AFB₁ exposure, effects, development of human cancer and mutations in the p53 tumor suppressor gene, the effect of diet, routes of exposure, vitamins, kinds of AFB₁-DNA adducts, methodology used for their study and their control.