Genotoxicity of aflatoxins and their precursors in human cells. (1st May 2018)

• Record Type: Journal Article
• Authors: Theumer, M.G.; Henneb, Y.; Khoury, L.; Snini, S.P.; Tadrist, S.; Canlet, C.; Puel, O.; Oswald, I.P.; Audebert, M.
• Is Part Of: Toxicology letters. Volume 287(2018)
• Page Start: 100
• Page End: 107
• Publication Date: 2018-05-01
• Subjects: Aflatoxin -- Genotoxicity -- H2AX -- Metabolism -- DNA damage; Toxicology -- Periodicals; 363.179
• DOI: 10.1016/j.toxlet.2018.02.007
• Languages: English
• ISSNs: 0378-4274

Abstract

Highlights: We examined the toxic potential of twelve aflatoxins and their precursors. Cytotoxicity and the genotoxicity was evaluated with the γH2AX ICW assay. Most genotoxic chemicals were in decreasing order ST, AFB1, AFL, AFG1 and VERA. Some precursors of aflatoxins demonstrated genotoxic potential greater to AFB1. Abstract: Aflatoxins are found as food contaminant and some of them demonstrate a carcinogenic effect. The aflatoxins biosynthetic pathway involves 15 successive steps. The aim of this study was to compare the toxicity of aflatoxins and their precursors in three human cell lines. We tested the four aflatoxins and two of their metabolites; three early metabolic precursors and two late biosynthetic precursors. Cyclopiazonic acid, synthesized in parallel with aflatoxins, was also tested. The cytotoxicity and the genotoxicity was evaluated with the γH2AX assay in three human cell lines with different bioactivation capacities. Our results indicated that the most genotoxic chemicals in the three cell lines were in decreasing order sterigmatocystin (ST), aflatoxin B1 (AFB1), aflatoxicol (AFL), aflatoxin G1 (AFG1) and versicolorin A (VERA). Aflatoxin M1 (AFM1) demonstrated genotoxic property in only one cell line. The other tested compounds did not demonstrate any genotoxic activity. Overall, our results suggested different genotoxic mechanisms of action for the tested compounds, involving specific bioactivation pathways. Moreover, some metabolic precursors of aflatoxins demonstrated genotoxic potential equivalent or greater to AFB1. This should be taking into account for the development of new strategies intended to reduce the aflatoxins exposure and for human risk assessment.