title: Deciphering the Anti-Aflatoxinogenic Properties of Eugenol Using a Large-Scale q-PCR Approach.
abstract: Produced by several species of Aspergillus, Aflatoxin B₁ (AFB₁) is a carcinogenic mycotoxin contaminating many crops worldwide. The utilization of fungicides is currently one of the most common methods; nevertheless, their use is not environmentally or economically sound. Thus, the use of natural compounds able to block aflatoxinogenesis could represent an alternative strategy to limit food and feed contamination. For instance, eugenol, a 4-allyl-2-methoxyphenol present in many essential oils, has been identified as an anti-aflatoxin molecule. However, its precise mechanism of action has yet to be clarified. The production of AFB₁ is associated with the expression of a 70 kB cluster, and not less than 21 enzymatic reactions are necessary for its production. Based on former empirical data, a molecular tool composed of 60 genes targeting 27 genes of aflatoxin B₁ cluster and 33 genes encoding the main regulatory factors potentially involved in its production, was developed. We showed that AFB₁ inhibition in Aspergillus flavus following eugenol addition at 0.5 mM in a Malt Extract Agar (MEA) medium resulted in a complete inhibition of the expression of all but one gene of the AFB₁ biosynthesis cluster. This transcriptomic effect followed a down-regulation of the complex composed by the two internal regulatory factors, AflR and AflS. This phenomenon was also influenced by an over-expression of veA and mtfA, two genes that are directly linked to AFB₁ cluster regulation.
authors.affiliation: Toxalim, Université de Toulouse, INRA, ENVT, INP Purpan, UPS, Toulouse, France. isauracaceres@hotmail.com.
authors.forename: Isaura
authors.initials: I
authors.lastname: Caceres
authors.affiliation: Toxalim, Université de Toulouse, INRA, ENVT, INP Purpan, UPS, Toulouse, France. rhodakhoury@gmail.com.|Laboratoire de Mycologie et Sécurité des Aliments (LMSA), Département de Biochimie, Faculté des Sciences, Université Saint-Joseph, P.O. Box 11-514, Beirut 1107 2050, Lebanon. rhodakhoury@gmail.com.
authors.forename: Rhoda
authors.initials: R
authors.lastname: El Khoury
authors.affiliation: Applied Mycology Group, School of Energy, Environment and AgriFood, Cranfield University, Cranfield MK43 0AL, Bedfordshire, UK. a.medinavaya@cranfield.ac.uk.
authors.forename: Ángel
authors.initials: Á
authors.lastname: Medina
authors.affiliation: Toxalim, Université de Toulouse, INRA, ENVT, INP Purpan, UPS, Toulouse, France. yannick.lippi@toulouse.inra.fr.
authors.forename: Yannick
authors.initials: Y
authors.lastname: Lippi
authors.affiliation: Toxalim, Université de Toulouse, INRA, ENVT, INP Purpan, UPS, Toulouse, France. claire.naylies@toulouse.inra.fr.
authors.forename: Claire
authors.initials: C
authors.lastname: Naylies
authors.affiliation: Laboratory of Microbiology, Department of Natural Sciences and Earth, Faculty of Sciences I, Lebanese University, Hadath Campus, P.O. Box 11-8281, Beirut, Lebanon. a.atoui@cnrs.edu.lb.
authors.forename: Ali
authors.initials: A
authors.lastname: Atoui
authors.affiliation: Laboratoire de Mycologie et Sécurité des Aliments (LMSA), Département de Biochimie, Faculté des Sciences, Université Saint-Joseph, P.O. Box 11-514, Beirut 1107 2050, Lebanon. andre.khoury@usj.edu.lb.
authors.forename: André
authors.initials: A
authors.lastname: El Khoury
authors.affiliation: Toxalim, Université de Toulouse, INRA, ENVT, INP Purpan, UPS, Toulouse, France. ioswald@toulouse.inra.fr.
authors.forename: Isabelle P
authors.initials: IP
authors.lastname: Oswald
authors.affiliation: Toxalim, Université de Toulouse, INRA, ENVT, INP Purpan, UPS, Toulouse, France. jd.bailly@envt.fr.
authors.forename: Jean-Denis
authors.initials: JD
authors.lastname: Bailly
authors.affiliation: Toxalim, Université de Toulouse, INRA, ENVT, INP Purpan, UPS, Toulouse, France. olivier.puel@toulouse.inra.fr.
authors.forename: Olivier
authors.initials: O
authors.lastname: Puel
mesh_terms: D016604:Aflatoxin B1 / Q000096:biosynthesis* / Q000235:genetics; D001231:Aspergillus flavus / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D005054:Eugenol / Q000494:pharmacology*; D005656:Fungal Proteins / Q000235:genetics; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects; D005800:Genes, Fungal; D016133:Polymerase Chain Reaction
chemical_list: D005656:Fungal Proteins; D005054:Eugenol; D016604:Aflatoxin B1
keywords: Aflatoxin B1; Aspergillus flavus; aflatoxinogenesis; eugenol; gene regulation; molecular tool