Detoxification of Aflatoxin B1 Contaminated Maize Using Human CYP3A4

J Microbiol Biotechnol. 2020 Aug 28;30(8):1207-1213. doi: 10.4014/jmb.2003.03032.

Abstract

Aflatoxin B1 (AFB1) is a mycotoxin produced by Aspergillus flavus (A. flavus). AFB1 is reported to have high thermal stability and is not decomposed by heat treatment during food processing. Therefore, in this study, knowing that AFB1 is metabolized by cytochrome P450 (CYP), our aim was to develop a method to detoxify A. flavus-contaminated maize, under normal temperature and pressure, using Escherichia coli expressing human CYP3A4. First, the metabolic activity of AFB1 by recombinant human CYP3A4 was evaluated. As a result, we confirmed that recombinant human CYP3A4 metabolizes 98% of AFB1. Next, we found that aflatoxin Q1, a metabolite of AFB1 was no longer mutagenic. Furthermore, we revealed that about 50% of the AFB1 metabolic activity can be maintained for 3 months when E. coli expressing human CYP3A4 is freeze-dried in the presence of trehalose. Finally, we found that 80% of AFB1 in A. flavus-contaminated maize was metabolized by E. coli expressing human CYP3A4 in the presence of surfactant triton X-405 at a final concentration of 10% (v/v). From these results, we conclude that AFB1 in A. flavus-contaminated maize can be detoxified under normal temperature and pressure by using E. coli expressing human CYP3A4.

Keywords: Aflatoxin B₁; CYP3A4; cytochrome P450; detoxification.

MeSH terms

  • Aflatoxin B1 / metabolism*
  • Aflatoxins
  • Aspergillus flavus
  • Cytochrome P-450 CYP3A / genetics
  • Cytochrome P-450 CYP3A / metabolism*
  • Escherichia coli / genetics
  • Escherichia coli / metabolism
  • Food Contamination*
  • Gene Expression Regulation, Bacterial
  • Humans
  • Mutagenicity Tests
  • Recombinant Proteins
  • Zea mays / metabolism*
  • Zea mays / microbiology

Substances

  • Aflatoxins
  • Recombinant Proteins
  • aflatoxin Q1
  • Aflatoxin B1
  • Cytochrome P-450 CYP3A
  • CYP3A4 protein, human