Inhibition of Fungal Aflatoxin B1 Biosynthesis by Diverse Botanically-Derived Polyphenols

W Zhou,Hz Mo,My Wang,Y Zhao,H Zhang,Lb Hu

doi:10.4314/tjpr.v14i4.7

Abstract

Purpose: To identify and characterize the capacity of diverse botanically-derived polyphenols to inhibit aflatoxin B1 (AFB1) production by Aspergillus flavus.Methods: A tea-derived polyphenol mixture and numerous individual polyphenols were tested for their effects on A. flavus growth and AFB1 production. Fungal spores were cultured for 60 h with polyphenols (range 0 ‒ 1,000 μg/mL). The fungi were enumerated by hemocytometry, and AFB1 in culture supernatants was quantified by high-performance liquid chromatography (HPLC).Results: Neither the tea-derived polyphenol mixture nor individual polyphenol compound, except quercetin, inhibited A. flavus growth. Quercetin detectably inhibited growth at 800 μg/mL; none of the remaining polyphenols inhibited fungal proliferation, even at 1,000 μg/mL. However, catechin mixture and all individual polyphenols differentially inhibited fungal AFB1 biosynthesis. Non-ester catechin derivatives revealed stronger inhibitory activity than ester derivatives.Conclusion: Quercetin exhibits the strongest inhibitory effect on AFB1 production and is the only test compound that also inhibits fungal proliferation. Botanically-derived polyphenols are, therefore, promising reagents for controlling fungal contamination and associated toxic aflatoxin deposition in harvested crops and in food processing operations.Keywords: Polyphenols, Quercetin, Aflatoxin B1, Inhibition, Antioxidation

Highlights

Aflatoxin B1 (AFB1) is a potently carcinogenic food contaminant produced by the filamentous fungus Aspergillus flavus, which constitutes a general food safety problem [1,2,3]
The current study further elucidated the activity of tea extract components, by comparing the effects of tea-derived polyphenol mixture and 10 polyphenol monomers present in tea extracts on fungal growth and AFB1 production
We evaluated the effect of a tea-derived polyphenol mixture and various individual polyphenols on A. flavus proliferation, after 60 h of treatment in culture

Summary

Introduction

Aflatoxin B1 (AFB1) is a potently carcinogenic food contaminant produced by the filamentous fungus Aspergillus flavus, which constitutes a general food safety problem [1,2,3]. The current study further elucidated the activity of tea extract components, by comparing the effects of tea-derived polyphenol mixture and 10 polyphenol monomers present in tea extracts on fungal growth and AFB1 production. Effect of tea-derived polyphenol mixture on fungal AFB1 production The tea-derived polyphenol mixture, containing four tea catechin polyphenols, inhibited fungal AFB1 production, though the inhibitory effect was not stringently polyphenol concentrationdependent (Fig 1).

Results

Conclusion