Inhibition of Aspergillus flavus growth and detoxification of Aflatoxin B1 by the medicinal plant leaf extract- Cymbopogon citratus

Abstract

Aflatoxin contamination in food is a major qualititative problem affecting human health and trade. Detoxification of these aflatoxins has been considered as one of the best strategies to decontaminate the food and animal feed. The aim of the present study was to isolate, identify and detoxify the aflatoxin produced by A.flavus from infected ground nut. The present study was focused on isolation, identification of A. flavus from infected groundnut pods on Czapek Dox Agar medium, and the toxigenic strains were confirmed on Coconut Cream Agar Medium (CCA). Aqueous extracts of C. citratus were tested against aflatoxin producing strains of A. flavus at various concentrations (1, 2.5 and 5% v/v). Further, the detoxifying capacity of these leaf extracts was studied at these concentrations on AFB1 using TLC and HPLC. The toxigenic strain of A. flavus was confirmed based on PCR amplification. Results indicated that C. citratus extracts exhibited high antifungal activity showing inhibition of fungal mycelium to a maximum extent at 5% v/v concentration. However, the other two concentrations of C. citratus were also found to be effective in inhibition of A. flavus mycelia. Detoxification studies indicated lesser levels of AFB1 at all the concentrations under study. Maximum degradation of the toxin was obtained at 5% v/v concentration from 2154 μg/L to 183 μg/L. It was observed that the extract of C. citratus showed significant detoxification and inhibitory effect of growth of A. flavus. Our future studies are directed in characterizing the active principle of the C. citratus plant extract and application of these extracts on detoxification of Aflatoxins.