Screening of the Anti-Aflatoxin B1 Activity of Peruvian Plant Extracts: Relation with their Composition

Aflatoxin B1 (AFB1) is the most hazardous mycotoxin for humans. It is mainly produced by Aspergillus flavus and A. parasiticus in a wide range of crops. Alternative strategies to the use of pesticides are more and more studied in order to limit the fungal development as well as the synthesis of aflatoxins in food and feeds. The use of aqueous plants extracts with high an-tioxidant activity has been the issue of different studies because of their impact on AFB1 production. The identification of plant extracts able to block aflatoxinogenesis could represent an ecofriendly and sustainable strategy for small producers to protect their crops from contamination, taking advantage of the local plant ressources. In this study, we characterized the antifungal and anti-aflatoxin B1 activity of 10 Peruvian plants selected for their known biological activities. For some plant extracts, the activity against AFB1 production was correlated with their composition and especially their polyphenols content and subsequent antioxidant activity. This is the case for Aloysia citrodora (AC) that inhibited 78% of the AFB1 synthesis, followed by Annona muricata (AM) (69%), Uncaria tomentosa (UT) (58%), and Myrciaria dubia (MD) (32%). By contrast, extracts of Dysphania ambrosioides (DA) and mainly Minthostachys mollis (MM) were effective against AFB1 synthesis inhibiting 47% and 89% of the production respectively but displayed a very limited antioxidant activity (IC50 DDPH > 400 mg/L), suggesting another route of inhibition. This is the first study demonstrating the anti-aflatoxin B1 effect of aqueous extracts of these plants.