Nanoencapsulated plant-based antifungal formulation against the Aspergillus flavus and aflatoxin B1 contamination: Unraveling the biochemical and molecular mechanism of action

Aflatoxin B1 (AFB1) is one of the most toxic fungal secondary metabolites associated with Aspergillus flavus contaminated food products. Although a range of synthetic chemicals has been used to control molds contamination, most of them possess a risk to the health and environment. The study reports the efficacy of nanoencapsulated plant-based synergistic antifungal formulation (Ne-CGT) as a green chemical agent against Aspergillus flavus and AFB1 contamination. The antifungal formulation (CGT) was prepared using the mathematical model based on different proportions of plant compounds (citral (C), geraniol (G), and terpineol (T)) and encapsulated inside the chitosan. Ne-CGT exhibited enhanced antifungal and AFB1 activity (0.15 μl/ml) compared to its free form CGT (0.3 μl/ml). Toxicity mechanism was related with impairment in functioning in the cell membrane (ergosterol and ion leakage), biochemical perturbance (mitochondrial membrane potential, enzyme activity Superoxide dismutase (SOD), Catalase (CAT), Glutathione reductase (GR), and carbon source metabolism), and functioning of aflatoxin biosynthesis gene Ver-1 and Nor-1. In addition, Ne-CGT effectively preserves the nutrition properties (lipid peroxidation, total carbohydrate, and crude protein) of Sorghum bicolor seed. The quantitative structure-activity relationship (QSAR) approach revealed the favorable safety profile and ecological acceptability of Ne-CGT. Hence, the study recommends its application as a plant-based antifungal agent to manage the growth of fungal and AFB1 contamination in agricultural food products.