The mechanisms of neocryptolepine inhibiting Aspergillus flavus growth and aflatoxin B1 accumulation in corn

Mycotoxins, toxic secondary metabolites produced by pathogenic fungi contaminating agricultural commodities, represent a significant threat to food safety and human health. Notably, Aspergillus flavus and its associated aflatoxins are primary food contaminants requiring rigorous prevention and control strategies. This study elucidates the mechanism by which neocryptolepine, a natural antifungal compound, inhibits A. flavus growth and aflatoxin B1 accumulation in corn. Neocryptolepine effectively impedes the vegetative growth of A. flavus filaments and spores, disrupting cellular integrity by interfering with cell wall component synthesis. Furthermore, neocryptolepine treatment induces mitochondrial dysfunction in A. flavus cells, leading to disruptions in energy metabolism and reactive oxygen species homeostasis. Transcriptomic sequencing revealed that neocryptolepine downregulates the expression of aflatoxin biosynthetic gene clusters, such as aflJ, and related global regulatory factors, thereby suppressing aflatoxin biosynthesis. Importantly, the drug protected corn kernels from A. flavus infection without affecting their germination capacity. These findings suggest that neocryptolepine holds promise as a potential eco-friendly mycotoxin inhibitor for application in agricultural and food production.