Flavonoids modulate Aspergillus flavus proliferation and aflatoxin production

Authors: Castano-Duque, Lina; Lebar, Matthew; Carter-Wientjes, Carol; Ambrogio, Cesar; Rajasekaran, Kanniah - Rajah

Submitted to: The Journal of Fungi
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/9/2022
Publication Date: 11/16/2022
Citation: Castano-Duque, L., Lebar, M.D., Carter-Wientjes, C., Ambrogio, D., Rajasekaran, K. 2022. Flavonoids modulate Aspergillus flavus proliferation and aflatoxin production. The Journal of Fungi. 8(1):1211. https://doi.org/10.3390/jof8111211.
DOI: https://doi.org/10.3390/jof8111211

Interpretive Summary: Aflatoxins, highly carcinogenic toxins produced by the fungus Aspergillus flavus, contaminate major food crops, particularly corn, and are a worldwide concern. The molecular mechanism linking flavonoids to regulation of fungal growth and production of aflatoxin is not well understood. In this study, we determined that flavonoids are acting as potential signaling molecules that are taken inside the fungal cells in spehere-like structures, can change the oxidative state of the environment, and lead to changes in fungal proliferation/recovery, development, and aflatoxin production. These results contribute to the field of fungal biology to understand how and what factors modulate A. flavus growth and toxin production.

Technical Abstract: In this study, we determined the effects of three flavonoids (apigenin, luteolin and quercetin) on Aspergillus flavus proliferation and aflatoxin production. We determined that low concentrations of apigenin and luteolin can inhibit fungal proliferation and significantly decrease aflatoxin production, while higher concentrations lead to the opposite effect. No visible mycelia disruption or cytosolic leakage in response to fungal exposure to flavonoids was observed at any of the flavonoid concentrations tested. All three flavonoids assimilated into the fungal cells in sphere-like structures. Additionally, the highest quercetin concentrations affected the developmental stages of the fungus. Low concentrations of apigenin, luteolin, and quercetin resulted in lower antioxidant capacity compared to controls. Our results indicate that flavonoids are acting as potential signaling molecules that are taken inside the fungal cells in vesicle-like structures, can change the oxidative state of the environment, and lead to changes in fungal proliferation/recovery, development, and aflatoxin production.