Abstract
Aflatoxins, particularly Aflatoxin B(1) (AFB(1)), produced by Aspergillus flavus and other species, pose significant health risks due to their carcinogenic properties. This study investigates the inhibitory effects of Protocatechuic Acid (PCA) on mycotoxigenic fungi and AFB(1) production. PCA demonstrated significant dose-dependent antifungal activity against various Aspergillus species, with A. flavus showing inhibition zones ranging from 5.3 mm to 16.7 mm at concentrations of 50 µg/ml to 250 µg/ml, while A. ochraceus exhibited the highest sensitivity, with zones up to 23.6 mm. Additionally, PCA effectively reduced AFB(1) production in liquid media, achieving up to 80.21% inhibition at 250 µg/ml, and decreased the mycelial weight of A. flavus by 60.8%. Gene expression analysis revealed that PCA significantly downregulated the expression of the AFB(1) biosynthetic genes nor-1 (95% reduction) and omt-A (74% reduction), suggesting that PCA disrupts multiple stages of aflatoxin synthesis. Furthermore, PCA demonstrated efficacy in controlling AFB(1) contamination in postharvest corn grains, with inhibition percentages of 44.8%, 55.7%, and 64.6% at 150, 200, and 250 µg/ml, respectively. These findings indicate PCA's potential as a natural antifungal agent, offering promising applications in food safety and postharvest management.