Unraveling the antifungal and aflatoxin B1 inhibitory efficacy of nano-encapsulated caraway essential oil based on molecular docking of major components

Abstract

Abstract Aspergillus flavus and its secondary metabolites, particularly aflatoxin B (AFB1), pose significant threats to global crop production. Essential oils are considered excellent antifungal agents; however, their volatile nature and oxidative instability limit their practical use. This research aimed to develop a chitosan nanoemulsion loaded with caraway essential oil through the ionic-gelation process, utilizing sodium tripolyphosphate as a cross-linker. The nanoencapsulation was characterized using SEM, DLS, and FTIR analyses. The CEO-CSNPs inhibited A. flavus (35 mm at a concentration of 1000 ppm) and reduced aflatoxin production by 92.84% compared to free CEO. Down regulation of the relative expression of aflatoxin genes (aflaD, aflaR, and aflaS) in the aflatoxin biosynthesis pathway demonstrated its anti-aflatoxigenic mechanism. Molecular docking studies revealed that carvone and D-limonene exhibited strong binding energies for the three enzymes of A. flavus. These compounds showed decreased binding energies and various interactions at the active sites of important enzymes, suggesting their potential to inhibit these regulatory enzymes and consequently suppress AFB1 production.