Chitosan-based nanoencapsulation of Toddalia asiatica (L.) Lam. essential oil to enhance antifungal and aflatoxin B<sub>1</sub> inhibitory activities for safe storage of maize
Int J Biol Macromol. 2022 Feb 10:S0141-8130(22)00262-8. doi: 10.1016/j.ijbiomac.2022.02.026. Online ahead of print.
The present study reports the enhanced antifungal, aflatoxin B1 (AFB1) inhibitory activities and mode of action of chitosan-based nanoencapsulated Toddalia asiatica essential oil (neTAEO). Twenty-seven different chemical components were recognized from T. asiatica essential oil (TAEO) using gas chromatography-mass spectrometry (GC-MS). The caryophyllene oxide (CO) (25.4%), and 1,3-hexadiene, 3-ethyl-2,5-dimethyl- (HED) (24.08%) were documented as significant compounds. The Z-average particles diameter (Z-APD) of the neTAEO ranged between 18.41 and 131.8 nm. The neTAEO showed enhanced and most promising antifungal and AFB1 inhibitory activity than TAEO. In viable maize model assay, neTAEO effectively preserved the maize from fungal invade and AFB1 biosynthesis. The neTAEO significantly disturbs membrane integrities of Aspergillus flavus by inhibiting ergosterol biosynthesis followed by the extreme release of ions (Mg2+ and K+) and UV-absorbing (260 and 280 nm) cellular constituents. The in-silico molecular docking showed that the major active components of TAEO viz., CO and HED were active against AFB1 synthesizing leading genes Ver-1 and Omt-A with docking scores ranging from -4.8 to -7.7. The obtained results confirm that neTAEO showed promising antifungal and AFB1 inhibitory activities; hence, it could be used as an alternative green strategy to protect food grains from fungal invade and AFB1 production during storage.