Assessing the antibacterial, antifungal, and antiaflatoxigenic activity of a developed nanoformulation based on a combination of Syzygium aromaticum leaf and bud essential oils

Abstract

The increase in mycotoxin contamination and antimicrobial resistance draws attention towards the development of natural broad-spectrum antimicrobial compounds. Recent studies have highlighted the use of nanoencapsulated essential oils as a promising natural antimicrobial agent and a safer alternative to the synthetic ones. This study investigates the inherent antibacterial, antifungal, and antiaflatoxigenic potential of a nanoencapsulated formulation developed from a combination of essential oils extracted from Syzygium aromaticum leaves and buds. The GC-MS analysis of this combination (SACEO) confirmed the presence of meta-eugenol as the major bioactive component. The SACEO demonstrated synergistic activity, which was further stabilized via nanoencapsulation (Ne-SACEO) and was found to have steady dispersion, a favorable zeta potential, and a homogeneous size through physicochemical characterization. Ne-SACEO demonstrated significant antioxidative potential, lower MAIC and MIC values than SACEO for aflatoxin B₁ (0.15; 0.2 µL mL⁻¹), Aspergillus flavus (0.35; 0.40 µL mL⁻¹), B. cereus (50; 72.66 ppm), E. coli (56.66; 67.33 ppm), S. enterica (54.66; 64.66 ppm), and S. flexneri (64; 76 ppm) respectively, indicating increased bioefficacy. According to mechanistic investigations, Ne-SACEO impaired the integrity of fungal and bacterial cells, leading to cell death. The combined antimicrobial and anti-aflatoxigenic activity of Ne-SACEO, supported by sustained release, improved solubility, and membrane permeability, highlights its potential as a green multifunctional biopreservative agent in food safety and sustainability.