Abstract

Nanotechnology seems to be a valuable strategy to improve the physicochemical properties of the bacteriocins, although comprehensive toxicity studies, especially in vivo, are limited. Therefore, the objective of the current study was to investigate the lethal and the sub-chronic influences of bacteriocin, zinc oxide (ZnO) nanoparticles, and the new bacteriocin-ZnO composite after their oral administration to Albino mice. Bacteriocin was partially purified from Lactobacillus acidophilus, while ZnO nanoparticles were synthesized via an eco-friendly green method using Escherichia coli filtrate. The median lethal dose (LD50) of both compounds was determined using the Up-and-Down method, through which the acceptable daily intake was established. Totally, 42 albino mice were divided equally into seven groups (G1-G7), which were orally given different concentrations of bacteriocin, the nanoparticles, or the nanocomposite, with the last group being the negative control. After two months of the experiment, all animals were sacrificed to evaluate the biochemical, histopathological, and genotoxic impact of these compounds on mice. The findings showed that the biological effect of the bacteriocin-ZnO nanocomposite is strictly dose-dependent. At low concentrations, the composite exhibited significant protective synergistic effects, enhancing renal efficiency and maintaining DNA stability. Conversely, higher concentrations induced severe systemic toxicity, characterized by significant histopathological alterations such as glandular atrophy, hepatic necrosis, and extensive DNA fragmentation. The findings suggest that the composite formulation, when utilized at low doses, serves as a promising, safe food additive with improved bioavailability and reduced toxicity compared to its individual components.

Key words: Bacteriocin, Food additives, Genotoxic effects, ZnO, Nanoparticles