Fe3O4 Nanoparticles Attenuated Salmonella Infection in Chicken Liver Through Reactive Oxygen and Autophagy via PI3K/Akt/mTOR Signaling

Recently nanomaterials have received substantial attention in biotechnology areas for their innovative properties in physical and chemical function. One of the most arrestive properties of nanomaterials that has been reported is their bacteriostatic activity. Our previous research found that Fe₃O₄ magnetic nanoparticles (Fe₃O₄-NPs) could effectively reduce the viability of intracellular Salmonella Enteritidis in chicken cells. There is an essential need to explore whether the bacteriostatic activity of Fe₃O₄-NPs is available in vivo. As an extension of this research, we conducted the present study to investigate the potential effect of Fe₃O₄-NPs used for S. Enteritidis control in chickens and to extensively investigate the underlying mechanisms in the process. The overall study included the evaluation of pathological sections, antioxidant status, inflammation, and the autophagy status of chicken liver, including the signaling pathway involved in the process. Results indicated that Fe₃O₄-NPs pretreatment can effectively inhibit the invasion of S. Enteritidis in chicken liver. Fe₃O₄-NPs pretreatment significantly increased reactive oxygen species (ROS) generation in chickens, including antioxidant enzyme activities. S. Enteritidis infection significantly increased the protein expression of the autophagy marker LC3. Additionally, the inflammation response and pathological changes caused by S. Enteritidis infection were alleviated by Fe₃O₄-NPs pretreatment. Phosphorylated mTOR was significantly increased in S. Enteritidis infected chickens, but showed no difference in chickens pretreated with Fe₃O₄-NPs. In summary, the results demonstrated that ROS and autophagy were involved in the inhibition of S. Enteritidis in chickens by Fe₃O₄-NPs pretreatment. The redox balance and inflammation response appeared normal in the process, as did the expression of the PI3K/Akt/mTOR signaling pathways. Taken together, our research demonstrate that the bacteriostatic activity of Fe₃O₄-NPs in chickens is avaliable and safe, which can be an alternative to antibiotics for bacterial inhibition in poultry industry.