The Effect of Ag, Cu, and ZnO Nanoparticles on TNF-α Expression in Staphylococcus aureus-Infected Balb/C Mice

Subject Areas : Molecular Microbiology

Behnaz Esfandiari ^{1 *}

1 - Department of Biology, ISIC, Islamic Azad University, Islamshahr, Iran

Received: 2025-08-30 Accepted : 2025-08-30 Published : 2025-08-30

Keywords: Staphylococcus aureus, MRSA, TNF-α, Nanoparticles, MIC, MBC.,

Abstract :

Background and Objective: Antibiotic resistance, especially in methicillin-resistant Staphylococcus aureus (MRSA), is a global challenge. Nanoparticles (NPs) such as silver (Ag), copper (Cu), and zinc oxide (ZnO) have shown antibacterial potential. This study aimed to evaluate the effectiveness of these nanoparticles against MRSA and their impact on TNF-α gene expression in Balb/c mice.

Materials and Methods: Sixty-three mice were divided into nine groups of seven. Groups 5 to 9 were infected with MRSA and then treated with Ag (15.625 mg/L), Cu (62.5 mg/L), ZnO nanoparticles, vancomycin, or saline solution. TNF-α expression in the spleen was measured by Real-Time PCR on days 1 and 5. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the nanoparticles were also determined.

Results: Ag and Cu nanoparticles showed inhibitory and bactericidal effects, while ZnO was ineffective. On day 5, TNF-α expression significantly increased in the vancomycin group, followed by Ag, Cu, and ZnO groups. On day 1, only vancomycin, Ag, and Cu increased TNF-α expression.

Conclusion: Ag nanoparticles had the strongest effect on TNF-α expression, indicating their superior antibacterial potential. These findings support the use of nanoparticles as alternatives or supplements to antibiotics in treating MRSA infections.