Nanoparticles are emerging as a fascinating alternative to antibiotics. When stabilized by chemical compounds, magnetite nanoparticles (MagNPs) consistently exhibit bactericidal effects across different types of bacteria. This study describes the synthesis, characterization, and antibacterial properties of magnetite MagNPs prepared by the coprecipitation method under continuous sonication. Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), and Dynamic Light Scattering (DLS) techniques revealed Fe₃O₄-NPs as spherical, uniform particles with an average size of approximately 16 nm. The antibacterial efficacy of MagNPs was investigated by combining them with methanolic extracts of three medicinal plants known for their antibacterial properties: Aloysia triphylla, Sarcopoterium spinosum, and Urtica pilulifera. The combined effect was assessed against both wild type and resistant strains of Staphylococcus aureus and Escherichia coli. The antibacterial synergistic effect of MagNPs and plant extracts was evaluated by the MIC test, which showed significant inhibitory properties against the growth of the four bacterial strains as compared to control samples of plant extracts alone. Furthermore, the synergistic effect of MagNPs combined with extracts from Rosmarinus officinalis, Anchusa azurea, Quercus infectoria, and Urtica pilulifera significantly prevented biofilm development in both sensitive and resistant strains of Staphylococcus aureus.

The aim of this study was to evaluate the in vitro antimicrobial activity of medicinal methanolic plant extracts against multidrug-resistant bacteria to determine the cytotoxicity of these extracts on eukaryotic cells, and to confirm their efficacy against Methicillin-Resistant Staphylococcus aureus (MRSA) in experimental animals. The effects of the methanol extract of sixty folk plants were investigated on; MRSA, Extended Spectrum Beta-Lactamase E. coli and MDR Pseudomonas aeruginosa by disc diffusion and MIC assay. Cytotoxicity was determined using MTT and hemolysis of human erythrocytes. Three plant extracts with the highest antimicrobial activities were tested using a challenge experiment on mice. Systemic infection was performed by intraperitoneal inoculation of (5 × 10⁶ CFU/mL) of MRSA isolate. Then mice received 300 mg/kg body weight of the plant extracts daily for seven days. The efficacy of plant extracts was evaluated by general health, mortality rate, gross lesion, and histopathology study of inoculated mice. Only ten plants showed activities against different MDR bacteria with inhibitory zones ranging from (8 to 22 mm) in diameter. Of the ten medicinal plant extracts, Camellia sinensis and Aloysia citrodora showed the highest activities against MRSA and MSSA isolates, with MIC value ranging from 0.5 to 1.5 mg/ml, followed by Hibiscus sabdariffa, Thymus vulgaris, and Glycyrrhiza glabra. Furthermore, the extract of the effective plants showed low toxicity against Vero and fibroblasts cell lines, along with inhibitory activities to erythrocytes membrane disruption. The in vivo study demonstrated that Camellia sinensis showed significant activity against MRSA infections in mice. The results validate that these plants are effective and safe antibacterial agents against multidrug-resistance bacteria, and have the potential to be utilized as an alternative to antibiotics for the treatment of bacterial infections.

Many early-generation antibiotics, previously deemed ineffective due to bacterial resistance. This study aimed to reconsider the potential use of antibiotics to