Treatment of <scp><i>Pseudomonas aeruginosa</i></scp>–Induced Lung Infection Using Iron Nanoparticles Green‐Formulated by <scp><i>Syzygium aromaticum</i></scp> Leaf Aqueous Extract

ABSTRACT Due mostly to the relative lack of effective chemotherapeutic methods, the lung infections' incidence caused by Pseudomonas aeruginosa categorized as multi‐drug resistant has significantly increased. This study demonstrated the strong antioxidant and anti‐infectious properties of iron nanoparticles prepared using a Syzygium aromaticum aqueous extract in vivo. We employed UV–Vis, FE‐SEM, XRD, FT‐IR, and TEM to determine the characteristics of the iron nanoparticles (FeNPs) that were created when an iron salt solution and aqueous S. aromaticum extract reacted. The existence of metallic iron nano crystallites that were absorbed by the SPR of the FeNPs was suggested by the energy dispersive spectra, which displayed strong spectrum peaks corresponding to Fe at 7.13, 6.44, and 0.71 keV. The signals are indexed as (311), (400), and (440) planes with 2θ values of 38.3, 44.3, and 64.5. The size range of the produced Ag NPs was usually 25–35 nm. The fatal dosage of P. aeruginosa is assessed in Swiss albino mice as part of an in vivo investigation, and the clinical manifestations—such as bacteremia, hypothermia, and weight loss—are analyzed 48 h after infection. Infected mice's physical manifestations revealed a 20% weight loss after the trial and a considerable drop in body temperature, from 38.7°C (0 h) to 34.6°C (after 48 h). Furthermore, using bacteremia, histology, and radiological examination, the effectiveness of FeNPs against lung infection caused by the projected fatal dose was assessed. On Day 7, the bacterial burden was 0.2 Log10CFU/mL in the FeNPs group, which was much lower than the bacterial burden on Day 1, which was 1.8 Log10CFU/mL. According to the study, 50 μg/kg of the FeNPs extract is effective against P. aeruginosa –induced lung infections. The goal of the current work was to build a powerful regimen against this dangerous infection by further using the biological features of FeNPs. Histopathological findings revealed infiltrates in every lung segment of infected mice, as well as a more widespread and patchy buildup of inflammatory cells inside the alveolar space.