Green synthesised zinc oxide nanoparticles reveal potent in vivo and in vitro antibacterial efficacy against Proteus mirabilis isolates.

Currently, the spread of antimicrobial resistance dissemination is expanding at an accelerated rate. Therefore, numerous researchers haveinvestigatedalternative treatments in an effort to combat this significant issue. This study evaluated the antibacterial properties of zinc-oxide nanoparticles (ZnO NPs) synthesised by Cycas circinalis against Proteus mirabilis clinical isolates. HPLC was utilised for the identification and quantification of C. circinalis metabolites. The green synthesis of ZnO NPs has been confirmed using UV-VIS spectrophotometry. The Fourier transform infrared spectrum of metal oxide bonds has been compared to the free C. circinalis extract spectrum. The crystalline structure and elemental composition were investigated using X-ray diffraction and Energy-dispersive X-ray techniques. The morphology of nanoparticles was assessed by scanning and transmission electron microscopies, which revealed an average particle size of 26.83 ± 5.87 nm with spherical outlines. The dynamic light scattering technique confirms the optimum stability of ZnO NPs with a zeta potential value equal to 26.4 ± 0.49 mV. Using agar well diffusion and broth microdilution methods, we elucidated the antibacterial activity of ZnO NPs in vitro. MIC values for ZnO NPs ranged from 32 to 128 µg/mL. In 50% of the tested isolates, the membrane integrity was compromised by ZnO nanoparticles. In addition, we assessed the in vivo antibacterial capacity of ZnO NPs by a systemic infection induction using P. mirabilis bacteria in mice. The bacterial count in the kidney tissues was determined, and a significant decrease in CFU/g tissues was observed. The survival rate was evaluated, and the ZnO NPs treated group had higher survival rates. The histopathological studies demonstrated that kidney tissues treated with ZnO NPs had normal structures and architecture. Moreover, the immunohistochemical examinations and ELISA revealed that ZnO NPs substantially decreased the proinflammatory mediators NF-kß, COX-2, TNF-α, IL-6, and IL-1ß in kidney tissues. In conclusion, the results of this study suggest that ZnO NPs are effective against bacterial infections caused by P. mirabilis.

Antimicrobial Activity of Brassica rapa L. Flowers Extract on Gastrointestinal Tract Infections and Antiulcer Potential Against Indomethacin-Induced Gastric Ulcer in Rats Supported by Metabolomics Profiling.

INTRODUCTION: The gastrointestinal tract (GIT) is vulnerable to various diseases. In this study, we explored the therapeutic effects of Brassica rapa flower extract (BRFE) on GIT diseases. METHODS: Liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) was used for phytochemical identification of the compounds in BRFE. The antibacterial activity of BRFE was investigated, and its impact on the bacterial outer and inner membrane permeability and membrane depolarization (using flow cytometry) was studied. In addition, the immunomodulatory activity of BRFE was investigated in vitro on lipopolysaccharide (LPS)-stimulated peripheral blood mononuclear cells (PBMCs) using quantitative reverse transcription polymerase chain reaction (qRT-PCR). Furthermore, the anti-inflammatory activity of BRFE was investigated by histopathological examination and qRT-PCR on indomethacin-induced gastric ulcers in rats. RESULTS AND DISCUSSION: LC-ESI-MS/MS phytochemically identified 57 compounds in BRFE for the first time. BRFE displayed antibacterial activity against bacteria that cause GIT infections, with increasing outer and inner membrane permeability. However, membrane depolarization was unaffected. BRFE also exhibited immunomodulatory activity in LPS-stimulated PBMCs by attenuating the upregulation of cyclooxygenase 2 (COX-2), inducible nitric oxide synthase (iNOS), interleukin (IL)-6, tumor necrosis factor-alpha (TNF-α), and nuclear factor kappa B (NF-κB) gene expression compared with untreated LPS-stimulated PBMCs. In addition, BRFE exhibited anti-inflammatory activity required for maintaining gastric mucosa homeostasis by decreasing neutrophil infiltration with subsequent myeloperoxidase production, in addition to an increase in glutathione peroxidase (GPx) activity. Histopathological findings presented the gastroprotective effects of BRFE, as a relatively normal stomach mucosa was found in treated rats. In addition, BRFE modulated the expression of genes encoding IL-10, NF-κB, GPx, and myeloperoxidase (MPO). CONCLUSION: BRFE can be a promising source of therapeutic agents for treatment of GIT diseases.