Histopathological and hematological investigations of mice model inoculated with nickel oxide nanoparticles and bacterial pathogens: In-vitro and in-vivo antibacterial studies

Abstract

The Paeonia emodi (P. emodi) leaf extract was manipulated for the phytogenic fabrication of nickel oxide nanoparticles (NiO NPs) for in-vivo and in-vitro antibacterial activity against Escherichia coli (E. coli: (ATCC #: 15224)) and Staphylococcus aureus (S. aureus (ATCC #: 6538)). The surface area was found to be 78 m2/g and was determined by the BET method using N2 adsorption–desorption data. The cubic geometrical shape of NiO NPs was confirmed through X-ray diffractogram (XRD) analysis, and the enumerated crystallite size is 22.37 nm. The microstructure analysis was carried out via scanning electron microscopy (SEM), whereas the elemental composition was investigated by energy dispersive X-ray (EDX). The band gap energy of 1.93 eV was determined on the basis of the transmittance edge seen in the diffuse reflectance (DRS) spectrum. The surface functional moieties were identified by manipulating Fourier transform infrared (FTIR) spectroscopy. The MIC (minimum inhibitory concentration) value for E. coli (7.02 μg/mL) was found to be higher than that for S. aureus (3.51 μg/mL), whereas the dose-dependent in-vitro analysis was also carried out. In both bacteria, 3 × 107 CFUs was the tolerable concentration that causes maximum infection (no death) in mice. To explore the in-vivo therapeutic effectiveness of NiO NPs, 11 pm suspension was injected as the tolerated dose. The haematological and histopathological analysis discloses that the significant reduction in the bacterial infection was seen after the synchronous inoculation of NiO NPs and the bacterial suspensions.

Keywords

• Phytogenic synthesis
• Nickel Oxide
• Bacterial infection
• Histopathology
• Hematology