In-vivo toxicity and therapeutic efficacy of Paeonia emodi-mediated zinc oxide nanoparticles: In-vitro study

Microsc Res Tech. 2022 Jan;85(1):181-192. doi: 10.1002/jemt.23894. Epub 2021 Aug 14.

Abstract

This study was planned to explore the in-vitro and in-vivo therapeutic significance of Paeonia emodi-mediated zinc oxide nanoparticles (ZnO NPs) against the Staphylococcus aureus and Escherichia coli. The texture parameters were derived from nitrogen adsorption-desorption data using Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) methods, and the surface area (SBET ) was found to be 214 m2 /g with a pore size of 2.3 nm. The crystallographic parameters were investigated through X-ray diffraction analysis, and the calculated crystallite size is 29.13 nm. The microstructure was examined through transmission and scanning electron microscopies (TEM and SEM, respectively), and the average particle size estimated from a TEM image is 44.40 nm. The chemical composition and attached function groups were identified through energy-dispersive X-ray and Fourier transform infrared spectroscopies. The in-vitro minimum inhibitory concentration (MIC) for both bacterial species results was found less than 2 μg/ml. The tolerance limit of mouse models was evaluated by the inoculation of different concentrations of ZnO suspension where the concentration above 23 ppm was proved lethal. The maximum infection was caused in mouse models by inoculation of 3 × 107 CFUs (Colony forming unit) of the both bacterial species. The concentration higher than 3 × 107 CFUs led to the ultimate death of the mice. The histopathological and hematological studies reveal that the after simultaneous inoculation of both ZnO NPs and bacterial suspensions (tolerated amount), no/negligible infection was found in the mice model.

Keywords: Paeonia emodi; bacterial infection; hematology; histopathology; zinc oxide.

MeSH terms

  • Animals
  • Anti-Bacterial Agents
  • Metal Nanoparticles* / toxicity
  • Mice
  • Nanoparticles* / toxicity
  • Paeonia*
  • X-Ray Diffraction
  • Zinc Oxide* / toxicity

Substances

  • Anti-Bacterial Agents
  • Zinc Oxide