A novel approach for the biosynthesis of silver oxide nanoparticles using aqueous leaf extract of Callistemon lanceolatus (Myrtaceae) and their therapeutic potential

This study describes a novel biological route for the biosynthesis of silver oxide nanoparticles utilising the aqueous extract of Callistemon lanceolatus D.C. leaves. Formation of silver oxide nanoparticles was confirmed by UV-visible spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscope-energy dispersive X-ray spectroscopy and X-ray diffraction spectroscopy analysis. The biologically synthesised silver oxide nanoparticles were found to be 3-30 nm in size with spherical and hexagonal shape by high-resolution transmission electron microscope analysis. Furthermore, the biogenic silver oxide nanoparticles demonstrated significant (p < 0.05) dose-dependent antioxidant activity in various in vitro antioxidant methods. These particles also exhibited significant (p < 0.05) dose-dependent and time-dependent cytotoxic activity towards brine shrimp nauplii. Moreover, the reported method is a simple, cost-effective and eco-friendly approach for the synthesis of silver oxide nanoparticles with useful pharmacological properties.