Green Synthesis of Zinc Oxide Nanoparticles Using Viscum album Extracts: Unveiling Bioactive Compounds, Antibacterial Potential, and Antioxidant Activities

Abstract

The current study explored the antioxidant and antibacterial capabilities of zinc oxide nanoparticles (ZnONPs) synthetized using methanolic leaf extracts of the medicinal herb Viscum album. Through TEM investigation and UV–Vis analysis, which peaked at 406 nm, the synthesis of ZnONPs was verified. TEM analyses showed that the synthesized ZnONPs had a size distribution with an average of 13.5 nm and a quasi-spherical shape. Forty-four phytoconstituents were found in the methanolic leaf extracts of V. album. Additionally, a comparison of the antibacterial effectiveness and antioxidant capacity of aqueous and methanolic extracts of wild-grown V. album phytomedicine and green-manufactured ZnONPs was conducted. The green-generated ZnONPs were examined against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa and shown to have superior antibacterial activity by 22%, 66%, and 44%, respectively, as compared to wild herbal medicinal extracts. Since the ZnONPs’ aqueous extracts had higher concentrations of DNA gyrase-B inhibitory components, they were shown to be more effective in limiting bacterial growth. In contrast to the percentages of 49% and 57% for a wild plant extract, the aqueous- and methanolic-extract-mediated green ZnONPs, with a 100 g/mL concentration, showed 94% and 98% scavenging capacity for DPPH free radicals, respectively. However, methanolic extracts were more effective than aqueous extracts in terms of the antioxidant analyses. This study establishes that greenly produced ZnONPs have the potential to be used in nanomedicine to treat bacteria that are resistant to a variety of drugs, as well as those with reactive oxygen species toxicity.