Evaluation of Antibacterial and Antioxidant Activities of Biosynthesized Zinc oxide Nanoparticles using Aqueous Extract of Eriobotrya Japonica Seeds

Introduction: Recently, much attention has been paid to the biosynthesis of nanoparticles (NPs) due to their eco-friendly, cost-effective, and easily applied nature. This study aimed to synthesize zinc oxide (ZnO) NPs using Eriobotrya Japonica seed aqueous extract. Moreover, it was attempted to evaluate their antioxidant and antibacterial activities. Materials & Methods: Initially, the Eriobotrya Japonica seed aqueous extract was prepared, and the total phenolic and flavonoid contents were measured in this study. After the preparation of ZnO NPs by the extract, the antioxidant activity of ZnO NPs was evaluated using DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging method. In addition, the antibacterial activities of the extract and NPs were determined using a disc diffusion method against Staphylococcus aureus gram-positive bacteria and Escherichia coli gram-negative bacteria. Ethics code: Ir.ausmt.rec.1398.11.33 Findings: The results showed that aqueous extract had a specific amount of phenolic and flavonoids (9.86 mg/g and 27 mg/g dry weight of extract, respectively). Moreover, the synthesized ZnO NPs were