Biosynthesis of silver nanoparticles using Origanum onites extract and investigation of their antioxidant activity

Abstract

The current study was designed for green synthesis of silver nanoparticles (AgNPs) using Origanum onites extract and evaluation of their antioxidant activity. Origanum onites was extracted with hexane and methanol sequentially and methanol extract was used for synthesis of the AgNPs. The structure of silver nanoparticles was elucidated by UV-Vis, FTIR, XRD, and SEM analyses. Antioxidant activity of AgNPs and extract was carried out using DPPH, ABTS and reducing power assays. The absorption peak at 450 nm in UV-Vis spectrum confirmed the establishment of AgNPs. SEM analysis identified the formation of spherical-shaped nanoparticles with the average size of 54.2 nm. FTIR analysis displayed the possible content of secondary metabolites in silver nanoparticles of crude extract. XRD study displayed the crystalline nature of AgNPs. The AgNPs revealed the significant ABTS•+ scavenging effect (IC50, µg/mL, 5.16 ± 0.07) compared to standard, BHT (IC50, µg/mL, 7.03 ± 0.19). The AgNPs revealed the better activity than the methanol extract. The best activity of extract was observed in ABTS•+ assay (IC50, µg/mL, 6.24 ± 0.04). Due to the importance of O. onites in the pharmacy and food industry, the green synthesized silver nanoparticles could be valuable materials in the bio-medicinal field.