Biosynthesis of silver nanoparticles using Origanum majorana L. and evaluation of their antioxidant activity

Abstract

The aerial part of Origanum majorana L. was extracted with deionized water and then filtered. The liquid extract was treated with silver nitrate to yield the AgNPs. The maximum absorption was observed at 483 nm in the UV-Vis spectrum. SEM analysis exhibited the spherical shape of silver nanoparticles with an average size of 72.01 nm. The XRD diffraction peaks at 2θ degrees revealed the face-centered cubic crystalline structure. Antioxidant activity of AgNPs and water extract was carried out by DPPH^•, ABTS^•+, and reducing power assays. AgNPs revealed higher DPPH^• scavenging activity (IC₅₀, µg/mL, 12.25) than that of the extract (21.66). Moreover, AgNPs exhibited outstanding ABTS^•+ activity (3.87) compared to the standards. The reducing power activity of AgNPs was found (µmol TE/mg extract, 5.09 ± 0.21) the same as the BHT. AgNPs and extract exhibited excellent antioxidant activity promising for usage in food and pharmaceutical applications.

Keywords:

• Nanoparticles
• Origanum majorana
• natural product
• antioxidant activity

Conflict of interest

The authors did not declare any conflict of interest.