Evaluation of antimicrobial and antioxidant effects of silver nanoparticles synthesized with leaves of Lepidium draba L.

Abstract

Nanoscience is a prominent scientific field with great potential and many novel and cost-effective applications. Numerous green and environmentally friendly synthesis methods have been introduced that use different plant extracts to produce silver, gold, copper, and iron antibacterial nanoparticles. Plant extracts contain rejuvenating compounds which, when exposed to metal salts (in this research, silver nitrate), facilitate their reduction to metal ions. In the present investigation, Lepidium draba was used as a regenerating factor. Silver nanoparticles (AgNPs) containing Azmak leaf extract were synthesized under optimal conditions including silver nitrate concentration, time, temperature, and pH. These nanoparticles were then evaluated for their characteristics using transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), dynamic light scattering (DLS), and zeta potential analyses. Subsequently, the antibacterial properties of nanoparticles were assessed using the broth microdilution method. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) method was also employed to examine the antioxidant properties of synthesized nanoparticles. Structural analyses revealed the formation of spherical, stable, and pure AgNPs with a size of 20–35 nm. The synthesized AgNPs exhibited strong antibacterial activity against Gram-negative and Gram-positive bacteria. In addition, investigation of the antioxidant activity of the nanoparticles showed 89% inhibition at a concentration of 250 μg/mL. AgNPs synthesized using the Azmak leaf extract can be employed as low-cost and efficient nanoparticles for environmental and biomedical applications and their dual antimicrobial and antioxidant characteristics could potentially position them as candidates for treating infectious wound.