Rapid green synthesis of noncytotoxic iron oxide nanoparticles using aqueous leaf extract of Thymbra spicata and evaluation of their antibacterial, antibiofilm, and antioxidant activity

Abstract

Herein the green synthesis of iron oxide (FeO) nanoparticles (NPs) was achieved by using Thymbra spicata leaf extract. The antibacterial activity of FeONPs was evaluated against both gram-positive and gram-negative bacteria by using broth microdilution assay. Further, the antioxidant and cytotoxic potential of FeONPs was determined by using standard protocols. The effects of nanoparticles on Staphylococcus aureus growth and on their biofilm formation were investigated. FeONPs at the concentration of 100 µg/mL exhibited excellent bactericidal action against Salmonella typhimurium. Also, the biogenic nanoparticles inhibited the growth rate of S. aureus. Furthermore, FeONPs showed noncytotoxic characteristics on L929 mouse fibroblast cells. All these results revealed that FeONPs obtained by simple and eco-friendly synthesis process through T. spicata extract could be considered a promising candidate as antibacterial agent for many different applications. Also, biogenic FeONPs with their antibiofilm activity on S. aureus could serve as potent antibacterial agents against pathogenic biofilm-forming bacteria.