Evaluation of anti-bacterial (Escherichia coli and Staphylococcus aureus) and anticancer effects of silver nanoparticles synthesized by Melissa officinalis L. extract on several cancer cells (A549, MCF-7, and HeLa)

Silver nanoparticles (AgNPs) with antimicrobial and anticancer properties have been widely used in a variety of fields. This research investigated the antimicrobial effects and toxicity of AgNPs synthesized using the extract of the medicinal plant lemon balm, Melissa officinalis L., on 3 cancer cell lines (A549, MCF-7, and HeLa). AgNPs were biologically synthesized using the extract of M. officinalis. After physical and chemical evaluation, the anti-bacterial properties of the synthesized nanoparticles were evaluated in Escherichia coli and Staphylococcus aureus. Finally, the inhibitory effect of synthesized nanoparticles was assessed by the MTT assay on 3 cancer cell lines. With an average size of 17 nm, the nanoparticles synthesized by M. officinalis L. extract had a significant inhibitory and lethal effect on 2 bacteria. The findings indicated that the synthesized nanoparticles had more inhibitory and bactericidal effects on S. aureus as a gram-positive bacterial strain. The MBC of nanoparticles synthesized by M. officinalis extract was 500 μg/mL for S. aureus and 700 μg/mL for E. col. At a concentration of 50 g/mL, the synthesized AgNPs showed more than 50% inhibitory effect on different cell lines. Our results demonstrate that medicinal plants can be used in the successful synthesis of biological AgNPs. The synthesized AgNPs can be utilized as effective medicinal agents in the management of several cancers due to their coating made of effective secondary metabolites and the release of silver ions (Ag+).