<i>In vitro</i> antibacterial effect of silver nanoparticles synthetized using <i>Agastache foeniculum</i> plant and callus extracts

Abstract

<abstract> Green synthesis is an environmentally friendly, safe, affordable and low-cost method for various morphologies nanoparticles producing using bacterial, fungi or plant aqueous extracts. Antimicrobial activity of silver nanoparticles obtained from <italic>Agastache foeniculum</italic> plants and callus aqueous extracts has been demonstrated against hospital infections—<italic>Staphylococcus aureus</italic>, <italic>Staphylococcus haemolyticus</italic>, <italic>Klebsiella pneumonia</italic> and <italic>Streptococcus pneumonia</italic>. The synthesized nanoparticles were characterized by UV-spectroscopy and transmission electron microscopy. The nanoparticles had a spherical shape with an average size diameter of 19.81 ± 5.32 nm and 9.51 ± 1.55 nm for synthesis based on plant and callus extracts respectively. The minimum inhibitory concentration for the nanoparticles was 6.25 to 25.00 mg/L for all tested strains, except for <italic>Acinetobacter baumannii</italic>, which experimental cultivation conditions were inappropriate. Antioxidant capacity of the extracts expressed in total phenolic and flavonoid contents also has been shown. Total phenolic content of callus extract was 1.97 ± 0.06 mg/g in hydroquinone equivalents, which is higher than plant's extract. Supposedly biogenic nanoparticles morphology depends on the concentration of compounds with antioxidant activity in extracts. Initial extracts have proved low-cytotoxicity, indicating synthesis safety. The nanoparticles can be used as a basis for products development to prevent hospital infections spreading, including those with antibiotic resistance. </abstract>