Green synthesis of silver nanoparticles by using aqueous mint (Mentha piperita) and cabbage (Brassica oleracea var. capitata) extracts and their antibacterial activity

Green synthesis of silver nanoparticles by using aqueous mint (Mentha piperita) and cabbage (Brassica oleracea var. capitata) extracts and their antibacterial activity. The objective of this study was the synthesis of silver nanoparticles (Ag-NP) using leaves of mint and cabbage extracts as the reducing and stabilising agents. The presence of nanoparticles was initially confirmed by the obtained colour and next by transmission electron microscope (TEM). Analysis of TEM of obtained Ag-NP indicated that their size ranged 5–50 nm for mint and 10–150 nm for cabbage. The antibacterial activity of nanoparticles against pathogenic strains Escherichia coli, Staphylococcus aureus and Salmonella enterica were assessed by evaluation of metabolic activity, using the PrestoBlue and XTT test. The higher inhibition of bacterial viability was observed against Gram-negative (E. coli, S. enterica) than Gram-positive (S. aureus) bacteria.