The aim of this study is to green-synthesize gold nanoparticles (GNPs) by leaf infusion of Achillea wilhelmsii (AW) and to evaluate their biological effects. The synthesized AW-GNPs were characterized by UV–Vis spectroscopy, Fourier transform infrared, X-ray diffraction (XRD), transmission electron microscopy (TEM) and dynamic light scattering analyses. The antibacterial and cytotoxicity activities of AW infusion and AW-GNPs were evaluated. Antioxidant activity was evaluated by 1, 1-diphenyl-2-picrylhydrazyl test. Moreover, the electrochemical activity of AW-GNPs as a modifier ata glassy carbon electrode (GCE) was studied. The surface plasmon resonance absorption band at 540nm in the UV–Vis spectrum discloses the reduction of gold cations into GNPs. The XRD pattern of GNPs shows the crystal structure of AW-GNPs, and TEM image displays the spherical shape of GNPs with small size (2.7–38.7 nm). The AWinfusion and AW-GNPs demonstrated a maximum antioxidant activity of 68 and 58%, respectively. AW-GNPs showed antibacterial activity against gram-positive bacteria, without affecting gram-negative bacteria. Also, AW-GNPs exhibited the cytotoxicity effects against MDA-MB-468 cancer cell line, and the electrochemical study indicated a significant electrocatalytic activity of AW-GNPs. The results indicate the advantages of using AW leaf infusion for the production of GNPs with antibacterial, antioxidant, cytotoxic and electrocatalytic activities.

The isolated and pure biological compounds have been widely used in natural-based nanoparticles, entailing applications in medicine, cosmetics and nutrition. In this study, the toxic effects (in vitro) and biomedical applications of isoimperatorin-mediated green synthesized silver nanoparticles (Iso-AgNPs) were investigated. The in vitro antioxidant, antibacterial and cytotoxic potential were determined by using standard protocols. Besides, blood compatibility was determined by hemolysis and coagulation tests. Based on the obtained results, Iso-AgNPs showed enhanced antioxidant capacity in comparison with the crude isoimperatorin and were found effective against the pathogenic bacterial strains.Cell viability study reveals the safety of Iso-AgNPs on H1299 and MCF-7 cell lines, and no significant cytotoxicity was observed. The non-hemolytic effect of Iso-AgNPs on erythrocyte cells (RBCs) and the absence of coagulation indicate high blood compatibility of these nanoparticles, which make them unique in comparison to the other silver nanoparticles. Altogether, our finding confirms the biological advantages of Iso-AgNPs as a cyto- and blood-compatible antibacterial and antioxidant nano-metal.