Microwave assisted green synthesis of nano-sized biogenic silver in extract of Phlomis linearis: potential anticancer and antimicrobial activities

Silver nanoparticles (AgNPs) are known for their significant anticancer and antimicrobial activities in the field of medicine. In the present study, AgNPs were synthesized using a microwave-assisted green synthesis process, in which Ag(I) ions were reduced by organic compounds extracted from the leaves and stems of Phlomis linearis, an endemic plant which acted as both reducing and stabilizing agents. Although various species of the Phlomis genus have been studied in the literature, the synthesis of the nano-sized biogenic silver with reducing Ag(I) in the extract of the endemic plant P. linearis is reported here for the first study time, along with the evaluations of its bioactive properties. The obtained AgNPs were characterized by optical, structural, morphological, etc. techniques such as Ultraviolet–visible spectroscopy (UV–Vis.), Fourier-Transform Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), transmission electron microscopy (TEM), dynamic light scattering (DLS), and photoluminescence (PL). Gas chromatography − mass spectrometry (GC–MS) and FT-IR techniques were used in order to evaluate the biochemical-reduction mechanism. When their antimicrobial activities were determined by the well diffusion method on six bacterial strains, the results showed that P. linearis exhibited antimicrobial activity against all tested bacteria. Additionally, the investigation of the anticancer activity of the particles by using the MTS method on a breast cancer cell line (MCF-7) and a healthy human cell population (human umbilical vein endothelial cells [HUVEC]) revealed that our AgNPs were more cytotoxic toward the cancerous cells compared to the non-cancerous ones (p < 0.001).