Green Synthesized Ag Nanoparticles as Promising Antibacterial and Antitumor Agents: In Vitro Studies

In this work, we used a biocompatible and safe approach for the treatment of health-threatening diseases using the Spinacia oleracea plant. Practically, Ag nanoparticles were green synthesized applying Spinacia oleracea to use against breast cancer cells (MCF-7 and MDA-MB-231 cell lines) and bacteria (S. aureus, S. epidermidis, and P. aeruginosa). Next, analytical techniques (FT-IR, XRD, DLS, TEM, and SEM) were employed for the characterization of nanoparticles. Nanometric size (10 nm to 25 nm in diameter), crystallinity, and spherical and semi-spherical morphology were determined for the biosynthesized Ag nanoparticles. Then, several biomedical tests (MIC, MBC, cell viability (MTT), quantitative gene expression (qRT-PCR), cell cycle arrest, and apoptosis) were performed for investigating the cell suppression capability of Ag nanoparticles and extracted plant precursor. These results indicated MIC of 20 nM, 35 nM, and 35 nM for S. epidermidis, P. aeruginosa, and S. aureus after treatment with Ag nanoparticles, respectively. Cell viabilities of 35% to 90% (for plant precursor) and 55% to 85% (for Ag nanoparticles) were observed for both cancer cells. Expression levels of BRCA1 (3 to 6 folds decrease), BRCA2 (4 to 15 folds decrease), Caspase9 (3.5 folds increase), Bcl2 (3 folds decease), Beclin1 (no considerable shift), and ATG (1.3 folds increase) genes were ascertained in cancer cells after treatment with Ag nanoparticles. Also, the cell cycle arrest (18- and 19-fold increase for MCF-7 and MDA-MB-231, respectively) and apoptosis (22% necrosis for MCF-7 and 17.5% apoptosis for MDA-MB-231) assays have remarkably confirmed the potency of biosynthesized Ag nanoparticles in the treatment of diseases.