Synthesis, Physicochemical Properties, and Cytotoxicity of Silver Nitrate Nanoparticles of <i>Achillea filipendulina</i> L. Extract in Lung Cancer Cells

Background: Silver nanoparticles (AgNPs) with varied physicochemical properties have garnered substantial attention in recent years for their applications in imaging, diagnosis, treatment, and drug delivery within nanopharmaceuticals. This study synthesized AgNPs using Achillea filipendulina (A.F) extract as a reducing and stabilizing agent. Methods: The synthesized nanoparticles underwent characterization via UV-Vis spectroscopy, FTIR, FESEM, DLS, and zeta potential analysis. The total phenolic content (TPC) method was also employed to estimate the quantity of A. filipendulina extract loaded onto the AgNPs. The antioxidant capacity of A.F-AgNPs was evaluated using the FRAP and DPPH methods and compared to crude extract. The study also investigated the impact of process variables, such as the mixing ratio of reactants, type of solvent, and use of polymers, on the size of A.F-AgNPs to attain optimal sizing. Finally, the cytotoxicity of the nanoparticles was assessed via the MTT assay on the lung adenocarcinoma cell line (A549) and the regular lung fibroblast cell line (MRC-5), comparing it with silver nitrate (AgNO3) and extract. Results: The findings indicated a 24% loading of the extract in the synthesized nanoparticles, which mitigated the toxicity of silver nitrate in both cancer and regular cell lines. However, the resulting formulation exhibited more significant toxicity on the cancer cell line. In addition, the in vitro antioxidant assay demonstrated that the extract’s antioxidant potency was four times higher than that of A.F-AgNPs at a concentration of 3.2 mg/mL, which was directly in relationship with drug loading in synthesized nanoparticles. Conclusion: The results suggested that polyphenolic compounds or pure phenolic structures act as capping and reducing agents, with more selective effects on cancer cells to minimize side effects on normal lung cells.