Comparative Cytotoxic Effects of Silver Nanoparticles Synthesized from Humulus lupulus, Inula viscosa, and Olea europaea on Saos-2 and MCF-7 Cells

Abstract Recent advances in green nanotechnology have enabled the development of plant-mediated silver nanoparticles (AgNPs) as promising anti-cancer agents. This study characterizes AgNPs biosynthesized using aqueous extracts of three medicinal plants— Humulus lupulus (hops), Inula viscosa , and Olea europaea (olive)—and evaluates their cytotoxic effects against Saos-2 osteosarcoma and MCF-7 breast cancer cell lines. Ultraviolet–Visible Spectroscopy (UV–Vis) confirmed nanoparticle formation through characteristic surface plasmon resonance (SPR) peaks (400–420 nm), while scanning electron microscopy revealed spherical particles (30–70 nm) with moderate aggregation. Additionally, X-ray diffraction (XRD) analysis confirmed the crystalline nature of the synthesized silver nanoparticles. The viability assay demonstrated significant dose- and time-dependent cytotoxicity, with I. viscosa -AgNPs showing particularly strong effects. Comparative analysis revealed plant-synthesized AgNPs exhibited enhanced biocompatibility and selective toxicity compared to chemically synthesized counterparts. The green synthesis approach employed in this study not only eliminates toxic chemical reductants but also enhances therapeutic potential through synergistic phytochemical-nanoparticle interactions. These results position plant-mediated AgNPs as a sustainable and effective alternative for targeting aggressive cancers like osteosarcoma and hormone-resistant breast cancer. The study highlights the importance of integrating traditional medicinal knowledge with modern nanotechnology for developing novel cancer therapeutics.