Anticancer Activity of Green Synthesized ZnO Nanoparticles from Ficus benghalensis Bark in Osteosarcoma Cells

Osteosarcoma is the third most common malignancy among children and adolescents, necessitating the development of effective therapeutic strategies. This study investigated the anticancer activity of green-synthesized zinc oxide nanoparticles (ZnO-NPs) fabricated using bark extract of Ficus benghalensis against the human osteosarcoma Saos-2 cell line. The synthesized ZnO-NPs were characterized using UV–Vis spectroscopy, Fourier Transform Infrared (FTIR), and X-ray Diffraction (XRD), confirming nanoparticle formation and a hexagonal wurtzite crystalline structure. Cytotoxicity evaluation revealed significant dosage-dependent inhibition of Saos-2 cell proliferation, with an IC50 value of 75 μg mL−1. Morphological alterations and 4′,6-diamidino-2-phenylindole (DAPI) staining confirmed apoptotic cell death following ZnO-NPs treatment. Furthermore, ZnO-NPs induced oxidative stress by increasing nitric oxide (NO) and lipid peroxidation (LPO) levels while significantly reducing antioxidant markers, including catalase (CAT), superoxide dismutase (SOD), and glutathione (GSH). Flow cytometry analysis demonstrated G0/G1cell cycle arrest, accompanied by elevated caspase-8 activity. Gene expression analysis showed upregulation of Bax and p53 and downregulation of Bcl-2, indicating activation of the mitochondrial apoptotic pathway. Collectively, these findings demonstrate that phytochemical-mediated ZnO-NPs exert potent anticancer effects against Saos-2 cells through oxidative stress-induced apoptosis and cell-cycle arrest, highlighting their potential for osteosarcoma therapy.