ROS-mediated cytotoxic activity of ZnO and CeO2 nanoparticles synthesized using the Rubia cordifolia L. leaf extract on MG-63 human osteosarcoma cell lines

In the present scenario, the synthesis and characterization of zinc oxide (ZnO) and cerium oxide (CeO2) nanoparticles (NPs) through biological routes using green reducing agents are quite interesting to explore various biomedical and pharmaceutical applications, particularly for the treatment of cancer. This study was focused on the phytosynthesis of ZnO and CeO2 NPs using the leaf extract of Rubia cordifolia L. The active principles present in the plant extract were liable for rapid reduction of Zn and Ce ions to metallic nanocrystals. ZnO and CeO2 NPs were characterized by UV-visible spectroscopy, X-ray diffraction analysis (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray spectroscopy (EDAX), and photoluminescence (PL) techniques. ZnO and CeO2 NPs were partially agglomerated with a net-like structure. Biomedical activities of ZnO and CeO2 NPs were tested against MG-63 human osteosarcoma cells using MTT and reactive oxygen species (ROS) quantification assays. In treated cells, loss of cell membrane integrity, oxidative stress, and apoptosis was observed and it is well correlated with cellular damage immediately after induction. Overall, this study shed light on the anti-cancer potential of ZnO and CeO2 NPs on MG-63 human osteosarcoma cells through differential ROS production pathways, describing the potential role of greener synthesis.