Green-Synthesised Zinc Oxide Nanoparticles Derived from Saurauia vulcani: Physicochemical Characterization, Cytotoxicity, and Intracellular ROS-Associated Response in MCF-۷ Cells

Zinc oxide nanoparticles (ZnO NPs) have attracted considerable interest for biomedical applications due to their distinctive physicochemical properties and potential biological activity. In the present study, ZnO NPs were synthesized using an aqueous extract of Saurauia vulcani through a green synthesis approach and subsequently characterized for their physicochemical properties and preliminary in vitro cytotoxic activity against MCF-۷ breast cancer cells. The formation of ZnO NPs was visually indicated by the appearance of a light whitish precipitate, with a yield of ۴۶.۲ mg/۱۰۰ mL (۵۶.۸%). UV–Vis analysis showed a characteristic absorption band at ۳۶۰–۳۸۰ nm, while Tauc plot analysis indicated an optical bandgap of ۳.۰۶ eV. FTIR analysis revealed the presence of oxygenated functional groups associated with plant-derived phytochemicals and a distinct Zn–O band below ۶۰۰ cm⁻¹, whereas XRD confirmed the formation of phase-pure hexagonal wurtzite ZnO. Microscopic and elemental analyses further supported the successful formation of the synthesized nanomaterial. Cytotoxicity evaluation by the MTT assay demonstrated a dose-dependent response in MCF-۷ cells, with an estimated IC₅₀ value of ۸۹۷ µg/mL. Cell viability remained relatively stable at ۲۰۰–۸۰۰ µg/mL, whereas a marked reduction was observed at ۱,۰۰۰–۱,۲۰۰ µg/mL. Intracellular ROS-associated fluorescence analysis using DCFH-DA-based flow cytometry showed a progressive leftward shift in the fluorescence histogram and a marked decline in the gated cell population with increasing concentration. Overall, these findings indicate that green-synthesized ZnO NPs derived from Saurauia vulcani possess confirmed physicochemical characteristics and preliminary in vitro cytotoxic potential against MCF-۷ breast cancer cells, particularly at higher concentrations.

کلیدواژه ها:

Saurauia vulcani ، Zinc oxide nanoparticles ، Green synthesis ، physicochemical characterisation ، MCF-۷ ، Cytotoxicity