The cytotoxic potency of green synthesis of zinc oxide nanoparticles (ZnO-NPs) using Origanum majorana

This work aims to generate green synthesized ZnO-NPs using Origanum majorana (O. majorana) with water (OW-ZnO-NPs) or ethanol (OE-ZnO-NPs) and compare their anticancer and cytotoxicity activities. We studied the effect of preparation using water and ethanol with different techniques, including the color change to brownish yellow and yellowish white, respectively. In addition, Zeta-potential showed a negatively charged surface, and the Energy Dispersive X-ray (EDX) exhibited different elements with various ratios (zinc > oxygen > carbon). Furthermore, Transmission and Scanning Electron Microscopy (TEM and SEM) were used to illustrate the spherical structures. Next, the cytotoxicity for the synthesized nanoparticles was determined by MTT assay, and 50 % cytotoxic concentration (CC50) for OW-ZnO-NPs were 152.95, 92.89, >1000 and > 1000 mu g/mL, and for OE-ZnO-NPs, 105.14, 52.54, >1000 and 736.57 mu g/mL were evaluated against MCF7, HepG2, HSF and OEC cells, respectively. In conclusion, the results of this study demonstrate a simple, affordable, and eco-friendly method for synthesizing ZnO-NPs using readily available plant extract. In addition, OE-ZnO-NPs have higher anticancer activity than OW-ZnO-NPs and less toxic activity against normal cell lines.