Cytotoxic Effect of ZnO on the Human Lung Cancer (A549) and HUVEC as a Normal Cell Line

Background and Aim: Lung cancer is one of the most common cancers inboth men and women and it is growing worldwide. Previous studies havereported that using nano zinc oxide (ZnO) can be a promising agent incancer treatment because of their unique properties. Our purpose in thisstudy was investigating the cytotoxic effect of ZnO on the human lungcancer cells (A549) and HUVEC as a normal cell line.Methods: A549 and HUVEC cells were seeded at a density of 1×104 in96-well plates and were treated with different concentrations of ZnO for1, 3, 5 and 7 days. Cell viability was evaluated by trypan blue stainingand MTT assay. In addition, Giemsa and AO/EB staining were used toinvestigate morphological changes of cells and detect apoptosis.Results: In this study, treatment of A549 cells with ZnO at a concentrationof 100 μg/mL resulted in a decrease in cell viability to 49%, 22.1%, 8.65%,and 6.28% respectively after 1, 3, 5 and 7 days. Moreover, treatment of HUVEC cells with ZnO at a concentration of 40 μg/mL decreased the cellviability to 51%, 10.19%, 4.58% and 3.19% correspondingly after 1, 3,5 and 7 days. Indeed, the Trypan blue and AO/EB results were consistentwith the MTT results.Conclusion: In conclusion, our results suggested that ZnO was able toinduce apoptosis dependent on the proliferation rate of cells. So that,HUVEC cells as the normal cells were more sensitive than A549 as thecancer cells to ZnO cytotoxicity because of high proliferation rate of thecells.