Cyto/Genotoxicity study of polyoxyethylene (20) sorbitan monolaurate (tween 20)

Polyoxyethylene (20) sorbitan monolaurate (tween 20) is a non-ionic surfactant that is widely used as an emulsifier and stabilizer in pharmaceutical formulations, food and cosmetic industries. Although a number of studies have showed its non-toxic impacts on target cells, still, it is essential to investigate its effect on target cells. Therefore, in the present study, the anti-cell proliferation and cyto/genotoxicity effects of tween 20 are reported to address the possible mechanism for induction of apoptosis. At 40%-50% confluency, A549 cells and human umbilical vein endothelial cells were exposed to tween 20 at a recommended concentration for 24 h. After 24 h, to detect apoptosis and DNA damage, the treated cells were subjected to 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, fluorescein isothiocyanate (FITC)-labeled annexin V flow cytometry, DAPI staining, comet, and DNA ladder assays. Tween 20 decreased the growth of treated cells dose and time dependently, and single-strand DNA cleavage has been confirmed by comet assay. In addition, morphological alteration of DAPI-stained cells showed clear fragmentation in the chromatin and DNA rings within the nucleus of tween 20-treated cells. In addition, flow cytometry and DNA fragmentation assays confirmed DAPI staining assay results and indicated the occurrence of a programmed cell death (apoptosis) in the treated cells. These results demonstrate that, despite consideration of tween 20 as a safe non-ionic surfactant, it can induce apoptosis in target cells.