Fludioxonil is fungicide used in agriculture, which is present in fruits and vegetables. In this study, the effects of fludioxonil on human immune cell viability, apoptosis, cell cycle arrest, and mitochondrial membrane potential were examined in human immune cells, such as Jurkat T cells and Ramos B cells. To examine the cell viability, Jurkat T cells and Ramos B cells were treated with fludioxonil (10-9-10-5 M) for 24 h and 48 h. Water soluble tetrazolium salt assay showed that fludioxonil decreased Jurkat T cell and Ramos B cell viability. Jurkat T cell viability decreased at 24 and 48 h, but Ramos B cell viability decreased only at 48 h. JC-1 dye revealed decreased mitochondrial membrane potential in fludioxonil-treated Jurkat T cells and Ramos B cells. To evaluate apoptosis, annexin-V conjugated FITC, AF488, and propidium iodide (PI) were used and to evaluate cell cycle arrest PI was used. Apoptosis and cell cycle arrest were induced by fludioxonil (10-7-10-5 M) in the Jurkat T cells at 24 and 48 h and Ramos B cells at 48 h. Moreover, the protein levels of pro-apoptotic proteins, such as p53, BAX, and cleaved caspase 3, were increased and anti-apoptotic protein Bcl-2 was decreased by fludioxonil. Expression of the Fas receptor related to the extrinsic apoptosis pathway was increased by fludioxonil. Additionally, cyclin D1 and cyclin E1 were decreased by fludioxonil. In the present study, fludioxonil induced immunotoxicity in human T cells and B cells through apoptosis and cell cycle arrest. Therefore, the present study suggests that fludioxonil induces the cellular toxicity in immune cells.
Keywords: apoptosis; cell cycle arrest; fludioxonil; lymphocyte.