In-vitro Cytotoxic and Genotoxic Effect of Arsenic Trioxide on Human Jurkat T- Cells Using the Mtt and Alkaline Single Cell Electrophoresis (comet) Assays

Abstract: Arsenic trioxide (As2O3) has cytotoxic effects on several cancer cell lines. However, the molecular mechanisms of action remain to be elucidated. Hence, the aim of the present study was to evaluate the cytotoxicity and genotoxicity induced by As2O3 in a human Jurkat T-cell line using the MTT [3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] and alkaline single cell gel electrophoresis (Comet) assays, respectively. Jurkat Tcells were treated with different doses of As2O3 for 24 h prior to cytogenetic assessment. Data obtained from the MTT assay indicated that As2O3 significantly (p < 0.05) reduced the viability of Jurkat T-cells in a dose-dependent manner, showing a LD50 value of 15 + 3.84 μg/mL, upon 24 hours of exposure. Similar data was obtained with the trypan blue exclusion test. Data generated from the comet assay also indicated a significant dose-dependent increase in DNA damage in Jurkat T-cells associated with As2O3 exposure. We observed a significant increase (P < 0.05) in comet tail-length, tail arm and tail moment, as well as in percentages of DNA cleavage at all doses tested, showing an evidence As2O3 of -induced genotoxic damage in Jurkat T-cells. This study confirms that the comet assay is a sensitive and effective method to detect DNA damage caused by heavy metals such as arsenic. Taken together, our findings suggest that As2O3 exposure significantly (p < 0.05) reduces cellular viability and induces DNA damage in Jurkat T-cells as assessed by MTT and alkaline single cell gel electrophoresis assays, respectively.