Modulation of the Arsenic Effects on Cytotoxicity, Viability, and Cell Cycle in Porcine Endothelial Cells by Selenium.

The differential effects of arsenic compounds and the effect of selenium on arsenic-induced changes in cytotoxicity, viability, and cell cycle of porcine aorta endothelial cells (PAECs) were investigated. MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) assay indicated that arsenic trioxide (As 2 O 3 ) and sodium arsenite (NaAsO 2 ) showed similar cytotoxicity, whereas sodium arsenate (Na 2 HAsO 4 ) did not show cytotoxicity in PAECs. As 2 O 3 and NaAsO 2 at 20 μM decreased PAEC viability, decreased G0/G1 phase, and increased apoptosis. An increased G2/M phase was observed in NaAsO 2 -treated PAECs, whereas an increase in secondary necrosis (late apoptosis) was observed in As 2 O 3 -treated PAECs. As 2 O 3 -induced apoptosis was associated with upregulation of p53 and caspase 3, whereas NaAsO 2 -induced apoptosis was associated with p53 upregulation. Sodium selenite (Na 2 SeO 3 ) at 1 nM reduced 20 μM As 2 O 3 -induced cytotoxicity, but not apoptosis, at 24 h. Increased glutathione peroxidase (GPX) activity by Na 2 SeO 3 pretreatment in 20 μM As 2 O 3 -treated PAECs suggests that Na 2 SeO 3 modulates As 2 O 3 -induced cytoxicity by GPX modulation. [ABSTRACT FROM AUTHOR]