A comparative study on subacute toxicity of arsenic trioxide and dimethylarsinic acid on antioxidant status in Crandell Rees feline kidney (CRFK), human hepatocellular carcinoma (PLC/PRF/5), and epithelioma papulosum cyprini (EPC) cell lines.

Arsenic (As) is a global contaminant of terrestrial and aquatic environments posing concern for environmental and human health. The effects of subacute concentrations of arsenic trioxide (As) and dimethylarsinic acid (DMA) were examined using Crandell Rees feline kidney (CRFK), human hepatocellular carcinoma (PLC/PRF/5), and epithelioma papulosum cyprini (EPC). Whole monolayer with suffering cells (confluence 100%, pyknosis and refractive cells; value scale = 2) led to identification of subacute As concentrations for the three cell lines. The selected As concentrations were 1.33 µM for CRFK and 33.37 µM for PLC/PRF/5 and EPC, at 48 hr time point. The selected DMA concentrations were 0.67 mM for PLC/PRF/5, 1.33 mM for CRFK, and 2.67 mM for EPC for 48 hr. Unlike the As test, the three cell lines did not exhibit marked susceptibility to DMA-mediated toxicity. Several oxidative stress biomarker levels, directly or indirectly associated with reactive oxygen species (ROS) elimination including superoxide dismutase, catalase, glutathione peroxidases, glutathione reductase, glutathione S-transferase, glyoxalase I, glyoxalase II, and total glutathione, were determined in the three cell lines at 24 and 48 hr. Antioxidant responses in metal-treated cells were significantly altered compared to controls, suggesting a perturbation of redox state. The weakening of antioxidant pathway in either healthy or tumoral cells was greater using As than DMA. Differences in level of several oxidative stress biomarkers suggest that the oxidative stress mechanism induced by As is distinctly different from DMA. Multifaceted mechanisms of action underlying ROS generation in tumor and nontumor cells versus As and DMA exposure are thus involved. Since As-mediated toxicity is quite complex, more data regarding both oxidant-enhancement and oxidant-lowering strategies may be useful to improve knowledge regarding the influence of As on human and animal cells.