Efeitos citotóxicos do trióxido de antimônio (Sb2O3) em diferentes linhagens celulares

Abstract

Antimony (Sb) is a metalloid that can be in the form of sulfides or oxides. Its trivalent form (antimony trioxide - Sb2O3) had an increase in availability in the environment, a consequence of anthropogenic activities and its use as a synergist mainly in the manufacture of flame retardant materials, plastic resins such as PVC and catalysts for PET production. However, knowledge about the toxic effects cells is limited. Given that, it is essential to expand knowledge about its cytotoxic potential. In this context, the present study aimed to test the cytotoxic capacity of Sb2O3 on different cell lines to describe the possible cell changes resulting from exposure to this compound. For that, cell lines with different origins were used: 3T3, HeLa, PC12, Neuro-2a and SHSY5Y. The cells were exposed to different concentrations and exposure times with Sb2O3 and the cell viability analyzed by the MTT reduction method. Sb2O3 showed cytotoxicity in all cells tested. Nerve cells were less susceptible to treatment when 3T3 and HeLa cells were compared. The 50% inhibitory concentration of cell viability (IC50) in 24 hours was 6.87µM for the 3T3 line and 26.06 µM for HeLa and in 48 hours it was 7.09µM and 12.94 µM for 3T3 and HeLa, respectively. PC12 cells showed a reduction in cell viability only at the highest tested concentration of 128 µM and the IC50 was 94.22 µM and 84.91 µM in 24 and 48 hours, respectively. The IC50 obtained for Neuro-2a in 24 and 48 hours was 30.61 µM and 25.46 µM, respectively. For SH-SY5Y the estimated IC50 was 127.35 µM and 80.35 µM in 24 and 48 hours. SH-SY5Y cells did not show viability reduction due to prolonged exposure time (120 hours) in concentrations up to 32 µM. The May Grunwald-Giemsa staining assay showed evidence of death from apoptosis in HeLa and SH-SY5Y cells. These data demonstrate that Sb2O3 has cytotoxic activity in tumors and non-tumor cell lines. The mechanisms involved in this cytotoxicity have yet to be clarified, but they may be involved in the production of reactive oxygen species (ROS).