A possible role of oxidative stress in the vanadium-induced cytotoxicity in the MC3T3E1 osteoblast and UMR106 osteosarcoma cell lines

The cytotoxicity and free radical production induced by vanadium compounds were investigated in an osteoblast (MC3T3E1) and an osteosarcoma (UMR106) c ell lines in culture. Vanadate induced cell toxicity, reactive oxygen speci es (ROS) formation and thiobarbituric acid reactive substances (TEARS) incr eased in a concentration-dependent manner (0.1-10 mM) after 4 h. The concen tration-response curve of vanadate-induced cytotoxicity and oxidative stres s in MC3T3E1 cells was shifted to the left of the UMR106 curve, suggesting a greater sensitivity of the non-transformed cells in comparison to the ost eosarcoma UMR106 cells. Supplementing with vitamin E acetate (80 mu M) sign ificantly inhibited ROS and TEARS formation but did not improve the vanadat e-dependent decrease in cell number. Other vanadium compounds (vanadyl, per vanadate, and VO/Aspi, a complex of vanadyl(IV) with aspirin) showed differ ent degrees of cell toxicity and induced oxidative stress. Altogether these results suggest that oxidative stress is involved in vanadium induced oste oblastic cytotoxicity, although the mechanism is unknown. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.