MIHAELA ROCSANA LUCA*, RALUCA CIUBǍR**, CRISTINA IANCU CIOFRÂNGEANU**, VALENTINA MITRAN**, ANIŞOARA CÎMPEAN**, DANA IORDǍCHESCU**
*Bios Diagnostic, Bucharest, Romania
**Department of Biochemistry and Molecular Biology, University of Bucharest, 93, Splaiul Independenţei, Bucharest 6, Romania
Abstract. Evaluation of biological effects of chromium (VI) is very important taking into account its toxicity seen at people with organ prostheses manufactured from chrome alloys and at workers in galvanic chromium plating and the beneficial effects of chromium on serum glucose and lipid and insulin resistance in diabetic patients. We have evaluated the effects of sodium chromate on the viability and oxidative status of human embryonary fibroblasts (HEF). Our results show that hexavalent chromium has not cytotoxic effects upon HEFs at 5 – 50 μM concentration. Addition of 100 – 200 μM Cr (VI) in the culture medium caused decreases in cell viability in a time and dose-dependent manner and an appreciable increase in intracellular ROS production. GSH depletion in cells treated with the highest doses tested may be explained by its scavanging role as well as by Cr (VI) reduction by GSH to Cr (V). Catalase (CAT) and glutathione peroxidase (GPx) activities were increased after 3-h and decreased after 24-h exposure to higher doses of chromate. The activity of Cu,Zn-superoxide dismutase (SOD) was inhibited only as result of cell incubation for 24 h with 200 μM Na2CrO4 while MnSOD activity was activated by 100 μM Cr (VI) and inhibited after 24-h exposure to 200 μM chromate.
Key words: chromium (VI), fibroblasts, reactive oxygen species, TBARS, glutathione, glutathione peroxidase, catalase, superoxide dismutase.