INTERPRETATION OF THE CYTOSTATIC PROPERTIES OF SODIUM MORPHOLYLDITHIOCARBAMATE, A CHELATING AGENT

The antioxidant properties of sodium morpholyldithiocarbamate (MorDTC) were studied in order to contribute to the interpretation of its anti tumor activity and synergetic effect over cis-platinum. MorDTC inhibit s pyrogallol autooxidation better than vitamin C but does not dismutat e the superoxide radical generated by the xanthine-xanthine oxidase sy stem. Nevertheless, the complexes formed in situ between MorDTC and Mn (II), Co(II), Ni(II), and Cu(II) do dismutate the superoxide radical w ith a SOD-like activity (SOD = superoxide dismutase), expressed in ter ms of IC50 values within the range of 3.2 to 62 mu M. The highest acti vity corresponds to Mn(II) and Cu(II) complexes. The possible inhibito ry action of MorDTC on erythrocyte SOD was also studied in vitro; howe ver, the results were negative. Therefore, MorDTC should dismulate the superoxide radical after chelating metals without inhibiting SOD, the enzyme playing this role in vivo.