Influence of ascorbate on anti-HeLa effect of Fe(III)-heteropolyanion: concentration ratio 1:5

This study aims to assess the the effect of L(+)-ascorbic acid sodium salt (ascorbate) on the cytotoxic activity of Fe(III)-substituted monolacunary Wells-Dawson polyoxometalate (Fe-WD), K7[FeIII(α2- P2W17O61)(H2O)] (Fe-WD/ascorbate ratio 1:5) against cervical carcinoma HeLa cells. HeLa cells were treated in vitro with Fe-WD, ascorbate, and Fe-WD/ascorbate mixtures (concentration ratio 1:5) for 48 and 72 hours at 37 °C. Single and simultaneous treatments with Fe-WD/ascorbate resulted in concentration- and time-dependent HeLa cell cytotoxicity with different potencies. Fe-WD showed remarkably more potent cytotoxic action compared with ascorbate, inducing approximately 10-15 times lower IC50 values for both exposure times. The results obtained for the simultaneous exposure to Fe-WD/ascorbate mixtures (1:5) demonstrated that the presence of ascorbate does not significantly affect Fe-WD-induced anti-HeLa action. This effect might be associated with the fact that the concentration ratio of Fe-WD and ascorbate 1:5 causes ascorbate consumption due to its autoxidation in the presence of Fe(III) ions