Effects of combined vanadate and magnesium treatment on erythrocyte antioxidant defence system in rats

Abstract

The effect of vanadate and magnesium treatment on erythrocyte defence system was studied in outbred 2-month-old, albino male Wistar rats (14 rats/each group) which daily received: Group I (Control)—deionized water to drink; Group II—water solution of sodium metavanadate (NaVO 3; SMV) at a concentration of 0.125 mg V/mL; Group III—water solution of magnesium sulfate (MgSO 4; MS) at a concentration of 0.06 mg Mg/mL, Group IV—water solution of SMV–MS at the same concentrations over a 12-week time. The fluid intake and the concentration of reduced glutathione (GSH) as well as the activity of Cu, Zn-superoxide dismutase (Cu, Zn-SOD), catalase (CAT) and glutathione reductase (GR) were significantly decreased in the rats receiving SMV alone (Group II) or in combination with MS (Group IV) compared with Groups I and III. The cellular glutathione peroxidase (cGSH-Px) activity was unchanged in all the treated groups. The activity of glutathione S-transferase (GST) fell in the animals in Group II, compared with the rats in Groups I, III and IV; whereas in the rats in Group III its activity was higher than in the control animals. These results showed that V (as SMV) consumed by the rats with drinking water at a dose of 12 mg V/kg b.w./24 h for 12 weeks may attenuate defence system in rats’ erythrocytes (RBCs), which is probably a consequence of vanadium pro-oxidant potential. Therefore, reactive oxygen species (ROS) are suggested to be involved in the alterations in antioxidant defence system in these cells. Mg (as MS) at the dose ingested (6 mg Mg/kg b.w./24 h) at co-exposure to SMV was not able to counteract its deleterious effect. The results also provide evidence that V–Mg interactions may be involved in the decrease of erythrocyte GR activity and Mg concentration in the plasma under concomitant treatment with both metals at the doses of 12.6 mg V and 6 mg Mg/kg b.w./24 h.