Magnesium sulfate affords protection against oxidative damage during severe preeclampsia.

Abstract Introduction MgSO 4 is the drug of choice to prevent seizures in preeclamptic pregnant women, but its mechanism of action at the molecular level remains an enigma. In previous works, we found that treating preeclamptic women with MgSO 4 reduces the lipid peroxidation of their red blood cell membranes to normal levels and leads to a significant reduction in the osmotic fragility of the red blood cells that is increased during preeclampsia. In addition, the increase in lipid peroxidation of red cell membranes induced by the Fenton reaction does not occur when MgSO 4 is present. Methods The antioxidant protection of MgSO 4 was evaluated in UV-C-treated red blood cell ghosts and syncytiotrophoblast plasma membranes by measuring their level of lipid peroxidation. The interaction of MgSO 4 with free radicals was assessed for its association with the galvinoxyl radical, the quenching of H 2 O 2 -induced chemiluminescence and its effect on sensitized peroxidation of linoleic acid. Results a) MgSO 4 protected red blood cell ghosts and the syncytiotrophoblast plasma membranes of normotensive pregnant women against lipid peroxidation induced by UV-C irradiation. b) MgSO 4 does not seem to scavenge the galvinoxyl free radical. c) The quenching of the H 2 O 2 -enhanced luminol chemiluminescence is increased by the presence of MgSO 4 . d) The peroxidation of linoleic acid is significantly blocked by MgSO 4 . Discussion MgSO 4 may provide protection against oxidative damage of plasma membranes through interactions with alkyl radicals.