Objective: To investigate antioxidant activity of sera and the plasma blood levels of two potent antioxidant in women with pre-eclampsia and normotensive pregnancies.
Study design: The antioxidant activity of sera and the blood levels of ascorbic acid and alpha-tocopherol were assayed in women with normal pregnancies (n = 33), mild pre-eclampsia (n = 8), and severe pre-eclampsia (n = 16) between 20 and 40 weeks' gestation. Ascorbic acid and alpha-tocopherol concentrations were analyzed by high-performance liquid chromatography. Antioxidant activity of sera was measured as the percent inhibition of spontaneous autoxidation of a standard brain homogenate.
Results: Plasma levels of ascorbic acid in women with mild and severe pre-eclampsia were significantly lower than normal pregnancies (P < 0.05). Sera alpha-tocopherol levels were significantly decreased only in severe pre-eclampsia (P < 0.05). Sera antioxidant activity were significantly decreased in mild (73%) and severe (51%) pre-eclampsia compared with normal (86%) pregnancies (P = 0.02, P = 0.000, respectively).
Conclusions: In women with pre-eclampsia, sera antioxidant activity and antioxidant level of plasma are decreased when compared with normotensive pregnancies. Impaired antioxidant activity and the reduction of antioxidant levels which increase the level of lipid peroxidation products may cause peroxidative damage of vascular endothelium and result in clinical symptoms of pre-eclampsia.