Yazeed A. Al-Sheikh* and Khaled Y. AL-Zahrani
Purpose: In the light of contradictory results and paucity of information, this comprehensive study examines the activities and levels of key antioxidants and oxidants/pro-oxidants in preeclamptic patients.
Methods: Antioxidants including glutathione peroxidase, glutathione reductase, glutathione-S-transferase, superoxide dismutase, catalase, reduced glutathione, selenium, zinc, copper and manganese, as well as marker oxidants/pro-oxidants including hydrogen peroxide, superoxide anions, malondialdehyde, protein carbonyls and oxidized glutathione were determined in plasma and placental tissues of non-pregnant, healthy pregnant and preeclamptic subjects.
Results: Data indicated that all plasma antioxidants underwent moderate but significant decreases (p< 0.05) in healthy pregnant women, , and much more significant ones (p< 0.0001) in preeclamptic patients, when both were compared to non-pregnant subjects. Furthermore, whereas all plasma antioxidants underwent significant decreases (p< 0.001) in preeclamptic patients compared to healthy pregnant subjects, their placental activities and levels were very significantly decreased (p< 0.0001). However, copper plasma and placental levels were unchanged in all study groups. In contrast, there were increases similar in magnitude and significance of all plasma and placental oxidants/pro-oxidants compared among the three study groups leading to equally significant decreases in the reduced/oxidized glutathione ratios. In addition, gene transcripts of all antioxidant enzymes underwent marked downregulation (p< 0.0001) in placental tissue of preeclamptic patients compared to healthy pregnant subjects.
Conclusion: Data indicated a metabolic shift in favor of oxidative stress more pronounced in placental tissue of preeclamptic patients compared to healthy pregnant/non-pregnant subjects. We postulate that selenium, zinc and manganese supplements could be beneficial for alleviation of the noted oxidative stress in preeclamptic patients.
Preeclampsia, placental tissue, oxidative stress, micronutrients, antioxidant gene transcripts.
Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Saud University, Riyadh, Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Saud University, Riyadh