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Abstract

Reactive oxygen species (ROS) pose a serious threat to maternal and fetal health during pregnancy. However, there is little information on the oxidative damage caused by ROS and its protection during prenatal life. The present study highlights the status of various antioxidants in human placental and fetal tissues at different phases of gestation. The activity profile of scavenging enzymes, superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase as well as the concentrations of non-enzymatic antioxidants, ascorbic acid, alpha-tocopherol, bilirubin and glutathione have been determined in human placental whole homogenate, placental brush border membrane and fetal liver over gestational periods ranging from 6 weeks of pregnancy till birth. The ontogenic profile of lipid peroxidation, a marker of oxidative damage has also been investigated in the feto-placental system. Catalase, superoxide dismutase and glutathione reductase activities increased significantly, but glutathione peroxidase activity remained almost the same throughout development. Except alpha-tocopherol and bilirubin, the concentrations of other non-enzymic scavengers followed a significant increasing trend with advancement of pregnancy. Results indicate that there is gradual suppression of lipoperoxide formation with the progress of gestation to protect the fetus against oxygen toxicity.

Differential effects of docosahexaenoic acid on preterm and term placental pro-oxidant/antioxidant balance

“…This is consistent with the known developmental pattern of enzymatic antioxidant expression and activity and the availability of non-enzymatic antioxidants across gestation. The activity of the primary enzymatic antioxidants (catalase, superoxide dismutase and glutathione reductase) increases over pregnancy, while that of placental glutathione peroxidase remains unchanged (Qanungo & Mukherjea 2000). Conversely, serum or plasma levels of non-enzymatic antioxidants, including vitamin A (De Vriese et al 2001) and b-carotene (Oostenbrug et al 1998), decrease throughout pregnancy, while levels of a-tocopherol increase (Oostenbrug et al 1998, De Vriese et al 2001.…”

Effects of marginal iron overload on iron homeostasis and immune function in alveolar macrophages isolated from pregnant and normal rats

“…Pregnancy is a condition that favours oxidative stress; serum lipid peroxidation products are increased in normal pregnant women, particularly during the second trimester (Qanungo and Mukherjea 2000;Uotila et al 1991) while other cytoprotective enzymes and antioxidants are also elevated (Casanueva and Viteri 2003). Enhanced activities of superoxide dismutase were assayed in latent alveolar macrophages isolated from pregnant rats ± iron supplement on day 21.…”

Future applications of antioxidants in premature infants

“…Qanungo and colleagues found that SOD, catalase, GPx, and glutathione reductase activities increased with gestational age, as evidence of lipid peroxidation decreased in human placental and fetal tissues (5). Development of the antioxidant system during fetal life must also include redox signaling in the maintenance of pregnancy through uterine-placental-fetal interactions (6).…”