Combined Treatment with Vitamin E and Vitamin C Decreases Oxidative Stress and Improves Fetal Outcome in Experimental Diabetic Pregnancy

Abstract

The aim was to investigate whether dietary supplementation of a combination of the two antioxidants, vitamin E and vitamin C, would protect the fetus in diabetic rat pregnancy at a lower dose than previously used. Normal and streptozotocin-induced diabetic rats were mated and given standard food or food supplemented with either 0.5% vitamin E ϩ 1% vitamin C or 2% vitamin E ϩ 4% vitamin C. At gestational d 20, gross morphology and weights of fetuses were evaluated. Vitamins E and C and thiobarbituric acid reactive substances were measured in maternal and fetal compartments. In addition, protein carbonylation was estimated in fetal liver. Maternal diabetes increased the rate of malformation and resorption in the offspring. High-dose antioxidant supplementation decreased fetal dysmorphogenesis to near normal levels. The low-dose group showed malformations and resorptions at an intermediate rate between the untreated and the high-dose groups. Thiobarbituric acid reactive substances were increased in fetal livers of diabetic rats and reduced to normal levels already by low-dose antioxidative treatment. Protein carbonylation rate was also increased in fetal liver of diabetic rats; it was normalized by high-dose treatment but only partially reduced by low-dose antioxidants. We conclude that combined antioxidative treatment with vitamins E and C decreases fetal malformation rate and diminishes oxygen radicalrelated tissue damage. However, no synergistic effect between the two antioxidants was noted, a result that may influence future attempts to design antiteratogenic treatments in diabetic pregnancy. Oxidatively modified proteins may be teratogenically important mediators in diabetic embryopathy. Maternal type-1 diabetes during pregnancy causes an increased rate of malformation in the fetus despite insulin treatment and glucose monitoring (1-3). The incidence of fetal malformations in type-1 diabetic pregnancies is estimated to be 5-10% in recent studies (4 -8). Several clinical studies have demonstrated that high maternal HbA1c levels during early pregnancy are associated with an increased risk for malformations (4, 9, 10). It is, however, likely that the pathogenesis of diabetic embryopathy is multifactorial (11), and in experimental work not only maternal serum levels of glucose but also levels of triglycerides, ␤-hydroxybutyrate, branched-chain amino acids, and creatinine correlate positively with increased resorption and malformation rates (12). Also, genetic factors may predispose for the development of malformations in maternal diabetes (13,14).The putative role of ROS in the development of diabetic complications has been investigated for several decades (15-17). Evidence of ROS involvement in hyperglycemia-induced embryopathy was first obtained in studies in which antioxidant enzymes proved to be protective in vitro (18,19). Increased ROS production (20, 21) and lipid peroxidation (22) have subsequently been found in rat embryos cultured in high glucose and in embryos of diabetic rat mothers. Enzymatically prod...

Transgenic mice overproducing human thioredoxin-1, an antioxidative and anti-apoptotic protein, prevents diabetic embryopathy

“…All PCRs were performed using a real-time PCR 7300 system. Gene expres- Measurement of TBARS Thiobarbituric acid reactive substances (TBARS) are lipid peroxides, and are a major indicator of oxidative stress [34]. TBARS were determined fluorometrically after heating samples with thiobarbituric acid (TBA) [34][35][36].…”

“…Gene expres- Measurement of TBARS Thiobarbituric acid reactive substances (TBARS) are lipid peroxides, and are a major indicator of oxidative stress [34]. TBARS were determined fluorometrically after heating samples with thiobarbituric acid (TBA) [34][35][36]. Briefly, 100 μl of a tissue homogenate of fetal livers at day 17 of gestation was heated to 95°C for 60 min together with 100 μl of SDS solution and 2.5 ml of TBA/buffer reagent (TBARS Assay Kit, ZeptoMetrix, Buffalo, NY, USA).…”

Influence of maternal serum levels of vitamins C and E during the second trimester on birth weight and length

“…As vitamin C is a hydrophilic antioxidant, it counteracts several hydroxyl radicals and may contribute in protecting the fetus from oxygen free radical damage (Rose, 1990;Cederberg et al, 2001). Vitamin E is a lipophilic antioxidant and interferes with lipid peroxidation (Hubel et al, 1989;Di Mascio et al, 1991).…”

Association of antioxidant vitamins and oxidative stress levels in pregnancy with infant growth during the first year of life

“…Many observational studies, as well as clinical trials, have aimed at determining the association of maternal vitamin or mineral status with birth outcomes (12)(13)(14)(15)(16)(17)(18) . Vitamins A, C and E are essential in a wide range of physiological processes such as pregnancy, promotion of general growth, ameliorating increased oxidative stress during pregnancy, and the provision of antioxidant defence to the foetus (19,20) .…”