The plasma antioxidant vitamin status of the INTAPP cohort examined: The unsuspected importance of ß-carotene and γ-tocopherol in preeclampsia.

OBJECTIVE: Examine the levels of plasma antioxidant vitamins before and during a treatment with placebo or vitamin E + C supplement to prevent preeclampsia (PE). STUDY DESIGN: Per-protocol analysis of a subset group of pregnant women (n = 295) from the International Trial of Antioxidants for the Prevention of PE (INTAPP) randomized case-control study. Normotensive receiving placebo or vitamins (n = 115 and 87 respectively) were compared to gestational hypertension (GH) without proteinuria (n = 30 and 27) and PE (n = 21 and 15). Vitamin quantification was performed at 12-18, 24-26 and 32-34 weeks of gestation. MAIN OUTCOME MEASURES: Coenzyme (Co) Q10, ß-carotene and vitamins E (α and γ forms) plasma levels. RESULTS: Vitamin E + C supplementation was found to increase the α-tocopherol levels by 40% but was associated with a 57% decrease in the γ-tocopherol isoform for all study groups (p < 0.001). The ß -carotene was lower in the PE than in the normotensive and GH groups (p < 0.001) while the level of CoQ10 remained unaffected. CONCLUSIONS: A more personalized approach that target the suboptimal levels of specific antioxidants without disturbing the α/γ-tocopherol ratio could be a more successful approach to counteract oxidative stress in PE.

Plasma interleukin-18 (IL-18) levels are correlated with antioxidant vitamin coenzyme Q(10) in preeclampsia.

OBJECTIVE: Alteration of cytokines level and oxidative stress are both associated with preeclampsia (PE). We have investigated if IL-6 and IL-18 levels were related to coenzyme Q(10) (CoQ(10)), an antioxidant and a marker of oxidative stress in the plasma from normotensive and preeclamptic pregnancies. DESIGN: IL-6 and IL-18 levels were determined by enzyme-linked immunosorbent assays in plasmas from preeclamptic (n = 29) and normotensive pregnancies (n = 30). The concentrations of CoQ(10) in the different redox forms were measured in plasma using liquid chromatography coupled to electrochemical detection. Data were analyzed using the Wilcoxon Rank-Sum test and correlations were obtained by the Spearman's Rho test. MAIN OUTCOME MEASURES: IL-6 concentrations were 2.8-fold higher in preeclamptic plasmas than in controls (p = 0.0006), and IL-18 concentrations were found significantly lower in preeclamptic samples than in controls (p = 0.007). No correlation was found between IL-18 or IL-6 and antioxidant vitamin CoQ(10) in plasmas from normotensive pregnant women. However, in PE, IL-18 level was positively correlated with the reduced form of CoQ(10) (r = 0.3680, p = 0.0495). CONCLUSION: This is the first demonstration that IL-18 is potentially linked to oxidative stress in PE, since its level correlates with the concentration of the powerful antioxidant CoQ(10). These results also associate the immune system with the oxidant/antioxidant imbalance observed in PE.

Absorption, transport, and bioavailability of vitamin e and its role in pregnant women.

Vitamin E is an important lipophilic antioxidant. The term refers to eight essential naturally occurring fat-soluble nutrients called tocopherols or tocotrienols. Among these isomers, alpha-tocopherol has the highest biologically active form and is found in all lipoprotein fractions. Vitamin E deficiency during pregnancy may cause miscarriage, preterm birth, preeclampsia, and intrauterine growth restriction. This review highlights recent findings that have led to a better understanding of vitamin E absorption, transport, bioavailability, and its role in pregnancy, and that underline the need for re-evaluation of the potential benefits of vitamin E supplementation in pregnant women.