Detrimental effects of high levels of antioxidant vitamins C and E on placental function: Considerations for the Vitamins in Preeclampsia (VIP) trial

Abstract

AIM: Supplementation with antioxidant vitamins has been proposed to reduce the risk of preeclampsia and perinatal complications. In a recent study, it has been shown that this supplementation to above physiological doses does not reduce the risk of preeclampsia, but increases the rate of low birthweight babies, suggesting a detrimental effect on placental function, given the lower birthweight. The aim of the present study was to investigate the effects of high levels of antioxidants vitamins C and E on placental cells in vitro. METHODS: Isolated fresh human cytotrophoblasts were exposed to high concentrations of vitamins C and E for 48 h. Then the secretion of human chorionic gonadotropin (hCG) and the production of tumor necrosis factor-alpha (TNF-alpha) were assessed. RESULTS: High levels of vitamins C and E, separately or combined, decrease the secretion of hCG by cytotrophoblasts and increase their production of TNF-alpha. CONCLUSION: Exposure of cytotrophoblasts to high levels of antioxidant vitamins C and E may affect placental function, as reflected by decreased secretion of hCG; and placental immunity, as reflected by increased production of TNF-alpha. Such alterations are known to lead to endothelial dysfunction and adverse pregnancy outcomes, such as fetal growth restriction (FGR).