Evaluation of the action of epigallocatechin-3-gallate, flavonoid present in the green tea, on eNOS activation and nitric oxide production in a model preeclampsia

Abstract

Preeclampsia (PE) is a hypertensive disorder responsible for both high maternal and fetal morbidity and mortality, especially in underdeveloped and developing countries such as Brazil. The etiology of PE has not yet been well elucidated, but it is believed that a limitation of the invasion of spiral arterioles by the trophoblast (pseudovasculogenesis) is responsible for generating ischemia in the placenta that leads to the release of placental factors in the maternal circulation and consequently to a dysfunction of the vascular endothelium. Among the vascular imbalances that contribute to this endothelial dysfunction is the decrease in nitric oxide (NO) bioavailability and the oxidative stress generated by an imbalance between oxidative and antioxidant forces in the organism. Studies have shown the strong antioxidant action of phytochemicals found in food and beverages and how some, including flavonoids, may be able to lower blood pressure. Among these flavonoids is Epigallocatechin-3-gallate (EGCG), found in green tea, which through a series of protein phosphorylations, is able to activate endothelial nitric oxide synthase (eNOS), NO precursor enzyme, consequently increasing its production and promoting vasodilatation. Observing these effects in hypertensive diseases, human umbilical vein endothelial cells (HUVECS) will then be incubated with plasma from preeclamptic, hypertensive and healthy pregnant women in the presence or absence of EGCG to evaluate the action of this phytochemical in PE.