Antioxidant Effect of green tea (Catechin, EpiCatechin and EGCG) Detection and Determination of Polyphenols or metabolites in RBC, Bound to RBCs, Lipoprotein and Plasma

Antioxidants and prevention of risk factors contributing to heart disease and cancer have garnered a tremendous amount of media spotlight within the last decade. Flavonoid compounds in particular are found in large quantities in many of the plant food and vegetables consumed by humans. A low bioavailability of these compounds within the human body following ingestion has long been an issue in explaining their importance as free radical scavengers. Previous research in the transport of these antioxidants has indicated that plasma proteins act as transporters within blood. It is postulated that a portion of the polyphenols absorbed from green tea can be carried inside or bound to red blood cells. To analyze the abilities of green tea polyphenols to bind to the plasma lipoprotein. Albumin and RBCs, studies incubating these compounds at various physiological concentrations were conducted in porcine whole blood. Catechin was conducted both in whole blood and packed cells in order to assess the competitive effects of protein binding in the plasma. The uptake of Catechin by RBCs was significantly higher within the packed cells indicating that albumin and plasma proteins compete with RBCs for these polyphenols. The following ranking indicates the absorption of the tested polyphenols by RBCs: Catechin > EpiCatechin > EGCG. Results indicate that RBCs do indeed act as transporters of antioxidant polyphenol compounds at physiological concentrations in whole blood. RBCs may also contribute higher concentrations of these compounds in vivo via the enzyme metabolism to their O-methylated forms