Role of Galloylation and Polymerization in Cytoprotective Effects of Polyphenolic Fractions against Hydrogen Peroxide Insult

• Published in: Journal of agricultural and food chemistry 2011-03, Vol.59 (5), p.2113-2119
• Main Authors: Mitjans, Montserrat, Ugartondo, Vanessa, Martínez, Verónica, Touriño, Sonia, Torres, Josep L, Vinardell, M. Pilar
• Format: Article
• Language: English
• Subjects: 3T3 Cells; Animals; antioxidant activity; antioxidants; bark; Biological and medical sciences; byproducts; cytotoxicity; erythrocytes; Flavonoids - chemistry; Flavonoids - pharmacology; Food industries; foods; forest industries; Fruit - chemistry; Fundamental and applied biological sciences. Psychology; Gallic Acid - analysis; Gallic Acid - chemistry; grape pomace; grapes; Hamamelis - chemistry; hemolysis; Hemolysis - drug effects; Humans; hydrogen peroxide; Hydrogen Peroxide - pharmacology; lipid peroxidation; Lipid Peroxidation - drug effects; Mice; Oxidation-Reduction; Oxidative Stress - drug effects; Phenols - chemistry; Phenols - pharmacology; Pinus - chemistry; Plant Bark - chemistry; Plants - chemistry; Polymerization; Polyphenols; Structure-Activity Relationship; Toxicology in Agriculture and Food; Vitis - chemistry; wastes
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf1025532

Byproducts and wastes generated by agricultural, food, and forestry industries contain large amounts of polyphenols, which can be potentially used as sources of natural or semisynthetic antioxidants. This study examined and compared the protection against peroxidative damage induced in erythrocytes and 3T3 cell line of polyphenolic fractions from white grape pomace, pine bark, and witch hazel bark. The work pays special attention to the different degrees of polymerization and galloylation of the extracts to contribute to the understanding of their mechanisms of action. Fractions demonstrated different protections against erythrocyte lipid peroxidation, hemolysis, and 3T3 cytotoxicity caused by H2O2. Galloylation is claimed to be related to antioxidant protective capacity, and it is also responsible for the pro-oxidant effect observed at high doses. The results show that not only the percentage of galloylation but also the degree of polymerization are important modulators of their antioxidant capacity. In this sense, it is crucial that novel polyphenolic fractions were prepared attending a value of 3 for the mean degree of polymerization and did not exceed a 30% of galloylation to reach the highest antioxidant capacity with the lowest cytotoxic effects. For this reason, the grape extracts appear to be the best strategy to fight against hydrogen peroxide cell damage.