Departament de Fisiologia, Facultat de Farmàcia, Universitat de Barcelona, Avinguda Joan XXIII s/n, 08028 Barcelona, Spain.
J Agric Food Chem. 2011 Mar 9;59(5):2113-9. doi: 10.1021/jf1025532. Epub 2011 Feb 4.
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 H(2)O(2). 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.
农业、食品和林业产业产生的副产品和废物含有大量的多酚，这些多酚可以作为天然或半合成抗氧化剂的潜在来源。本研究考察并比较了白葡萄渣、松树皮和金缕梅树皮中的多酚级分对红细胞和 3T3 细胞系过氧化损伤的保护作用。这项工作特别关注提取物的聚合度和酯化度的不同，以帮助理解它们的作用机制。各馏分对 H2O2 引起的红细胞脂质过氧化、溶血和 3T3 细胞毒性有不同的保护作用。据称，酯化与抗氧化保护能力有关，而且在高剂量下还会产生促氧化作用。结果表明，不仅酯化度的百分比，而且聚合度也是调节其抗氧化能力的重要因素。在这方面，重要的是要制备新型多酚级分，使其平均聚合度达到 3，并且酯化度不超过 30%，以在产生最低细胞毒性的情况下达到最高的抗氧化能力。出于这个原因，葡萄提取物似乎是对抗过氧化氢细胞损伤的最佳策略。
