Characterization of traditional and exotic apple varieties from Portugal. Part 2 – Antioxidant and antiproliferative activities

Apples are known to have many health-promoting activities, especially anticancer, antiradical and antioxidant effects. Most of these actions are believed to be due to their polyphenolic components which vary greatly between different varieties.In this work, four traditional Portuguese apple cultivars (Bravo de Esmolfe, Malápio Fino, Malápio da Serra and Pêro Pipo) and five exotic varieties (Golden, Starking, Fuji, Gala Galaxy and Reineta Parda) were evaluated in terms of their bioactivity using both cell-based and cell-free assays; 17 parameters were evaluated for each sample. Results obtained were submitted to principal component analysis (PCA) and it was possible to conclude that Malápio Fino and Bravo de Esmolfe apple varieties have the highest antioxidant effect and Reineta Parda variety is the best cultivar in promoting antiproliferative effect against human colon (HT29) and gastric (MKN45) cancer cells. Correlations of the data obtained showed that among phenolic compounds catechin, epicatechin and procyanidin B1 were the major contributors to the antioxidant activity of apples whereas procyanidins (B1 and B2), phloridzin and epicatechin played an important role against human cancer cell proliferation.