Protective Effect of Annurca Apple Extract Against Oxidative Damage in Human Erythrocytes

Apple is one of the most worldwide-consumed fruits and a number of cultivars, differing in organo-leptic and nutritional characteristics are available for the market. Annurca apple is a Campania region variety (Southern Italy). This fruit is known for crispness, special taste and long shelf life. The object of this study is to evaluate the capacity of polyphenols extracted from Annurca apple (APE) to protect red blood cells (RBCs) from oxidative stress. The in vitro oxidative stress on human RBCs was induced by t-butyl hydroperoxide. Pre-treatment of cells with 10 μM APE provides a remarkable protection against oxidative damage, particularly decrease ROS production (-35%), lipid perossidation (-81%) and methemoglobin formation (-13%). Moreover, APE incubation decreased the RBC morphological alterations (shrunken cytoplasm and the number of echinocytes) caused by t-BHP. APE protective effect seems to be associated with the antioxidant activity of polyphenolic compounds. Our results indicate that Annurca polyphenols may directly influence erythrocyte properties. Our data confirm higher antioxidant power of Annurca apple, that may therefore represent accessible sources of natural antioxidants with potential application in nutritional/pharmaceutical fields, as preventive or therapeutic agents in diseases in which free radicals are implicated.