PROTECTIVE EFFECT OF BLUEBERRY LEAF METHANOLIC EXTRACT AGAINST HYDROGEN PEROXIDE-INDUCED DAMAGE IN PC-12 CELLS

The purpose of this study was to evaluate the antioxidative activities of methanolic extracts from blueberry leaves (MEBL). The total polyphenol and flavonoid content of MEBL was 139.27 +/- 4.15 milligram gallic acid equivalents (mg GAE/g) and 126.44 +/- 3.80 catechin equivalents in milligram per gram (mg CE/g), respectively. The antioxidant effects of MEBL were evaluated, including 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity and ferric reducing antioxidant power (FRAP). We also evaluated the protection effect on hydroxyl radical-induced oxidative damage in PC-12 cells via propidium iodide staining using a flow cytometer MEBL decreased cell death in PC-12 cells due to hydroxyl radical-induced oxidative damage in a dose-dependent manner. In addition, MEBL regulated the expression of Bcl-2 and Bax proteins in PC-12 cells. The findings of this study suggested that MEBL has the potential to protect against hydrogen peroxide-induced cell damage and should be considered as a prospective functional food.