Acai (Euterpe oleraceae Mart.) berry extract exerts neuroprotective effects against β-amyloid exposure in vitro

The native South American palm acai berry (Euterpe oleraceae Mart.) has high polyphenolic and antioxidant levels. This study examined whether acai berry extract afforded protection against beta-amyloid (A beta)-mediated loss of cell viability and oxidative stress associated with anti-fibrillar effects. PC12 cells were exposed to either A beta(1-42), A beta(25-35) or tert butyl hydroperoxide (t-BHP), alone or in the presence of acai extract (0.5-50 mu g/ml). Thioflavin T (ThT) binding assay and transmission electron microscopy were used to determine effects of acai extract on A beta(1-42) fibril morphology and compared to acai phenolics gallic acid, cyanidin rutinoside and cyanidin glucoside. Exposure to A beta(1-42), A beta(25-35) or t-BHP decreased PC12 cell viability. Pretreatment with acai extract significantly improved cell viability following A beta(1-42) exposure, however A beta(25-35) or t-BHP-mediated viability loss was unaltered. Acai extract inhibited ThT fluorescence and disrupted A beta(1-42) fibril and aggregate morphology. In comparison with other phenolics, acai was most effective at inhibiting A beta(1-42) aggregation. Inhibition of beta-amyloid aggregation may underlie a neuroprotective effect of acai. (C) 2013 Elsevier Ireland Ltd. All rights reserved.