Amyloid beta-peptide (A beta) has been implicated in the pathogenesis of AD. it can cause cell death in AD by evoking a cascade of oxidative damage to neurons. So antioxidant compounds may throw a light on the treatment of AD. in the present study, we investigated the protective effect of acteoside (AS), an antioxidative phenylethanoid glycoside, on A beta(25-35)-induced SH-SY5Y cell injury. Exposure of cells to 25 mu M A beta(25-35) for 24 h caused viability loss, apoptotic increase and reactive oxygen species (ROS) increase, pre-treatment with acteoside for 1.5 h significantly reduced the viability loss, apoptotic rate and attenuated A beta-mediated ROS production. In addition, AS strikingly inhibited A beta(25-35)-induced mitochondrial dysfunctions, including lowered membrane potential, increased Bax/Bcl-2 ratio, cytochrome c release and the cleavage of caspase-3. Taken together, these results indicated that acteoside could protect SH-SY5Y cells against beta-amyloid-induced cell injury by the attenuating ROS production and the modulating apoptotic signal pathway through Bcl-2 family, cytochrome c, and caspase-3. (C) 2009 Elsevier B.V. All rights reserved.