Neuroprotective effects of Eriobotrya japonica against β-amyloid-induced oxidative stress and memory impairment.

The generation of oxygen free radicals and oxidative damage is believed to be involved in the pathogenesis of neurodegenerative disorders. Eriobotrya japonica has been used to treat several diseases in East Asia. In this study, we investigated the protective effect of an E. japonica extract against Aβ peptide-induced oxidative stress. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay demonstrated that the E. japonica extract scavenged approximately 40% of DPPH radicals. Also, treatment of the E. japonica extract inhibited Aβ(1-42)-mediated neuronal cell death. Furthermore, treatment of E. japonica extract efficiently suppressed the increase in intracellular ROS triggered by the Aβ(1-42) peptide. Importantly, mice pre-treated with the E. japonica extract showed restoration of alternation behavior and reversal of Aβ(1-42)-induced memory impairment. Consequently, the E. japonica extract substantially inhibited the increase in lipid peroxidation and restored superoxide dismutase activity. These results suggest that E. japonica protects from oxidative stress and cognitive deficits induced by the Aβ peptide.