Anthocyanin-Loaded PEG-Gold Nanoparticles Enhanced the Neuroprotection of Anthocyanins in an Aβ1–42 Mouse Model of Alzheimer’s Disease

Nanomedicine is an emerging research area. In this study, we investigated the neuroprotective efficacy of anthocyanin-loaded polyethylene glycol-gold nanoparticles (PEG-AuNPs) for enhancing the neuroprotective efficacy of anthocyanins in an amyloid beta (Aβ)1–42 mouse model of Alzheimer’s disease. We observed that both anthocyanin-loaded PEG-AuNPs and anthocyanins treatment (12 μg/g/day for 14 days) ameliorated memory impairments in the Aβ1–42-injected mice. However, the anthocyanin-loaded PEG-AuNPs were more effective than free anthocyanins. Anthocyanin-loaded PEG-AuNPs protected pre- and post-synaptic proteins from Aβ1–42-induced synaptic dysfunction. Interestingly, the anthocyanin-loaded PEG-AuNPs also regulated the p-PI3K/p-Akt/p-GSK3β pathway and, as a result, prevented the hyperphosphorylation of tau protein at serines 413 and 404 in the Aβ1–42-injected mice. Western blot results of cytochrome c, Bax/Bcl2, caspases and poly (ADP-ribose) polymerase-1 expression levels, and immunohistochemical Nissl and Fluoro-Jade B staining also indicated that the anthocyanin-loaded PEG-AuNPs inhibited apoptosis and neurodegeneration in the Aβ1–42-injected mice. Our results suggest that the conjugation of dietary polyphenolic compounds with gold nanoparticles, such as anthocyanin-loaded PEG-AuNPs, is a novel approach that may represent an important and promising nanomedicine strategy to prevent age-associated neurodegenerative diseases.