Fermented rice peptides attenuate scopolamine-induced memory impairment in mice by regulating neurotrophic signaling pathways in the hippocampus

Abstract

This study investigated the preventive effects of fermented rice peptides (FRPs) against scopolamine-induced memory impairment in mice and their potential mechanisms. Mice were pretreated with FRPs (25 and 100 mg/kg body weight) via intraperitoneal injection for 7 days, followed by intraperitoneal injection of scopolamine. FRP pretreatment suppressed scopolamine-induced cognitive impairment in passive-avoidance test and significantly upregulated levels of brain-derived neurotrophic factor (BDNF) and induced the phosphorylation of cAMP response element binding (CREB) protein and extracellular signal-regulated kinase (ERK) in the hippocampus of scopolamine-treated mice. Additionally, scopolamine-treated mice showed significantly decreased acetylcholine levels and increased acetylcholine-esterase activity in the hippocampus as compared with controls; however, these changes were suppressed by FRP pretreatment. Among the fractions separated by size-exclusion chromatography, the non-glycosylated peptide fraction of FRP suppressed H2O2-induced neuronal damage in SK-N-SH cells via upregulated BDNF levels. Our findings demonstrated that FRP prevented memory impairment, and that the underlying mechanism might involve regulation of the ERK/CREB/BDNF signaling pathway. These results suggest FRP as a potential agent for the prevention of age-related cognitive decline and dementia.