Ameliorative effect of the oil components derived from sweet potato shochu on impaired short-term memory in mice after amyloid β25-35 injection

Abstract

Sweet potato shochu oil is a by-product of shochu production and usually discarded although some physiological functions are considered. In this study, we investigated the effects of shochu oil on short-term memory using a murine model of spontaneous alternating behavior induced by the intracerebroventricular (ICV) administration of amyloid β25-35 (Aβ25-35). Mice were orally administered shochu oil for 15 days. Experiments with a Y-maze model revealed that the Aβ25-35 caused a significant decrease in spontaneous alternation behavior, and supplementation with shochu oil significantly improved this behavior. DNA microarray analysis revealed that the administration of shochu oil downregulated the expression of S100a9 and Ptgs2, which reportedly exacerbate amyloid β deposition in Alzheimer's disease. The administration of shochu oil upregulated the expression of Dnaja1 and PP2A, which is typically downregulated in Alzheimer's disease. These data suggest that shochu oil possible ameliorates on impaired short-term memory in mice after amyloid β25-35 injection, as indicated by its effects on improving spontaneous alternation behavior and modulating the expressions of related genes.