Neuroprotective Effects of Poria cocos (Agaricomycetes) Essential Oil on Aβ1-40-Induced Learning and Memory Deficit in Rats

Alzheimer's disease (AD) is a neurodegenerative disease that has become a leading cause of death in recent years. The present study aimed to explore the possible prophylactic effects of Poria cocos essential oil (PCEO) against memory deficits in Aβ rats. Adult male Wistar rats were given Aβ1-42 via ICV injection. The effect of 30 d administration of PCEO by oral gavage was investigated. Novel object recognition (NOR) test, Morris water maze (MWM) test, and passive avoidance memory retention (PAM) task were performed. Aβ decreased the cognitive memory in NOR, spatial memory in MWM, and passive avoidance memory in PAM tests. In contrast, PCEO improved learning and memory in the treated group. The PCEO treatment halts the activity of AChE in the hippocampus and cortex of the AD rats. The central neuronal degeneration in Aβ-injected rats was not only ascertained by the histopathological changes but also confirmed indirectly by the concomitant increase in GFAP immunostaining. The beneficial effects in AD of increasing cellular GPx, GR, CAT, Na+ K+ ATPase and GST through the administration of PCEO may not only result in protection against neurodegeneration but also result in improvement in cognitive function. PCEO may be recommended as a prophylactic and/or adjunct medication for neurodegenerative diseases.