Alzheimer’s disease (AD) is a neurodegenerative disorder characterised by deposition of Aβ and hyperphosphorylated tau in the brain. In addition, hyperactivation of glial cells, cerebrovascular damage, and structure changes of white matter are also observed in AD brain. We previously found that diosgenin regenerated axons in the brain and improved memory impairment in AD model mouse (5XFAD). However, other beneficial effects of diosgenin leading to memory recovery remain unknown. This study aimed to investigate the effect of diosgenin on morphology of glial cells, blood vessels, and myelin in 5XFAD mouse brains.
Vehicle solution or 0.1μmol/kg diosgenin were orally administered to wild-type and 5XFAD mice for 14 days. Diosgenin administration significantly improved object recognition memory in 5XFAD mice. The brain slices were served for immunohistochemistry. Diosgenin administration did not remarkably influence the areas of GFAP⁺ astrocytes, Iba1⁺ microglia and CD31⁺ blood vessels at least in the prefrontal cortex, hippocampus, and perirhinal cortex in 5XFAD mice. We are currently evaluating myelin formation and neurogenesis.
This study indicated that diosgenin administration didn’t provide no numerical changes of astrocytes, microglia, and blood vessels in the 5XFAD mouse brains. Therefore, we are now narrowing down the most contributing factor to memory improvement by diosgenin.