Effect of hachimijiogan on memory impairment induced by beta‐amyloid combined with cerebral ischemia in rats

Abstract

ABSTRACTAimAlzheimer's disease (AD) is a chronic neurodegenerative condition most often found in older people. Cerebrovascular disease is commonly found in patients with AD. Hachimijiogan (HJG) is a herbal medicine commonly used to treat age‐related disease. The aim of this study was therefore to investigate whether HJG could improve memory impairment in rats treated with amyloid‐β protein (Aβ) and cerebral ischemia (Aβ + CI).MethodsRats were prepared by a combination of intracerebroventricular Aβ injection and transient cerebral ischemia. Spatial memory was evaluated on water maze and eight‐arm radial maze tasks. HJG (1000 mg/kg/day) or donepezil (DPZ; 10 mg/kg/day) was given orally once per day for 7 days before behavioral task assessment.Results HJG reduced the increased time to reach the platform position in Aβ + CI rats in the water maze task as well as DPZ did. Additionally, HJG reduced the increase in errors in Aβ + CI rats in the eight‐arm radial maze task as well as DPZ did.Conclusion HJG ameliorated memory impairment in Aβ + CI rats, indicating that it may be useful for treating AD.