Angelica tenuissima Nakai Ameliorates Cognitive Impairment and Promotes Neurogenesis in Mouse Model of Alzheimer's Disease

Objective

To research Angelica tenuissima Nakai (ATN) for use in novel Alzheimer’s disease (AD) therapeutics.

Methods

The effect of a 30% ethanol extract of ATN (KH032) on AD-like cognitive impairment and neuropathological and neuroinflammatory changes induced by bilateral intracerebroventricular injections of β-amyloid (Aβ) peptide (Aβ_1-42) was investigated. Male C57Bl/6 mice were randomly divided into 4 groups, 10 in each group. KH032-treated groups were administrated with a low or high dose of KH032 (50 and 200 mg/kg, respectively), intragastrically for 16 days; distilled water was applied in the sham and negative groups. Open fifield test, Y maze and Morris water maze test were used for behavior test and cognitive ability. In addition, the neuroprotective effects of KH032 in Aβ_1-42-infused mice on the histopathological markers [neuronspecific nuclear protein (NeuN), Aβ_1-42] of neurodegeneration were examined. The levels of glial fibrillary acidic protein (GFAP), NeuN, phosphorylation extracellular signal-regulated kinase (ERK)/ERK, brain-derived neurotrophic factor (BDNF), phosphorylation cAMP response element-binding (CREB)/CREB protein expression were measured by Western blot.

Results

KH032 treatment ameliorated cognitive impairments, reduced the overexpression of Aβ_1-42, and inhibited neuronal loss and neuroinflammatory response in the Aβ_1-42-infused mice. Moreover, KH032 treatment enhanced BDNF expression levels in the hippocampus. Finally, KH032 treatment increased phosphorylation of ERK1/2 and CREB, vital for ERK-CREB signaling.

Conclusions

KH032 attenuated cognitive defificits in the Aβ_1-42-infused mice by increasing BDNF expression and ERK1/2 and CREB phosphorylation and inhibiting neuronal loss and neuroinflflammatory response, suggesting that KH032 has therapeutic potential in neurodegenerative disorders such as AD.