Synergistic Neuroprotective Effects of Mature Silkworm and Angelica gigas Against Scopolamine-Induced Mild Cognitive Impairment in Mice and H2O2-Induced Cell Death in HT22 Mouse Hippocampal Neuronal Cells.

We previously reported that mature Bombyx mori silkworm (SW) ameliorated scopolamine (Sco)-induced amnesia, and Angelica gigas (AG) prevented cognitive impairment. SW is known for its gastroprotective effects such as improving liver function and alleviating the effects of Parkinson's disease. AG is known for its neuroprotective effects and for lowering the effects of low-density lipoprotein cholesterol. However, the neuroprotective effect of combined SW and AG (SWA-1) treatment and the underlying molecular mechanism by which SWA-1 regulates neurodegenerative diseases remains unclear. We evaluated the neuroprotective effect of SWA-1 against Sco-induced mild cognitive impairment in mice and H2O2-induced cell death in HT22 mouse hippocampal neuronal cells and elucidated the underlying molecular mechanism. Morris water maze and Y-maze tests were performed to examine the learning and memory abilities of mice. The underlying molecular mechanism was investigated by using western blotting. We demonstrated that SWA-1 significantly protects against H2O2-induced cell death in HT22 mouse hippocampal neuronal cells. SWA-1 also significantly reversed Sco-induced spatial learning and memory impairment. Specifically, SWA-1 upregulates the protein levels of phosphorylated extracellular signal-related kinase (Erk1/2) and phosphorylated p38 MAP kinase (p38). SWA-1 remarkably decreased the apoptotic index Bax/Bcl2 expression in the hippocampus of Sco-treated mice. Our results suggest that SWA-1 may be administered as alternative therapy for cognitive impairment and neurodegenerative diseases and should be studied further in human trials.

Evaluating the Memory Enhancing Effects of Angelica gigas in Mouse Models of Mild Cognitive Impairments.

(1) Background: By 2050, it is estimated that 130 million people will be diagnosed with dementia, and currently approved medicines only slow the progression. So preventive intervention is important to treat dementia. Mild cognitive impairment is a condition characterized by some deterioration in cognitive function and increased risk of progressing to dementia. Therefore, the treatment of mild cognitive impairment (MCI) is a possible way to prevent dementia. Angelica gigas reduces neuroinflammation, improves circulation, and inhibits cholinesterase, which can be effective in the prevention of Alzheimer's disease and vascular dementia and the progression of mild cognitive impairment. (2) Methods: Angelica gigas (AG) extract 1 mg/kg was administered to mildly cognitive impaired mice, models based on mild traumatic brain injury and chronic mild stress. Then, spatial, working, and object recognition and fear memory were measured. (3) Result: Angelica gigas improved spatial learning, working memory, and suppressed fear memory in the mild traumatic brain injury model. It also improved spatial learning and suppressed cued fear memory in the chronic mild stress model animals. (4) Conclusions: Angelica gigas can improve cognitive symptoms in mild cognitive impairment model mice.