The effects of Danggui-Shaoyao-San on neuronal degeneration and amyloidosis in mouse and its molecular mechanism for the treatment of Alzheimer's disease

The abnormal deposition of the extracellular amyloid-beta peptide is the typical pathological hallmark of Alzheimer's disease. Strategies to reduce the amyloid-beta deposition effectively alleviate the neuronal degeneration and cognitive deficits of Alzheimer's disease. Danggui-Shaoyao-San has been considered a useful therapeutic agent known for the treatment of Alzheimer's disease. However, the mechanism of Danggui-Shaoyao-San for the treatment of Alzheimer's disease remains unclear. We investigated Danggui-Shaoyao-San's effect on amyloidosis and neuronal degeneration in an APP/PS1 mouse model. We found Danggui-Shaoyao-San alleviated the cognitive deficits in APP/PS1 mice. Additionally, Danggui-Shaoyao-San ameliorated the neuronal degeneration in these mice. Danggui-Shaoyao-San reduced the amyloidosis and amyloid-beta(1-42) deposition in APP/PS1 mouse brain and down-regulated the receptor for advanced glycation end products, and up-regulated the level of low-density lipoprotein receptor-related protein-1. However, the protein expression of the beta-amyloid precursor protein, beta-Secretase and presenilin-1 (PS1) in the amyloid-beta production pathway, and the expression of neprilysin and insulin-degrading enzyme in the amyloid-beta degradation pathway were not altered. Our findings collectively suggest that Danggui-Shaoyao-San could ameliorate the amyloidosis and neuronal degeneration of Alzheimer's disease, which may be associated with its up-regulation lipoprotein receptor-related protein-1 and down-regulation of the receptor for advanced glycation end products.