Bushen-Tiansui Formula Improves Cognitive Functions in an Aβ(1–42) Fibril-Infused Rat Model of Alzheimer's Disease

Bushen-Tiansui Formula (BTF) was empirically updated from a classical prescription named Kong-Sheng-Zhen-Zhong pill. It is based on the traditional Chinese medicine theory of the mutual relationship between the brain and the kidney and is intended to treat neurodegenerative diseases. This formulation has been used for several years to treat patients with Alzheimer's disease- (AD-) like symptoms in our clinical department. However, the medicinal ingredients and the mechanisms by which BTF improves cognition and memory functions have not been characterized. In this study, we used UPLC-MS to generate a chromatographic fingerprinting of BTF and identified five possible active ingredients, including stilbene glycoside; epimedin A1, B, and C; and icariin. We also showed that oral administration of BTF reversed the cognitive defects in an Aβ(1–42) fibril-infused rat model of AD, protected synaptic ultrastructure in the CA1 region, and restored the expression of BDNF, synaptotagmin (Syt), and PSD95. These effects likely occurred through the BDNF-activated receptor tyrosine kinase B (TrkB)/Akt/CREB signaling pathway. Furthermore, BTF exhibited no short-term or chronic toxicity in rats. Together, these results provided a scientific support for the clinical use of BTF to improve learning and memory in patients with AD.