Compounds schisandrin A, schisandrol A, schisandrin, schisandrol B, schisandrin C, schisantherin A, schisanhenol, gomisin J, gomisin D, and gomisin G were purchased from Sichuan Weikeqi Company (Chengdu, Sichuan, China). The purity of these compounds was above 95%. All other reagents were of HPLC grade or of the highest grade commercially available.

Human neuroblastoma cell line (SH-SY5Y) was purchased from The Cell Resource Centre of Institute of Basic Medicine, Chinese Academy of Medical Sciences. Schisandrin (purity>98%) was purchased from Weikeqi Biological Technology Company, Ltd (Sichuan, China). LY294002 and Aβ 1–42 were purchased from Sigma Company, Ltd (Beijing, China).

authenticated by Professor Xijun Wang of the Department of Pharmacognosy, Heilongjiang University of Chinese Medicine. Schisandrin, schisandrol B, schisantherin A, deoxyschisandrin, and schisandrin B were purchased from Weikeqi Biotechnology Co., (Sichuan, P. R. China).

Twelve-month-old mice were randomly divided into three groups (n=6 per each group): WT group, AD group, and AD+SCH group. C57BL/6 WT mice served as blank control. The mice in the AD+SCH group were administrated SCH (2 mg/kg/day, Weikeqi Biological Technology Company, Ltd., Sichuan, China) by means of intragastric administration for 2 weeks. The mice in the AD group were given the same volume of distilled water for 2 weeks.

Schisandrin (purity>98%) was provided by Sichuan Weikeqi Biological Technology Co. Ltd(Sichuan, China). Radix Ginseng (produced in Jilin, Product ID:0907020SK1), Radix Ophiopogonis Japonici (produced in Sichuan, product ID0808010018) and Fructus