Ginsenoside rd

UPLC-grade acetonitrile was purchased from Merck (Darmstadt, Germany). Formic acid was purchased from Sigma-Aldrich (Mo, USA). Leucine enkephalin was obtained from Waters Corporation (Milford, MA, USA). Distilled water was obtained from Watson's Food & Beverage (Guangzhou, China).
The PC12 cells were purchased from Jiangsu KeyGEN BioTECH Corp., Ltd (Nanjing, China). Ginsenoside Rb1, ginsenoside Rb2, ginsenoside Rb3, ginsenoside Rc, ginsenoside Rd, ginsenoside Re, ginsenoside Rf, ginsenoside Rg1, notoginsenoside R1, 20(S)-notoginsenoside R2, notoginsenoside Fa, gypenosides A, and gypenosides XLIX were purchased from Chengdu Must Bio-Technology Co., Ltd. (Chengdu, China). The 20(S)-ginsenoside Rb2, galantamine HBr, and berberine were purchased from the National Institutes for Food and Drug Control (Beijing, China). The structure of these compounds is shown in Figure 2. Dulbecco's modified Eagle medium (DMEM) and phosphate buffer saline (PBS) were purchased from Jiangsu KeyGEN BioTECH Corp., Ltd. (Nanjing, China). Fetal bovine serum (FBS), trypsin, and dimethyl sulfoxide (DMSO) were purchased from Gibco (Thermo Fisher Scientific, Inc., Waltham, MA, USA). Amyloid β-protein fragment 25–35 was purchased from Sigma-Aldrich (St. Louis, MO, USA). YZG was produced by Guangxi Wanshoutang Pharmaceutical Co., Ltd., and formulated by water into suspension.

Ginsenoside Rd (with a purity >98%) was purchased from Chengdu Must Biotechnology, A stock solution of GS-Rd (50 mM) was prepared with DMSO (Sigma, D2650). The following strains were used in this work: CL4176 (dvIs27 [myo-3p:Aβ (1–42):let-851 30 UTR) + rol-6 (su1006)]); CL 2006 (dvIs2 [pCL12 (unc-54/human Aβ peptide 1–42 minigene) + pRF4]) and TJ356 (zls356 [daf-16p:daf-16a/b:GFPC + rol-6). These were provided by the Caenorhabditis Genetic Center (CGC). All worms were propagated at 16 °C except TJ356, which was propagated at 20 °C on nematode growth medium (NGM) and seeded with the standard food resource of E. coli OP50.