Dendrobium was collected from Dendrobium planting regions of Xintian Traditional Chinese Medicine Industry Development co., LTD of Guizhou Province in 2014. The dried stems of the herb (10 kg) were extracted by 95% ethanol solution. DNLA was isolated from the extracts, and analyzed by LC-MS/MS. Alkaloids accounted for 79.8% of DNLA, and mainly contained Dendrobine (C16H25O2N, 92.6%), Dendrobine-N-oxide (C16H25O3N, 3.3%), Nobilonine (C17H27O3N, 2.0%), Dendroxine (C17H25O3N, 0.9%), 6-Hydroxy-nobilonine (C17H27O4N, 0.32%), and 13-Hydroxy-14-oxodendrobine (C16H23O4N, 0.07%). The chemical structures of these ingredients were shown in the Fig. 1A , and the chromatograms of the sample solutions were shown in the Fig. 1B .
Aβ25–35 (Sigma, St Louis, MO, USA) was dissolved in physiological saline to a final concentration of 2.5 g/L, and incubated for one week at 37 °C to reach a state of aggregation. CNTF antibodies (ab190985) and GDNF antibodies (ab18956) were obtained from Abcam (Cambridge, England). BDNF (sc-546) was purchased from Santa Cruz Biotechnologies (Santa Cruz, CA, USA). TUNEL kits (In Situ Cell Death Detection Kit and POD) were purchased from Roche (Switzerland).
Aβ25–35 (Sigma, St Louis, MO, USA) was dissolved in physiological saline to a final concentration of 2.5 g/L, and incubated for one week at 37 °C to reach a state of aggregation. CNTF antibodies (ab190985) and GDNF antibodies (ab18956) were obtained from Abcam (Cambridge, England). BDNF (sc-546) was purchased from Santa Cruz Biotechnologies (Santa Cruz, CA, USA). TUNEL kits (In Situ Cell Death Detection Kit and POD) were purchased from Roche (Switzerland).