3β,23,28-Trihydroxy-12-oleanene 3β-Caffeate from Desmodium sambuense-Induced Neurogenesis in PC12 Cells Mediated by ER Stress and BDNF–TrkB Signaling Pathways

3β,23,28-Trihydroxy-12-oleanene 3β-caffeate (compound 1) is a neuritogenic pentacyclic triterpenoid, which was isolated from Desmodium sambuense based on a PC12 cell bioassay system. Compound 1 induced neurite outgrowth dose-dependently in PC12 cells and primary cortical neurons at doses of 0.1, 0.3, and 1 μM. The potential target of compound 1 was predicted by ChemProteoBase profiling, and the mechanism of action was investigated using specific...