BACE1 and Alzheimer disease: 2009). Meanwhile, tenuigenin can reduce the level of Aβ in human neuroblastoma SH-SY5Y APP695 cells via inhibiting the activity of BACE1 (Jia et al. 2004). In the AD rat model, tenuigenin inhibits Aβ1–40 aggregation, decrease phosphorylation level of TauSer396 by down-regulating of ubiquitin expression and up-regulating activity of ubiquitin ligase E3 and 26S proteasome at doses of 37.0 and 74.0 mg/kg. This result indicates that the role of tenuigenin in combating AD may be related to the ubiquitin–proteasome pathway (Chen et al. 2015).