APP and Alzheimer disease: Ginsenoside Rd, salvianolic acid B and icariin can also treat AD by increasing the expression of α-secretase and soluble amyloid precursor protein alpha (sAPPα), which are negatively related to Aβ formation, or by decreasing the expression of β-secretase, γ-secretase, BACE1, sAPPβ, and amyloid precursor protein (APP), which stimulates Aβ production (Tang et al., 2016; Yan et al., 2017; Jin et al., 2019).