CDK5 and Alzheimer disease: In vitro and in vivo preclinical studies have demonstrated that ginsenosides, gintonin, and other active components from ginseng or formulas containing ginseng mainly regulate PI3K/Akt, AMPK-mTOR, MAPK, GSK-3β/CDK5, NF-κB, and mitochondrial apoptotic signaling pathways to improve key pathological processes of AD development (Figure 2).