MTOR and Alzheimer disease: Ginsenosides, gintonin, extracts/fractions from ginseng, and formulas containing ginseng are widely studied in cells and animal models, which demonstrate that ginseng exerts neuroprotective effects in the prevention and treatment of AD through regulating multiple signaling pathways, such as PI3K/Akt, AMPK-mTOR, and NF-κB pathways, to block or improve pathological processes, including Aβ accumulation, tau phosphorylation, neuroinflammation, neurotrophic factors, apoptosis, and mitochondrial dysfunction in different stages of AD (Figure 3).