CREB1 and Alzheimer disease: Ginsenoside Rg1, an active ingredient of ginseng, was reported to improve cognitive impairment and memory in SAMP8 mice and may regulate PKA/CREB activity via the blood-brain barrier [35]; the effective ingredients of rhubarb are anthraquinone derivatives, including emodin, aloe-emodin, chrysophanol, rhein, physcion, and danthron, and these can improve central nervous system diseases such as traumatic brain injury, brain tumors, and Alzheimer's disease [36].