NPC1 and Alzheimer disease: In a study by Mao and coworkers, it was demonstrated that 100 μL of AT extract (equal to 200 mg AT per 20 g of mouse body weight) and its active compounds, asarones, promoted NPC proliferation, and neurogenesis in the hippocampus of aged mice and retarded deficits of NPC proliferation and neurogenesis in transgenic AD model mice when treated by gavage once per day for 28 days.