Efficacy, Safety and Response Predictors of Astragalus Membranaceus on the Improvement of Cognitive Function in Mild-to-Moderate Alzheimer's Disease

Inclusion criteria

• ✓. Male or female aged ≥50 years and ≤85 years
• ✓. Memory loss for at least 6 months, with a progressive worsening trend Patients with mild or moderate disease degree, that is, the total score of MMSE: 14 points \< total score of MMSE \<24 points, 0.5≤CDR≤2 points, and the total score of HAMD (24-item version) ≤20 points
• ✓. Brain magnetic resonance imaging shows the degree of hippocampal atrophy is greater than or equal to grade 1
• ✓. The modified Hachinski Ischemia Scale (m-HIS) score was \< 4 points
• ✓. The criteria described by the diagnostic and statistical manual of mental disorder-V for the diagnosis of dementia comply with the National Institute on Aging - Alzheimer's Association "Very likely AD" (National Institute of Aging-Alzheimer's Association, 2011).
• ✓. There are no obvious positive signs in nervous system examination;
• ✓. The subjects have the ability of reading, writing and communication, have a stable caregiver, accompany to attend the visit.
• ✓. The basic treatment of AD before enrollment remained unchanged, and if long-term users needed to use it steadily for more than 4 weeks before randomization,the dose was kept as stable as possible during the study. Such drugs include: cholinesterase inhibitors.