The effectiveness and safety of Jihwang-eumja (Dihuang Yizi) compared to Western medications in patients with Alzheimer's disease: A systematic review and meta-analysis

Jihwang-eumja is reported to be effective in decreasing β-amyloid expression and activating monoamine oxidase and acetylcholinesterase in rat models. This systematic review aims to evaluate the effectiveness of Jihwang-eumja in Alzheimer's disease compared to Western medications.We searched Medline, Embase, CENTRAL, CINAHL, CNKI, ScienceON, KISS, and Kmbase. Randomized controlled trials comparing the effectiveness of Jihwang-eumja and Western medications on the cognition and the activities of daily living in Alzheimer's disease were included. The results were synthesized using meta-analysis. The risk of bias was evaluated using the Cochrane risk-of-bias tool, and the evidence level of each outcome was suggested using the GRADE system.A total of 165 studies were screened, and six were included in the systematic review and meta-analysis. A total of 245 and 240 participants were included in the intervention and comparison groups, respectively. The results showed that Mini-Mental State Examination was 3.19 (95%CI: 1.68-4.70) higher, and the standardized mean difference of activities of daily living was 1.13 (95%CI: 0.89-1.37) higher in the Jihwang-eumja group than in Western medications group. The included studies contained some concerns of the risk of bias, and the certainty of the evidence was considered moderate.Despite the small number of studies and high heterogeneity, we could verify the applicability of Jihwang-eumja for Alzheimer's disease.