摘要OBJECTIVE:To evaluate the effect of Ginkgo biloba extract on Alzheimer's disease using meta-analysis.DATA SOURCES:The following sources were used for articles concerning Ginkgo biloba extract for the treatment of Alzheimer's disease:Western biomedical journal literature databases,Chinese Biomedical Literature Database,Chinese Journal Full-text Database,Chinese Science and Technology Journal Full-text database.DATA SELECTION:Randomized controlled trials addressing Ginkgo biloba extract for the treatment of Alzheimer's disease were selected.The pathway and method of information collection were identical between treatment and control groups.Mild and moderate Alzheimer's disease patients scoring ≤ 26 points on the mini-mental state examination were included.Subjects met the diagnostic criteria for dementia by the American Psychiatric Association's "Diagnostic and Statistical Manual of Mental Disorders" Fourth revised edition.The quality of included literature was assessed by two authors.Meta-analysis was performed by RevMan4.2 software which was provided by the Cochrane Collaboration.Heterogeneity,sensitivity analysis,and bias evaluation were conducted.MAIN OUTCOME MEASURES:Scores of mini-mental state examination,ADAS-cog,and Syndrom-Kurztest.RESULTS:The five included randomized controlled trials contained 819 patients.Meta-analysis showed that the Syndrom-Kurztest score was significantly decreased (weighted mean difference = -2.32;95%CI = -3.12,-1.52;P＜0.01) compared with the control group.No significant difference was found in the mini-mental state examination and ADAS-cog score (P＞.05).However,there was a tendency to elevate mini-mental state examination score and to reduce the ADAS-cog score.CONCLUSION:Ginkgo biloba extract shows good therapeutic effects for mild and moderate Alzheimer's disease.However,high-quality,randomized,double-blind,and controlled trials are needed to further confirm its therapeutic effects.