Efficacy and safety of standardized Ginkgo biloba L. leaves extract as an adjuvant therapy for sudden sensorineural hearing loss: A systematic review and meta-analysis

Ginkgo biloba L. has been used for medical purposes in China for centuries. Standardized Ginkgo biloba L. leaves extract (GBE) is a widely used botanical drug which displays a variety of pharmacological effects against sudden sensorineural hearing loss (SSNHL).To evaluate the efficacy and safety of GBE as an adjuvant therapy, administered with corticosteroids, for the initial management of patients with SSNHL.We searched seven databases for randomized clinical trials (RCTs) comparing GBE plus corticosteroids with corticosteroids alone for SSNHL treatment. Data analysis was carried out by Review Manager 5.4 and Stata 16.0 software. The study was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline. We subsequently evaluated the certainty of evidence using the GRADE (Grading of Recommendation Assessment, Development and Evaluation) approach.A total of 11 RCTs involving 1069 patients were included. Meta-analysis indicated that the clinical cure rate (RR = 1.33, 95% CI = 1.12 to 1.58, P = 0.001) and total effective rate (RR = 1.24, 95%CI = 1.17 to 1.31, P < 0.001) in SSNHL patients receiving GBE plus corticosteroids was superior to patients receiving corticosteroids alone. After treatment, pure tone average (PTA) improvement of observation group was better than that in the control group (WMD = 10.33, 95%CI = 6.46 to 14.21, P < 0.001). The levels of whole blood high shear viscosity (WMD = 0.93, 95%CI = 0.28 to 1.59, P = 0.005), whole blood medium shear viscosity (WMD = 0.53, 95%CI = 0.11 to 0.95, P = 0.01), whole blood low shear viscosity (WMD = 1.26, 95%CI = 0.80 to 1.72, P < 0.001), plasma viscosity (WMD = 0.19, 95%CI = 0.09 to 0.30, P < 0.001) and fibrinogen (WMD = 0.80, 95%CI = 0.25 to 1.35, P = 0.004) were lower than those in the control group. There was no significant difference in the change of hematokrit between two groups (WMD = 4.23, 95%CI = -0.54 to 8.99, P = 0.08). GBE was generally well tolerated, and there was no significant difference in the incidence of adverse reactions between two groups (RR = 1.01, 95%CI = 0.57 to 1.79, P = 0.97).The results of the current study suggested that GBE might be effective and promising as an adjuvant to corticosteroids in the initial treatment of moderate to profound SSNHL. However, the GRADE assessment indicated that the overall strength of evidence was not high. Further studies with high methodological quality and low risk of bias are needed to confirm the positive results. PROSPERO registration No. CRD 42020190113.