Ginkgo biloba on focal cerebral ischemia: a systematic review and meta-analysis

Gingko biloba extract (EGB) has been used in traditional medicines for centuries, and although its application to cerebral ischemia has been of great interest in recent years, high quality evidence-based clinical trials have not been carried out. This systematic review and meta-analysis aimed to examine the neuroprotective effect of EGB on focal cerebral ischemia in animal models. A systematic literature search was performed using five databases spanning January 1980-July 2013. The outcome was assessed using the effect size, which was based on infarct size and/or neurological score. A total of 42 studies with 1,232 experimental animals matched our inclusion criteria. The results revealed that EGB improved the effect size by 34% compared to the control group. The animal species, the method and time to measure outcome, and the route and dosage of EGB administration affected the variability of the effect size. Mechanisms of EGB neuroprotection were reported as anti-apoptotic, anti-oxidative, and anti-inflammatory. In conclusion, EGB exerts a significant protective effect on experimental focal cerebral ischemia. However, possible experimental bias should be taken into account in future clinical studies.