The neuroprotective mechanism of ginkgo biloba extract is clear in two aspects: on the one hand, it can reduce the damage caused by platelet activating factor (PAF) during cerebral ischemia by antagonizing PAF; On the other hand, it can remove free radicals in the body, produce antioxidant effect, and reduce the damage of brain tissue caused by excessive free radicals produced in the body during cerebral ischemia (Noorbala and Akhondzadeh, 2006). Here, PCLAF is linked to brain ischemia.