Ginkgolides and Neuroprotective Effects

Ginkgo biloba is commonly known asmaidenhair tree, available as a popular herbal supplementary in Asian, European, and American countries. Extensive in vitro, in vivo, and clinical studies demonstrated and confirmed the neuroprotective effects of a commercial standard ginkgo extract formulation known as EGb-761. Terpene trilactone comprises 5â€Â'7 % in EGb-761, collectively called as ginkgolides (G-A, G-B, G-C, G-J, G-K, G-L and G-M) and bilobides. Its clinical application gained popularity in herbal medicine due to treatment of early-stage Alzheimer’s disease, cerebrovascular disorders, PAF antagonism, and vestibular disorders. In addition, ginkgolides showed potent antioxidant activities via scavenging of reactive oxygenand nitrogen species. The physiological dosage of ginkgo extracts ranges between 120 and 240 mg/day in humans, and it is readily available as an over the counter product/supplementary product. According to the recent clinical findings, EGb-761 did not confirm its effect on long-term cognitive functioning, while it showed effectiveness and enhancement in shor-term cognitive and related activities. Ginkgo is generally well tolerated, but in a high dose, it can cause gastric upset, skin allergy, and increase the risk of bleeding in patients with risk factors (anticoagulant or antiplatelet treatment, surgery, etc.). Neuropharmacology, clinical issues of safety and usage are addressed in this book chapter.