Magnitude of Effect and Special Approach to Ginkgo biloba Extract EGb 761® in Cognitive Disorders

Abstract

In the early 70's, improvements in methodical procedures of extraction and standardization of ginkgo preparation allowed the production of a highly concentrated and stable extract (EGb 761) (definition see editorial) by the company Dr. Willmar Schwabe, which could be systematically tested in scientific programs. Consequently, numerous studies have been undertaken and provided replicable outcomes to demonstrate its efficacy in human population. EGb 761 is currently registered as an ethical drug in more than 50 countries around the world, and is prescribed for a range of neurological and vascular disorders including dementia, arterial occlusive disease, retinal deficit, and tinnitus. The following chapter will focus on the relevant data that support EGb 761 efficacy in the treatment of cognitive disorders in general, and dementia in particular. Besides the published data, the author will provide original results unveiling different factors that could interfere with EGb 761 efficacy and may be the source of the variations observed among studies in the EGb 761 literature. In the author's opinion, such factors should be taken into consideration when implementing the design of future research and optimizing individual EGb 761 response in the clinical practice. Within the framework of this new approach, the author will not only answer the question as to whether EGb 761 works over placebo in cognitive disorders, but also attempt to estimate how well it works in particular conditions.

Ginkgo biloba Extract in Alzheimer’s Disease: From Action Mechanisms to Medical Practice

“…The leaves of the Ginkgo tree have a long history of being used for medicinal purposes. In the early 1970s, Dr. Willmar Schwabe Pharmaceuticals (Karlsruhe, Germany) successfully improved methodical procedures for the extraction and standardization of Ginkgo biloba preparation and produced highly concentrated and stable extracts from Ginkgo biloba leaves [1]. The extract of Ginkgo biloba leaves (EGb761) since then has been standardized to contain 24% flavonoid glycosides (containing quercetin, kaempferol, isorhamnetin ect.…”

Nutraceuticals in cognitive impairment and Alzheimer’s disease

“…For this reason, several in vivo studies from humans have been performed and beneficial effects of Gb in prevention and treatment of neurodegenerative disorders like AD have been shown. Improvement of cognitive performance (Le Bars et al, 1997; Kanowski and Hoerr, 2003), memory (Kanowski and Hoerr, 2003), and attention (Le Bars, 2003; Chan et al, 2007) were consistently observed. Two large RCTs on the use of Gb extracts (the GEM and the GuidAge study) did not show less cognitive decline over time in older adults with normal cognition or MCI taking Gb than those assuming placebo (Snitz et al, 2009; Vellas et al, 2012).…”

Neurogenic Traditional Chinese Medicine as a Promising Strategy for the Treatment of Alzheimer’s Disease

“…In the early 1970s, Willmar Schwabe Pharmaceuticals (Karlsruhe, Germany) standardized the extraction procedures of stable extracts (EGb761) from Ginkgo leaves [92]. The extract of G. biloba leaves contains 24% flavonoid glycosides, making them the major constituent of the extract, followed by 6% terpenoids and 5%–10% organic acids.…”