Ginkgo biloba, commonly known as the maidenhair tree, is one of the oldest species of trees on the planet. This ancient tree has been revered for centuries not only for its unique fan-shaped leaves and resilience but also for its diverse uses in traditional medicine. Nowadays, it is recognised as one of the most researched and effective herbal medicines globally.
Historical and Folklore Perspective
Ginkgo biloba is often referred to as a 'living fossil' because it is the only surviving member of the ancient Ginkgoaceae family, with a history that can be traced back more than 270 million years. This tree, native to China, has a rich history in Chinese literature, art, and traditional medicine. It was often depicted in ancient Chinese paintings and poetry as a symbol of longevity and vitality.
In traditional Chinese medicine, ginkgo seeds were used to treat various conditions like asthma, bronchitis, and urinary tract issues. The tree was also a common motif in Buddhist art, representing endurance and hope, as it can live up to 1,000 years and can withstand various environmental stressors.
Traditional and Current Usage
Traditionally, Ginkgo biloba was used in various forms. The leaves were made into a tea, the seeds were eaten, and the extract from the leaves was used in topical applications. It is important to note that raw seeds are toxic in high amounts, and traditional usage often involved cooking or roasting the seeds.
In modern times, the primary medicinal use of Ginkgo biloba is centred around its leaves. Extracts from the leaves are used to make tablets, capsules, or teas, which are commonly used for their antioxidant and anti-inflammatory effects.
Ginkgo biloba extract (GBE) is now one of the most widely used dietary supplements, especially popular for its reported cognitive benefits. It is used for improving concentration and memory, and for conditions such as dementia, Alzheimer’s disease, and anxiety.
Cultivation, Harvesting, and Processing
Ginkgo trees are generally grown from seeds, but this process is laborious and time-consuming. Commercial cultivation of ginkgo typically involves growing the trees in plantations. The trees are hardy and adaptable, making them suitable for various environments.
Harvesting of ginkgo leaves occurs in late summer to early autumn when the leaves turn golden yellow and the concentration of beneficial compounds is highest. After harvesting, leaves are dried and then processed to create the extract. The process can involve a complex extraction that includes a series of purification steps to concentrate the beneficial compounds and remove unwanted toxins.
Medicinal Benefits and Constituents of Ginkgo
Scientific research has shown that ginkgo biloba has several health benefits, mainly attributed to its unique combination of phytochemicals including flavonoids, terpenoids, and organic acids. Flavonoids are known for their antioxidant properties, protecting the cells from damage by free radicals. Terpenoids, including ginkgolides and bilobalide, improve blood flow by dilating blood vessels and reducing the stickiness of platelets.
These compounds are believed to work together to enhance cognitive function by improving blood flow to the brain and protecting neurons from oxidative damage. Numerous clinical trials have shown that GBE can improve cognitive function and behaviour in patients with dementia and Alzheimer’s disease.
Furthermore, ginkgo has been found to have anti-inflammatory effects, which may contribute to its therapeutic effects in conditions like asthma and cardiovascular disease.
- Ahlemeyer, B., & Krieglstein, J. (2003). Neuroprotective effects of Ginkgo biloba extract. Cellular and molecular life sciences, 60(9), 1779-1792.
- DeFeudis, F. V., Drieu, K. (2000). Ginkgo biloba extract (EGb 761) and CNS functions: basic studies and clinical applications. Current Drug Targets, 1(1), 25-58.
- Diamond, B. J., Shiflett, S. C., Feiwel, N., Matheis, R. J., Noskin, O., Richards, J. A., & Schoenberger, N. E. (2000). Ginkgo biloba extract: mechanisms and clinical indications. Archives of physical medicine and rehabilitation, 81(5), 668-678.
- Maclennan, K. M., Darlington, C. L., Smith, P. F. (2002). The CNS effects of Ginkgo biloba extracts and ginkgolide B. Progress in Neurobiology, 67(3), 235-257.
- Smith, P. F., Maclennan, K., & Darlington, C. L. (1996). The neuroprotective properties of the Ginkgo biloba leaf: a review of the possible relationship to platelet-activating factor (PAF). Journal of ethnopharmacology, 50(3), 131-139.
- Van Beek, T. A. (2002). Chemical analysis of Ginkgo biloba leaves and extracts. Journal of chromatography A, 967(1), 21-55.
- Woelk, H., Arnoldt, K. H., Kieser, M., & Hoerr, R. (2007). Ginkgo biloba special extract EGb 761® in generalized anxiety disorder and adjustment disorder with anxious mood: A randomized, double-blind, placebo-controlled trial. Journal of psychiatric research, 41(6), 472-480.
- Yoshitake, T., Yoshitake, S., & Kehr, J. (2010). The Ginkgo biloba extract EGb 761® and its main constituent flavonoids and ginkgolides increase extracellular dopamine levels in the rat prefrontal cortex. British journal of pharmacology, 159(3), 659-668.
- Yuan, Q., Wang, C. W., Shi, J., & Lin, Z. X. (2017). Effects of Ginkgo biloba on dementia: An overview of systematic reviews. Journal of ethnopharmacology, 195, 1-9.