Scientific name: Ginkgo Biloba
Common names: Maidenhair Tree, Fossil Tree, Maidenhair Tree, Japanese Silver Apricot, Baiguo, Bai Guo Ye, Kew Tree, Yinhsing
Ayurvedic names: Balkuwari
Chinese names: Yin-hsing or yin xing yi
Bangladesh names: Balkuwari
Arabic names: الجنكة (al jinka)
Rain Forest names:
Approximate number of species known:
Common parts used: Leaf, fruit, seed
Height: 66-120 feet (20-35m)
Actions: Astringent, Antibiotic, Circulatory stimulant, Pulmonary, Vesicant
Known Constituents: Many flavonol glycosides, biflavones, .5-1% mono, di and tri-glycosides including the flavones quercetin, kaempferol and isorhamnetin including comaric acid esters of flavanoids. Terpene lactones (terpenoids) including bilbalide and ginkgolides A,B, C, J; Bioflavonoids, ginkgolic acids, sterols, procyanidins, polysaccharides, proanthocyanidins, alkylphenols, simple phenolic acids, 6-hydroxykynurenic acid, 4-O-methylpyridoxine and polyprenols.
One common extract of Ginkgo, called EGb761, was developed in 1975 by Schwabe Pharmaceuticals in Germany. This extract is standardised to 24% ginkgo flavonoid glycosides including quercetin, myricetin, kaempferol and isorhamnetin and 6% terpene lactones including ginkgolides A, B, C and bilobalide.
Other constituents include proanthocyanidins, rhamnose, D-glucaric, ginkgolic acids, glucose.
Flavonols are a subclass of flavonoids which have antioxidant and free radical scavenging effects, and along with Proanthocyanidins have been shown to strengthen capillaries.
A slow growing large tree, up to 40m, with large seeds. The tree can grow up to 10m before the branches extend from the side of the erect trunk. The leaves are alternate. Yellowish-green, fan-like leaves, are in clusters with veins that run parallel. Both, thick catkins of male and singular rounded female flowers are yellow-green. The fruit is yellow, fleshy and droops. The pulp and the seed has a disagreeable smell when ripe. The inner shell has a creamy white nut which is edible surrounded by a shell. It is native to east China.
Grows best in soil that is well watered and well drained. In Autumn the leaves go a deep yellow. It’s been suggested that Ginkgo is a good pollution absorber and hence air purifier.
When the leaves turn yellow in Autumn, they are collected.
Ginkgo biloba is believed to be both the most widely prescribed herbal medicine in the world and the world’s oldest living tree, being over 200 million years old, and a being a long-term descendant of the seed fern. Its name is believed to come from the Japanese word gin kyo meaning “Silver Apricot.
It is spelled Ginkgo, but pronounced “Gink-o” with a silent ‘g’ which has led to some confusion around it’s spelling, with some people spelling it Ginko, without the ‘g’, by mistake.
Native to China, it is believed that this tree would have become extinct if it wasn’t for the Chinese replanting it around their temples 1500 years ago. All other trees in this Ginkgophyta division are now extinct making Ginkgo the only known survivor in the family.
Ginkgo is used as a circulatory enhancing agent including as a brain tonic to enhance
cerebral function including memory, mental alertness, concentration and cognition.
Ginkgo is used for disorders involving the cranium, including the sight and sound, and for those in the peripheries of the body including hands and feet, as well as to promote circulation to the skin, and reproductive organs including sexual function such as erectile dysfunction caused by decreased genital blood flow.
It is believed to help open the smaller veins which improves micro-circulation and has been used to promote blood supply to the head for tinnitus when cerebral circulatory insufficiency was a factor.
It’s been used for age-related neuro-degenerative disorders such as Dementia, and Alzheimer’s.
It is known as well to be used as support for persons with eye disorders including glaucoma, cataracts and macular degeneration, multiple sclerosis, vitiligo, general and peripheral circulation, and as a vasodilator.
It’s been employed to increase energy, and a reduce fatigue. It’s been taken for headaches, depression, mood swings, arthritis, as well as to promote blood flow in fluid retention related circulatory disorders.
It has been used for dizziness, anxiety, acute cochlear deafness, early stages of dementia, cerebrovascular insufficiency, reduced retinal flow as well as for head injuries and memory loss.
The leaves and seeds are used in Chinese Medicine for lung problems. Ginkgo seeds are used for urinary incontinence. The seeds are antibacterial and anti-fungal.
The seeds contain a toxin, given the label, ginkgotoxin, but the leaves appear to contain little or none of this. When the kernel (seed) is collected, the toxic flesh is removed and it is cooked. It is used in soups and porridges when boiled and tastes sweet, similar to pine nut. Cooked seed is used to stabilize spermatogenesis. The seed also gives an edible oil.
The Chinese have used it for over 5000 years for asthma and heart problems. The Chinese once used the nuts only for medicine as an anti-asthmatic.
It has been suggested this is due to relaxation of the bronchi. It dilates the blood vessels and bronchial tubes, aiding reduction of allergic inflammatory responses. It has also been used to treat coughs with sticky, thick phlegm. It has been proposed that it may play a role in heart and stroke prevention including dilating blood vessels containing cholesterol.
It is thought that it may have a protective effect on the nervous system.
The tree is Japan’s capital, Tokyo’s, official tree with the Ginkgo leaf being its symbol.
Ginkgo biloba and tinnitus
One of its key applications is in tinnitus, dizziness, and headache. (German Commission E, ESCOP, WHO.)
Ginkgo biloba and neurodegenerative alzheimer’s and dementia
EGb 761 at 240mg once a day has been shown to improve cognitive functioning, neuropsychiatric symptoms and functional abilities in vascular dementia and Alzheimers disease.
Ginkgo biloba and ocular blood flow including glaucoma, macular degeneration and pterygium
There is an anti-ischaemic effect with protection from hypoxia from the extract. The permeability of capillaries is decreased while damaging free radicals are trapped and so the cell membrane is protected. Fluidity of blood is improved, increasing cerebral blood flow with decrease in platelet and erythrocyte aggregation as well as platelet adhesion, and blood and plasma viscosity.
Ginkgo and macular degeneration
Beneficial effects have been shown in treatment of age-related macular degeneration (Ramassamy and others 2007). Improved blood circulation appears to come from stimulation of endothelium derived relaxing factor (Amri and others 1996; Pietri and others 1997a; DeFeudis and Drieu 2000; Smith and Luo 2004).
Ginkgo and pterygium
The proliferation of human pterygium fibroblasts was inhibited by Ginkgo biloba extra in vitro.
[J];International Eye Science;2012-07
Ginkgo and the visual field
The use of Ginkgo biloba extract has been shown to slow the progression of visual field damage in patients with normal tension glaucoma.
Ginkgo and peripheral blood flow
Based on the vascular theory of glaucoma pathogenesis, a study evaluated the effect of Ginkgo biloba extract (GBE) on peripapillary blood flow in patients with normal tension glaucoma (NTG).
Thirty patients with NTG were randomly placed in the GBE-treated or control groups. The GBE-treated group received 80 mg GBE orally, twice a day for four weeks, and the control group received a placebo twice a day for four weeks.
Complete ocular examinations including visual field, Heidelberg retina flowmeter, and systemic examinations were performed on the first study day and on the day treatment was completed.
After GBE treatment, the mean blood flow, volume, and velocity increased at almost all points, and there was a statistically significant increase in blood flow at almost all points, in comparison to the placebo.
Blood volume significantly increased only in the superior nasal and superior temporal neuroretinal rim areas. GBE also significantly increased blood velocity in areas of the inferior temporal neuroretinal rim and superior temporal peripapillary area.
Ginkgo and anti-oxidant activity in schizophrenia
Extract of Ginkgo biloba (EGb) is a potent antioxidant, possessing free radical-scavenging activities. A study evaluated the efficacy of EGb-761, a standardized extract given in capsule form, in treating TD in schizophrenia patients in a mainland China Veterans Affairs psychiatric hospital. They were randomly assigned to 12 weeks of treatment with either EGb-761, 240 mg/d or a placebo in a double-blind manner.
EGb-761 appears to be an effective treatment for reducing the symptoms of TD in schizophrenia patients, and improvement may be mediated through the well-known antioxidant activity of this extract.
Ginkgo and dementia
Ginkgo appeared to make modest changes in cases of dementia over six months to one year.
Ginkgo and dying neuron prevention
Ginkgo was implicated as a preventative for dying neurons exposed to oxidative stress from hydrogen peroxide.
Ginkgo and people suffering sexual dysfunction due to anti-depressant use
Ginkgo appeared to help in cases of people suffering sexual dysfunction due to anti-depressant use.
Ginkgo as a scavenger for nitric oxide
Ginkgo appeared to be a scavenger for nitric oxide.
Ginkgo and cerebral insufficiency
Positive results for Ginkgo for cerebral insufficiency but more studies needed.
Ginkgo and dementia and alzheimer’s disease
Clinical efficacy of Ginkgo in dementia and Alzheimer’s was confirmed and was well tolerated.
Ginkgo’s implications in alzheimer’s, stroke, oedema, tinnitus and macular degeneration
Ginkgo shows promise in treating some of the neurologic sequelae associated with Alzheimer’s disease, TBI, stroke, normal aging, edema, tinnitus, and macular degeneration. Mechanisms of action may include antioxidant, neurotransmitter/receptor modulatory, and antiplatelet activating factor properties.
Ginkgo and neuromodulation
Ginkgo biloba extract has notable neuromodulatory effects in vivo.
Ginkgo and memory impairment
Thirty-one patients over the age of 50 years and showing a mild to moderate degree of memory impairment entered a 6-month double-blind, placebo controlled, parallel group design study.
Ginkgo and antioxidant enzymes in brain tissue
Reactive oxygen species may play a role in the mechanism that has been proposed to explain the biological side effects of MP, and Gb prevents the MP-induced oxidative stress to preserve antioxidant enzymes activity in brain tissue.
Ginkgo and cognition
Although Ginkgo biloba appears to have no extreme side effects and is thought to improve cognition, there are inconsistent results in more modern trials in comparison to earlier smaller trials. Clinical trials using more modern methodology with ‘intention-to treat analysis’ are suggested.
Ginkgo and anticholinesterase and antidementic properties with cognitive enhancement
There were significant anticholinesterase and antidementic properties due to decrease in AChE-specific activity with cognitive enhancing properties at 30 and 60mg/kg dose.
Ginkgo the mitochondria, ATP and anti-stress
Membrane lipid peroxidation is inhibited due to flavonoid and ginkgolide constituents in EGb 761. The antioxidant and free radical-scavenging effects decrease reactive oxygen species (ROS) levels. Through the respiratory control ratio of mitochondria being increased via Bilobalide, increases of ATP levels come about through regulation of the utilization of cerebral glucose due to EGb 761 and associated protection against uncoupling of oxidative phosphorylation.
An anti-stress effect comes about from the expression of the peripheral benzodiazepine receptor (PBR) in the adrenal cortex being decreased due to the ginkgolide constituents of EGb.
Ginkgo and the rescue of hippocampal cells
There was increase of cell survival and viability of hippocampal cell cultures was slightly, but significantly, increased when control groups were treated with 100 μg/ml EGb 761 compared with the vehicle-treated group. Moreover, the flavonoid fraction CP 205 (25 μg/ml) alone was also able to rescue hippocampal cells when applied 2 h after a preexposure to SNP.
Ginkgo, morphological changes, liver mitochondria and oxidative damage in the brain
Old animals with potential morphological changes had these partially prevented when treated with Ginkgo biloba extract EGb 761. There were benefits also on liver mitochondria and the indices of oxidative damage in the brain.
Ginkgo and anti-angiogenic activity
The antioxidant, gene-regulatory and anti-angiogenic actions of Ginkgo biloba may be associated with chemopreventative (anticancer) properties showing in animal studies using leaf extracts. The flavonoid and terpenoid constituents appear to contribute to the anti-lipoperoxidative and antioxidant benefits with antioxidant activity affecting an inhibition of nitric oxide synthase which contributes to anti-angiogenic activity.
Ginkgo and oxidative stress
Oxidative stress induced by ultra-violet light and chromosome damaging radiation factors associated with cancers have been inhibited by Ginkgo extracts. The effect is shown of terpenoid constituents in inhibiting DNA damage where there have been human bladder cancer cells and also effects on gene expression has helped constrain highly aggressive breast cancer cell lines in mice from spread.
For optimal effects, total extracts are suggested as it is thought that both flavonoid and terpenoid constituents being necessary to act in a complementary manner to inhibit a number of carcinogenesis-related processes.
Ginkgo and ocular blood flow
Ocular blood flow increased with significant improvement in diastolic velocity in the ophthalmic artery showing in glaucoma patients taking Ginkgo biloba extract 40mg three times daily for 2 days with no change in arterial blood pressure or heart rate.
Ginkgo and memory retention
In studies re appetitive operant conditioning on mice, EGb 761 at a daily dose of 100mg/kg showed improved retrieval of the learned response with a facilitation of memory processes with increased in number of correct responses and incorrect responses reduced sooner and faster.
Ginkgo and anti-tumour activity
There are seven long-chain phenols which have been isolated from Ginkgo biloba L. There was antitumour activity against Sarcoma 18 ascites in mice from three of the phenols – anacardic acid (Ib), bilobol (IIa), and cardanol (IIIa) with the first two phenols also having weak antimicrobial activity.
Ginkgo and alzheimer’s disease
Both basal and induced levels of Hydrogen peroxide (H202) rose both in vitro and in vivo AD-associated transgenic models expressing the Aβ peptide compared with the wild type controls when cells were treated with Ginkgo biloba EGb 761 extract.
Ginkgo and working memory
In a double-blind, placebo-controlled clinical trial of 61 participants, significant improvements in working memory, executive and information processing were attributed to EGb with thoughts that it may be useful as a nootropic agent to improve intelligence in healthy young persons.
Ginkgo and the visual field
In this study, although no significant changes were from in heart rate, blood pressure or intraocular pressure, there were significant improvement in visual fields indices.
Ginkgo and neuro protective properties
The mechanism of action of EGb 761 (standard Ginkgo biloba leaf extract) on cell survival following apoptosis induced by serum-deprivation or treatment with staurosporine (STS) showed treatment of PC12 cells prevent serum deprivation and STS-induced mitochondrial damage, inhibiting STS-induced activation of the caspase-3 enzyme, attenuate release of cytochrome c and DNA fragmentation. Bilobalide B and ginkgolide C, two of the EGb 761 components, show more significant inhibition than the EGb 761 extract.
Ginkgo and neuro protective properties
EGb 761 is suggested to mediate multiple neuroprotective effects in inhibiting apoptotic machinery.
Ginkgo and alzheimer’s disease
EGb 761 and a component, ginkgolide A has been shown to reduce chemotaxis behaviour and 5-HT hypersensitivity in a transgenic C. elegans and alleviates Aβ-induced pathological behaviors, including paralysis. The protection against Aβ toxicity by EGb 761 is mediated, not through reduction of oxidative stress, but primarily by modulating Aβ oligomeric species, and ginkgolide A and so has therapeutic prospects for prevention and treatment of Alzheimer’s disease.
Ginkgo and atherosclerosis
There are possibilities of usefulness of Ginkgo biloba in treatment of atherosclerosis due to the effects of downregulation of intracellular reactive oxygen species formation along with activation of nuclear factor-kB and activator protein 1 to reduce cytokine-stimulated endothelial adhesiveness.
Park JW, Kwon HJ, Chung WS, Kim CY, Seong GJ. “Short-Term Effects Of Ginkgo Biloba Extract On Peripapillary Retinal Blood Flow In Normal Tension Glaucoma.” 2011 October
Zhang WF, Tan YL, Zhang XY, Chan RC, Wu HR, Zhou DF. “Extract Of Ginkgo Biloba Treatment For Tardive Dyskinesia In Schizophrenia: A Randomized, Double-Blind, Placebo-Controlled Trial.” 2011 May