Modern research focuses on the standardization of G. The tree produces biflavones, constituents in its leaves: the terpene trilactones ginkgolides A, B, C, J, P, and Q, and bilobalides many flavonol glycosides, proanthocyanidins, alkylphenols, simple phenolic acids, 6-hydroxykynurenic acid, 4-O-methylpyridoxine, and polyphenols.
Ginkgo leaf extract is used in medicine due to its therapeutic actions in regulating cerebral blood flow, protection against free radicals, and delaying the progress of dementia and diabetes. The range declined until 2 million years ago, when the trees were restricted to a small area in China.
The most plausible ancestral group of the order Ginkgoales is Peltaspermales, while the closest living relatives of the clade are cycads that share the characteristics of motile sperm with the extant G. Evidence indicates that the decline was due to decreased temperatures. The vigorous young ginkgo tree is pyramidal with a principal central leader and wide-spaced whorls of lateral branches that grow out at a diagonal orientation to the trunk; increase in height slows at maturity when the tree fills out the sparse, branched juvenile structures in a spreading crown formation.
The leaves are deciduous, petiolate, fan-shaped, bilobed, thickened at the margin, broader than they are long, dichotomous-veined, and arranged in an alternate or clustered fashion of on the short shoots. The catkins of males emerge before the leaves fall off and after pollen is shed, and pollination is facilitated by the wind, while the ovules of females are produced in pairs and borne at the ends of stalks mm long.
Once inside, a male gametophyte undergoes 4 months of development that result in the production of a pair of multiflagellated spermatozoids. One of the spermatozoids fertilizes the egg cell while the ovule remains on the tree. Embryo maturation completes in weeks after seeds fall, and the foul odor from the fruits indicates that they are mature.
The behavior of G. The therapeutic effect and pharmacological action are due to the joint effect of multiple components, and no individual component is regarded to solely exert the effect.
Phytochemical constituents in G. Novel phytochemicals are terpenes and trilactones ginkgolides and bilobalides , flavonoids, and other compounds. Apart from this, two new diterpenoid compounds, ginkgolides P and Q are isolated from leaves. These two end products react to produce geranylgeranyl pyrophosphate, which converts to levopimaradiene, leading to the synthesis of dehydroabietane transported from plastids to the cytoplasm; this is in turn converted to ginkgolides through a series of oxidation reaction steps.
The biosynthesis occurs in active-growing tissues and aerial parts of the ginkgo plant. Trilactones in G. The flavonoids are flavones, biflavones, flavonols, tannins, and associated glycosides,[ 51 ] which have antioxidant, antifeeding, and antinutritive action against insect herbivores; significant differential levels of quercetin and kaempferol are observed when Spodoptera littoralis feed upon ginkgo compared to instances of mechanical damage.
The biflavones include amentoflavone, 5-methoxybilobetol, bilobetol, isoginkgetin, ginkgetin, and sciadopitysin. The leaves of G. The few recent studies on the anticancer activity of the extract in in vitro models showed inhibited cell proliferation, tumor suppression, and DNA damage repair effect of the extract. The last few decades saw an increase in published works on the phytochemistry, pharmacological activity, and uses of G.
Current interest focuses on the pharmacology, toxicology, and clinical research on the neuroprotective importance of ginkgo leaf extract. The pharmaceutical value of the extract is gaining increasing recognition, and efforts to standardize the extract are being made via incorporation into the pharmacopeia of many European countries. Standardization of the extract into dosage for safe human use as a herbal drug is facilitated by the regulatory agencies in these countries, and safety measures are taken.
The recent and growing developments in studying the neuroprotective role of ginkgolides may, it is hoped, address the problems of clinical therapy of neurodegenerative diseases. In Korea the ginkgo is cultivated for the beauty of its leaves, and for its edible and medicinal nuts; in parts of Japan it is widely planted according to its status in Confucianism.
Male trees do not produce malodorous seeds. Although cultivated trees exist throughout the world, there is no certainty whether G. Propagation is achieved through application of in vitro microcuttings along with other tissue culture techniques. Several selections of G. These cultivated forms include ovulate trees that produce seeds attached to leaves, trees having a narrow and upright growth habit, trees with a spreading growth habit comprising exclusive horizontal branches, and an unstable form of trees having leaves striped with yellow or white.
The propagation of the cultivars is by grafting on seedling rootstocks, and nuts are produced at 5 years along with light crops in alternate years. Among propagation methods, micropropagation by cuttings and microcuttings has aided the clonal propagation of Ginkgo trees. In vitro regeneration of the ginkgo shoot is derived from embryo and cotyledon, immature zygotic embryos, apical and nodal bud explants, and rooting performed on a medium added with endosperm extract.
Addition of methyl jasmonate repressed cell growth and induced browning, with damage to G. When cultures are treated with a combination of methyl jasmonate and salicylic acid, further enhancement of the yield of the compounds occurred; the addition of precursors increased cell growth without any effect on the elicitation of triterpene lactones, but their ratio is modified. Preculture of G. Post-thaw regrowth of calli is occasional, regardless of sugar concentration in the medium, while pretreatment with ABA and sucrose ensured stable regrowth after cryopreservation, and are associated with changes in content and composition of endogenous soluble sugars in the calli.
The worldwide sales of ginkgo leaf products are difficult to estimate but believed to be worth around half a billion USD or more, and establishing plantations to cultivate the species to meet the industrial demand for ginkgo leaf raw material is a promising approach for conserving the species. Application of biotechnology through tissue culture and genetic engineering are choice approaches for conservation of the species and to meet industrial raw material demands for production of ginkgo herbal supplements.
The low yield of ginkgolides and bilobalides and the slow growth of the tree along with low yield of the compounds in undifferentiated tissue are impediments to the supply of the compounds, especially the ginkgolide B that shows promise as highly antagonist against platelet-activating factor, which is involved in the development of many respiratory, cardiovascular, renal, and central nervous system disorders.
In order to overcome existing shortcomings, the selection of high-yield genotypes, optimization of culture conditions through culture medium selection, elicitation, permeabilization, and precursor feeding will be promising. Considering the recent increase in knowledge about the metabolism and regulation of key enzymes involved in the biosynthesis of the compounds, the development of transgenic ginkgo with enhanced production of those metabolites is a serious possibility.
Phytochemical and population genetic studies are unraveling many threads of information regarding the medicinal importance and phytogeographic history of G. At present, no wild population of the species is in existence, and a program for the transfer of cultivated trees to the wild is yet to be established, but at the local levels the tree is conserved through plantation for ornamental and for religious or spiritual purposes.
It is hoped that in the future, conservation measures to restore the population of G. Special appreciation is owed to Hamdard University New Delhi for providing research facilities.
Source of Support: Nil. Conflict of Interest: None declared. National Center for Biotechnology Information , U. Journal List Pharmacogn Rev v. Pharmacogn Rev. Tasiu Isah. Author information Article notes Copyright and License information Disclaimer.
Address for correspondence: Dr. E-mail: ku. This is an open-access article distributed under the terms of the Creative Commons Attribution-Noncommercial-Share Alike 3.
This article has been cited by other articles in PMC. Abstract Ginkgo biloba G. Keywords: Bilobalides, conservation, Ginkgo biloba , ginkgolides, short shoots, triterpene lactones. Open in a separate window. Figure 1. Biology and chemistry of Ginkgo biloba. Zhou Z, Zheng S. The missing link in Ginkgo evolution. Fu-hsiung W, Zu-keng C. A contribution to the embryology of Ginkgo with a discussion of the affinity of the Ginkgoales.
Acta Bot Sin. Hasebe M. Molecular phylogeny of Ginkgo biloba : Close relationship between Ginkgo biloba and cycads. Ginkgo Biloba -A Global Treasure. Tokyo: Springer-Verlag; Del Tredici P. The architecture of Ginkgo biloba L.
In: Edelin C, editor. Montpellier, France: Naturalia Monspeliensia; Fact Sheet ST, U. Forest Service, Department of Agriculture. The Evolution, Ecology, and Cultivation of G. Ginkgo Biloba. Netherlands: Harwood Academic Publishers; Diseases of Trees and Shrubs. Cornstock Publishing Associates Ithaca. Ginkgos and insects. Mohanta TK. Advances in Ginkgo biloba research: Genomics and metabolomics perspectives. African J Biotechnol. Advances in the study of flavonoids in Ginkgo biloba leaves.
J Med Plant Res. Effects of Ginkgo biloba in dementia: Systematic review and meta-analysis. BMC Geriatr. Ginkgo biloba extract enhances glucose tolerance in hyper insulinism-induced hepatic cells. J Nat Med. Quantitative analysis of flavonol glycosides in Ginkgo biloba : A comparison of two analytical methods.
Phytochem Anal. Tralau H. The phytogeographic evolution of the genus Ginkgo L. Patients with diabetes should not use gingko without first checking with a physician. As with any medication, care is needed to prevent interactions with other drugs and other risks. Even ibuprofen combined with Gingko can increase the risk of internal bleeding. Patients with blood circulation disorders or individuals on anticoagulants, such as aspirin , are at risk of experiencing undesirable effects after taking ginkgo.
Those taking selective serotonin reuptake inhibitors SSRI as antidepressants should not take ginkgo as it inhibits monoamine oxidase, reducing the effectiveness of the medications. Combining the two may also increase the risk of a potentially fatal condition known as serotonin syndrome.
Gingko can also exaggerate both the good and bad effects of another type of antidepressant, known as monoamine oxidase inhibitors MAOIs. Ginkgo leaves contain long-chain alkylphenols, which are highly allergenic. People who are allergic to poison ivy and other plants with alkylphenols should completely avoid taking ginkgo. The National Center for Complementary and Integrative Health state that eating raw or roasted ginkgo seeds can be poisonous and may lead to serious side effects.
Introduced very early to human history, the trees were originally cultivated for consumption and as a traditional medicine. Ginkgo biloba was first used for its medicinal properties in Ancient China. The Chinese took ginkgo for its claimed cognitive benefits and to alleviate symptoms of asthma. According to the Institute for Natural Products Research, other traditional uses of ginkgo biloba include:. Engelbert Kaempfer was the first European to discover ginkgo, in the late s.
Ginkgo biloba supplements are available to purchase in many health food stores and online. Ashwagandha is a herbal treatment that people use for its medicinal properties. Learn about its uses, benefits, dosage, and possible side effects here. Natural aphrodisiacs promise to enhance our sex lives — but what does the science behind the claims say? More evidence is slowly emerging.
Given the number of medications and supplements that may interact with ginkgo, it's a good idea to consult your primary care provider before taking ginkgo. Ginkgo contains a compound called ginkgotoxin. Although ginkgotoxin is found in the largest amounts in ginkgo nuts, it's also present in small quantities in the leaves.
Structurally similar to vitamin B6, it has been found to block vitamin B6 activity. According to one case report, a woman developed generalized tonic-clonic seizure after eating large amounts of ginkgo nuts and had lowered blood vitamin B6 levels.
After treatment, which included vitamin B6 medication, her symptoms resolved and no seizures recurred. There is no established standard dose for gingko biloba. Different formulations and doses have been used in research studies investigating the herb's effect on various conditions. The right dose for you may depend on several factors, including your age, gender, medical history, and formulation used. As always, speak with your healthcare provider to get personalized advice regarding the right dose for you.
Gingko is known by many other names, including bai guo ye, yinhsing, and fossil tree. But the supplement is most popularly known as gingko biloba and you will most likely see it on store shelves labeled as such.
Many health food markets and vitamin shops sell this product. To make sure that you get the proper dose, the National Institutes of Health NIH recommends that you look for a Supplement Facts label on the product that you buy. This label will contain vital information including the amount of active ingredients per serving. You can also find out if other ingredients have been added to the product such as fillers, binders, and flavorings.
Lastly, the organization suggests that you look for a product that contains a seal of approval from a third-party organization that provides quality testing.
These organizations include U. Pharmacopeia, ConsumerLab. A seal of approval from one of these organizations does not guarantee the product's safety or effectiveness but it does provide assurance that the product was properly manufactured, contains the ingredients listed on the label, and does not contain harmful levels of contaminants. Learn the best ways to manage stress and negativity in your life.
Review of ginkgo biloba-induced toxicity, from experimental studies to human case reports. Ginkgo biloba extract for essential hypertension: a systemic review. Effects of ginkgo biloba in dementia: systematic review and meta-analysis.
BMC Geriatr. Substances of interest that support glaucoma therapy.
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