The Ginkgo Biloba; (Ginkgo is derived from the Japanese word ginkyo, meaning “silver apricot”, referring to the fruit, which is eaten in Japan; and biloba, translates as “two-lobed”, referring to the split-in-the-middle character of its fan-shaped leaf blades., frequently misspelled as “Gingko”, and also known as the Maidenhair Tree, is a unique tree with no close living relatives. It is classified in its own division, the Ginkgophyta, comprising the single class Ginkgoopsida, order Ginkgoales, family Ginkgoaceae, genus Ginkgo and is the only extant species within this group. It is one of the best known examples of a living fossil. In the past it has also been placed in the divisions Spermatophyta or Pinophyta. Ginkgo is a gymnosperm: its seeds are not protected by an ovary wall. The apricot-like structures produced by female ginkgo trees are technically not fruits, but are the seeds having a shell that consists of a soft and fleshy section (the sarcotesta), and a hard section (the sclerotesta).
For centuries it was thought to be extinct in the wild, but is now known to grow wild in at least two small areas in Zhejiang province in eastern China, in the Tian Mu Shan Reserve. However, as this area has known human activity for over a thousand years, the wild status of ginkgos there is uncertain.

Medicinal History

The seeds (baigo) are most used in Traditional Chinese Medicine, the leaves in western medicine.
In Japan the seeds are called ginnan. The Japanese way of using Ginkgo as a medicine originates from the Chinese tradition.

The seeds’ medicinal use is mentioned in the ‘Great Herbal’ Pen Tsao Kang Mu compiled by Li Shih-chen (1578) which in still in use in TCM.
Dr. C.A. Stuart and Dr. F. Porter Smith translated and researched this herbal and used it as a working base for their publication of ‘Chinese Medicinal Herbs’ (1911).
In their work they write: “The seeds are supposed to benefit asthma, coughs, irritability of the bladder, blenorrhoa and uterine fluxes.
Eaten raw they destroy cancer and are counter-vinous. Cooked they are said to be peptic and anthelmintic, and are similarly used by the Japanese to promote digestion.
In some cases they appear to cause peculiar symptoms of intoxication.”
They also mention the use of the wood for seals used as charms by quacks in the treatment of disease.
Kaempfer mentions the seeds as an aid for digestion and bladder. Thunberg writes in Flora Japonica (1784) that the seeds are eaten raw or roasted in Japan and in 1819 Franz von Jaquin notes in ‘Ueber den Ginkgo’ the use as a digestive aid.

The earliest record of the use of the leaves as a medicine is said to be mentioned in the Chinese Materia Medica Shen Nung Pen Tsao Ching (which should originate from about 2800 BC or from the Han dynasty [206BC-220AD]) as an aid for blood circulation and the lungs. This record cannot be confirmed however because the original of this work has never been found.
Dian Nan Ben Cao (Lan Mao) (1436) mentions the use of the leaves for skintreatment, head sores and freckles. They are also used for chilblains and as a wound plaster.
The internal use is first mentioned in the Ben Cao Pin Hui Jing Yao (1505) by Liu Wen-Tai as used against diarrhea.
In 1932 the Japanese Furukawa isolated the ginkgolidesfor the first time, which were further investigated for their chemical structure by Nakanishi in 1966.

The tree that survived Hiroshima

At the end of World War II on August 6th 1945 an atomic bomb was dropped on Hiroshima by the Americans. The plants and trees in the area around the epicentre were examined in September 1945.
The Ginkgo situated near a temple about 1.1 km away from the blast center appeared to bud after the blast without any major deformations (the temple itself was destroyed). The temple-site in Housenbou was smaller after the war and they considered transplanting or cutting down the Ginkgo to rebuild the temple. In 1994 it was decided to leave it there and adjust the temple to it, so now the main building has stairs in front divided into left-and right hand sides, protecting the Ginkgo inside this U-shape.
Engraved on it “No more Hiroshima” and people’s prayers for peace.
Four atomic bombed Ginkgo trees are still alive.

Cultivation and uses

The Ginkgo has the intriguing distinction of being one of the world’s most urban-tolerant trees, often growing where other trees cannot survive. Some claim that only one tree species, the Tree-of-heaven, is as urban-tolerant. Ginkgos rarely suffer disease problems, even in urban conditions, and are attacked by few insects. For this reason, and for their general beauty, ginkgos are excellent urban and shade trees, and are widely planted along many streets. The ginkgo is the official tree of the city of Kumamoto, and two leaves form the symbol of the University of Tokyo, the main campus of which is famous for its numerous ginkgos.
Ginkgos are also popular subjects for growing as penjing and bonsai; they can be kept artificially small and tended over centuries. Furthermore, the trees are easy to propagate from seed.

Culinary use

The nut-like gametophytes inside the seeds are esteemed in and outside of Asia, and are a traditional Chinese food. Called yín xìng (literally “silver apricot”) or bái guó (literally “white fruit”), Ginkgo nuts are used in congee, and are often served at special occasions such as weddings and the Chinese New Year (as part of the vegetarian dish called Buddha’s delight). In Chinese culture, they are believed to have health benefits; some also consider them to have aphrodisiac qualities. Japanese cooks add Ginkgo seeds to dishes such as chawanmushi, and cooked seeds are often eaten along with other dishes. The seeds are available canned, sold as “White Nuts”, and can be found in many Asian food stores in the West. Usually only a few are added for a portion enough for ten people.
When eaten by children, in large quantities (over 5 seeds a day), or over a long period of time, the raw gametophyte (meat) of the seed can cause poisoning by MPN (4-methoxypyridoxine). MPN is heat-stable. Studies have demonstrated that convulsions caused by MPN can be prevented or terminated with pyridoxine.
Some people are sensitive to the chemicals in the sarcotesta, the outer fleshy coating. These people should handle the seeds with care when preparing the seeds for consumption, wearing disposable gloves. The symptoms are dermatitis or blisters similar to that caused by contact with poison-ivy. However, seeds with the fleshy coating removed are perfectly safe to handle.

Ornamental use

Most Ginkgos live as ornamental trees, specimen are planted in many parts of the world, it is nearly cosmopolitan.
It is used as a landcape tree because it is picturesque, has an unusual shape of the crown, provides shade and gives a bold accent. In average sized landscapes it may become too large, therefore several varieties are available, incl. columnar types, with finer growth habit, better fall colour etc. (see also on my page The tree).
Smaller selections can also be planted in gardens.
Due to its natural resistance to diseases, insects, air pollution, fire and even radioactive radiation it is also used as a street tree in cities and urban areas. It is also planted in parks and along boulevards because of its unique form and yellow leaf colour in fall. For instance in Japan many are planted in parks and along avenues, esp. in Tokyo.
However so far not many are used as a roadside tree in the USA and Europe.
Mostly male trees are planted in cities because of the smell the female seeds produce when fallen on the ground and decaying.

Medical use

Ginkgo seeds have been used in traditional Chinese medicine for thousands of years, and cooked seeds are occasionally eaten. More recently, ginkgo leaf extract has been used to treat a variety of ailments and conditions, including asthma, bronchitis, fatigue, and tinnitus (ringing in the ears).
Today, people use ginkgo leaf extracts hoping to improve memory; to treat or help prevent Alzheimer’s disease and other types of dementia; to decrease intermittent claudication (leg pain caused by narrowing arteries); and to treat sexual dysfunction, multiple sclerosis, tinnitus, and other health conditions.

How It Is Used

Extracts are usually taken from the ginkgo leaf and are used to make tablets, capsules, or teas. Occasionally, ginkgo extracts are used in skin products.

What Science Says

  • Numerous studies of ginkgo have been done for a variety of conditions. Some promising results have been seen for Alzheimer’s disease/dementia, intermittent claudication, and tinnitus among others, but larger, well-designed research studies are needed.
  • Some smaller studies for memory enhancement have had promising results, but a trial sponsored by the National Institute on Aging of more than 200 healthy adults over age 60 found that ginkgo taken for 6 weeks did not improve memory.
  • NCCAM is conducting a large clinical trial of ginkgo with more than 3,000 volunteers. The aim is to see if the herb prevents the onset of dementia and, specifically, Alzheimer’s disease; slows cognitive decline and functional disability (for example, inability to prepare meals); reduces the incidence of cardiovascular disease; and decreases the rate of premature death.
  • Ginkgo is also being studied by NCCAM for asthma, symptoms of multiple sclerosis, vascular function (intermittent claudication), cognitive decline, sexual dysfunction due to antidepressants, and insulin resistance. NCCAM is also looking at potential interactions between ginkgo and prescription drugs.

Side effects

Ginkgo may have some undesirable effects, especially for individuals with blood circulation disorders and those taking anti-coagulants such as aspirin and warfarin, although recent studies have found that ginkgo has little or no effect on the anticoagulant properties or pharmacodynamics of warfarin. Ginkgo should also not be used by people who are taking monoamine oxidase inhibitors (MAOI) or by pregnant women without first consulting a doctor.
Ginkgo side effects and cautions include: possible increased risk of bleeding, gastrointestinal discomfort, nausea, vomiting, diarrhea, headaches, dizziness, and restlessness. If any side effects are experienced, consumption should be halted immediately.Sources: wikipedia, xs4all.nl, nih.gov

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