Hawkes Nature: Gingko

Hawkes Nature: Gingko

One of the most commonly planted trees in cities worldwide, Ginkgo is seen by millions daily, serving a key role in connecting people to the natural world. When overlanding, you are sure to come across Gingko but did you know these trees, with their golden fan-shaped leaves, are some of the most medical and widely researched in the world?

Three fun facts about Gingko: 

  1. The ginkgo biloba tree can grow for thousands of years. A gingko tree found in China is said to be over 3,500 years old.
  2. The fruits mature after autumn and smell of rancid butter during the ripening process.
  3. The leaves are used as bookmarks, as they are known to protect the books from silverfish and booklice as the leaves contain chemical properties against pests.

A free Gingko monograph for Hawkes Journal readers.

Common name
GINKGO

Scientific name
Ginkgo biloba L.

Family 

Kingdom: Plantae

Order: Ginkgoales

Family: Ginkgoaceae

Genus: Ginkgo L. – ginkgo

Non-scientific names

银杏 (Yínxìng), イチョウ (Ichou), Bai Gou, Fossil tree, Ginkgo, Ginkyo, Japanese silver apricot, Kew tree, Maidenhair tree, Temple tree.

Description and habitat

Perhaps the world’s most distinctive tree, Ginkgo stands out by virtue of its unique foliage, foul smelling ‘fruit’ and long association with vitality. It is one of the world’s oldest living plant species. Native to China, Ginkgo remains stubbornly unchanged, often referred to as a ‘living fossil’. With origins stretching back 270 million years, Ginkgo is a monotypic dioecious plant with no close relatives. Ginkgos can reach 50 meters in height with trunks of up to 7 meters, and survive over 2,500 years. The grey bark is fissured, while its unique fan-shaped leaves are akin to cerebral hemispheres, with parallel venation and a blade length of 5–20 cm. During autumn the leaves turn golden and can drop all at once. 

Wild Ginkgos are rare, and listed as endangered in the IUCN red list of threatened species.

Cultivation or wild crafting

Grown from seeds or cuttings worldwide. 

The oldest wild Ginkgos are found near Taoist and Buddhist temples in China and are thought to have played a significant role in the preservation and propagation of the species. Ginkgo was introduced to Japan from China approximately 800 years ago, appearing in Europe at the botanical garden in Utrecht, Netherlands in 1740 and Kew Gardens, London in 1754. 

Parts and form used

Western: Leaves.
TCM: Seed (respiratory complaints e.g., asthma).

Harvest, drying and storing

Leaves should be harvested in the autumn as they turn yellow, when the medicine is at its peak.

Harvest: Mild day, after the morning dew has evaporated and before the heat of the sun. If handled gently, the robust leaves are ideal for drying.

Active drying: Dehydrator 42°C/108° for 12 hours or longer, depending on moisture in the stems. Ensure the leaves and stems are thoroughly dried before storing in an airtight container away from direct sunlight. 

Active constituents

  • Diterpene lactones (Ginkgolides A, B, C and J).
  • Sesquiterpene lactone (bilobalides).
  • Flavonol glycosides (flavone glycosides, including ginkgetin, quercetin and kaempferol).

Flavonoids generally are cancer preventative, anti-aging, and cardio-protective. In Ginkgo they increase oxygen and glucose utilisation and blood flow, resulting in tissue oxygenation and a reduction in inflammation, especially in the cerebral and cardiovascular blood vessels.

With hundreds of clinical studies on Ginkgo, we can conclude the total extract with the constituents working synergistically provides more therapeutic value compared to isolated single components. Other unknown compounds yet undiscovered are likely to play a part in the therapeutic effects. 

Actions, indications and applications

  • Antiallergenic
  • Antiasthmatic 
  • Antiinflammatory
  • Antiplatelet
  • Antioxidant
  • Antispasmodic 
  • Antithrombotic
  • Astringent
  • Bitter
  • Boosts energy 
  • Circulatory tonic
  • Diuretic
  • Improves cognitive function
  • Increases microcirculation
  • Neuroprotective
  • Nutritive
  • PAF-antagonist
  • Peripheral vasodilator
  • Relaxant

Toxicity and safety considerations

Ginkgo is included on the General Sale List in the UK and is generally a safe and well tolerated plant medicine. 

Contraindications

  • Hypersensitivity, in particular to ginkgolic acid. 
  • Patients with coagulant disorders and taking anticoagulant and/or antiplatelet medication. 
  • Treatment should be stopped at least 36 hours before planned surgery.
  • In pregnancy and lactation, there are no adequate studies so it is not recommended.

Undesirable effects

  • Headaches have been reported when used for the treatment of dementia.
  • In large doses may cause vitamin B6 deficiency.

Preparations

Dried leaves are most commonly used to prepare medicine but fresh can also be used. 

  • Standardised extract and tincture 55-70% alcohol. 
  • Capsules and tablets. 
  • Infusions.

Dosage and duration of use

Standardised extract is preferred to ensure active constituents (24% ginkgo flavone glycosides and approx. 6% terpenoids).

Adults

  • Standardised extract (50:1) 40-60mg TDS 
  • Standard liquid extract 1-4ml (2:1) TDS 
  • Dried leaves 6-8g 

Infusion: 2-4g/ 200ml hot water, infuse 15-30mins, TDS. 


Folklore

Ginkgo as a phytomedicine was introduced into Western herbal practice in Germany in 1965, and has since become one of the world’s most commonly used over-the-counter herbal preparations. 

Ginkgo is admired for its ability to thrive in brutal surroundings. Famously, the Ginkgos at Hiroshima survived the blast of the first atomic bomb, becoming a symbol of endurance and hope in the midst of adversity. 

Organoleptic properties: Ginkgo leaves have a subtle characteristic odour and taste mildly bitter.

Summary

Ginkgo has a wide range of applications but is perhaps most widely known for treating cerebrovascular insufficiency and cardiovascular disease. A question mark remains regarding actual contraindications. The European Medicine Agency advises caution in patients taking anticoagulants and antiplatelet medications, amongst others. However, it is rare for drug interactions to be reported. One of the most commonly planted trees in cities worldwide, Ginkgo is seen by millions daily, serving a key role in connecting people to the natural world. Ginkgo should not be reduced to its long list of therapeutic benefits, as perhaps its greatest gift lies in reminding us of our connection to the past, to nature, and to ourselves.

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