Synonymy: It is also sometimes known as “Gutta-percha tree” or “Chinese rubber tree“, but is not related to either the true Gutta-percha tree of southeastern Asia, nor to the South American rubber tree.
Habitat:Eucommia is native to China.This tree is also occasionally planted in botanical gardens and other gardens in Europe, North America and elsewhere, being of interest as the only cold-tolerant (to at least -30°C) rubber-producing tree.
Fossils of Eucommia have been found in 10–35 million year old brown coal deposits in central Europe and widely in North America (Call & Dilcher 1997), indicating that the genus had a much wider range in the past.
Eucommia grows to about 15 m tall. The leaves are deciduous, arranged alternately, simple ovate with an acuminate tip, 8–16 cm long, and with a serrated margin. If a leaf is torn across, strands of latex exuded from the leaf veins solidify into rubber and hold the two parts of the leaf together. It flowers from March to May. The flowers are inconspicuous, small and greenish; the fruit, June to November, is a winged samara with one seed, very similar to an elm samara in appearance, 2–3 cm long and 1–2 cm broad.
The bark is used in traditional Chinese medicine to treat lower back pain, aching knees, and to prevent miscarriage. Also used to “tonify” the Yang.
MODERN USES OF EUCOMMIA
More than 50 years ago, eucommia was shown to have hypotensive action in laboratory studies conducted in the Soviet Union and China, and there was already some initial clinical use of the herb for this purpose. In fact, a formula with eucommia and other hypotensive Chinese herbs was developed at that time: Tianma Gouteng Yin (Gastrodia and Uncaria Combination). It was described in New Approaches to Patterns and Treatments in Complex Diseases (a text relaying research conducted during the 1950s). This formula has since become well-known as a treatment for hypertension. Additional studies were undertaken since then, mainly in China, and the primary hypotensive constituent was identified as pinoresinol diglucoside, one of 27 lignans found in eucommia .
This component, also found in the Chinese herb forsythia, is present in eucommia bark in only small concentrations. However, it has a significant dilating effect on the blood vessels. The herb and its extracts are now commonly found in Chinese patent remedies for hypertension , but this component is not alcohol soluble and is not useful in tinctures. Compound Cortex Eucommia Tablets are sold as a hypertension remedy and the package lists eucommia as the prime ingredient (others mentioned on the label are uncaria, prunella, and scute, all of which are attributed antihypertensive properties). During an evaluation of potential anti-hypertensive Chinese herbs that could be clinically tested in the U.S., ITM developed a six herb formulation with the four herbs just mentioned (eucommia, uncaria, prunella, and scute) plus loranthus and tang-kuei.
Aucubin and the other iridoids of eucommia are likely responsible for the anti-inflammatory effect, which is attained by inhibiting the arachidonic acid pathway . This may partly explain its use in treatment of arthritis. Rehmannia, which also contains iridoid glycosides (including aucubin) as major active components, is often used with eucommia in the formulas for arthralgia.
It has been found that eucommia leaves can substitute for the bark, and hence these are increasingly used in China in order to get a larger amount of the desired medicinal agents from the limited cultivated groves. Eucommia leaves have also been made into a health beverage .
The information presented herein is intended for educational purposes only. Individual results may vary, and before using any supplements, it is always advisable to consult with your own health care provider.