Du Zhong

Scientific Name(s): Eucommia ulmoides Oliv.
Common Name(s): Du zhong (Chinese), Tochu (Japanese)

Medically reviewed by Drugs.com. Last updated on Dec 9, 2021.

Clinical Overview

Use

The medical literature includes numerous studies on the use of Eucommia ulmoides (du zhong) for treating diabetes, inflammation, and obesity. One clinical study exists for its use in treating hypertension.

Dosing

E. ulmoides is commercially available as a combination product or alone as a capsule, tablet, powder, or tea, primarily for treating hypertension. Tablets: 3 to 5 (100 mg) tablets 3 times per day with warm water after meals. One clinical study used a 500 mg standardized extract 3 times daily for 8 weeks.

Contraindications

Avoid use in patients who are hypersensitive to any components of E. ulmoides. The herb may be contraindicated in patients diagnosed with estrogen-dependent cancers.

Pregnancy/Lactation

Information regarding safety and efficacy in pregnancy and lactation is lacking.

Interactions

None well documented.

Adverse Reactions

One clinical study of E. ulmoides documented moderately severe headache, dizziness, edema, and onset of a cold.

Toxicology

No information in humans is available.

Scientific Family

• Eucommiaceae

Botany

E. ulmoides is native to China and is the only species of Eucommiaceae. It is a deciduous and dioecious woody species distributed throughout the valleys, hills, and mountains of central and eastern China, growing to 10 to 15 m in height. The oval-shaped leaves are 8 to 16 cm long, arranged alternately with a serrated margin. The plant’s small, green flowers are typically in bloom from March to May, and the fruits ripen between June and November.1, 2, 3

History

Use of the plant in traditional Chinese medicine began as early as 2,000 years ago.1 The plant's bark and leaves contain the lignan pinoresinol diglucoside, which has potent antihypertensive properties. In folk medicine, the dried and heated outer portion of the stem has been used for supporting muscle and lung function, lowering blood pressure, preventing miscarriages, improving the tone of the liver and kidneys, and increasing longevity.4, 5 The leaves have been used in foods. An aqueous leaf extract known as du zhong tea is popular in China and Japan for treating hypertension and improving health. In traditional Chinese medicine, the seed oil is commonly used to treat hypertension, rheumatoid arthritis, back pain in the lumbar region, and hip pain.6

The whole plant, except the transport tissue xylem, contains an isomer of natural rubber (Eucommia rubber) that is of high economic value and used as a raw material in the organic chemical industry. Commercial cultivation of E. ulmoides started in the 1980s, and utilization and overexploitation have threatened the existence of the species in the wild.1, 2, 7

Chemistry

E. ulmoides produces more than 30 active compounds in its bark and leaves.3 More than 70 components have been identified in E. ulmoides.8

The dominant fatty acid components in E. ulmoides seed oil are linolenic (57%), linolelaidic (13%), oleic (16%), palmitic (10%), and stearic (4%) acid. The percentage of polyunsaturated fatty acids in the seed oil is 70% and the fraction of monounsaturated versus saturated fatty acids is 17% and 13%, respectively.6