Rhubarb

Scientific Name(s): Rheum officinale Baillon, Rheum palmatum L., Rheum rhabarbarum L.
Common Name(s): Bo ye da huang, Chinese rhubarb, Da-huang, Danning Pian, Number Ten, Radix et rhizoma rhei, Rhaptonic, Rheum, Rhubarb, Ta-huang, Turkey rhubarb

Medically reviewed by Drugs.com. Last updated on May 13, 2022.

Clinical Overview

Use

Rhubarb is extensively used in traditional Chinese medicine. Rhubarb has been studied for the management of GI and renal function disorders, and for the treatment of hyperlipidemia, cancer, and acute ischemic stroke. However, sound clinical evidence for its use is lacking.

Dosing

Dried rhubarb extract 20 to 50 mg/kg daily has been used in clinical trials.

Contraindications

Contraindications have not been identified.

Pregnancy/Lactation

Avoid dosages higher than those found in food because safety and efficacy are unproven.

Interactions

Interaction with cardiac glycosides (digoxin) and a reduction in the absorption of orally administered drugs have been noted when rhubarb is taken in large quantities.

Adverse Reactions

A few reactions, primarily GI effects, have been reported in clinical trials.

Toxicology

The leaf blades (but not the stalks) of rhubarb contain enough oxalic acid to cause poisoning. Acute renal failure has been associated with long-term anthraquinone use.

Scientific Family

• Polygonaceae (Buckwheat family)

Botany

Rhubarb is derived from several Rheum species. The perennial herb has a conical rootstock, that is fleshy and yellow inside and produces large, cordate, 7-lobed leaves 30 to 46 cm long. The blade or green leaves of the plant are often considered the most poisonous due to high oxalic acid concentration; however, other chemical constituents of the plant are also toxic. The edible stalks are up to 45 cm long and 2.5 to 5 cm in diameter, and are used in pies, jams, jellies, sauces, and juices.1, 2

Medicinal rhubarb consists of the dried rhizome and root of R. officinale Baillon or R. palmatum, of related species/hybrids grown in China (Chinese rhubarb), or of Rheum emodi or Rheum webbianum native to India, Pakistan, or Nepal (Indian rhubarb).3

History

Rhubarb was first recorded and rated as one of the inferior remedies in the oldest Chinese herbal books, from 22 to 250 AD.4 In the 1780s, the active constituents responsible for the root's cathartic action and astringency were still unknown. Initially, researchers learned that the medicinal root came from several varieties or species of rhubarb. By the end of the 19th century, it became clear that the particular medicinal characteristics of rhubarb were affected by conditions under which the roots grew, such as soil composition and climate.5

Rhubarb has been used medicinally in Europe since the 13th century. The herb was brought from the eastern Mediterranean by way of the Silk Road, which stretches from China across central Asia. The first reported sighting of the plant in situ was in the mountains of Bulgaria. In 1731, a rhubarb commission was set up at the Mongolian border to import the best possible root at a fixed price. At the same time, the British East India Company secured their positions in Chinese ports. Both companies supplied Europe with rhubarb.5

In the 1830s and 1840s, the cooked stems of rhubarb emerged as a culinary delight, especially in Britain and the United States.5, 6

Chemistry

The Rheum species contains a numb...