Yellow dock

Other common name
Curled dock

Botanical name
Rumex crispus

Native habitat
Europe, Africa

Plant parts used
Root

Common uses
Root traditionally used to treat skin disorders (including psoriasis), rheumatism, jaundice, scurvy, constipation, bleeding of lungs, inflammation of nasal passages and respiratory tract; and as general tonic and blood cleanser. This plant is not used in foods..Yellow dock is a botanical relative of sheep's sorrel (Rumex acetosella), one of the chief ingredients in the Essiac formula, a folk anti-cancer therapy. It is believed to minimize the debitating effects of cancer and cancer treatments.

Active compounds
Root contains anthraquinones/antracene derivatives (aglycones of chrysophanol, emodin, aloe-emodin, rhein, physician plus their glycosides), naphthalene derivatives (e.g., neopodin, lapodin), and tannins (catechol)); other plant parts contain oxalic acid, oxalates, chrysophanic acid, emodin, tannin, complex essential oil.

Forms available
Available as liquid extract and capsules of ground powder.

Customary dose
Dried root: 3-4 g or by decoction 3 times a day.
Liquid extract (1:1 in 25% alcohol): 2-4 ml 3 times a day.
Tincture (1:5 in 45% alcohol): 1-2 ml 3 items a day

Side effects
Excessive use of yellow dock may lead to laxative-like side effects such as stomach cramping and diarrhea. Yellow dock also contains oxalic acid, an acidic phytochemical. Oxalic acid reportedly can interfere with normal calcium levels in the blood, leading to complications with blood coagulation. Yellow dock has caused dermatitis in livestock that have eaten it. There have been several cases of animal deaths from oxalate poisoning.

How it may work
Rhein, one of the active compounds in Rumex crispus, has shown antitumor activity in mice.

Evidence for effectiveness
Yellow dock is a source of emodin and rhein, two phytochemicals with known anti-tumor activity in laboratory animals. These plant compounds are also found in several herbs in the Hoxsey and Essiac formulas. The Hoxsey formula contains wild indigo, burdock root, licorice, Oregon grape root, cascara sagrada, buckthorn, poke root, and prickly ash. The main herbs in the Essiac formula include burdock root, Indian rhubarb, sheep's sorrel, and slippery elm bark. Sheep's sorrel, Rumex acetosa, is a botanical relative of yellow dock.

References:

Dickie CW; Hamann MH; Carroll WD; Chow F. Oxalate (Rumex venosus) poisoning in cattle. J Am Vet Med Assoc. 1978. 173(1):73-4.

Gladstar R. Herbal Healing for Women. 1993. New York: Fireside.

Grieve. M. A Modern Herbal. Vol. I. New York: Dover 1971

Gruenwald, J; Brendler, T; Christof, J. PDR for Herbal Medicines. Montvale, NJ:Medical Economics Company 1998

Ito H. Effects of the antitumor agents from various natural sources on drug-metabolizing system, phagocytic activity and complement system in sarcoma 180-bearing mice. Jpn J Pharmacol. 1986. 40(3):435-43.

Newall, C; Anderson, L; Phillipson, J. Herbal Medicines: A Guide for Health-care Professionals. London: Pharmaceutical Press 1996

Panciera RJ; Martin T; Burrows GE; Taylor DS; Rice LE. Acute oxalate poisoning attributable to ingestion of curly dock (Rumex crispus) in sheep. J Am Vet Med Assoc. 1990. 196(12):1981-4.