Slippery Elm
Ulmus rubra Muhl. Also known as U. fulva Michx. Family: Ulmaceae
Slippery elm , red elm , Indian elm , moose elm , sweet elm
 
Clinical Overview
Uses
Slippery elm has been used as an emollient and in lozenges. It protects irritated skin and intestinal membranes in such conditions as gout, rheumatism, cold sores, wounds, abscesses, ulcers, and toothaches.

Dosing
Slippery elm inner bark has been used for treatment of ulcers at doses of 1.5 to 3 g/day. It is commonly decocted with ethyl alcohol. No formal clinical studies support this dosage.

Contraindications
Contraindications have not yet been identified.

Pregnancy/Lactation
Documented abortifacient effects. Avoid use.

Interactions
None well documented.

Adverse Reactions
Extracts from slippery elm have caused contact dermatitis, and the pollen has been reported to be allergenic.

Toxicology
The FDA has declared slippery elm to be a safe and effective oral demulcent.

 
Botany
The genus Ulmus contains 18 species of deciduous shrubs and trees. 1
The slippery elm tree is native to eastern Canada and eastern and central United States, where it is found most commonly in the Appalachian mountains. The trunk is reddish brown with gray-white bark on the branches. The bark is rough, with vertical ridges. The slippery elm can grow to 18 to 20 meters in height. 2 In the spring, dark brown floral buds appear and open into small, clustered flowers at the branch tips. 3 White elm ( U. americana ) is a related species used in a similar manner. 2
 
History
North American Indians and early settlers used the inner bark of the slippery elm not only to build canoes, shelter, and baskets, but as a poultice or as a soothing drink. 2 , 4 , 5 Upon contact with water, the inner bark, collected in spring, yields a thick mucilage or demulcent that was used as an ointment or salve to treat urinary tract inflammation and was applied topically for cold sores and boils. A decoction of the leaves was used as a poultice to remove discoloration around blackened or bruised eyes. Surgeons during the American Revolution treated gun-shot wounds in this manner. 3 Early settlers boiled bear fat with the bark to prevent rancidity. 1 , 4 Late in the 19th century, a preparation of elm mucilage was officially recognized in the United States Pharmacopoeia. 6
 
Chemistry
Slippery elm contains carbohydrates including starches with mucilage being the major constituent. It contains hexoses, pentoses, and polyuronides. 2 , 7 The plant also has phytosterols, sesquiterpenes, calcium oxalate, cholesterol, and tannins (3% to 6.5%) as constituents. 2 , 4 , 7 Isolation and structure of a cyanidanol glycoside has been reported from related species U. americana . 8
 
Uses and Pharmacology
Slippery elm prepared as a poultice coats and protects irritated tissues such as skin or intestinal membranes. The powdered bark has been used in this manner for local application to treat gout, rheumatism, cold sores, wounds, abscesses, ulcers, and toothaches. 4 , 7 It has also been known to “draw out” toxins, boils, splinters, or other irritants. 2
Powdered bark is incorporated into lozenges to provide demulcent action (soothing to mucous membranes) in the treatment of throat irritation. 9 It is also used for its emollient and antitussive actions, to treat bronchitis and other lung afflictions, and to relieve thirst. 1 , 2 , 3 , 5 , 7
When slippery elm preparations are taken internally, they cause reflex stimulation of nerve endings in the GI tract, leading to mucus secretion. 2 This may be the reason they are effective for protection against stomach ulcers, colitis, diverticulitis, gut inflammation, and acidity. Slippery elm is also useful for diarrhea, constipation, hemorrhoids, irritable bowel syndrome, and to expel tapeworms. It also has been used to treat cystitis and urinary inflammations. 2 , 3 , 4 , 7
The plant is also used as a lubricant to ease labor, 3 , 4 as a source of nutrition for convalescence or baby food preparations, 2 and for its activity against herpes and syphilis. 4 The tannins present are known to possess astringent actions. 7
 
Administration & Dosage
Slippery elm inner bark has been used for treatment of ulcers at doses of 1.5 to 3 g/day. It is commonly decocted with ethyl alcohol. No formal clinical studies support this dosage.
 
Pregnancy/Lactation
Documented abortifacient effects. 10 Avoid use.
 
Interactions
None well documented.
 
Adverse Reactions
An oleoresin from several Ulmus species has been reported to cause contact dermatitis 6 and the pollen is allergenic. 4
 
Toxicology
The FDA has declared slippery elm to be a safe and effective oral demulcent. 5 Preparations of slippery elm had been used as abortifacients, a practice that has not remained popular. 1 , 7 Generally, there are no known problems regarding toxicity of slippery elm or its constituents. 7
 
References
 

1. Hocking G. A Dictionary of Natural Products. Medford, NJ: Plexus Publishing Inc. 1997;826-27.

 

2. Chevallier A. Encyclopedia of Medicinal Plants. New York, NY: DK Publishing. 1996;144.

 

3. Low T, et al, eds. Magic and Medicine of Plants. Surry Hils, NSW:Reader's Digest Assoc. Inc. 1994;385.

 

4. Duke J. CRC Handbook or Medicinal Herbs. Boca Raton, FL: CRC Press, Inc. 1989;495-96.

 

5. Tyler V. Herbs of Choice, The Therapeutic Use of Phytomedicinals. Binghamton, NY: Pharmaceutical Products Press. 1994;93,94.

 

6. Lewis W, Elvin-Lewis MPF. Medical Botany. New York, NY: J. Wiley and Sons, 1977.

 

7. Newall C, et al. Herbal Medicines. London, England: Pharmaceutical Press. 1996;248.

 

8. Langhammer I. Isolation and structure of a rarely occurring cyanidanol glycoside from Cortex betulae . Planta Medica 1983 Nov;49:181-82.  PubMed

 

9. Morton J. Major Medicinal Plants. Springfield, IL: C.C. Thomas, 1977.

 

10. Rotblatt M, Ziment I. Evidence-Based Herbal Medicine . Philadelphia, PA: Hanley & Belfus; 2002.