American elm, Indian elm, moose elm, red elm, sweet elm, winged elm
Botanical Name / Family
Ulmus fulvus or Ulmus rubra (family Ulmaceae)
According to current botanical nomenclature, it should now be referred to as Ulmus rubra.
Plant Part Used
Dried inner bark
The dried inner bark of the slippery elm tree was a popular remedy used by many Native American tribes, and subsequently taken up by European settlers. It was mixed with water and applied topically to treat wounds, bruises and skin irritations, and used internally for sore throat, coughs and gastrointestinal conditions. When mixed with milk, it was used as a nutritious gruel for children and convalescents. It also gained a reputation as an effective wound healer among soldiers during the American Civil War. From 1820 until 1960 it was listed in the US Pharmacopeia as a demulcent, emollient and antitussive. The name ‘slippery elm’ refers to the slippery consistency of the inner bark when it comes into contact with water.
The inner bark chiefly contains mucilage (various hexoses, pentoses, methylpentoses), glucose, polyuronides, tannins, galacturonicacid, L-rhamnose, D-galactose, starches, fat, phytosterols, sesquiterpenes, and cholesterol (US Department of Agriculture Phytochemical Database 2003). The bark provides 2740 kilocalories per kilogram. It contains a variety of nutritional factors such as glucose, calcium, iron, vitamin C, thiamin, zinc, magnesium and potassium, providing support for its traditional use as a nutritious gruel.
Clinical note— Mucilages
Mucilages are hydrophilic structures, capable of trapping water, which causes them to swell in size and develop a gel-like consistency. The gels tend to have soothing properties and can be broken down by bowel flora when taken internally (Mills & Bone 2000). Mucilages are known to have beneficial effects on burns, wounds and ulcers when applied externally and on gastric inflammation, irritations and diarrhea when taken internally.
Slippery elm: Main Actions
The pharmacological actions of slippery elm have not been significantly investigated in clinical studies. Therefore, information is generally based on what is known about key constituents found within the herb.
SOOTHES IRRITATED AND INFLAMED TISSUE
The large amount of mucilage found in slippery elm bark will coat the surface of mucous membranes or wounds and sores when it comes in contact with water, and form a gel-like layer. Laboratory research has shown that mucilaginous medicinal plants, such as slippery elm, can decrease local irritation in acute gastritis.
A number of constituents, such as starch, glucose, calcium, iron, vitamin C, thiamine, zinc, magnesium and potassium are present in slippery elm, making it a source of many nutritional factors.
In vitro studies show a free radical scavenging activity that may relate to its anti-inflammatory action.