Comfrey

Symphytum officinale

Ass-ear Blackwort Bruisewort Comfrey Consormol Knitback Knitbone Parts used Uses Habitat and cultivation Research Constituents How much to take How it works in the body Applications Reconstituting ointment

Comfrey is used in folk medicine in the form of an externally applied poultice for healing wounds. Comfrey is also taken internally as a tea or blended plant extract (so-called green drink) to heal stomach ulcers and to act as a "blood purifier". Less restrained advocates preach its virtue in treating cuts and wounds, burns, respiratory ailments of the lungs and bronchial passages, and ulcers of the bowels, stomach, liver, and gallbladder. It is even said to facilitate the healing of broken bones, but this almost certainly comes from a misunderstanding of one of the common names of the plant, knitbone. It may have once been used to reduce the swelling and inflammation around a broken bone, but not to heal the bone itself.

Whatever healing properties comfrey may have are probably caused by its content of allantoin, an agent that promotes cell proliferation. Quantities of tannin and mucilage are also present. The underground parts contain 0.6 to 0.7 percent allantoin and 4 to 6.5 percent tannin; the leaves are poorer in allantoin, containing only about 0.3 percent, but richer in tannin, 8 to 9 percent. Large amounts of mucilage are present in both roots and leaves. Much has been made of the vitamin B12 content of comfrey, but compared to the more customary natural source, liver, the concentration in the plant is not especially high.

Although comfrey has been one of the most common herbs sold to the American public over the past thirty years, there is reason to believe that using comfrey internally is definitely hazardous to the health. All comfrey species investigated have been found to contain hepatotoxic pyrrolizidine alkaloids (PAs), but the literature on the subject is confused due to a glaring lack of attention to proper botanical identification of the various Symphytum species studied. Common comfrey contains principally 7-acetylintermedine and 7-acetylly-copsamine in addition to their unacetylated precursors and symphytine. It does not contain high levels of echimidine, probably the most toxic comfrey PA. Echimidine has been identified, along with symphytine and six other PAs, in Russian comfrey. Russian comfrey was heavily promoted in the back-to-the-land movement, and most of the comfrey cultivated in home gardens is the Russian hybrid. The former alkaloid is also present in prickly comfrey. Comfrey root contains about ten times the concentration of PAs found in the leaves.

Using echimidine as a marker, it becomes relatively easy to determine if samples of common comfrey are properly labeled. A Canadian study of thirteen commercial samples labeled either "comfrey" or "comfrey/Symphytum officinale" revealed that six of them contained echimidine and were therefore probably not derived from common comfrey (S. officinale) but from prickly comfrey (S. asperurn) or Russian comfrey (S. x uplandicum). Products containing echimidine are barred from sale in Canada for medicinal purposes, but, lacking chemical analysis, this cannot be determined accurately because the commercial labeling is so unreliable. However, the specific prohibition against echimidine products should not cause anyone to underestimate the potential danger of common comfrey that does contain other hepatotoxic PAs. All comfrey root-containing products are no longer acceptable in Canada.

Comfrey is the prime first aid remedy. When applied to the skin allantoin diffuses easily into the underlying tissues so that when applied over a fractured bone it can accelerate healing and closure. Applied fresh to wounds, sores or ulcers, the mucilage in the roots or leaves seeps out onto the injured skin, dries and then thickens and contracts, drawing the sides of the wound together, inhibiting infection. Where the wound is fairly superficial comfrey will heal the skin with little scarring.

A poultice or ointment can be used for bruises, sprains and strains, gout, arthritis, bleeding piles, varicose veins, phlebitis, and ulcers, swellings and burns. A decoction of the root or infusion of the leaves makes a good eyewash for sore, inflamed eyes and a wash for skin problems such as psoriasis, eczema, acne, and boils.

The leaves have healing properties and a particular affinity with the respiratory, digestive and urinary systems. Comfrey is used for sore throats and laryngitis, as a soothing expectorant for dry coughs, pleurisy and bronchitis. In the gut comfrey soothes and heals gastritis, gastric and duodenal ulcers and can be used to reduce irritation causing diarrhea, dysentery and ulcerative colitis. In the urinary system comfrey relaxes urinary spasm, soothes cystitis and clears irritation and infection. Comfrey is taken for gout and arthritis, as well as other painful or inflamed conditions such as tendinitis, sprains, and fractures.

PARTS USED

Aerial parts, root.

USES

Past uses - Comfrey has been used to treat stomach ulcers, irritable bowel syndrome, and a range of respiratory conditions, including bronchitis and pleurisy.
Injuries - Comfrey's ability to promote the healing of bruises, sprains, fractures, and broken bones has been known for thousands of years. Comfrey encourages ligaments and bones to knit together firmly. A comfrey compress applied immediately to a sprained ankle can significantly reduce the severity of the injury. The combination of tannins, and mucilage helps to soothe bruises and scrapes.
Skin problems - Comfrey oil or ointment is used to treat acne and boils and to relieve psoriasis. Comfrey is also valuable in the treatment of scars.
Other medical uses - Hantavirus, Housemaid's knee.

HABITAT AND CULTIVATION

An indigenous European plant, comfrey grows in all temperate regions of the world, including western Asia, North America, and Australia. Comfrey thrives in moist, marshy places. Comfrey can be grown from seed in spring or by root division in autumn, and the leaves and flowering tops are harvested in summer. The root is unearthed in autumn.

RESEARCH

Allantoin - Comfrey contains allantoin, a cell-proliferant that helps repair damaged tissue.
Rosmarinic acid - Comfrey has a significant anti-inflammatory action, partly due to the presence of rosmarinic acid and other phenolic acids.
Pyrrolizidine alkaloids - Research shows that, as isolated substances, the pyrrolizidine alkaloids are highly toxic to the liver. It is still unclear whether they are toxic in the context of the whole plant, as they are only present in minute amounts, often being completely absent from samples of dried aerial parts. The highest concentration is in the root and, until its safety is confirmed (or denied), comfrey root should not be used internally. (The aerial parts are considered safe.) The legitimate question mark over comfrey's safety as a medicine needs to be balanced by a deeper understanding of its therapeutic properties.

CONSTITUENTS

• Allantoin (up to 4.7%)
• Mucilage (about 29%)
• Triterpenoids
• Phenolic acids (rosmarinic acid)
• Asparagine
• Pyrrolizidine alkaloids(0.02-0.07%)
• Tannins

HOW MUCH TO TAKE

The leaf may be made as a tincture, and used under the direction of a herbal or medical practitioner for the purpose of healing stomach ulcers and other disorders, and in the respiratory system for conditions such as bronchitis. The leaf may also be made as a poultice or compress, and applied to sprains or bruised areas. It is also possible to make an infused oil from the leaf, which may be applied to the skin over an area where fractures or a break in the bone has occurred, and to scar tissue. Comfrey infused oil can be used as a massage oil to relieve stiff and aching joints in arthritic conditions. Comfrey ointment may be used instead of the oil in all cases mentioned.

HOW IT WORKS IN THE BODY

The principal ingredient allantoin works to promote the healing of tissues within the body. It is complemented by the rosmarinic acid, an anti-inflammatory agent. The mucilage is demulcent and works to soothe irritative conditions, both internally and externally. The tannins act as an astringent. The pyrrolizidine alkaloids are thought to be damaging to the liver. These pyrrolizidine alkaloids are mainly concentrated in the root of the plant, and therefore there is common agreement by the main bodies of herbal practitioners that this should not be taken internally. It has, however, also been substantiated that the leaf does not present this problem, and may be taken internally under the guidance of a qualified herbal or medical practitioner. Both the leaf and the root can be safely used externally.

APPLICATIONS

AERIAL PARTS/ROOT:

POULTICE - Puree the leaves only, and apply to minor fractures that would not normally be set in plaster, such as broken toes, ribs, or hairline cracks in larger bones.

CREAM - Use for bone or muscle damage, including osteoarthritis.

INFUSED OIL - Make by the hot infusion method, and use on arthritic joints, bruises, sprains, and other traumatic injuries; also for inflamed bunions.

ROOT:

POULTICE - Make a paste of powdered root with a little water and use on varicose ulcers and other stubborn wounds; also for bleeding hemorrhoids.

RECONSTITUTING OINTMENT

To prepare this ointment, first macerate 3 oz (100 g) comfrey root, cut and dried, in 3 T (50 ml) good-quality olive oil for 2 weeks.

• 1 cup (250 ml) castor oil
• 20 drops lavender essential oil
• 1 1/4 oz (40 g) beeswax

Strain the olive oil and comfrey. Melt the wax in a saucepan. Stir in the 2 kinds of vegetable oils, then the drops of essential oil. Pour into small, dark green jars. Let cool.
This is a multipurpose ointment: it is effective against cuts, wounds, contusions, tendonitis, fractures and even wrinkles!