| General
info
· An ancient herb
known since 400 B.C., used by the Greeks to treat bronchial problems,
wound healing and mending of broken bones. The name "Comfrey"
is a corruption of con firma,
the uniting of bones.
· The healing constituent is allantoin. Ingredients may be steeped
or dissolved in hot water; boiling should be avoided as this may cause
the breakdown of allantoin.
Botany
Hardy, leafy perennial.
Thick rhizomes, black outside and white inside, containing a mucilaginous
juice. Leaves are entire, lanceolate to ovate-lanceolate, up to 10 inches
long, deep green and hairy. Flowers are variable in color, blue, yellow
or white, borne on short curved racemes, with five-lobed calyx and five
stamens. Fruits are nutlets.
Distribution
Introduced in the Philippines
in the late 60s; cultivated; propagated by seed.
Caution !
• Hepatotoxicity: Since the late
70's, subject of persisting concerns and debate on certain alkaloid
contents that may cause liver damage, veno-occlusive liver disease,
ascites and hepatic fibrosis.
• Advice is given against use of comfrey as salad green or tea.
• In July 2001, the US FDA took steps to stop the marketing of
comfrey as a dietary supplement. (Source)
Parts
utilized
Leaves , flowers
and roots.
Chemical constituents
and properties
· Considered antitussive,
expectorant, haemostatic, vulnerary, homepathy.
• Contains allantoin, between 0.6 to 0.8 % to which is attributed
its wound-healing properties.
• Phenolic acids: rosmarinic, chloogenic, caffeic and lithospermic
acids.
• Contains potentially hepatotoxic compounds: pyrrolizidine alkaloids,
including heliosupine and cynoglossine. The alkaloid concentration is
highest in small, young leaves. Roots are also contain high levels of
these compounds.
Uses
Nutrition
Confirmed source of vitamin
B12, although in negligible amounts that would require consumption of
4 pounds of comfrey daily for minimum daily requirement.
Folkloric
· Decoction of leaves used for a variety of illnesses: Asthma,
cough, ulcers, constipation, hypertension.
· Poultice of fresh leaves used for sprains and fractures, inflammatory
swelling, external wounds, sores, athlete's foot, burns, insect bites,
and abscesses.
· Used for excessive menstrual flow, cancer, angina, gums disease
· Juice of leaves used for a variety of skin ailments and wounds
healing; apply three times daily.
· Decoction of tea as a sleep-aid.
· Roots and leaves used for broken bones and wounds.
· In Ayuveda, used for peptic ulcer.
Studies
· Mutagenic effects of aqueous extracts of Symphytum officinale
L. and of its alkaloidal fractions.
• Roots reported to increase incidence of liver tumors in rats;
other studies suggest it is carcinogenic.
• Action of some proteic and carbohydrate components of Symphytum
officinale upon normal and neoplastic cells. Results showed the extract and its proteic
fraction stimulated the in vivo proliferation of studied neoplastic
cells with an antimitotic effect of human T lymphocytes.
• Analysis of herbal teas
made from the leaves of comfrey (Symphytum officinale): reduction of
N-oxides results in order of magnitude increases in the measurable concentration
of pyrrolizidine alkaloids: The concentration of symphytine
and echimidine varied considerably in different tea leaves preparation.
Since alklaoids are known to be hepatotoxic, consumption of comfrey
herbal teas, in native or packaged forms, is not advised.
Safety
studies
· Probably safe
when used topically on unbroken skin. Use should be limited to 4 to
6 weeks per year at less than 100 mcg of unsaturated pyrrolizidine alkaloids.
However, with toxicity concerns, it is advisable to seek alternatives.
· Avoid oral use. Probably not safe
when taken orally. Potential for liver toxicity.
· Contraindicated in pregnancy and lactation.
Availability
Wildcrafted
Ointments
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