PDR for Herbal Medicines

HERBAL MONOGRAPHS COMFREY /213

Demultant Effect—The mucilages act as demultants for a

soothing and irritation reduction effect.

Hypotensive Effect—Symphytoxide A, a triterpene saponin,

exhibited hypotensive activity in anesthetized rats (Ahmad,

4P 1993).

Tissue/Nerve Stimulation—Allantoin, a component in Com-

frey, stimulates tissue repair and wound healing through cell

proliferation (Rieth, 1968). Allantoin has also had significant

effect on cellular multiplication in degenerating and regener-

ating peripheral nerves (Loots, 1979).

CLINICAL TRIALS

The anti-inflammatory effects of Comfrey were studied in

musculoskeletal disorders. Forty-one patients with musculo-

skeletal rheumatism were treated with either a pyrrolizidine

alkaloid-free ointment or placebo for 4 weeks. The patient

illnesses consisted of epicondylitis, tendovaginitis, and peri-

arthritis. Efficacy was determined by evaluation of different

pain parameters (tenderness on pressure, pain at rest, pain on

exercise). There was significant improvement with the

ointment compared to placebo at weeks 1, 2. and 4 in

patients with epicondylitis. There was improvement with

M. tendovaginitis at week 1 and 2, but not at week 4 with the

ointment compared to placebo. There was no improvement

in the peri-arthritis patients in either of the two treatment

groups (Petersen, 1993).

INDICATIONS AND USAGE

Approved by Commission E:

• Blunt injuries

Externally, Comfrey is used for bruises, sprains and promo-

tion of bone healing.

Unproven Uses: The root has been used externally as a

mouthwash and gargle for gum disease, pharyngitis, and

strep throat. Internally, the root has been used for gastritis

and gastrointestinal ulcers. In Folk medicine, the root of the

plant has been used for rheumatism, pleuritis, and as an anti-

diarrheal agent.

CONTRAINDICATIONS
Comfrey is contraindicated in pregnancy and in nursing
Jfr mothers.

PRECAUTIONS AND ADVERSE REACTIONS

Hepatotoxicity: Internal administration of the drug, due to

the presence of pyrrolizidine alkaloids, has resulted in

hepatocyte membrane injury with hemorrhagic necrosis and

loss of microvilli (Yeong, 1993). Hepatic veno-occlusive

disease and severe portal hypertension has been associated

with Comfrey ingestion, and in one case report, death

resulted by liver failure (Ridker, 1989; Yeong, 1990).

Carcinogenic/Mutagenic Effects: Mutagenic effects are asso-

ciated with aqueous extracts of the alkaloid fractions

(Furmanowa, 1983). Hepatocelluar adenomas have been

reported in animal models receiving diets containing Com-

frey roots and leaves (Hirono, 1978). Comfrey also has

chromosome-damaging effects in human lymphocytes (Beh-

ninger, 1989).

Gastrointestinal/Kidney/Pancreas Effects: Comfrey, through

the pyrrolizidine alkaloids, has been shown to produce

lesions in the gastrointestinal tract, pancreas, and renal

glomeruli in animal models (Winship, 1991).

Respiratory Effects: Pulmonary endothelial hyperplasia from

the pyrrolizidine alkaloids has been seen in animal models

(Miskely, 1992).

Use in Pregnancy: The drug is contraindicated during

pregnancy.

Use in Nursing Mothers: Use of the drug while nursing is

contraindicated.

DOSAGE

Mode of Administration: The crushed root, extracts, and

pressed juice of the fresh plant are used as semi-solid

preparations and poultices for external use. The drug is a

component of standardized preparations of analgesics, anti-

rheumatic agents, antiphlogistics, antitussives, and

expectorants.

How Supplied:

Cream—1.25 oz„ 2 oz.

Preparation: To make an infusion, pour boiling water over 5

to 10 gm comminuted or powdered drug, steep 10 to 15

minutes, then strain (1 teaspoonful = 4 gm drug). For

external application, a decoction of 1:10 is used, or the fresh

roots are mashed.

Daily Dosage:

External Use—The daily dosage should not exceed 1 meg of

pyrrolizidine alkaloids for external preparations calculated

with 5 to 7% drug, maximum 1 ppm/gm for commercial

pharmaceutical preparations. The drug should be used for a

maximum of 4 weeks.

Tea—When using the infusion, take 1 cup 2 to 3 times daily,

but not for a long duration (SEE PRECAUTIONS).

LITERATURE

Ahmad VU; Noorwala M; Mohammad FV et al. Symphytoxide

A, a triterpenoid saponin from the roots of Symphytum

officinale. Phytochemistry 1993 Mar;32(4): 1003-6.

Behninger C; Abel G; Roder E et al. Studies on the effect of

an alkaloid extract of Symphytum officinale on human

lymphocyte cultures. Planta Med 1989 Dec;55(6):518-22.