COLTSFOOT -- Tussilago farfara L. (Asteraceae/Compositae) +

HERBAL

MEDICINAL

PLANT

COLTSFOOT

Tussilago farfara  L. (Asteraceae/Compositae) +

 

BY

 

RETTODWIKART THENU

-------------

COLTSFOOT

(koeltz’ fut)

 

 

Tussilago farfara  L. (Asteraceae/Compositae) +

 

SUMMARY AND PHARMACEUTICAL COMMENT

 

The majority of the traditional uses associated with coltsfoot can be attributed to the mucilage content. However, coltsfoot also contains toxic pyrrolizidine alkaloids albeit at a low concentration. The risk of exposure to low concentrations of unsaturated pyrrolizidine alkaloids is unclear although hepatotoxicity following prolonged exposure has been documented (see Comfrey). The regular or excessive consumption of coltsfoot, especially in the form of herbal teas, should therefore be avoided.

 

 

TRADE NAMES

British Tobacco, Bullsfoot, Butterbur,  Rower Velure, Foal's-Foot, Horse-Foot, Horsehoof, Ass's Foot, Foalswort

 

OTHER COMMON NAMES

Coughwort, Donnhove, Farfara, Fieldhove, Filiusante Patrem, Flower Velure, Hallfoot, Kuandong Hua, Pas Diane

 

DESCRIPTION

MEDICINAL PARTS: The medicinal parts are the dried inflorescences, the dried leaves and the fresh leaves.

FLOWER AND FRUIT: The yellow compound flowers are in small, solitary capitula at the end of the scapes. The lateral florets are lingual, narrow and female. The disc florets are tubular-campanulate, 5-petalled and male. The involucral bracts are almost as long, linear-lanceolate and have a scarious margin. The fruit is 3 to 11 mm long, cylindrical, brown, glabrous and stemmed. The pappus is in a number of rows and consists of long, glossy white hairs, which are much lonser than the fruit.

LEAVES, STEM AND ROOT: The plant is a perennial, 10 to 30 cm high. It has a broadly branched, underground shoot and root system with a thin round, scaly base. There is also an up to 1.8 m long, far-reaching, creeping shoot. The flower stern is a scaly, round, tomentose scape covered with lanceolate, reddish scales, which is 30 cm long when the fruit ripens. The leaves, which appear after flowering, are basal, coriaceous, cordate-round, angular, irregularly dentate, long-petioled and tomentose beneath. The leaves can reach a diameter of up to 30 cm.

CHARACTERISTICS: The taste and texture is slimy-sweet and the leaves have a honey-like smell when they are rubbed.

HABITAT: The plant grows wild in most of Europe, central, western and northern Asia. It has spread to the mountains of northern Africa and has been introduced into North America.

PRODUCTION: Colt's Foot flower consists of the fresh or dried flowers of Tussilago farfara. Colt's Foot herb consists of the fresh or dried, above-ground parts of Tussilago farfara. Colt's Foot root consists of the fresh or dried, below-ground parts of Tussilago farfara.

NOT TO BE CONFUSED WITH: The leaves of various Petasites species, but petasine and flavonoids can be identified using thin layer chromatography.

 

SPECIES (FAMILY)

Tussilago farfara L. (Asteraceae/Compositae)  +

 

SYNONYM(S)

Farfara

 

ORIGIN

Coltsfoot is a perennial found in Europe; the United States; Canada; and central, western and northern Asia.

 

PHARMACOPODIAL AND OTHER MONOGRAPHS

BHC 1992(G6)

BHP 1983(G7)

Complete German Commission E(G3)

Martindale 35th edition(G85)

 

LEGAL CATEGORY (LICENSED PRODUCTS)

GSL(G37)

 

CONSTITUENTS

The following is compiled from several sources, including General Reference G2.

Acids Caffeic acid, caffeoyltartaric acid, ferulic acid, gallic acid, p-hydroxybenzoic acid, and tannic acid (phenolic); malic acid and tartaric acid (aliphatic).(1)

Alkaloids Pyrrolizidine-type. Senkirkine 0.015% and senecionine (minor) (unsaturated)(2, 3) and tussilagine (saturated).(4)

Carbohydrates Mucilage (water-soluble polysaccharides) 7–8% yielding various sugars following hydrolysis (e.g. arabinose, fructose, galactose, glucose, uronic acid and xylose); inulin (polysaccharide).(5)

Flavonoids Flavonols (e.g. kaempferol, quercetin) and their glycosides.(1)

Tannins Up to 17% (type unspecified).

Other Constituents Bitter (glycoside), choline, paraffin (fatty acid), phytosterols (sitosterol, stigmasterol, taraxasterol), triterpene (amyrin), tussilagone (sesquiterpene)(6) and volatile oil.

 

CHEMICAL COMPONENTS

COMPOUNDS: COLT'S FOOT FLOWER

Mucilages (7%): acidic polysaccharides

Tannins

Triterpenes: including beta-amyrin, arnidiol. faradiol

Steroids: including beta-sitosterol

Pyrrolizidine alkaloids (traces, not in plants from all places of origin): tussilagine, isotussilagine, senkirkine. senecionine

Flavonoids

 

COMPOUNDS: COLT'S FOOT HERB

Mucilages (8%): acidic polysaccharides

Tannins (5%)

Triterpenes: including alpha-amyrin, beta-amyrin

Steroids: including beta-sitosterol, campesterol

Pyrrolizidine alkaloids (not in plants from all places of origin): senkirkine (0.01%), senecionine. tussilagine, isotussilagine

Flavonoids

 

COMPOUNDS: COLTS FOOT ROOT

The roots have not been fully investigated. Only the presence of triterpenes and sterols has been established.

 

COMPOUNDS: COLT'S FOOT LEAF

Mucilages (8%): acidic polysaccharides

Tannins (5%)

Pyrrolizidine alkaloids (traces, not from all sources): tussilagine, isotussilagine, senkirkine 0.01%), senecionin

Steroids: including beta-sitosterol, campesterol

Triterpenes: including alpha- and beta-amyrin

Flavonoids

 

 

USES

USES

Coltsfoot is used to treat respiratory conditions such as bronchitis, cough, and asthma. It is also used to treat infl ammation of the oral mucosa.

INVESTIGATIONAL USES

Research is underway concerning coltsfoot as an antimicrobial.

 

FOOD USE

Coltsfoot is not commonly used as a food but it is listed by the Council of Europe as a source of natural food flavouring (category N4). This category indicates that although coltsfoot is permitted for use as a food flavouring, there are insufficient data available for an assessment of toxicity to be made.(G16)

 

HERBAL USE

Coltsfoot is stated to possess expectorant, antitussive, demulcent and anticatarrhal properties. It has been used for asthma, bronchitis, laryngitis and pertussis.(G2, G7, G49,G64)

 

 

 

Figure 1. Coltsfoot (Tussilago farfara).

 

 

Figure 2. Coltsfoot – dried drug substance (leaf).

 

ACTIONS

Two studies have demonstrated the ability of coltsfoot to inhibit nitric oxide synthesis in macrophages. The clinical signifi cance of this fi nding is unknown, however (Ryu et al, 1999). Another study found that coltsfoot inhibits the binding of both platelet activating factor and Ca2+ entry blocker to membrane vesicles (Hwang, 1987). Other studies have focused on the toxic effects of Tussilago farfara L. and the isolation of new chemical components (Sperl et al, 1995; Wang et al, 1989; Liu et al, 2006). The screening of 16 medicinal plants showed that 6 possessed signifi cant antimicrobial action (Kokoska et al, 2002; Kim et al, 2006).

 

PHARMACOLOGICAL ACTIONS

IN VITRO AND ANIMAL STUDIES

Antibacterial activity has been documented for coltsfoot against various Gram-negative bacteria including Staphylococcus aureus, Proteus hauseri, Bordetella pertussis, Pseudomonas aeruginosa and Proteus vulgaris.(7–9)

Anti-inflammatory activity comparable to that of indometacin, determined in Selye's experimental chronic inflammation test, has been attributed to water-soluble polysaccharides in coltsfoot.(10) Weak acute anti-inflammatory activity has been reported for coltsfoot when tested against carrageenan-induced rat pawoedema.(11, 12)

Platelet-activating factor (PAF) is known to be involved in various inflammatory, respiratory and cardiovascular disorders. The aggregating action of PAF is known to be weaker if intracellular concentrations of calcium are low. A sesquiterpene, L-652469, isolated from coltsfoot buds has been reported to be a weak inhibitor of both PAF receptor binding and calcium channel blocker binding to membrane vesicles.(13) This combination of actions was found to effectively block PAF-induced platelet aggregation. L-652469 was also found to be active orally, inhibiting PAF-induced rat paw oedema.(13) Interestingly, L-652469 was reported to interact with the cardiac calcium channel blocker receptor complex (dihydropyridine receptor), but was also found to be a calcium channel blocker.(13)

Tussilagine has been reported to be a potent cardiovascular and respiratory stimulant.(6, 14) Dose-dependent pressor activity following intravenous injection has been observed in the cat, rat and dog.(14) The pressor effect is stated to be similar to that of dopamine, but without tachyphylaxis. A significant stimulation of respiration was also observed.(6) Cardiovascular and respiratory effects are thought to be mediated by peripheral and central mechanisms, respectively.(6)

 

CLINICAL STUDIES

There is a lack of clinical research assessing the effects of coltsfoot and rigorous randomised controlled clinical trials are required.

 

ACTIVITIES

Antiaggregant (1; APA; CAN); Antibacterial (1; CAN; CRC; PH2); Anticholinergic (f; CRC); Antiedemic (1; CAN; HH2); Antihistaminic (f; CRC; FAD); Antiinflammatory (2; CAN; KOM; PH2); Antiirritant (2; PHR); Antimitotic (2; KOM); Antispasmodic (1; CAN; CRC; HH2); Antitussive (1; CAN; CRC; DAA); Calcium Antagonist (1; CAN); Callus-Promoter (2; KOM); Carcinogenic (1; APA; CRC; PH2); Cardiotonic (1; CAN); CNS-Depressant (1; DAA); Collyrium (f; CRC); Demulcent (1; CAN; CRC; FAD; PH2); Diaphoretic (f; CRC; MAD; PIP); Diuretic (f; CRC; PIP); Emollient (f; CRC); Expectorant (1; CAN; CRC; FAD); Fumitory (f; PH2); Hemostat (f; CRC); Hepatotoxic (1; APA; CAN; FAD; PH2); Hypertensive (1; APA); Immunostimulant (1; CAN); Pectoral (f; CRC; MAD); Phagocytotic (1; CAN); Respirotonic (1; CAN); Tonic (f; CRC); Vulnerary (1; PIP).

 

INDICATIONS

Adenopathy (f; PHR; PIP); Ague (f; CRC); Anorexia (F; MAD); Apoplexy (f; CRC; DAA); Asthma (1; APA; CAN; GMH; PHR); Bacteria (1; CAN; CRC; DAA; PH2); Bleeding (f; CRC); Bronchosis (2; CAN; FAD; KOM; PH2); Cancer (f; CRC); Cancer, liver (f; JLH); Cancer, lung (f; CRC; LMP); Carbuncle (f; HAD); Catarrh (2; CAN; CRC; GMH; KOM); Cold (2; CRC; PIP); Congestion (f; CRC; FAD; LMP); Cough (2; FAD; GMH; KOM; PH2; PIP); Cramp (1; CAN; CRC; HH2); Diarrhea (f; CRC; POP); Dyspepsia (f; CRC); Dysphagia (f; DAA); Edema (1; HH2); Emphysema (f; HH2); Enterosis (f; FEL); Erysipelas (f; GMH; MAD); Escherichia (f; HH2); Fever (f; CRC; DAA; MAD; PIP); Flu (f; CRC; DAA; LMP; MAD; PHR); Fistula (f; HAD); Gastrosis (f; CRC; FEL); Headache (f; CRC; FEL); Hematemesis (f; HAD); Hemoptysis (f; CRC; DAA; LMP); Hoarseness (2; APA; KOM; MAD; PIP); Immunodepression (1; CAN); Induration (f; CRC; JLH); Infection (1; CRC); Inflammation (2; CAN; FAD; KOM; PH2); Laryngosis (1; CAN; FEL); Low Blood Pressure (1; APA); Mucososis (2; CRC; FAD; KOM; PH2); Neurosis (f; CRC); Nicotinism (f; PH2); Ophthalmia (f; CRC); Pertussis (f; CAN; FEL); Pharyngosis (2; KOM; PH2; PIP); Phthisis (f; CRC; DAA); Plethora (f; CRC); Pleurosis (f; MAD); Pulmonosis (f; CRC; FAD); Respirosis (2; KOM; 2; PIP); Rheumatism (f; CRC; PH2); Rhinosis (f; CRC; FEL); Scrofula (f; CRC; FEL; GMH); Sinusosis (f; CRC); Sore Throat (f; PHR; PIP); Stomatosis (2; APA; PHR; PH2; PIP); Swelling (1; CAN; CRC; HH2; MAD); Tonsillosis (f; PHR; PIP); Tracheosis (f; MAD); Tuberculosis (f; CRC; DAA; DEM; MAD); Tumor (f; CRC); Wart (f; MAD); Water Retention (f; CRC; PIP).

 

INDICATIONS AND USAGE

 

COLT'S FOOT FLOWER. HERB, AND ROOT

UNPROVEN USES: When added to Colt's Foot leaf, the flower, herb, and root are used to treat rheumatism.

 

COLT'S FOOT LEAF'

Approved by Commission E:

• Cough

• Bronchitis

• Inflammation of the mouth and pharynx

UNPROVEN USES: Colt's Foot leaf is used for inflammation of the oraFand pharyngeal mucosa. In addition, cigarettes made of the leaves are used to help cure smoking addiction.

 

PRODUCT AVAILABILITY

Dried Herb, Extract, Syrup, Tea, Tincture

PLANT PARTS USED: Dried Flowers, Leaves, Roots

 

DOSAGES

 

DOSAGES

·         Adult PO decoction: 0.6-2.9 g dried herb

·         Adult PO dried herb: 4.5-6 g/day (Blumenthal, 1998)

·         Adult PO fl uid extract: 0.6-2 ml tid (1:1 dilution in alcohol 25% concentration)

·         Adult PO syrup: 2-8 ml tid (1:4 dilution)

·         Adult PO tea: 1-3 tsp dried herb in 8 oz boiling water, let stand 10 min, strain, take tid

 

 

DOSAGES

Dosages for oral administration (adults) for traditional uses recommended in standard herbal reference texts are given below.

·         Dried Herb 0.6–2.0 g by decoction three times daily.(G6)

·         Liquid Extract 0.6–2.0 mL (1 : 1 in 25% alcohol) three times daily.(G7)

·         Tincture 2–8mL (1 : 5 in 45% alcohol) three times daily.(G7)

·         Syrup 2–8mL (liquid extract 1 : 4 in syrup) three times daily.(G7)

 

DOSAGES

·         2 tsp powdered leaf/cup water (APA; WIC); 0.3–0.6 g solid leaf extract (PNC); 2–4 ml liquid leaf extract (PNC);

·         4.5–6 g leaf, 0.6–2.0 ml liquid extract (1:1 in 25% ethanol) 3 ×/day (CAN); 0.6–2.0 g herb as tea 3 ×/day (CAN);

·         2–8 ml tincture (1:5 in 45% alcohol) 3 ×/day (CAN); 2–8 ml syrup (1:4 liquid extract in syrup) 3 ×/day (CAN);

·         4 g root as diaphoretic (MAD); 1.5–2.5 g leaf or flower/cup tea, to 6 g day (PH2); 0.6–2 ml liquid flower extract (PNC).

 

DOSAGES

COLT'S FOOT FLOWER, HERB, AND ROOT

MODE OF ADMINISTRATION: The drug is used internally through the use of tea and standardized remedies.

PREPARATION: To prepare a tea, add l .5 to 2.5 gm cut drug to boiling water, then strain after 5 to 10 minutes.

STORAGE: Protect the drug from light and store it tightly sealed.

 

COLT'S FOOT LEAF

MODE OF ADMINISTRATION: Whole, cut, and powdered drug used in teas, infusions, extracts, and tinctures.

PREPARATION: To make an infusion, pour hot water over 1.5 to 2.5 gm of drug and allow to draw for 10 minutes. Other preparations are made as follows: liquid extract: 1:1 with 20% ethanol; extract: 1.1 with 25% ethanol; tincture: 1:5 with 45% ethanol.

DAILY DOSAGE: The total daily dose is 4.5 to 6 gm of drug. The maximum daily dosage must not be more than 1 meg of total pyrrolizidine alkaloids with 1.2 unsaturated necine structure. The tea is given several times a day. The dosage for the extract is 2 ml 3 times daily; for the tincture, it is 8 ml 3 times daily.

STORAGE: Protect the drug from light and store it tightly sealed.

 

 

PRECAUTIONS AND ADVERSE REACTIONS

 

COLT'S FOOT FLOWER, HERB, AND ROOT

Because of the possible hepatotoxic and carcinogenic pyrrolizidine alkaloid content, the administration of the blossoms should be avoided.

COLT'S FOOT LEAF

Colt's Foot leaves may no longer be brought into circulation in Austria. In Germany, dosages cannot exceed an intake of 10 meg pyrrolizidine alkaloids with l .2-unsaturated necic parent substances in the form of tea mixtures, and an intake of l meg in the form of extracts. Because even traces of the alkaloids present some danger, one should forgo any administration of the drug.

 

CONTRAINDICATIONS, INTERACTIONS, AND SIDE EFFECTS

CLASS 2B, 2D (FLOWER); LONGTERM USE DISCOURAGED. 2B, 2C, 2D (LEAF); do not exceed recommended dose; not for long-term use (AHP). Commission E reports flower, herb, root not permitted for therapeutic use. Contains hepatotoxic pyrrolizidine alkaloids (PAs) in all plant parts. Leaf is permitted for oral use. Contraindications in pregnancy and lactation. CAN cautions that the PAs are genotoxic, carcinogenic, and hepatotoxic. Because of the PAs, coltsfoot use in pregnancy and lactation is to be avoided (CAN). Dosage maximum 10 g PA/day (herbal tea) or maximum 1 g PA/day (extracts, expressed sap) for maximum 4–6 weeks/year (AEH). Commission E advises not to take more than 4 to 6 weeks of the year at 4.5 to 6 g/day. This is the only herb (1.5–6 g leaf/day) except related Petasites with toxic PAs still tolerated by Commission E. Still, CAN cautions that coltsfoot is phototoxic in guinea pig skin. In guinea pig sensitization experiments, it showed weak allergenic capacity, possibly due to the sesquiterpene lactones present in the plant. PAs are toxic to humans, with liver damage with cirrhosis and ascites, or seneciosis, or veno-occlusive disease (VOD) reported in almost all cases of severe or fatal intoxications, from intakes of 0.5 mg/kg to 3.3 mg/kg (AEH1). Effective July 1996, the AHP Board of Trustees recommends that all products with botanical ingredient(s) that contain toxic PAs, including Borago officinalis, display the following cautionary statement on the label, “For external use only. Do not apply to broken or abraded skin. Do not use when nursing” (AHP). Canadians do not allow in food (Blackburn, 1993). Bisset says there is no danger of acute poisoning when used as prescribed (Bisset, 1994). Hepatotoxicity of coltsfoot may be due to senkirkine (~150 ppm), highlighting the dangers of chronic exposure to even low doses of PAs. Rats fed more than 4% coltsfoot in their diet develop hepatic tumors. Newborn rats are more susceptible than weanlings to hepatotoxicity of senkirkine despite lacking the hepatic microsomal enzymes required to produce the toxic pyrrholic metabolites. Fatal hepatic venoocclusive disease was documented in a newborn infant whose mother chronically consumed herb teas during pregnancy (coltsfoot and senecio specified). The mother exhibited no signs of hepatic damage again suggesting increased sensitivity of the fetal liver to PA toxicity. Animal studies document placental transfer and secretion into breast milk of unsaturated Pas (CAN). Excessive doses may interfere with blood pressure and heart therapy (CAN).

 

CONTRAINDICATIONS AND PRECAUTIONS

COLT'S FOOT FLOWER. HERB, ROOT. AND LEAF

Administration during pregnancy and while nursing is contraindicated.

 

CONTRA-INDICATIONS, WARNINGS

In view of the known pyrrolizidine alkaloid content, excessive or prolonged ingestion should be avoided. In particular, herbal teas containing coltsfoot should be avoided.

Drug Interactions None documented. However, the potential for preparations of coltsfoot to interact with other medicines administered concurrently, particularly those with similar or opposing effects, should be considered. There is limited evidence from preclinical studies that tussilagine, a constituent of coltsfoot, has pressor activity. However, the clinical significance of this, if any, is not known.

Pregnancy and Lactation Coltsfoot should not be taken during pregnancy or lactation in view of the toxicity associated with the pyrrolizidine alkaloid constituents. Coltsfoot is reputed to be an abortifacient.(G30)

 

CONTRAINDICATIONS

CLASS 2B/2C/2D HERB (FLOWERS).

Coltsfoot should not be used during pregnancy and breastfeeding. It should not be given to children. Coltsfoot should not be used by persons with hepatic disease or those who are hypersensitive to ragweed, chamomile, or other members of the composite family. Persons with cardiac disease, or hypertension should use this herb cautiously. Coltsfoot should not be used for longer than 6 weeks. Pyrrolizidine alkaloid content should not exceed 10 mcg.

 

SIDE EFFECTS/ADVERSE REACTIONS

CNS: Fever

CV: Hypertension

GI: Nausea, vomiting, anorexia, diarrhea, jaundice, hepatotoxicity (rare)

INTEG: Hypersensitivity reactions

RESP: Upper respiratory infection

 

INTERACTIONS

Drug

Antiarrhythmics, antihypertensives: Coltsfoot may antagonize antiarrhythmics and antihypertensives; avoid concurrent use (theoretical).

Herb

Eucalyptus: Eucalyptus may increase the toxicity of coltsfoot; avoid concurrent use (theoretical) (Jellin et al, 2008).

Pyrrolizidine alkaloid (UPA)-containing herbs (borage, gravel root, agrimony, petasities, comfrey, dusty miller, ragwort): Use with these herbs and coltsfoot will lead to increased toxicity; do not use concurrently (Jellin et al, 2008).

Lab Test

AST, ALT, alkaline phosphatase: Coltsfoot may increase these levels.

 

 

EFFECTS

EFFECTS: COLT'S FOOT LEAF

The pyrrolizidine alkaloids are antibacterial, carcinogenic, and hepatotoxic. The mucin polysaccharides cause a demulcent, sequestering, and anti-inflammatory effect. In animal experiments there was evidence of a stimulating effect on the ciliated epithelium.

EFFECTS: COLT'S FOOT FLOWER, HERB, AND ROOT

The mucin contained in the drug has a sequestering effect and envelopes the mucous membrane with a layer that protects the throat from chemical and physical irritation and thereby reduces cough irritation. The pyrrolizidine alkaloids are antibacterial, carcinogenic, and hepatotoxic.

 

SIDE-EFFECTS, TOXICITY

There is a lack of clinical safety and toxicity data for coltsfoot and further investigation of these aspects is required. Coltsfoot has been reported to be phototoxic in guinea-pig skin.(15) Pyrrolizidine alkaloids with an unsaturated pyrrolizidine nucleus are known to be hepatotoxic in both animals and humans (see Comfrey). Of the pyrrolizidine alkaloids documented for coltsfoot, senecionine and senkirkine are unsaturated. Chronic hepatotoxicity has been described in rats following the incorporation of coltsfoot into their diet at concentrations ranging from 4–33%.(16) After 600 days, it was found that rats fed more than 4% coltsfoot had developed hepatic tumours (haemangioendothelial sarcoma) while none were observed in the control group.

Furthermore, histological changes associated with pyrrolizidine alkaloid toxicity, such as centrilobular necrosis of the liver and cirrhosis, were observed in many of the rats who had ingested coltsfoot but who had not developed tumours.(16) The hepatotoxicity of coltsfoot was attributed to senkirkine, which is present at a concentration of only 0.015%, thus highlighting the dangers associated with chronic exposure to low concentrations of pyrrolizidine alkaloids.

Newborn rats have been found to be more susceptible than weanlings to the hepatotoxic effects of senkirkine despite lacking the hepatic microsomal enzymes required for the formation of the toxic pyrrolic metabolites.(17) Fatal hepatic veno-occlusive disease has been documented in a newborn infant whose mother had regularly consumed a herbal tea during pregnancy.(18) Analysis of the herbal tea revealed the presence of 10 different plants including coltsfoot and a Senecio species (known source of pyrrolizidine alkaloids, see Liferoot). The mother exhibited no signs of hepatic damage, suggesting an increased sensitivity of the fetal liver to pyrrolizidine alkaloid toxicity.

Pre-blooming coltsfoot flowers are reported to contain the highest concentration of alkaloids.(3) Considerable loss of both senkirkine and senecionine has been observed upon prolonged storage of the dried plant material.(3) Senkirkine and senecionine are both easily extracted into hot water and, therefore, would presumably be ingested in a herbal tea prepared from the fresh plant.(3) A cup of tea prepared from 10 g pre-blooming flowers has been estimated to contain a maximum of 70 mg senecionine and 1.4 mg senkirkine. Tea from the young leaves or mature plant would presumably contain considerably lower concentrations of alkaloids.(3) These concentrations are not considered to represent a health hazard compared to the known hepatotoxicity of senecionine (intravenous LD50 64 mg/kg body weight, mice).(3)

However, prolonged exposure to low concentrations of pyrrolizidine alkaloids has resulted in hepatotoxicity (see Comfrey). Tussilagine LD50 (mice, intravenous injection) has been determined as 28.9 mg/kg.(14)

 

CLIENT CONSIDERATIONS

ASSESS

·         Assess the reason the client is using coltsfoot.

·         Assess for hypersensitivity reactions. If these are present, discontinue the use of this herb and administer antihistamines or other appropriate therapy.

·         Assess for hepatotoxicity (increased hepatic function tests, jaundice, clay-colored stools, right upper-quadrant pain). If these occur, herb use should be discontinued.

·         Assess for the use of antiarrhythmics and antihypertensives (see Interactions).

 

ADMINISTER

·         Instruct the client to store coltsfoot products in a cool, dry place, away from heat and moisture.

·         Because of the presence of hepatotoxic pyrrolizidine alkaloids, caution the client not to use coltsfoot for longer than 6 weeks.

 

TEACH CLIENT/FAMILY

·         Caution the client not to use coltsfoot in children or those who are pregnant or breastfeeding because hepatotoxicity may occur.

·         Advise the client to report any side effects to the provider.

·         Caution the client not to confuse peppermint with coltsfoot; they are similar in appearance.

 

 

PREPARATIONS

 

PROPRIETARY MULTI-INGREDIENT PREPARATIONS

Argentina: Arceligasol; Negacne. Czech Republic: Perospir; Species Pectorales Planta. Italy: Lozione Same Urto. Spain: Llantusil. UK: Antibron; Chesty Cough Relief.

 

 

 

REFERENCE

Barnes, J., Anderson, L. A., and Phillipson, J. D. 2007. Herbal Medicines Third Edition. Pharmaceutical Press. Auckland and London.

 

Duke, J. A. with Mary Jo Bogenschutz-Godwin, Judi duCellier, Peggy-Ann K. Duke. 2002. Handbook of Medicinal Herbs 2nd Ed. CRC Press LLC. USA.

 

Gruenwald, J., Brendler, T., Jaenicke, Ch. 2000.  PDR for Herbal Medicines.  Medical Economics Company, Inc. at Montvale, NJ 07645-1742. USA

 

Linda S-Roth. 2010. Mosby’s Handbook Of Herbs & Natural Supplements, Fourth Edition. Mosby Elsevier. USA