Coltsfoot is a low-growing perennial (up to 30 Om high) with fleshy, woolly leaves. In early spring, the 'Plant produces a stem with a single golden-yellow, nar?row, ligulate flower head that blooms from April to June. .As the stem dies, the hoof-shaped leaves appear. The plant is native to Europe, but also grows widely in sandy places throughout the United States and Canada. Colts?loot is collected widely from wild plants in the Balkans, astern Europe (Bulgaria, Czechoslovakia, Hungary, Po?land, the former Yugoslavia), and Italy. It has also been a part of Chinese folk medicine for centuries. The morphology and anatomy of coltsfoot have been described in etail, including the plant's underground parts? A later report on leaf differentiation is also available.
As part of its Latin name Tussi/ago implies, Goltsfoot is reputed as an antitussive. The buds, flowers, and leaves of coltsfoot have long been used in traditional medicine for dry cough and throat irritation. The plant has lound particular use in Chinese herbal medicine for the treatment of respiratory diseases, including cough, asthma, and acute and chronic bronchitis. It is also a component of numerous European commercial herbal preparations for the treatment of respiratory disorders. A mixture containing coltsfoot has been smoked for the management of coughs and wheezes, but the smoke is potentially irritating. Its silky seeds were once used as a stuffing for mattresses and pillows.6 Extracts of coltsfoot had once been used as flavorings for candies. All early references emphasize the usefulness of coltsfoot's muci?lage for soothing throat and mouth irritation.
Coltsfoot contains a number of diverse components including tannins, a mucilage, terpene alco?hols, carotenoids, and flavonoids. The mucilage is present in a concentration of about 8%. It yields sugars lollowing hydrolysis including arabinose, fructose, galac?tose, glucose, and others. Water-soluble polysaccha?rides from coltsfoot leaves have been reported. Mucilaginous polysacchrides have been investigated in another report. Tussilagone, a sesquiterpene, has been isolated from ether extracts of the plant. It is a potent cardiovascular and respiratory stimulant.
Acids found in coltsfoot include caffeic, caffeoyltartaric, lerulic, gallic, p-hydroxybenzoic, tannic, malic, and tar?taric,a Farfaratin, a novel sesquiterpenoid compound, has been isolated from flower buds collected from the Shaanxi Province in China. At least 7 pyrrolizidine alkaloids, including tussilagin, senkirkine, and senecionine6 have been identified in coltsfoot. Coltsfoot leaves contain 2.8 to 4.1 ppm and the flowers 2.4 ppm senkirkine. Quantitative gas chromatographical analyses of pyrrolizi?dine alkaloids have been performed for various commer?cial coltsfoot preparations.
Other constituents in coltsfoot include choline, paraffin, phytosterols, amyrin, and volatile oil.6,8 A recent report reviews chemistry and other aspects of the plant.
Coltsfoot preparations have long been used to soothe sore throats. The mucilage is most likely responsible for the demulcent effect of the plant. The mucilage is destroyed by burning; smoking the plant or inhaling vapors of the leaves steeped in water Would not be expected to provide any degree of symptomatic relief. Instead, the smoke may exacerbate existing respi?ratory conditions. However, one source mentions colts?foot in the form of a medicinal cigarette to help relieve asthma. Coltsfoot components have been found to increase the cilia activity in the frog esophagus, and this action may contribute to the plant's expectorant effect. Related. conditions for which coltsfoot has been used include bronchitis, laryngitis, pertussis, influenza, and lung congestion.5,6,8 It is one of the most popular Euro?pean remedies to treat chest ailments. Coltsfoot, in a mixture of Chinese herbs, has been evaluated in 66 cases of convalescent asthmatics and found useful in decreasing airway obstruction.
Coltsfoot polysaccharides and flavonoids have anti-in?flammatory actions. This effect was similar to that of indomethacin in one report. Weak anti-inflammatory actions have also been observed when tested against induced rat paw edema.
A compound designated L-652,469, was isolated from coltsfoot buds. This compound has been found to be a platelet-activating factor (PAF) inhibitor and a calcium channel blocker. PAF is known to be an integral component of the complex cascade mechanism involved in both acute and chronic asthma, and a number of naturally.