Botanical Name: Digitalis purpurea
Family: Plantaginaceae
Genus: Digitalis
Species: D. purpurea
Kingdom: Plantae
Order: Lamiales
Synonyms: Witches’ Gloves. Dead Men’s Bells. Fairy’s Glove. Gloves of Our Lady. Bloody Fingers. Virgin’s Glove. Fairy Caps. Folk’s Glove. Fairy Thimbles.
(Norwegian) Revbielde.
(German) Fingerhut.
Common Names: Foxglove, Common foxglove, Purple foxglove or Lady’s glove
Habitat: Digitalis purpurea is native and widespread throughout most of temperate Europe. It is also naturalised in parts of North America and some other temperate regions. The plants are well known as the original source of the heart medicine digoxin (also called digitalis or digitalin) It flourishes best in siliceous soil and grows well in loam, but is entirely absent from some calcareous districts, such as the chain of the Jura, and is also not found in the Swiss Alps. It occurs in Madeira and the Azores, but is, perhaps, introduced there. The genus contains only this one indigenous species, though several are found on the Continent.
Needing little soil, it is found often in the crevices of granite walls, as well as in dry hilly pastures, rocky places and by roadsides. Seedling Foxgloves spring up rapidly from recently-turned earth. Turner (1548), says that it grows round rabbitholes freely.
Description:
Digitalis purpurea is an herbaceous biennial or short-lived perennial plant. The leaves are spirally arranged, simple, 10–35 cm long and 5–12 cm broad, and are covered with gray-white pubescent and glandular hairs, imparting a woolly texture. The foliage forms a tight rosette at ground level in the first year.
The flowering stem develops in the second year, typically 1 to 2 m tall, sometimes longer. The flowers are arranged in a showy, terminal, elongated cluster, and each flower is tubular and pendent. The flowers are typically purple, but some plants, especially those under cultivation, may be pink, rose, yellow, or white. The inside surface of the flower tube is heavily spotted. The flowering period is early summer, sometimes with additional flower stems developing later in the season. The plant is frequented by bees, which climb right inside the flower tube to gain the nectar within….….click & see the pictures
The fruit is a capsule which splits open at maturity to release the numerous tiny (0.1-0.2 mm) seeds.
Cultivation:
The plant is popular as a garden subject, and numerous cultivars have been developed with a range of colours from white through pink to purple, such as “Dalmatian Purple”. Cultivated forms often show flowers completely surrounding the central spike, in contrast to the wild form, where the flowers only appear on one side. D. purpurea is easily grown from seed or purchased as potted plants in the spring.
Propagation: Seed – surface sow early spring in a cold frame. The seed usually germinates in 2 – 4 weeks at 20°c[175]. When they are large enough to handle, prick the seedlings out into individual pots and plant them out in the summer. If you have sufficient seed it can be sown outdoors in situ in the spring or autumn
Part Used in medicines: The Leaves.
Medicinal Uses:
Digitalis has been used from early times in heart cases. It increases the activity of all forms of muscle tissue, but more especially that of the heart and arterioles, the all-important property of the drug being its action on the circulation. The first consequence of its absorption is a contraction of the heart and arteries, causing a very high rise in the blood pressure.
After the taking of a moderate dose, the pulse is markedly slowed. Digitalis also causes an irregular pulse to become regular. Added to the greater force of cardiac contraction is a permanent tonic contraction of the organ, so that its internal capacity is reduced, which is a beneficial effect in cases of cardiac dilatation, and it improves the nutrition of the heart by increasing the amount of blood.
In ordinary conditions it takes about twelve hours or more before its effects on the heart muscle is appreciated, and it must thus always be combined with other remedies to tide the patient over this period and never prescribed in large doses at first, as some patients are unable to take it, the drug being apt to cause considerable digestive disturbances, varying in different cases. This action is probably due to the Digitonin, an undesirable constituent.
The action of the drug on the kidneys is of importance only second to its action on the circulation. In small or moderate doses, it is a powerful diuretic and a valuable remedy in dropsy, especially when this is connected with affections of the heart.
It has also been employed in the treatment of internal haemorrhage, in inflammatory diseases, in delirium tremens, in epilepsy, in acute mania and various other diseases, with real or supposed benefits.
The action of Digitalis in all the forms in which it is administered should be carefully watched, and when given over a prolonged period it should be employed with caution, as it is liable to accumulate in the system and to manifest its presence all at once by its poisonous action, indicated by the pulse becoming irregular, the blood-pressure low and gastro-intestinal irritation setting in. The constant use of Digitalis, also, by increasing the activity of the heart, leads to hypertrophy of that organ.
Digitalis is an excellent antidote in Aconite poisoning, given as a hypodermic injection.
Digoxigenin (DIG) is a steroid found exclusively in the flowers and leaves of the plants Digitalis purpurea and Digitalis lanata. It is used as a molecular probe to detect DNA or RNA. It can easily be attached to nucleotides by chemical modifications. DIG molecules are often linked to uridine nucleotides; DIG-labeled uridine (DIG-U) can then be incorporated into RNA probes via in vitro transcription. Once hybridisation occurs in situ, RNA probes with the incorporated DIG-U can be detected with anti-DIG antibodies conjugated to alkaline phosphatase. To reveal the hybridised transcripts, alkaline phosphatase can be reacted with a chromogen to produce a coloured precipitate.
Other Uses: Dye; Preservative…..An infusion of the plant prolongs the life of cut flowers. Root crops growing near this plant store better. An apple-green dye is obtained from the flowers.
Known Hazards:
Due to the presence of the cardiac glycoside digitoxin, the leaves, flowers and seeds of this plant are all poisonous to humans and some animals and can be fatal if ingested.
Extracted from the leaves, this same compound, whose clinical use was pioneered as digitalis by William Withering, is used as a medication for heart failure. He recognized it “reduced dropsy”, increased urine flow and had a powerful effect on the heart. Unlike the purified pharmacological forms, extracts of this plant did not frequently cause intoxication because they induced nausea and vomiting within minutes of ingestion, preventing the patient from consuming more.
The main toxins in Digitalis spp. are the two chemically similar cardiac glycosides: digitoxin and digoxin. Like other cardiac glycosides, these toxins exert their effects by inhibiting the ATPase activity of a complex of transmembrane proteins that form the sodium potassium ATPase pump, (Na+/K+-ATPase). Inhibition of the Na+/K+-ATPase in turn causes a rise not only in intracellular Na+, but also in calcium, which in turn results in increased force of myocardial muscle contractions. In other words, at precisely the right dosage, Digitalis toxin can cause the heart to beat more strongly. However, digitoxin, digoxin and several other cardiac glycosides, such as ouabain, are known to have steep dose-response curves, i.e., minute increases in the dosage of these drugs can make the difference between an ineffective dose and a fatal one.
Symptoms of Digitalis poisoning include a low pulse rate, nausea, vomiting, and uncoordinated contractions of different parts of the heart, leading to cardiac arrest and finally death.
Disclaimer : The information presented herein is intended for educational purposes only. Individual results may vary, and before using any supplement, it is always advisable to consult with your own health care provider.
Resources:
https://en.wikipedia.org/wiki/Digitalis_purpurea
http://www.botanical.com/botanical/mgmh/f/foxglo30.html
