Digitalis purpurea
Encyclopedia
Digitalis purpurea is a flowering plant
in the family Plantaginaceae
(formerly treated in the family Scrophulariaceae), native to most of Europe
.
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. 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 flower
s 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 corolla is spotted inside the bottom of the tube. The flowering period is early summer, sometimes with additional flower stems developing later in the season.
The fruit
is a capsule
which splits open at maturity to release the numerous tiny (0.1-0.2 mm) seed
s.
:
(Hybrid formula: Digitalis grandiflora
Mill. × Digitalis purpurea
L.).
digitoxin
, the leaves, flowers and seeds of this plant are all poison
ous to humans and some animals and can be fatal if eaten.
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 that it "reduced dropsy", increased urine
flow and had a powerful effect on the heart. Unlike the purified pharmacological forms, extracts of this plant didn't frequently cause intoxication because they induced nausea and vomiting within minutes of ingestion, preventing the patient from consuming more.
The main toxins in Digitalis are the two chemically similar cardiac glycosides: digitoxin
and digoxin
. Like other cardiac glycosides, the Digitalis 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.
Selected forms, either for colour or for dwarf habit, are sold as pot plants.
Use in Molecular Biology
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 that are conjugated to alkaline phosphatase
. To reveal the hybridised transcripts, alkaline phosphatase
can be reacted with a chromogen to produce a colour precipitate.
titled "Digitale Purpurea". It also inspired the Italian industrial metal
band Digitalis Purpurea
.
Flowering plant
The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...
in the family Plantaginaceae
Plantaginaceae
Plantaginaceae Juss. or plantain family, are a family of flowering plants in the order Lamiales. The type genus is Plantago L..In older classifications it used to be the only family of the order Plantaginales, but numerous phylogenetic studies, summarized by the Angiosperm Phylogeny Group, have...
(formerly treated in the family Scrophulariaceae), native to most of Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
.
Description
Digitalis purpurea is an herbaceousHerbaceous
A herbaceous plant is a plant that has leaves and stems that die down at the end of the growing season to the soil level. They have no persistent woody stem above ground...
biennial
Biennial plant
A biennial plant is a flowering plant that takes two years to complete its biological lifecycle. In the first year the plant grows leaves, stems, and roots , then it enters a period of dormancy over the colder months. Usually the stem remains very short and the leaves are low to the ground, forming...
or short lived perennial plant. The leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
are spirally arranged, simple, 10-35 cm long and 5-12 cm broad, and are covered with gray-white pubescent and glandular hairs. 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 flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
s 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 corolla is spotted inside the bottom of the tube. The flowering period is early summer, sometimes with additional flower stems developing later in the season.
The fruit
Fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...
is a capsule
Capsule (fruit)
In botany a capsule is a type of simple, dry fruit produced by many species of flowering plants. A capsule is a structure composed of two or more carpels that in most cases is dehiscent, i.e. at maturity, it splits apart to release the seeds within. A few capsules are indehiscent, for example...
which splits open at maturity to release the numerous tiny (0.1-0.2 mm) seed
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...
s.
Subspecies
There are three subspeciesSubspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
:
- Digitalis purpurea subsp. purpurea – most of Europe
- Digitalis purpurea subsp. heywoodii – Iberia
- Digitalis purpurea subsp. mariana – Iberia
Hybrids
- Digitalis x fulvaDigitalis x fulvaDigitalis x fulva, Lindl. 1821, common name Strawberry foxglove, is a hybrid between D. grandiflora and D. purpurea . This hybrid is considered fertile.-Description:...
, Lindl. 1821
(Hybrid formula: Digitalis grandiflora
Digitalis grandiflora
Digitalis grandiflora is a flowering plant in the family Plantaginaceae. In mountains it grows on warm, bushy slopes or areas left after logging....
Mill. × Digitalis purpurea
Digitalis purpurea
Digitalis purpurea , is a flowering plant in the family Plantaginaceae , native to most of Europe.-Description:...
L.).
Toxicity
Due to the presence of the cardiac glycosideCardiac glycoside
Cardiac glycosides are drugs used in the treatment of congestive heart failure and cardiac arrhythmia. These glycosides are found as secondary metabolites in several plants, but also in some animals, such as the milkweed butterflies. -Function:...
digitoxin
Digitoxin
Digitoxin is a cardiac glycoside. It has similar structure and effects to digoxin . Unlike digoxin , it is eliminated via the liver, so could be used in patients with poor or erratic kidney function. However, it is now rarely used in current Western medical practice...
, the leaves, flowers and seeds of this plant are all poison
Poison
In the context of biology, poisons are substances that can cause disturbances to organisms, usually by chemical reaction or other activity on the molecular scale, when a sufficient quantity is absorbed by an organism....
ous to humans and some animals and can be fatal if eaten.
Extracted from the leaves, this same compound, whose clinical use was pioneered as digitalis
Digitalis
Digitalis is a genus of about 20 species of herbaceous perennials, shrubs, and biennials that are commonly called foxgloves. This genus was traditionally placed in the figwort family Scrophulariaceae, but recent reviews of phylogenetic research have placed it in the much enlarged family...
by William Withering
William Withering
William Withering was an English botanist, geologist, chemist, physician and the discoverer of digitalis.-Introduction:...
, is used as a medication for heart failure. He recognized that it "reduced dropsy", increased urine
Urine
Urine is a typically sterile liquid by-product of the body that is secreted by the kidneys through a process called urination and excreted through the urethra. Cellular metabolism generates numerous by-products, many rich in nitrogen, that require elimination from the bloodstream...
flow and had a powerful effect on the heart. Unlike the purified pharmacological forms, extracts of this plant didn't frequently cause intoxication because they induced nausea and vomiting within minutes of ingestion, preventing the patient from consuming more.
The main toxins in Digitalis are the two chemically similar cardiac glycosides: digitoxin
Digitoxin
Digitoxin is a cardiac glycoside. It has similar structure and effects to digoxin . Unlike digoxin , it is eliminated via the liver, so could be used in patients with poor or erratic kidney function. However, it is now rarely used in current Western medical practice...
and digoxin
Digoxin
Digoxin INN , also known as digitalis, is a purified cardiac glycoside and extracted from the foxglove plant, Digitalis lanata. Its corresponding aglycone is digoxigenin, and its acetyl derivative is acetyldigoxin...
. Like other cardiac glycosides, the Digitalis toxins exert their effects by inhibiting the ATPase
ATPase
ATPases are a class of enzymes that catalyze the decomposition of adenosine triphosphate into adenosine diphosphate and a free phosphate ion. This dephosphorylation reaction releases energy, which the enzyme harnesses to drive other chemical reactions that would not otherwise occur...
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
Digitoxin
Digitoxin is a cardiac glycoside. It has similar structure and effects to digoxin . Unlike digoxin , it is eliminated via the liver, so could be used in patients with poor or erratic kidney function. However, it is now rarely used in current Western medical practice...
, digoxin
Digoxin
Digoxin INN , also known as digitalis, is a purified cardiac glycoside and extracted from the foxglove plant, Digitalis lanata. Its corresponding aglycone is digoxigenin, and its acetyl derivative is acetyldigoxin...
and several other cardiac glycosides, such as ouabain
Ouabain
Ouabain which is also named g-strophanthin, is a poisonous cardiac glycoside.-Sources:Ouabain is found in the ripe seeds of African plants Strophanthus gratus and the bark of Acokanthera ouabaio.-Function:...
, 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.
Uses
The plant is sometimes grown in gardens. In suitable conditions it generally seeds itself in partial shade, and can become a minor weed. The pollen contains up to 80% digitalis and this pollen can be found on neighboring plants stamens when they are in bloom. This effect can cause accidental digitalis exposure if the exposed stamens of other plants are consumed in any way by humans. During the peak pollen production, in some areas the pollen floats heavily in the air and will stick to exposed surfaces.Selected forms, either for colour or for dwarf habit, are sold as pot plants.
Use in Molecular BiologyMolecular biologyMolecular biology is the branch of biology that deals with the molecular basis of biological activity. This field overlaps with other areas of biology and chemistry, particularly genetics and biochemistry...
: DigoxigeninDigoxigeninDigoxigenin is a steroid found exclusively in the flowers and leaves of the plants Digitalis purpurea, Digitalis orientalis and Digitalis lanata , where it is attached to sugars, to form the glycosides Digoxigenin (DIG) is a steroid found exclusively in the flowers and leaves of the plants...
DigoxigeninDigoxigenin
Digoxigenin is a steroid found exclusively in the flowers and leaves of the plants Digitalis purpurea, Digitalis orientalis and Digitalis lanata , where it is attached to sugars, to form the glycosides Digoxigenin (DIG) is a steroid found exclusively in the flowers and leaves of the plants...
(DIG) is a steroid found exclusively in the flowers and leaves of the plants Digitalis purpurea and Digitalis lanata
Digitalis lanata
Digitalis lanata is a species of foxglove that is part of the Plantaginaceae family. It gets its name due to the texture of the leaves. Digitalis lanata, like some other foxglove species, is highly toxic in all parts of the plant...
. It is used as a molecular probe
Molecular probe
A molecular probe is a group of atoms or molecules attached to other molecules or cellular structures and used in studying the properties of these molecules and structures. Radioactive DNA or RNA sequences are used in molecular genetics to detect the presence of a complementary sequence by...
to detect DNA or RNA. It can easily be attached to nucleotides by chemical modifications. DIG molecules are often linked to uridine
Uridine
Uridine is a molecule that is formed when uracil is attached to a ribose ring via a β-N1-glycosidic bond.If uracil is attached to a deoxyribose ring, it is known as a deoxyuridine....
nucleotides; DIG labeled uridine
Uridine
Uridine is a molecule that is formed when uracil is attached to a ribose ring via a β-N1-glycosidic bond.If uracil is attached to a deoxyribose ring, it is known as a deoxyuridine....
(DIG-U) can then be incorporated into RNA
RNA
Ribonucleic acid , or RNA, is one of the three major macromolecules that are essential for all known forms of life....
probes via in vitro transcription. Once hybridisation occurs in situ, RNA
RNA
Ribonucleic acid , or RNA, is one of the three major macromolecules that are essential for all known forms of life....
probes with the incorporated DIG-U can be detected with anti-DIG antibodies that are conjugated to alkaline phosphatase
Alkaline phosphatase
Alkaline phosphatase is a hydrolase enzyme responsible for removing phosphate groups from many types of molecules, including nucleotides, proteins, and alkaloids. The process of removing the phosphate group is called dephosphorylation...
. To reveal the hybridised transcripts, alkaline phosphatase
Alkaline phosphatase
Alkaline phosphatase is a hydrolase enzyme responsible for removing phosphate groups from many types of molecules, including nucleotides, proteins, and alkaloids. The process of removing the phosphate group is called dephosphorylation...
can be reacted with a chromogen to produce a colour precipitate.
In Literature and Music
This plant inspired a famous poem by the Italian poet Giovanni PascoliGiovanni Pascoli
Giovanni Placido Agostino Pascoli was an Italian poet and classical scholar.- Biography :Giovanni Pascoli was born at San Mauro di Romagna , into a well-to-do family. He was the fourth of ten children of Ruggero Pascoli and Caterina Vincenzi Alloccatelli...
titled "Digitale Purpurea". It also inspired the Italian industrial metal
Industrial metal
Industrial metal is a musical genre that draws from industrial music and many different types of heavy metal, using repeating metal guitar riffs, sampling, synthesizer or sequencer lines, and distorted vocals. Founding industrial metal acts include Ministry, Godflesh, and KMFDM.Industrial metal's...
band Digitalis Purpurea
Digitalis Purpurea (band)
-Biography:Digitalis Purpurea is an industrial metal project creating music since 2000 from Turin, Italy. Digitalis Purpurea is the botanic name of the Purple Foxglove, a plant symbol of temptation, pleasant but at the same time destructive. Traditionally the foxglove was used as medical plant but...
.