St John's wort
Encyclopedia
St John's wort is the plant
species
Hypericum perforatum, and is also known as Tipton's Weed, Chase-devil, or Klamath weed.
With qualifiers, St John's wort is used to refer to any species of the genus Hypericum
. Therefore, H. perforatum is sometimes called Common St John's wort to differentiate it. The species of Hypericum are classified in the Hypericaceae
family, having previously been classified as Guttiferae or Clusiaceae
. Approximately 370 species of the genus Hypericum exist worldwide with a native geographical distribution including temperate and subtropical regions of North America
, Europe
, Turkey
, Russia
, India
, China
and Brazil
.
St John's wort is widely known as an herbal treatment for depression
.
herb
indigenous to Europe, which has been introduced to many temperate areas of the world and grows wild in many meadows. The common name comes from its traditional flowering and harvesting on St John's
day, 24 June. The genus
name Hypericum is derived from the Greek words hyper (above) and eikon (picture), in reference to the traditional use of the plant to ward off evil, by hanging plants over a religious icon in the house during St John's day. The species
name perforatum refers to the presence of small oil glands in the leaves that look like windows, which can be seen when they are held against the light.
St John's wort is a perennial plant
with extensive, creeping rhizomes. Its stems are erect, branched in the upper section, and can grow to 1 m high. It has opposing, stalkless, narrow, oblong leaves that are 12 mm long or slightly larger. The leaves are yellow-green in color, with transparent dots throughout the tissue and occasionally with a few black dots on the lower surface. Leaves exhibit obvious translucent dots when held up to the light, giving them a ‘perforated’ appearance, hence the plant's Latin name.
Its flowers measure up to 2.5 cm across, have five petals, and are colored bright yellow with conspicuous black dots. The flowers appear in broad cymes
at the ends of the upper branches, between late Spring and early to mid Summer. The sepals are pointed, with glandular dots in the tissue. There are many stamens, which are united at the base into three bundles.
When flower buds (not the flowers themselves) or seed pods are crushed, a reddish/purple liquid is produced.
The seeds can persist for decades in the soil seed bank
, germinating following disturbance.
Although Hypericum perforatum is grown commercially in some regions of south east Europe, it is listed as a noxious weed in more than twenty countries and has introduced populations in South and North America, India, New Zealand, Australia, and South Africa. In pastures, St John’s wort acts as both a toxic and invasive weed. It replaces native
plant communities and forage
vegetation to the dominating extent of making productive land nonviable or becoming an invasive species
in natural habitat
s and ecosystem
s. Ingestion by livestock can cause photosensitization, central nervous system depression, spontaneous abortion, and can lead to death. Effective herbicides for control of Hypericum include 2,4-D, picloram, and glyphosate. In western North America
three beetles Chrysolina quadrigemina, Chrysolina hyperici and Agrilus hyperici
have been introduced as biocontrol
agents.
St John's wort is widely known as an herbal treatment for depression
. In some countries, such as Germany
, it is commonly prescribed for mild depression, especially in children and adolescents.
A report from the Cochrane Review states,
Standardized extracts are generally available over the counter
, though in some countries (such as the Republic of Ireland
) a prescription is required. Extracts are usually in tablet
or capsule form, and also in teabags and tincture
s. Herbalists are more likely to use a fluid extract than a tincture. Hypericum was prescribed in ancient Greece
, and it has been used ever since.
An analysis of twenty-nine clinical trials with more than five thousand patients was conducted by Cochrane Collaboration
. The review concluded that extracts of St. John's wort were superior to placebo in patients with major depression. St John's wort had similar efficacy to standard antidepressants. The rate of side-effects was half that of newer SSRI
antidepressants and one-fifth that of older tricyclic antidepressants.
National Center for Complementary and Alternative Medicine (NCCAM) and other NIH-affiliated organizations hold that St John's wort has minimal or no effects beyond placebo in the treatment of major depression. This conclusion is based primarily on one trial of 340 volunteers, with negative outcome conducted by NCCAM. The authors of the study themselves, as well as several others, pointed out the low assay sensitivity
of this study, and how only limited conclusions can be drawn from its results. The same study also indicated that sertraline (Zoloft) has no positive effects vs. the same placebo.
St. John's wort has not been found to be effective for patients suffering from dysthymia, a less severe and more chronic variety of depression.
St. John's wort is "associated with aggravating psychosis in schizophrenia".
St. John's wort is being studied for effectiveness in the treatment of certain somatoform disorders. Results from the initial studies are mixed and still inconclusive; some research has found no effectiveness, other research has found a slight lightening of symptoms. Further study is needed and is being performed.
A a major constituent chemical, hyperforin
, may be useful for treatment of alcoholism
, although dosage, safety and efficacy have not been studied. Hyperforin has also displayed antibacterial properties against gram-negative bacteria, although dosage, safety and efficacy has not been studied. Traditional medicine
has also employed lipophilic extracts from St. John's wort as a topical remedy for wounds, abrasions, burns, and muscle pain
. The positive effects that have been observed are generally attributed to hyperforin due to its possible antibacterial and anti-inflammatory effects. For this reason hyperforin may be useful in the treatment of infected wounds and inflammatory skin diseases. In response to hyperforin's incorporation into a new bath oil, a study to assess potential skin irritation was conducted which found good skin tolerance of St. John's Wort.
A randomized controlled trial
of St John's wort found no significant
difference between it and placebo in the management of ADHD symptoms over eight weeks. However, the St. John's Wort extract used in the study, originally confirmed to contain 0.3% hypericin, was allowed to degrade to levels of 0.13% hypericin and 0.14% hyperforin. Given that the level of hyperforin was not ascertained at the beginning of the study, and levels of both hyperforin and hypericin were well below that used in other studies, little can be determined based on this study alone.
A research team from the Universidad Complutense de Madrid (UCM) published a study entitled, "Hypericum perforatum. Possible option against Parkinson's disease
", which suggests that St John's wort has antioxidant
active ingredients that could help reduce the neuronal degeneration caused by the disease.
Recent evidence suggests that daily treatment with St. Johns wort may improve the most common physical and behavioural symptoms associated with premenstrual syndrome.
St John's wort was found to be less effective than placebo
, in a randomized, double-blind, placebo-controlled trial, for the treatment of irritable bowel syndrome
.
St. John's Wort alleviated age-related long-term memory impairment in rats.
. The most common adverse effects reported are gastrointestinal symptoms, dizziness, confusion, tiredness and sedation.
St John's wort may rarely cause photosensitivity
. This can lead to visual sensitivity to light and to sunburns in situations that would not normally cause them. Related to this, recent studies concluded that the extract reacts with light, both visible and ultraviolet, to produce free radicals, molecules that can damage the cells of the body. These can react with vital proteins in the eye that, if damaged, precipitate out, causing cataract
s. This finding is contradicted by the results of another recent study, which found that St. John's wort inhibits free radical production in both cell-free and human vascular tissue, revealing antioxidant properties of the compound.
Women who use the contraceptive implant Implanon
are advised not to take St John’s Wort as it reduces the implant's effectiveness.
of the cytochrome P450 enzyme CYP3A4
, but also CYP2C9
. This results in the increased metabolism of those drugs, resulting in decreased concentration and clinical effect. The principal constituents thought to be responsible are hyperforin
and amentoflavone
.
St. John's wort also has been shown to cause drug interactions through the induction
of the P-glycoprotein (P-gp)
efflux transporter. Increased P-gp
expression results in decreased absorption and increased clearance of those drugs, which leads to lower clinical concentrations and efficacy.
For a complete list, see CYP3A4 ligands and CYP2C9 ligands. For further updating on interactions and appropriate management, see Herbological.com – St John's Wort Interactions table.
, a potentially life-threatening adverse drug reaction, in combination with other drugs that may elevate 5-HT (serotonin) levels in the central nervous system
(CNS).
Contains a high concentration of Melatonin. Herb and flowers contain various polyphenols: flavonoids (rutin
, hyperoside
, isoquercetin, quercitrin
, quercetin
, I3,II8-biapigenin, amentoflavone
, astilbin
, miquelianin), phenolic acids (chlorogenic acid
, 3-O-coumaroylquinic acid), and various naphtodianthrones: (hypericin
, pseudohypericin, protohypericin, protopseudohypericin), phloroglucinol
s (hyperforin
, adhyperforin). The naphthodianthrones hypericin and pseudohypericin along with the phloroglucinol derivative hyperforin are thought to be the active components. It also contains essential oils composed mainly of sesquiterpene
s.
The exact mechanism by which St John's wort functions is unclear and subject to conjecture. The St John's wort mechanism is believed to involve inhibition of serotonin (5-HT)
reuptake, much like the conventional selective serotonin reuptake inhibitor
(SSRI) antidepressants. The major active antidepressive constituents in St John's wort are thought to be hyperforin
and hypericin
, although other biologically active constituents present, for example, flavonoid
s and tannin
s, may also be involved.
Some believe that hyperforin
is the major constituent responsible for antidepressant activity, and it has been shown to inhibit the uptake of 5-HT, dopamine
, and noradrenaline. Hyperforin
also has affinity for GABA
and glutamate receptors. On the other hand, an hyperforin-free extract of St John's wort (Ze 117 – Remotiv) may still have significant antidepressive effects.
ous to grazing livestock
(cattle, sheep, goats, horses). Behavioural signs of poisoning are general restlessness and skin irritation. Restlessness is often indicated by pawing of the ground, headshaking
, head rubbing, and occasional hindlimb weakness with knuckling over, panting, confusion, and depression. Mania and hyperactivity may also result, including running in circles until exhausted. Observations of thick wort infestations by Australian graziers include the appearance of circular patches giving hillsides a ‘crop circle’ appearance, it is presumed, from this phenomenon. Animals typically seek shade and have reduced appetite. Hypersensitivity to water has been noted, and convulsions may occur following a knock to the head. Although general aversion to water is noted, some may seek water for relief.
Severe skin irritation is physically apparent, with reddening of non-pigmented and unprotected areas. This subsequently leads to itch and rubbing, followed by further inflammation, exudation, and scab formation. Lesions and inflammation that occur are said to resemble the conditions seen in foot and mouth disease. Sheep have been observed to have face swelling, dermatitis, and wool falling off due to rubbing. Lactating animals may cease or have reduced milk production; pregnant animals may abort
. Lesions on udder
s are often apparent. Horses may show signs of anorexia
, depression
(with a comatose state), dilated pupils, and injected conjunctiva
.
of lesions. Some affected animals may accidentally drown. Poor performance of suckling lambs (pigmented and non-pigmented) has been noted, suggesting a reduction in the milk production, or the transmission of a toxin in the milk.
. Plants may induce either primary or secondary photosensitisation:
Araya and Ford (1981) explored changes in liver function and concluded there was no evidence of Hypericum-related effect on the excretory capacity of the liver, or any interference was minimal and temporary. However, evidence of liver damage in blood plasma has been found at high and long rates of dosage.
Photosensitisation causes skin inflammation by a mechanism involving a pigment or photodynamic compound, which when activated by a certain wavelength of light leads to oxidation
reactions in vivo
. This leads to lesions of tissue, particularly noticeable on and around parts of skin exposed to light. Lightly covered or poorly pigment
ed areas are most conspicuous. Removal of affected animals from sunlight results in reduced symptoms of poisoning.
internally as an abortifacient
and externally as an anti-inflammatory
, astringent
, and antiseptic
.
St. John's wort's has long been used as a herbal tea.
St. John's wort is also a common flavoring agent in Japan
ese udon
noodles.
The flowers and stems of Hypericum perforatum have been used to produce red and yellow dye
s.
type of ornamental plant
used in garden
s, including drought tolerant landscaping.
Review articles
Plant
Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...
species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
Hypericum perforatum, and is also known as Tipton's Weed, Chase-devil, or Klamath weed.
With qualifiers, St John's wort is used to refer to any species of the genus Hypericum
Hypericum
Hypericum is a genus of about 400 species of flowering plants in the family Hypericaceae ....
. Therefore, H. perforatum is sometimes called Common St John's wort to differentiate it. The species of Hypericum are classified in the Hypericaceae
Hypericaceae
Hypericaceae is a plant family in the order Malpighiales. Molecular data supports its monophyly. Some systematists treat it as a subfamily of the Clusiaceae. When it is accepted as a distinct family, it contains the following genera:* Cratoxylum Blume...
family, having previously been classified as Guttiferae or Clusiaceae
Clusiaceae
The Clusiaceae or Guttiferae Juss. is a family of plants formerly including about 37 genera and 1610 species of trees and shrubs, often with milky sap and fruits or capsules for seeds. It is primarily tropical...
. Approximately 370 species of the genus Hypericum exist worldwide with a native geographical distribution including temperate and subtropical regions of North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
, 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...
, Turkey
Turkey
Turkey , known officially as the Republic of Turkey , is a Eurasian country located in Western Asia and in East Thrace in Southeastern Europe...
, Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
, India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
, China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
and Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
.
St John's wort is widely known as an herbal treatment for depression
Depression (mood)
Depression is a state of low mood and aversion to activity that can affect a person's thoughts, behaviour, feelings and physical well-being. Depressed people may feel sad, anxious, empty, hopeless, helpless, worthless, guilty, irritable, or restless...
.
Botanical description
Hypericum perforatum is a yellow-flowering, stoloniferous or sarmentose, perennialPerennial plant
A perennial plant or simply perennial is a plant that lives for more than two years. The term is often used to differentiate a plant from shorter lived annuals and biennials. The term is sometimes misused by commercial gardeners or horticulturalists to describe only herbaceous perennials...
herb
Herb
Except in botanical usage, an herb is "any plant with leaves, seeds, or flowers used for flavoring, food, medicine, or perfume" or "a part of such a plant as used in cooking"...
indigenous to Europe, which has been introduced to many temperate areas of the world and grows wild in many meadows. The common name comes from its traditional flowering and harvesting on St John's
John the Baptist
John the Baptist was an itinerant preacher and a major religious figure mentioned in the Canonical gospels. He is described in the Gospel of Luke as a relative of Jesus, who led a movement of baptism at the Jordan River...
day, 24 June. The genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
name Hypericum is derived from the Greek words hyper (above) and eikon (picture), in reference to the traditional use of the plant to ward off evil, by hanging plants over a religious icon in the house during St John's day. The species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
name perforatum refers to the presence of small oil glands in the leaves that look like windows, which can be seen when they are held against the light.
St John's wort is a perennial plant
Perennial plant
A perennial plant or simply perennial is a plant that lives for more than two years. The term is often used to differentiate a plant from shorter lived annuals and biennials. The term is sometimes misused by commercial gardeners or horticulturalists to describe only herbaceous perennials...
with extensive, creeping rhizomes. Its stems are erect, branched in the upper section, and can grow to 1 m high. It has opposing, stalkless, narrow, oblong leaves that are 12 mm long or slightly larger. The leaves are yellow-green in color, with transparent dots throughout the tissue and occasionally with a few black dots on the lower surface. Leaves exhibit obvious translucent dots when held up to the light, giving them a ‘perforated’ appearance, hence the plant's Latin name.
Its flowers measure up to 2.5 cm across, have five petals, and are colored bright yellow with conspicuous black dots. The flowers appear in broad cymes
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
at the ends of the upper branches, between late Spring and early to mid Summer. The sepals are pointed, with glandular dots in the tissue. There are many stamens, which are united at the base into three bundles.
When flower buds (not the flowers themselves) or seed pods are crushed, a reddish/purple liquid is produced.
Ecology
St John’s wort reproduces both vegetatively and sexually. It thrives in areas with either a winter- or summer-dominant rainfall pattern; however, distribution is restricted by temperatures too low for seed germination or seedling survival. Altitudes greater than 1500 m, rainfall less than 500 mm, and a daily mean January temperature greater than 24 degrees C are considered limiting thresholds. Depending on environmental and climatic conditions, and rosette age, St John’s wort will alter growth form and habit to promote survival. Summer rains are particularly effective in allowing the plant to grow vegetatively, following defoliation by insects or grazing.The seeds can persist for decades in the soil seed bank
Soil Seed Bank
The soil seed bank refers to the natural storage of seeds, often dormant, within the soil of most ecosystems. The study of soil seed banks started in 1859 when Charles Darwin observed the emergence of seedlings using soil samples from the bottom of a lake. The first scientific paper on the subject...
, germinating following disturbance.
Invasive species
Native plant
Native plant is a term to describe plants endemic or naturalized to a given area in geologic time.This includes plants that have developed, occur naturally, or existed for many years in an area...
plant communities and forage
Forage
Forage is plant material eaten by grazing livestock.Historically the term forage has meant only plants eaten by the animals directly as pasture, crop residue, or immature cereal crops, but it is also used more loosely to include similar plants cut for fodder and carried to the animals, especially...
vegetation to the dominating extent of making productive land nonviable or becoming an invasive species
Invasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
in natural habitat
Habitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
s and ecosystem
Ecosystem
An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the nonliving , physical components of the environment with which the organisms interact, such as air, soil, water and sunlight....
s. Ingestion by livestock can cause photosensitization, central nervous system depression, spontaneous abortion, and can lead to death. Effective herbicides for control of Hypericum include 2,4-D, picloram, and glyphosate. In western North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
three beetles Chrysolina quadrigemina, Chrysolina hyperici and Agrilus hyperici
Agrilus hyperici
Agrilus hyperici is a species of jewel beetle known by the common name St. John's wort root borer. It is used as an agent of biological pest control against the noxious weed known as common St. John's wort ....
have been introduced as biocontrol
BioControl
BioControl is a peer-reviewed scientific journal published by Springer Science+Business Media covering all aspects of basic and applied research in biological control of invertebrate, vertebrate, and weed pests, and plant diseases. The journal was established in 1956 as Entomophaga and published by...
agents.
Depression treatment use
Depression (mood)
Depression is a state of low mood and aversion to activity that can affect a person's thoughts, behaviour, feelings and physical well-being. Depressed people may feel sad, anxious, empty, hopeless, helpless, worthless, guilty, irritable, or restless...
. In some countries, such as Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
, it is commonly prescribed for mild depression, especially in children and adolescents.
A report from the Cochrane Review states,
The available evidence suggests that the Hypericum extracts tested in the included trials a) are superior to placebo in patients with major depression; b) are similarly effective as standard antidepressants; and c) have fewer side-effects than standard antidepressants.
There are two issues that complicate the interpretation of our findings:
1) While the influence of precision on study results in placebo-controlled trials is
less pronounced in this updated version of our review compared to the previous version (Linde 2005a), results from more precise trials still show smaller effects over placebo than less precise trials.
2) Results from German-language countries are considerably more favourable for hypericum than trials from other countries.
Standardized extracts are generally available over the counter
Over-the-counter drug
Over-the-counter drugs are medicines that may be sold directly to a consumer without a prescription from a healthcare professional, as compared to prescription drugs, which may be sold only to consumers possessing a valid prescription...
, though in some countries (such as the Republic of Ireland
Republic of Ireland
Ireland , described as the Republic of Ireland , is a sovereign state in Europe occupying approximately five-sixths of the island of the same name. Its capital is Dublin. Ireland, which had a population of 4.58 million in 2011, is a constitutional republic governed as a parliamentary democracy,...
) a prescription is required. Extracts are usually in tablet
Tablet
A tablet is a pharmaceutical dosage form. It comprises a mixture of active substances and excipients, usually in powder form, pressed or compacted from a powder into a solid dose...
or capsule form, and also in teabags and tincture
Tincture
A tincture is an alcoholic extract or solution of a non-volatile substance . To qualify as a tincture, the alcoholic extract is to have an ethanol percentage of at least 40-60%...
s. Herbalists are more likely to use a fluid extract than a tincture. Hypericum was prescribed in ancient Greece
Ancient Greece
Ancient Greece is a civilization belonging to a period of Greek history that lasted from the Archaic period of the 8th to 6th centuries BC to the end of antiquity. Immediately following this period was the beginning of the Early Middle Ages and the Byzantine era. Included in Ancient Greece is the...
, and it has been used ever since.
Dosage
Most studies of St. John's wort for treating depression used doses of 300 mg of an extract (standardized to 0.3 percent hypericin content) three times daily to achieve a therapeutic effect.Major depressive disorder
Cochrane Collaboration
The Cochrane Collaboration is a group of over 28,000 volunteers in more than 100 countries who review the effects of health care interventions tested in biomedical randomized controlled trials. A few more recent reviews have also studied the results of non-randomized, observational studies...
. The review concluded that extracts of St. John's wort were superior to placebo in patients with major depression. St John's wort had similar efficacy to standard antidepressants. The rate of side-effects was half that of newer SSRI
Selective serotonin reuptake inhibitor
Selective serotonin re-uptake inhibitors or serotonin-specific reuptake inhibitor are a class of compounds typically used as antidepressants in the treatment of depression, anxiety disorders, and some personality disorders. The efficacy of SSRIs is disputed...
antidepressants and one-fifth that of older tricyclic antidepressants.
National Center for Complementary and Alternative Medicine (NCCAM) and other NIH-affiliated organizations hold that St John's wort has minimal or no effects beyond placebo in the treatment of major depression. This conclusion is based primarily on one trial of 340 volunteers, with negative outcome conducted by NCCAM. The authors of the study themselves, as well as several others, pointed out the low assay sensitivity
Assay sensitivity
Assay sensitivity is a property of a clinical trial defined as the ability of a trial to distinguish an effective treatment from a less effective or ineffective intervention...
of this study, and how only limited conclusions can be drawn from its results. The same study also indicated that sertraline (Zoloft) has no positive effects vs. the same placebo.
St. John's wort has not been found to be effective for patients suffering from dysthymia, a less severe and more chronic variety of depression.
St. John's wort is "associated with aggravating psychosis in schizophrenia".
Other medical uses
A a major constituent chemical, hyperforin
Hyperforin
Hyperforin is a phytochemical produced by some of the members of the plant genus Hypericum, notably Hypericum perforatum .- Occurrence :...
, may be useful for treatment of alcoholism
Alcoholism
Alcoholism is a broad term for problems with alcohol, and is generally used to mean compulsive and uncontrolled consumption of alcoholic beverages, usually to the detriment of the drinker's health, personal relationships, and social standing...
, although dosage, safety and efficacy have not been studied. Hyperforin has also displayed antibacterial properties against gram-negative bacteria, although dosage, safety and efficacy has not been studied. Traditional medicine
Traditional medicine
Traditional medicine comprises unscientific knowledge systems that developed over generations within various societies before the era of modern medicine...
has also employed lipophilic extracts from St. John's wort as a topical remedy for wounds, abrasions, burns, and muscle pain
Myalgia
Myalgia means "muscle pain" and is a symptom of many diseases and disorders. The most common causes are the overuse or over-stretching of a muscle or group of muscles. Myalgia without a traumatic history is often due to viral infections...
. The positive effects that have been observed are generally attributed to hyperforin due to its possible antibacterial and anti-inflammatory effects. For this reason hyperforin may be useful in the treatment of infected wounds and inflammatory skin diseases. In response to hyperforin's incorporation into a new bath oil, a study to assess potential skin irritation was conducted which found good skin tolerance of St. John's Wort.
A randomized controlled trial
Randomized controlled trial
A randomized controlled trial is a type of scientific experiment - a form of clinical trial - most commonly used in testing the safety and efficacy or effectiveness of healthcare services or health technologies A randomized controlled trial (RCT) is a type of scientific experiment - a form of...
of St John's wort found no significant
Statistical significance
In statistics, a result is called statistically significant if it is unlikely to have occurred by chance. The phrase test of significance was coined by Ronald Fisher....
difference between it and placebo in the management of ADHD symptoms over eight weeks. However, the St. John's Wort extract used in the study, originally confirmed to contain 0.3% hypericin, was allowed to degrade to levels of 0.13% hypericin and 0.14% hyperforin. Given that the level of hyperforin was not ascertained at the beginning of the study, and levels of both hyperforin and hypericin were well below that used in other studies, little can be determined based on this study alone.
A research team from the Universidad Complutense de Madrid (UCM) published a study entitled, "Hypericum perforatum. Possible option against Parkinson's disease
Parkinson's disease
Parkinson's disease is a degenerative disorder of the central nervous system...
", which suggests that St John's wort has antioxidant
Antioxidant
An antioxidant is a molecule capable of inhibiting the oxidation of other molecules. Oxidation is a chemical reaction that transfers electrons or hydrogen from a substance to an oxidizing agent. Oxidation reactions can produce free radicals. In turn, these radicals can start chain reactions. When...
active ingredients that could help reduce the neuronal degeneration caused by the disease.
Recent evidence suggests that daily treatment with St. Johns wort may improve the most common physical and behavioural symptoms associated with premenstrual syndrome.
St John's wort was found to be less effective than placebo
Placebo
A placebo is a simulated or otherwise medically ineffectual treatment for a disease or other medical condition intended to deceive the recipient...
, in a randomized, double-blind, placebo-controlled trial, for the treatment of irritable bowel syndrome
Irritable bowel syndrome
Irritable bowel syndrome is a diagnosis of exclusion. It is a functional bowel disorder characterized by chronic abdominal pain, discomfort, bloating, and alteration of bowel habits in the absence of any detectable organic cause. In some cases, the symptoms are relieved by bowel movements...
.
St. John's Wort alleviated age-related long-term memory impairment in rats.
Adverse effects and drug interactions
St John's wort is generally well tolerated, with an adverse effect profile similar to placeboPlacebo
A placebo is a simulated or otherwise medically ineffectual treatment for a disease or other medical condition intended to deceive the recipient...
. The most common adverse effects reported are gastrointestinal symptoms, dizziness, confusion, tiredness and sedation.
St John's wort may rarely cause photosensitivity
Photodermatitis
Photodermatitis, sometimes referred to as "sun poisoning" or photoallergy is a form of allergic contact dermatitis in which the allergen must be activated by light to sensitize the allergic response, and to cause a rash or other systemic effects on subsequent exposure...
. This can lead to visual sensitivity to light and to sunburns in situations that would not normally cause them. Related to this, recent studies concluded that the extract reacts with light, both visible and ultraviolet, to produce free radicals, molecules that can damage the cells of the body. These can react with vital proteins in the eye that, if damaged, precipitate out, causing cataract
Cataract
A cataract is a clouding that develops in the crystalline lens of the eye or in its envelope, varying in degree from slight to complete opacity and obstructing the passage of light...
s. This finding is contradicted by the results of another recent study, which found that St. John's wort inhibits free radical production in both cell-free and human vascular tissue, revealing antioxidant properties of the compound.
Women who use the contraceptive implant Implanon
Implanon
Implanon, made by Organon International, is a single-rod long acting reversible hormonal contraceptive subdermal implant that is inserted just under the skin of a woman's upper arm. The 4 cm by 2 mm Implanon rod contains 68 milligrams of etonogestrel which is released over a three year...
are advised not to take St John’s Wort as it reduces the implant's effectiveness.
Pharmacokinetic interactions
St John's wort has been shown to cause multiple drug interactions through inductionEnzyme induction and inhibition
Enzyme induction is a process in which a molecule induces the expression of an enzyme.Enzyme inhibition can refer to* the inhibition of the expression of the enzyme by another molecule...
of the cytochrome P450 enzyme CYP3A4
CYP3A4
Cytochrome P450 3A4 , a member of the cytochrome P450 mixed-function oxidase system, is one of the most important enzymes involved in the metabolism of xenobiotics in the body. CYP3A4 is involved in the oxidation of the largest range of substrates of all the CYPs. As a result, CYP3A4 is present in...
, but also CYP2C9
CYP2C9
Cytochrome P450 2C9 is a protein that in humans is encoded by the CYP2C9 gene.- Function :CYP2C9 is an important cytochrome P450 enzyme with a major role in the oxidation of both xenobiotic and endogenous compounds. CYP2C9 makes up about 18% of the cytochrome P450 protein in liver microsomes...
. This results in the increased metabolism of those drugs, resulting in decreased concentration and clinical effect. The principal constituents thought to be responsible are hyperforin
Hyperforin
Hyperforin is a phytochemical produced by some of the members of the plant genus Hypericum, notably Hypericum perforatum .- Occurrence :...
and amentoflavone
Amentoflavone
Amentoflavone is a constituent of a number of plants with medicinal properties, including Ginkgo biloba and Hypericum perforatum .It is a biflavonoid ....
.
St. John's wort also has been shown to cause drug interactions through the induction
Enzyme induction and inhibition
Enzyme induction is a process in which a molecule induces the expression of an enzyme.Enzyme inhibition can refer to* the inhibition of the expression of the enzyme by another molecule...
of the P-glycoprotein (P-gp)
P-glycoprotein
P-glycoprotein 1 also known as multidrug resistance protein 1 or ATP-binding cassette sub-family B member 1 or cluster of differentiation 243 is a glycoprotein that in humans is encoded by the ABCB1 gene...
efflux transporter. Increased P-gp
P-glycoprotein
P-glycoprotein 1 also known as multidrug resistance protein 1 or ATP-binding cassette sub-family B member 1 or cluster of differentiation 243 is a glycoprotein that in humans is encoded by the ABCB1 gene...
expression results in decreased absorption and increased clearance of those drugs, which leads to lower clinical concentrations and efficacy.
| Class | Drugs |
|---|---|
| antiretrovirals | non-nucleoside reverse transcriptase inhibitors, protease inhibitor Protease inhibitor (pharmacology) Protease inhibitors are a class of drugs used to treat or prevent infection by viruses, including HIV and Hepatitis C. PIs prevent viral replication by inhibiting the activity of proteases, e.g.HIV-1 protease, enzymes used by the viruses to cleave nascent proteins for final assembly of new... s |
| benzodiazepine Benzodiazepine A benzodiazepine is a psychoactive drug whose core chemical structure is the fusion of a benzene ring and a diazepine ring... s |
alprazolam Alprazolam Alprazolam is a short-acting anxiolytic of the benzodiazepine class of psychoactive drugs. Alprazolam, like other benzodiazepines, binds to specific sites on the GABAA gamma-amino-butyric acid receptor... , midazolam Midazolam Midazolam is a short-acting drug in the benzodiazepine class developed by Hoffmann-La Roche in the 1970s. The drug is used for treatment of acute seizures, moderate to severe insomnia, and for inducing sedation and amnesia before medical procedures. It possesses profoundly potent anxiolytic,... |
| hormonal contraception Hormonal contraception Hormonal contraception refers to birth control methods that act on the endocrine system. Almost all methods are composed of steroid hormones, although in India one selective estrogen receptor modulator is marketed as a contraceptive. The original hormonal method—the combined oral contraceptive... |
combined oral contraceptives |
| immunosuppressant Immunosuppressant An immunosuppressant is any substance that performs immunosuppression of the immune system. They may be either exogenous, as immunosuppressive drugs, or endogenous, as ,e. g., testosterone... s |
calcineurin inhibitors, cyclosporine, tacrolimus Tacrolimus Tacrolimus is an immunosuppressive drug that is mainly used after allogeneic organ transplant to reduce the activity of the patient's immune system and so lower the risk of organ rejection... |
| antiarrhythmics | amiodarone Amiodarone Amiodarone is an antiarrhythmic agent used for various types of tachyarrhythmias , both ventricular and supraventricular arrhythmias. Discovered in 1961, it was not approved for use in the United States until 1985... , flecainide Flecainide Flecainide acetate is a class Ic antiarrhythmic agent used to prevent and treat tachyarrhythmias . It is used to treat a variety of cardiac arrhythmias including paroxysmal atrial fibrillation , paroxysmal supraventricular tachycardia Flecainide acetate is a class Ic antiarrhythmic agent used to... , mexiletine Mexiletine Mexiletine belongs to the Class IB anti-arrhythmic group of medicines. It is used to treat arrhythmias within the heart, or seriously irregular heartbeats. It slows conduction in the heart and makes the heart tissue less sensitive. Dizziness, heartburn, nausea, nervousness, trembling, unsteadiness... |
| beta-blockers | metoprolol Metoprolol Metoprolol is a selective β1 receptor blocker used in treatment of several diseases of the cardiovascular system, especially hypertension. The active substance metoprolol is employed either as metoprolol succinate or metoprolol tartrate... , carvedilol Carvedilol Carvedilol is a non-selective beta blocker/alpha-1 blocker indicated in the treatment of mild to moderate congestive heart failure . It is marketed under various trade names including Carvil , Coreg , Dilatrend , Eucardic , and Carloc as a generic drug ., and as a... |
| calcium channel blockers | verapamil Verapamil Verapamil is an L-type calcium channel blocker of the phenylalkylamine class. It has been used in the treatment of hypertension, angina pectoris, cardiac arrhythmia, and most recently, cluster headaches. It is also an effective preventive medication for migraine... , diltiazem Diltiazem Diltiazem is a non-dihydropyridine member of the class of drugs known as calcium channel blockers, used in the treatment of hypertension, angina pectoris, and some types of arrhythmia.... , amlodipine Amlodipine Amlodipine is a long-acting calcium channel blocker used as an anti-hypertensive and in the treatment of angina... |
| statin Statin Statins are a class of drugs used to lower cholesterol levels by inhibiting the enzyme HMG-CoA reductase, which plays a central role in the production of cholesterol in the liver. Increased cholesterol levels have been associated with cardiovascular diseases, and statins are therefore used in the... s (cholesterol-reducing medications) |
lovastatin Lovastatin Lovastatin is a member of the drug class of statins, used for lowering cholesterol in those with hypercholesterolemia and so preventing cardiovascular disease... , simvastatin Simvastatin Simvastatin is a hypolipidemic drug used to control elevated cholesterol, or hypercholesterolemia. Simvastatin is a member of the statin class of pharmaceuticals, is a synthetic derivate of a fermentation product of Aspergillus terreus.-Medical uses:The primary uses of simvastatin is for the... , atorvastatin Atorvastatin Atorvastatin , sold by Pfizer under the trade name Lipitor, is a member of the drug class known as statins, used for lowering blood cholesterol. It also stabilizes plaque and prevents strokes through anti-inflammatory and other mechanisms... |
| others | 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... , methadone Methadone Methadone is a synthetic opioid, used medically as an analgesic and a maintenance anti-addictive for use in patients with opioid dependency. It was developed in Germany in 1937... , omeprazole Omeprazole Omeprazole is a proton pump inhibitor used in the treatment of dyspepsia, peptic ulcer disease , gastroesophageal reflux disease , laryngopharyngeal reflux and Zollinger–Ellison syndrome... , phenobarbital Phenobarbital Phenobarbital or phenobarbitone is a barbiturate, first marketed as Luminal by Friedr. Bayer et comp. It is the most widely used anticonvulsant worldwide, and the oldest still commonly used. It also has sedative and hypnotic properties but, as with other barbiturates, has been superseded by the... , theophylline Theophylline Theophylline, also known as dimethylxanthine, is a methylxanthine drug used in therapy for respiratory diseases such as COPD and asthma under a variety of brand names. Because of its numerous side-effects, the drug is now rarely administered for clinical use. As a member of the xanthine family, it... , warfarin Warfarin Warfarin is an anticoagulant. It is most likely to be the drug popularly referred to as a "blood thinner," yet this is a misnomer, since it does not affect the thickness or viscosity of blood... , levodopa Levodopa L-DOPA is a chemical that is made and used as part of the normal biology of some animals and plants. Some animals including humans make it via biosynthesis from the amino acid L-tyrosine. L-DOPA is the precursor to the neurotransmitters dopamine, norepinephrine , and epinephrine collectively... , buprenorphine Buprenorphine Buprenorphine is a semi-synthetic opioid that is used... , irinotecan Irinotecan Irinotecan is a drug used for the treatment of cancer.Irinotecan prevents DNA from unwinding by inhibition of topoisomerase 1. In chemical terms, it is a semisynthetic analogue of the natural alkaloid camptothecin.... |
| Reference: Rossi, 2005; Micromedex | |
For a complete list, see CYP3A4 ligands and CYP2C9 ligands. For further updating on interactions and appropriate management, see Herbological.com – St John's Wort Interactions table.
Pharmacodynamic interactions
St John's wort may also contribute to serotonin syndromeSerotonin syndrome
Serotonin syndrome is a potentially life-threatening adverse drug reaction that may occur following therapeutic drug use, inadvertent interactions between drugs, overdose of particular drugs, or the recreational use of certain drugs...
, a potentially life-threatening adverse drug reaction, in combination with other drugs that may elevate 5-HT (serotonin) levels in the central nervous system
Central nervous system
The central nervous system is the part of the nervous system that integrates the information that it receives from, and coordinates the activity of, all parts of the bodies of bilaterian animals—that is, all multicellular animals except sponges and radially symmetric animals such as jellyfish...
(CNS).
| Class | Drugs |
|---|---|
| Antidepressant Antidepressant An antidepressant is a psychiatric medication used to alleviate mood disorders, such as major depression and dysthymia and anxiety disorders such as social anxiety disorder. According to Gelder, Mayou &*Geddes people with a depressive illness will experience a therapeutic effect to their mood;... s |
MAOIs, TCA Tricyclic antidepressant Tricyclic antidepressants are heterocyclic chemical compounds used primarily as antidepressants. The TCAs were first discovered in the early 1950s and were subsequently introduced later in the decade; they are named after their chemical structure, which contains three rings of atoms... s, SSRIs, SNRI SNRI SNRI may refer to:* Serotonin–norepinephrine reuptake inhibitor* Strategic Naval Research Institute... s, mirtazapine Mirtazapine Mirtazapine is a tetracyclic antidepressant used primarily in the treatment of depression. It is also sometimes used as a hypnotic, antiemetic, and appetite stimulant, and for the treatment of anxiety, among other indications... |
| Opioid Opioid An opioid is a psychoactive chemical that works by binding to opioid receptors, which are found principally in the central and peripheral nervous system and the gastrointestinal tract... s |
tramadol Tramadol Tramadol hydrochloride is a centrally acting synthetic opioid analgesic used in treating moderate pain. The drug has a wide range of applications, including treatment for restless legs syndrome and fibromyalgia... , meperidine (pethidine Pethidine Pethidine or meperidine Pethidine (INN) or meperidine (USAN) Pethidine (INN) or meperidine (USAN) (commonly referred to as Demerol but also referred to as: isonipecaine; lidol; pethanol; piridosal; Algil; Alodan; Centralgin; Dispadol; Dolantin; Mialgin (in Indonesia); Petidin Dolargan (in Poland);... ), dextromethorphan Dextromethorphan Dextromethorphan is an antitussive drug. It is one of the active ingredients in many over-the-counter cold and cough medicines, such as Robitussin, NyQuil, Dimetapp, Vicks, Coricidin, Delsym, and others, including generic labels. Dextromethorphan has also found other uses in medicine, ranging... |
| CNS stimulant Stimulant Stimulants are psychoactive drugs which induce temporary improvements in either mental or physical function or both. Examples of these kinds of effects may include enhanced alertness, wakefulness, and locomotion, among others... s |
phentermine Phentermine Phentermine, a contraction of "phenyl-tertiary-butylamine", is a psychostimulant drug of the phenethylamine class, chemically related to amphetamine. It is used medically as an appetite suppressant.... , diethylpropion, amphetamine Amphetamine Amphetamine or amfetamine is a psychostimulant drug of the phenethylamine class which produces increased wakefulness and focus in association with decreased fatigue and appetite.Brand names of medications that contain, or metabolize into, amphetamine include Adderall, Dexedrine, Dextrostat,... s, sibutramine Sibutramine Sibutramine is an oral anorexiant. Until 2010 it was marketed and prescribed as an adjunct in the treatment of exogenous obesity along with diet and exercise... , cocaine Cocaine Cocaine is a crystalline tropane alkaloid that is obtained from the leaves of the coca plant. The name comes from "coca" in addition to the alkaloid suffix -ine, forming cocaine. It is a stimulant of the central nervous system, an appetite suppressant, and a topical anesthetic... |
| 5-HT1 5-HT receptor The serotonin receptors, also known as 5-hydroxytryptamine receptors or 5-HT receptors, are a group of G protein-coupled receptors and ligand-gated ion channels found in the central and peripheral nervous systems. They mediate both excitatory and inhibitory neurotransmission... agonists |
triptan Triptan Triptans are a family of tryptamine-based drugs used as abortive medication in the treatment of migraines and cluster headaches. They were first introduced in the 1990s... s |
| Psychedelic drugs | methylenedioxymethamphetamine Methylenedioxymethamphetamine MDMA is an entactogenic drug of the phenethylamine and amphetamine class of drugs. In popular culture, MDMA has become widely known as "ecstasy" , usually referring to its street pill form, although this term may also include the presence of possible adulterants... (MDMA), lysergic acid diethylamide (LSD), psilocybin Psilocybin Psilocybin is a naturally occurring psychedelic prodrug, with mind-altering effects similar to those of LSD and mescaline, after it is converted to psilocin. The effects can include altered thinking processes, perceptual distortions, an altered sense of time, and spiritual experiences, as well as... /psilocin Psilocin Psilocin , an aromatic compound, sometimes also spelled psilocine, psilocyn, or psilotsin, is a psychedelic mushroom alkaloid. It is found in most psychedelic mushrooms together with its phosphorylated counterpart psilocybin... |
| Others | selegiline Selegiline Selegiline is a drug used for the treatment of early-stage Parkinson's disease, depression and senile dementia. In normal clinical doses it is a selective irreversible MAO-B inhibitor, however in larger doses it loses its specificity and also inhibits MAO-A... , tryptophan Tryptophan Tryptophan is one of the 20 standard amino acids, as well as an essential amino acid in the human diet. It is encoded in the standard genetic code as the codon UGG... , buspirone Buspirone Buspirone is an anxiolytic psychoactive drug of the azapirone chemical class, and is primarily used to treat generalized anxiety disorder Bristol-Myers Squibb gained FDA approval of buspirone in 1986 for treatment of GAD... , lithium Lithium pharmacology Lithium pharmacology refers to use of the lithium ion, Li+, as a drug. A number of chemical salts of lithium are used medically as a mood stabilizing drug, primarily in the treatment of bipolar disorder, where they have a role in the treatment of depression and particularly of mania, both acutely... , linezolid Linezolid Linezolid is a synthetic antibiotic used for the treatment of serious infections caused by Gram-positive bacteria that are resistant to several other antibiotics... , 5-HTP |
| Reference: Rossi, 2005 | |
Detection in body fluids
Hypericin, pseudohypericin, and hyperforin may be quantitated in plasma as confirmation of usage and to estimate the dosage. These three active substituents have plasma elimination half-lives within a range of 15–60 hours in humans. None of the three has been detected in urine specimens.Chemical composition
Rutin
Rutin, also called rutoside, quercetin-3-O-rutinoside and sophorin, is a citrus flavonoid glycoside found in buckwheat, the leaves and petioles of Rheum species, and asparagus...
, hyperoside
Hyperoside
Hyperoside is a chemical compound. It is the 3-O-galactoside of quercetin. It is a medicinally active compound that can be isolated from Drosera rotundifolia, from the Stachys plant, from Prunella vulgaris, from Rumex acetosella, Cuscuta Chinensis seeds and from St John's wort.In Rheum nobile and R...
, isoquercetin, quercitrin
Quercitrin
Quercitrin is a glycoside formed from the flavonoid quercetin and the deoxy sugar rhamnose. It is a constituent of the dye quercitron. It can be found in Tartary buckwheat ....
, quercetin
Quercetin
Quercetin , a flavonol, is a plant-derived flavonoid found in fruits, vegetables, leaves and grains. It also may be used as an ingredient in supplements, beverages or foods.-Occurrence:...
, I3,II8-biapigenin, amentoflavone
Amentoflavone
Amentoflavone is a constituent of a number of plants with medicinal properties, including Ginkgo biloba and Hypericum perforatum .It is a biflavonoid ....
, astilbin
Astilbin
Astilbin is a flavanonol, a type of flavonoid. Astilbin is the -isomer; neoisoastilbin is the -isomer and isoastilbin is the -isomer....
, miquelianin), phenolic acids (chlorogenic acid
Chlorogenic acid
Chlorogenic acid is a hydroxycinnamic acid, a member of a family of naturally occurring organic compounds. These are esters of polyphenolic caffeic acid and cyclitol -quinic acid. It is an important biosynthetic intermediate. It also is one of the phenols found in coffee, bamboo Phyllostachys...
, 3-O-coumaroylquinic acid), and various naphtodianthrones: (hypericin
Hypericin
Hypericin is a naphthodianthrone, a red-colored anthraquinone-derivative, which, together with hyperforin, is one of the principal active constituents of Hypericum . Hypericin is believed to act as an antibiotic and non-specific kinase inhibitor...
, pseudohypericin, protohypericin, protopseudohypericin), phloroglucinol
Phloroglucinol
Phloroglucinol is a benzenetriol. It is an organic compound that is used in the synthesis of pharmaceuticals and explosives. This molecule exists in two forms, or tautomers, 1,3,5-trihydroxybenzene, which has phenol-like, and 1,3,5-cyclohexanetrione , which has ketone-like character. These two...
s (hyperforin
Hyperforin
Hyperforin is a phytochemical produced by some of the members of the plant genus Hypericum, notably Hypericum perforatum .- Occurrence :...
, adhyperforin). The naphthodianthrones hypericin and pseudohypericin along with the phloroglucinol derivative hyperforin are thought to be the active components. It also contains essential oils composed mainly of sesquiterpene
Sesquiterpene
Sesquiterpenes are a class of terpenes that consist of three isoprene units and have the molecular formula C15H24. Like monoterpenes, sesquiterpenes may be acyclic or contain rings, including many unique combinations...
s.
Pharmacology
Serotonin
Serotonin or 5-hydroxytryptamine is a monoamine neurotransmitter. Biochemically derived from tryptophan, serotonin is primarily found in the gastrointestinal tract, platelets, and in the central nervous system of animals including humans...
reuptake, much like the conventional selective serotonin reuptake inhibitor
Selective serotonin reuptake inhibitor
Selective serotonin re-uptake inhibitors or serotonin-specific reuptake inhibitor are a class of compounds typically used as antidepressants in the treatment of depression, anxiety disorders, and some personality disorders. The efficacy of SSRIs is disputed...
(SSRI) antidepressants. The major active antidepressive constituents in St John's wort are thought to be hyperforin
Hyperforin
Hyperforin is a phytochemical produced by some of the members of the plant genus Hypericum, notably Hypericum perforatum .- Occurrence :...
and hypericin
Hypericin
Hypericin is a naphthodianthrone, a red-colored anthraquinone-derivative, which, together with hyperforin, is one of the principal active constituents of Hypericum . Hypericin is believed to act as an antibiotic and non-specific kinase inhibitor...
, although other biologically active constituents present, for example, flavonoid
Flavonoid
Flavonoids , are a class of plant secondary metabolites....
s and tannin
Tannin
A tannin is an astringent, bitter plant polyphenolic compound that binds to and precipitates proteins and various other organic compounds including amino acids and alkaloids.The term tannin refers to the use of...
s, may also be involved.
Some believe that hyperforin
Hyperforin
Hyperforin is a phytochemical produced by some of the members of the plant genus Hypericum, notably Hypericum perforatum .- Occurrence :...
is the major constituent responsible for antidepressant activity, and it has been shown to inhibit the uptake of 5-HT, dopamine
Dopamine
Dopamine is a catecholamine neurotransmitter present in a wide variety of animals, including both vertebrates and invertebrates. In the brain, this substituted phenethylamine functions as a neurotransmitter, activating the five known types of dopamine receptors—D1, D2, D3, D4, and D5—and their...
, and noradrenaline. Hyperforin
Hyperforin
Hyperforin is a phytochemical produced by some of the members of the plant genus Hypericum, notably Hypericum perforatum .- Occurrence :...
also has affinity for GABA
Gabâ
Gabâ or gabaa, for the people in many parts of the Philippines), is the concept of a non-human and non-divine, imminent retribution. A sort of negative karma, it is generally seen as an evil effect on a person because of their wrongdoings or transgressions...
and glutamate receptors. On the other hand, an hyperforin-free extract of St John's wort (Ze 117 – Remotiv) may still have significant antidepressive effects.
Clinical signs
In large doses, St John's wort is poisonPoison
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 grazing livestock
Livestock
Livestock refers to one or more domesticated animals raised in an agricultural setting to produce commodities such as food, fiber and labor. The term "livestock" as used in this article does not include poultry or farmed fish; however the inclusion of these, especially poultry, within the meaning...
(cattle, sheep, goats, horses). Behavioural signs of poisoning are general restlessness and skin irritation. Restlessness is often indicated by pawing of the ground, headshaking
Headshaking
Headshaking is a condition where the horse or pony shakes its head continuously, often while being ridden.Originally considered a bad habit, it is now thought that some horses are allergic to certain pollens, which causes them to headshake. However horses also normally react to flies, and...
, head rubbing, and occasional hindlimb weakness with knuckling over, panting, confusion, and depression. Mania and hyperactivity may also result, including running in circles until exhausted. Observations of thick wort infestations by Australian graziers include the appearance of circular patches giving hillsides a ‘crop circle’ appearance, it is presumed, from this phenomenon. Animals typically seek shade and have reduced appetite. Hypersensitivity to water has been noted, and convulsions may occur following a knock to the head. Although general aversion to water is noted, some may seek water for relief.
Severe skin irritation is physically apparent, with reddening of non-pigmented and unprotected areas. This subsequently leads to itch and rubbing, followed by further inflammation, exudation, and scab formation. Lesions and inflammation that occur are said to resemble the conditions seen in foot and mouth disease. Sheep have been observed to have face swelling, dermatitis, and wool falling off due to rubbing. Lactating animals may cease or have reduced milk production; pregnant animals may abort
Abortion
Abortion is defined as the termination of pregnancy by the removal or expulsion from the uterus of a fetus or embryo prior to viability. An abortion can occur spontaneously, in which case it is usually called a miscarriage, or it can be purposely induced...
. Lesions on udder
Udder
An udder is an organ formed of the mammary glands of female quadruped mammals, especially ruminants such as cattle, goats, sheep and deer. The udder is a single mass hanging beneath the animal, consisting of pairs of mammary glands...
s are often apparent. Horses may show signs of anorexia
Anorexia (symptom)
Anorexia is the decreased sensation of appetite...
, depression
Depression (mood)
Depression is a state of low mood and aversion to activity that can affect a person's thoughts, behaviour, feelings and physical well-being. Depressed people may feel sad, anxious, empty, hopeless, helpless, worthless, guilty, irritable, or restless...
(with a comatose state), dilated pupils, and injected conjunctiva
Conjunctiva
The conjunctiva covers the sclera and lines the inside of the eyelids. It is composed of rare stratified columnar epithelium.-Function:...
.
Early diagnosis
Increased respiration and heart rate is typically observed while one of the early signs of St John’s wort poisoning is an abnormal increase in body temperature. Affected animals will lose weight, or fail to gain weight; young animals are more affected than old animals. In severe cases death may occur, as a direct result of starvation, or because of secondary disease or septicaemiaSepsis
Sepsis is a potentially deadly medical condition that is characterized by a whole-body inflammatory state and the presence of a known or suspected infection. The body may develop this inflammatory response by the immune system to microbes in the blood, urine, lungs, skin, or other tissues...
of lesions. Some affected animals may accidentally drown. Poor performance of suckling lambs (pigmented and non-pigmented) has been noted, suggesting a reduction in the milk production, or the transmission of a toxin in the milk.
Photosensitisation
Most clinical signs in animals are caused by photosensitisationPhotosensitivity
Photosensitivity is the amount to which an object reacts upon receiving photons, especially visible light.- Human medicine :Sensitivity of the skin to a light source can take various forms. People with particular skin types are more sensitive to sunburn...
. Plants may induce either primary or secondary photosensitisation:
- primary photosensitisation directly from chemicals contained in ingested plants
- secondary photosensitisation from plant-associated damage to the liver.
Araya and Ford (1981) explored changes in liver function and concluded there was no evidence of Hypericum-related effect on the excretory capacity of the liver, or any interference was minimal and temporary. However, evidence of liver damage in blood plasma has been found at high and long rates of dosage.
Photosensitisation causes skin inflammation by a mechanism involving a pigment or photodynamic compound, which when activated by a certain wavelength of light leads to oxidation
Redox
Redox reactions describe all chemical reactions in which atoms have their oxidation state changed....
reactions in vivo
In vivo
In vivo is experimentation using a whole, living organism as opposed to a partial or dead organism, or an in vitro controlled environment. Animal testing and clinical trials are two forms of in vivo research...
. This leads to lesions of tissue, particularly noticeable on and around parts of skin exposed to light. Lightly covered or poorly pigment
Biological pigment
Biological pigments, also known simply as pigments or biochromes are substances produced by living organisms that have a color resulting from selective color absorption. Biological pigments include plant pigments and flower pigments...
ed areas are most conspicuous. Removal of affected animals from sunlight results in reduced symptoms of poisoning.
Other uses
Hypericum perforatum was also used by Native AmericansNative Americans in the United States
Native Americans in the United States are the indigenous peoples in North America within the boundaries of the present-day continental United States, parts of Alaska, and the island state of Hawaii. They are composed of numerous, distinct tribes, states, and ethnic groups, many of which survive as...
internally as an abortifacient
Abortifacient
An abortifacient is a substance that induces abortion. Abortifacients for animals that have mated undesirably are known as mismating shots....
and externally as an anti-inflammatory
Anti-inflammatory
Anti-inflammatory refers to the property of a substance or treatment that reduces inflammation. Anti-inflammatory drugs make up about half of analgesics, remedying pain by reducing inflammation as opposed to opioids, which affect the central nervous system....
, astringent
Astringent
An astringent substance is a chemical compound that tends to shrink or constrict body tissues, usually locally after topical medicinal application. The word "astringent" derives from Latin adstringere, meaning "to bind fast"...
, and antiseptic
Antiseptic
Antiseptics are antimicrobial substances that are applied to living tissue/skin to reduce the possibility of infection, sepsis, or putrefaction...
.
St. John's wort's has long been used as a herbal tea.
St. John's wort is also a common flavoring agent in Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
ese udon
Udon
is a type of thick wheat-flour noodle of Japanese cuisine.Udon is usually served hot as noodle soup in its simplest form as kake udon, in a mildly flavoured broth called kakejiru which is made of dashi, soy sauce , and mirin. It is usually topped with thinly chopped scallions...
noodles.
The flowers and stems of Hypericum perforatum have been used to produce red and yellow dye
Dye
A dye is a colored substance that has an affinity to the substrate to which it is being applied. The dye is generally applied in an aqueous solution, and requires a mordant to improve the fastness of the dye on the fiber....
s.
Gardens
Hypericum perforatum is a popular groundcoverGroundcover
Groundcover refers to any plant that grows over an area of ground, used to provide protection from erosion and drought, and to improve its aesthetic appearance .- Ecosystem :...
type of ornamental plant
Ornamental plant
Ornamental plants are plants that are grown for decorative purposes in gardens and landscape design projects, as house plants, for cut flowers and specimen display...
used in garden
Garden
A garden is a planned space, usually outdoors, set aside for the display, cultivation, and enjoyment of plants and other forms of nature. The garden can incorporate both natural and man-made materials. The most common form today is known as a residential garden, but the term garden has...
s, including drought tolerant landscaping.
See also
- Dietary supplementDietary supplementA dietary supplement, also known as food supplement or nutritional supplement, is a preparation intended to supplement the diet and provide nutrients, such as vitamins, minerals, fiber, fatty acids, or amino acids, that may be missing or may not be consumed in sufficient quantities in a person's diet...
- EU Food supplements directive
- List of plants poisonous to equines
Further reading
Books- British Herbal Medicine Association Scientific Committee (1983). British Herbal Pharmacopoeia. West Yorkshire: British Herbal Medicine Association. ISBN 0-903032-07-4
Review articles
- Carpenter, David J. ”St. John's wort and S-adenosyl methionine as "natural" alternatives to conventional antidepressants in the era of the suicidality boxed warning: what is the evidence for clinically relevant benefit?”, Alternative Medicine Review: a journal of clinical therapeutics (2011),16(1):17-39.
- Linde, Klaus ”St. John's wort –an overview”, Forschende Komplementärmedizin (2009),16(3):146-155.
External links
- Species Profile- St. Johnswort (Hypericum perforatum), National Invasive Species Information Center, United States National Agricultural LibraryUnited States National Agricultural LibraryThe United States National Agricultural Library is one of the world's largest agricultural research libraries, and serves as a National Library of the United States and as the library of the United States Department of Agriculture...
. Lists general information and resources for St. Johnswort.