| Vitex agnus-castus | |
|---|---|
| Vitex agnus-castus flowers with halictid bee, Hemingway, South Carolina | |
| Scientific classification | |
| Kingdom: | Plantae |
| (unranked): | Angiosperms |
| (unranked): | Eudicots |
| (unranked): | Asterids |
| Order: | Lamiales |
| Family: | Lamiaceae |
| Genus: | Vitex |
| Species: | V. agnus-castus |
| Binomial name | |
| Vitex agnus-castus L. |
|
Vitex agnus-castus, also called Vitex, Chaste Tree, Chasteberry, Abraham's Balm[1] or Monk's Pepper, is a native of the Mediterranean region. It is one of the few temperate-zone species of Vitex, which is on the whole a genus of tropical and sub-tropical flowering plants.[2] Theophrastus mentioned the shrub several times, as agnos (άγνος) in Enquiry into Plants.[3] Vitex, its name in Pliny the Elder, is derived from the Latin vieo, meaning to weave or to tie up, a reference to the use of Vitex agnus-castus in basketry.[4] Its macaronic specific name repeats "chaste" in both Greek and Latin.
Confusion with Vitex on the part of early settlers in the West Indies gave to Ricinus communis the name "Castor-oil plant".[5]
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Vitex agnus-castus is widely cultivated in warm temperate and subtropical regions for its delicate-textured aromatic foliage and lavender flowers in late summer. It grows to a height of 1–5 meters. It requires full sun or partial shade along with well-drained soil. Under ideal conditions it is hardy to USDA Zone 7, on the south shore of Long Island and Nantucket on the East Coast of North America and in the southwest of England.
Vitex, also a traditional plant in Africa, is a little-known fruit plant that has potential to improve nutrition, boost food security, foster rural development and support sustainable landcare.[6]
The leaves and tender stem growth of the upper 10 cm (4 inches), along with the flowers and ripening seeds, are harvested for medicinal purposes. The berries are harvested by gently rubbing the berries loose from the stem. The leaves, flowers, and/or berries may be consumed as a decoction, traditional tincture, cider vinegar tincture, syrup, elixir, or simply eaten straight off the plant as a medicinal food.[7] A popular way of taking Vitex is on awakening as a simple 1:1 fluid extract, which is said to interact with hormonal circadian rhythms most effectively.[8]
The berries are considered a tonic herb for both the male and female reproductive systems. The leaves are believed to have the same effect but to a lesser degree.[7][8]
In ancient times it was believed to be an anaphrodisiac, hence the name chaste tree. Pliny, in his Historia Naturalis, reports the use of stems and leaves of this plant by women as bedding "to cool the heat of lust" during the time of the Thesmophoria, when Athenian women left their husbands' beds to remain ritually chaste. At the end of the thirteenth century John Trevisa reports of it "the herbe agnus-castus is always grene, and the flowre therof is namly callyd Agnus Castus, for wyth smel and vse it maketh men chaste as a lombe".[9] Chaucer, in "The Flower and the Leaf," refers to it as an attribute of the chaste Diana, and in the 16th century the English herbalist William Turner reports the same anaphrodisiac properties of the seed, both fried and not fried. More recently, this plant has been called monk's pepper in the thought that it was used as anti-libido medicine by monks to aid their attempts to remain chaste. There are disputed accounts regarding its actual action on libido, with some claims that it is anaphrodisiac and others that it is aphrodisiac. Because of the complex mechanism of action it can be probably both, depending on concentration of the extract and physiologic variables (see below).
Clinical studies have demonstrated effectivness of standardised and controlled medications produced from extract of the plant in the management of premenstrual stress syndrome (PMS),[10][11][12] and cyclical breast pain (mastalgia).[13] The medication is recommended in Germany.[14][15]
The mechanism of action is not exactly understood[16] but it is assumed that it has dopaminergic effects resulting in changes of prolactin secretion. At low doses, such as might have been used in previous centuries for suppression of sexual desire, it inhibits activation of dopamine 2 receptor by competitive binding, causing a slight increase in release of prolactin. In higher concentrations, as in modern extracts, the binding activity is sufficient to reduce the release of prolactin. A study has found that treatment of 20 healthy men with higher doses of Vitex agnus-castus was associated with a slight reduction of prolactin levels, whereas lower doses caused a slight increase as compared to doses of placebo.[17] A decrease of prolactin will influence levels of Follicle-stimulating hormone (FSH) and estrogen in women; and testosterone in men. Dopaminergic compounds(diterpenes with prolactin-suppressive effects that were almost identical in their prolactin-suppressive properties than dopamine itself) present in Vitex agnus castus seem likely to be the clinically important compounds which improve premenstrual mastodynia and possibly also psycho-somatic symptoms of PMS.[18]
Flavonoids, alkaloids, diterpenoids, Vitexin, Casticin and steroidal hormone precursors have been isolated from the chemical analysis of Vitex agnus-castus.[17] It is believed that some of these compounds work on the pituitary gland which would explain its effects on hormonal levels. A study has shown that extracts of the fruit of VAC can bind to opiate receptors; this could explain why intake of VAC reduces PMS discomforts.[19]
Vitex agnus-castus is used to alleviate symptoms of various gynecological problems. All evidence is limited to standardised controlled extracts such as used in Germany, different extracts or herbal mixes may have significantly different properties and safety issues.
Good evidence and safety exists for these uses:[14]
No specific clinical studies but use partially supported by clinical evidence on symptoms and mechanism of action:
Emerging uses:
Prostate disorders Rarely used,[21][22] but given its mode of action theoretically interesting,[23][24]
It is recommended that Vitex agnus-castus be avoided during pregnancy due to the possibility of complications.[14][25]
Historical uses, uses outside the scope of medicine.
WHO Monographs on Selected Medicinal Plants - Volume 4 Fructus Agni Casti