Hypericum

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Hypericum
Hypericum calycinum Tasmania.jpg
Hypericum calycinum
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Rosids
Order: Malpighiales
Family: Hypericaceae
Subfamily: Hypericoideae
Tribe: Hypericeae
Genus: Hypericum
L.
Species

490, see text

Synonyms

Adenotrias Jaub. & Spach
Androsaemum Duhamel
Androsemum Link
Ascyrum L.
Lianthus N.Robson
Olympia Spach
Sanidophyllum Small
Sarothra L.
Takasagoya Y.Kimura
Triadenia Spach

Hypericum /ˌhˈpɪərɨkəm/[1] is a genus of 490[2] species of flowering plants in the family Hypericaceae (formerly often considered a subfamily of Clusiaceae). Hypericum is unusual for a genus of its size because a worldwide taxonomic monograph[2] was produced for it by N.Robson (working at the Natural History Museum, London, UK, between 1977 and 2012). Robson recognizes 36 sections within Hypericum.

The genus has a nearly worldwide distribution, missing only from tropical lowlands, deserts and polar regions. All members of the genus may be referred to as St. John's wort, though they are also commonly just called hypericum, and some are known as tutsan. The marsh St. John's-worts are nowadays separated into the genus Triadenum.

Hypericums vary from herbaceous annual or perennials 5–10 cm tall to shrubs and small trees up to 12 m tall. The leaves are opposite, simple oval, 1–8 cm long, either deciduous or evergreen. The flowers vary from pale to dark yellow, and from 0.5–6 cm in diameter, with five (rarely four) petals, most having prominent stamens. The fruit is usually a dry capsule which splits to release the numerous small seeds; in some species it is fleshy and berry-like.

Uses of Hypericum[edit]

Hypericum calycinum cv. 'Hidcote'

Some species are used as ornamental plants and have large, showy flowers. Numerous hybrids and cultivars have been developed for use in horticulture, such as H. × moserianum[3] (H. calycinum × H. patulum), H. 'Hidcote'[4] and H. 'Rowallane'.[5] All of the above cultivars have gained the Royal Horticultural Society's Award of Garden Merit.

St. John's-worts can occur as nuisance weeds in farmland and gardens. On pastures, some can be more than a nuisance, causing debilitating photosensitivity and sometimes abortion in livestock. The beetles Chrysolina quadrigemina, Chrysolina hyperici and the St. John's-wort Root Borer (Agrilus hyperici) like to feed on Common St. John's-wort (H. perforatum) and have been used for biocontrol where the plant has become an invasive weed.

Hypericum species are the only known food plants of the caterpillar of the Treble-bar, a species of moth. Other Lepidoptera species whose larvae sometimes feed on Hypericum include Common Emerald, The Engrailed (recorded on Imperforate St. John's-wort, H. maculatum), Grey Pug and Setaceous Hebrew Character.

Medical properties[edit]

Hypericum olympicum in Botanic garden Liberec
De medicina

Common St. John's-wort (H. perforatum) has long been used in herbalism. It was known to have medical properties in Classical Antiquity and was a standard component of theriacs, from the Mithridate of Aulus Cornelius Celsus' De Medicina (ca. 30 CE) to the Venice treacle of d'Amsterdammer Apotheek in 1686. Folk usages included oily extract ("St. John's oil") and Hypericum snaps.

H. perforatum is the most potent species and it is today grown commercially for use in herbalism and medicine; other St. John's-worts possess interesting properties and chemical compounds but are not well researched. As these secondary compounds appear to be related to deterring herbivores, they are present in varying and unpredictable quantities: still, a number of high-yield cultivars have been developed.

Two main compounds of interest have been studied in more detail: hyperforin and hypericin. However, the pharmacology of H. perforatum is not resolved, and at least its antidepressant properties are caused by a wide range of factors interacting. As psychiatric medication, it is usually taken as pills, or as tea. Standardised preparations are available, and research has mainly studied alcoholic extracts and isolated compounds. What research data exists supports a noticeable effect in many cases of light and medium depression,[6] but no significant improvement of severe depression and OCD.

The red, oily extract of H. perforatum may help heal wounds.[7][8] Both hypericin and hyperforin are reported to have antibiotic properties.[9] Justifying this view with the then-current doctrine of signatures, herbalist William Coles (1626–1662)[10] wrote in the 17th century that

"The little holes where of the leaves of Saint Johns wort are full, doe resemble all the pores of the skin and therefore it is profitable for all hurts and wounds that can happen thereunto."

Hypericum perforatum may also be capable of reducing the physical signs of opiate withdrawal.[11] Caution should be taken, as high-dosage H. perforatum interacts with a wide range of medications due to activation of the Pregnane X receptor detoxification pathway, and it also causes photosensitivity.

Hypericum extract, by inducing both the CYP3A4 and the P-glycoprotein (P-gp), can reduce the plasma concentrations of different antineoplastic agents such as imatinib, irinotecan and docetaxel, thus reducing the clinical efficacy of these drugs.[12]

Selected species[edit]

Hypericum inodorum cv. 'Magical Passion'

Cultivars[edit]

Cultivars include:

  • Hypericum calycinum 'Hidcote'
  • Hypericum perforatum 'Anthos'

See also[edit]

References[edit]

  1. ^ Sunset Western Garden Book, 1995:606–607
  2. ^ a b http://hypericum.myspecies.info/ Hypericum Online
  3. ^ "RHS Plant Selector". Royal Horticultural Society. Retrieved 19 May 2013. 
  4. ^ "RHS Plant Selector". Royal Horticultural Society. Retrieved 19 May 2013. 
  5. ^ "RHS Plant Selector". Royal Horticultural Society. Retrieved 19 May 2013. 
  6. ^ Szegedi, A; Kohnen, R; Dienel, A; Kieser, M (2005). "Acute treatment of moderate to severe depression with hypericum extract WS 5570 (St John's wort): Randomised controlled double blind non-inferiority trial versus paroxetine". BMJ 330 (7490): 503. doi:10.1136/bmj.38356.655266.82. PMC 552808. PMID 15708844. 
  7. ^ Samadi, S; Khadivzadeh, T; Emami, A; Moosavi, NS; Tafaghodi, M; Behnam, HR (2010). "The effect of Hypericum perforatum on the wound healing and scar of cesarean". Journal of alternative and complementary medicine 16 (1): 113–7. doi:10.1089/acm.2009.0317. PMID 20064022. 
  8. ^ Süntar, Ipek Peşin; Akkol, Esra Küpeli; Yılmazer, Demet; Baykal, Turhan; Kırmızıbekmez, Hasan; Alper, Murat; Yeşilada, Erdem (2010). "Investigations on the in vivo wound healing potential of Hypericum perforatum L". Journal of Ethnopharmacology 127 (2): 468–77. doi:10.1016/j.jep.2009.10.011. PMID 19833187. 
  9. ^ Schempp, Christoph M; Pelz, Klaus; Wittmer, Annette; Schöpf, Erwin; Simon, Jan C (1999). "Antibacterial activity of hyperforin from St John's wort, against multiresistant Staphylococcus aureus and gram-positive bacteria". The Lancet 353 (9170): 2129. doi:10.1016/S0140-6736(99)00214-7. PMID 10382704. 
  10. ^ Coles, William (1657). Adam in Eden, or, Natures paradise. OCLC 217197164. [page needed]
  11. ^ Subhan, F; Khan, N; Sewell, RD (2009). "Adulterant profile of illicit street heroin and reduction of its precipitated physical dependence withdrawal syndrome by extracts of St John's wort (Hypericum perforatum)". Phytotherapy research 23 (4): 564–71. doi:10.1002/ptr.2692. PMID 19067385. 
  12. ^ Caraci, F; Crupi, R; Drago, F; Spina, E (2011). "Metabolic drug interactions between antidepressants and anticancer drugs: Focus on selective serotonin reuptake inhibitors and hypericum extract". Current drug metabolism 12 (6): 570–7. doi:10.2174/138920011795713706. PMID 21395523. 
  13. ^ Hypericum ellipticum. USDA PLANTS Profile.

External links[edit]

"Hypericum Online". 

University of Illinois Extension. "Selecting Shrubs for Your Home - Kalm St. Johnswort (Hypericum kalmianum)".