Valerian has been used as a medicinal herb since at least the time of ancient Greece and Rome. Hippocrates described its properties, and Galen later prescribed it as a remedy for insomnia. In medieval Sweden, it was sometimes placed in the wedding clothes of the groom to ward off the "envy" of the elves. In the 16th century, the Anabaptist reformer Pilgram Marpeck prescribed valerian tea for a sick woman.
John Gerard's Herball states that his contemporaries found Valerian "excellent for those burdened and for such as be troubled with croup and other like convulsions, and also for those that are bruised with falls." He says that the dried root was valued as a medicine by the poor in the north of England and the south of Scotland, so that "no broth or pottage or physicall meats be worth anything if Setewale [Valerian] be not there."
The seventeenth century astrological botanistNicholas Culpeper thought the plant was "under the influence of Mercury, and therefore hath a warming faculty." He recommended both herb and root, and said that "the root boiled with liquorice, raisons and aniseed is good for those troubled with cough. Also, it is of special value against the plague, the decoction thereof being drunk and the root smelled. The green herb being bruised and applied to the head taketh away pain and pricking thereof."
Etymology and common names
The name of the herb is derived from the personal name Valeria and the Latin verb valere (to be strong, healthy). Other names used for this plant include garden valerian (to distinguish it from other Valeriana species), garden heliotrope (although not related to Heliotropium), setwall and all-heal (which is also used for plants in the genus Stachys). Red valerian, often grown in gardens, is also sometimes referred to as "valerian", but is a different species (Centranthus ruber), from the same family but not very closely related.
Known compounds detected in valerian that may contribute to its method of action are:
Valerian also contains isovaltrate, which has been shown to be an inverse agonist for adenosine A1 receptor sites. This action likely does not contribute to the herb's possible sedative effects, which would be expected from an agonist, rather than an inverse agonist, at this particular binding site. Hydrophilic extractions of the herb commonly sold over the counter, however, probably do not contain significant amounts of isovaltrate. Valerenic acid in valerian stimulates serotonin receptors as a partial agonist, including 5-HT5A which is implicated in the sleep-wake cycle.
The chief constituent of valerian is a yellowish-green to brownish-yellow oil present in the dried root, varying in content from 0.5 to 2.0%. This variation in quantity may be determined by location; a dry, stony soil yields a root richer in oil than moist, fertile soil. The volatile oils that form the active ingredient are pungent, somewhat reminiscent of well-matured cheese. Though some people remain partial to the earthy scent, some find it unpleasant, comparing the odor to that of unwashed feet.
The European Medicines Agency (EMA) approved the health claim that valerian can be used as a traditional herbal medicine to relieve mild nervous tension and to aid sleep; EMA stated that although there is insufficient evidence from clinical studies, its effectiveness as a dried extract is considered plausible.
Oral forms, use, and adverse effects
A bottle of Valerian capsules
Oral forms are available in both standardized and unstandardized forms. Standardized products may be preferable considering the wide variation of the chemicals in the dried root, as noted above. When standardized, it is done so as a percentage of valerenic acid or valeric acid.
Because the compounds in valerian produce central nervous system depression, they should not be used with other depressants, such as ethanol, benzodiazepines, barbiturates, opiates, kava, or antihistamine drugs. Although no liver problems are normally encountered with valerian use, there have been case studies in which hepatotoxicity has been observed in apparently hypersensitive individuals following short-term use (e.g. one month).
As an unregulated product, the concentration, contents, and potential contaminants in valerian preparations cannot be easily determined. Because of this uncertainty and the potential for toxicity in the fetus and hepatotoxicity in the mother, valerian use is discouraged during pregnancy.
Valerian is unusual in having flowers with "handedness", that is, having neither radial nor bilateral symmetry.
Valerian is considered an invasive species in many jurisdictions, including the US state of Connecticut where it is officially banned, and in New Brunswick, Canada where it is listed as a plant of concern.
V. officinalis flowers
19th-century illustration of Valeriana officinalis
Illustration of V. officinalis from Atlas des plantes de France, 1891.
^Although many sources list "catinine" as an alkaloid present in extracts from the root of Valeriana officinalis, those sources are incorrect. The correct spelling is "chatinine". It was discovered by S. Waliszewski in 1891. See: S. Waliszewski (15 March 1891) L'Union pharmaceutique, page 109. Abstracts of this article appeared in: "Chatinine, alcaloïde de la racine de valériane" Répertoire de pharmacie, series 3, vol. 3, pp. 166–167Archived 2013-06-19 at the Wayback Machine (April 10, 1891) ; American Journal of Pharmacy, vol. 66, p. 285Archived 2013-06-19 at the Wayback Machine (June 1891).
^Isovaleramide does not appear to be a naturally occurring component of valerian plants; rather, it seems to be an artifact of the extraction process; specifically, it is produced by treating aqueous extracts of valerian with ammonia.
^Isovaleric acid does not appear to be a natural constituent of V. officinalis; rather, it is a breakdown product that is created during the extraction process or by enzymatic hydrolysis during (improper) storage.
^ abc"Valerian". Office of Dietary Supplements, US National Institutes of Health. 15 March 2013. Retrieved 2 April 2018.
^ abGrieve, Maud (1971). A Modern Herbal: The Medicinal, Culinary, Cosmetic and Economic Properties, Cultivation and Folk-lore of Herbs, Grasses, Fungi, Shrubs, & Trees with All Their Modern Scientific Uses, Volume 2.
^Balandrin, M. F.; Van Wagenen, B. C.; Cordell, G. A. (1995). "Valerian-derived sedative agents. II. Degradation of Valmane-derived valepotriates in ammoniated hydroalcoholic tinctures". Journal of Toxicology – Toxin Review. 14 (2): 88–252. doi:10.3109/15569549509097280.
^Wills, R.B.H. & Shohet, D. (July 2009). "Changes in valerenic acids content of valerian root (Valeriana officinalis L. s.l.) during long-term storage". Food Chemistry. 115 (1): 250–253. doi:10.1016/j.foodchem.2008.12.011.
^ abMarder M, Viola H, Wasowski C, Fernández S, Medina JH, Paladini AC (2003). "6-methylapigenin and hesperidin: new valeriana flavonoids with activity on the CNS". Pharmacol Biochem Behav. 75 (3): 537–45. doi:10.1016/S0091-3057(03)00121-7. PMID12895671.
^Fernández S, Wasowski C, Paladini AC, Marder M (2004). "Sedative and sleep-enhancing properties of linarin, a flavonoid-isolated from Valeriana officinalis". Pharmacol Biochem Behav. 77 (2): 399–404. doi:10.1016/j.pbb.2003.12.003. PMID14751470.
^Holzl J, Godau P (1989). "Receptor binding studies with Valeriana officinalis on the benzodiazepine receptor". Planta Medica. 55 (7): 642. doi:10.1055/s-2006-962221.
^Mennini T, Bernasconi P, et al. (1993). "In vitro study in the interaction of extracts and pure compounds from Valerian officinalis roots with GABA, benzodiazepine and barbiturate receptors". Fitoterapia. 64: 291–300.
^Lacher, Svenja K.; Mayer, Ralf; Sichardt, Kathrin; Nieber, Karen; Müller, Christa E. (2007). "Interaction of valerian extracts of different polarity with adenosine receptors: Identification of isovaltrate as an inverse agonist at A1 receptors". Biochemical Pharmacology. 73 (2): 248–58. doi:10.1016/j.bcp.2006.09.029. PMID17097622.
^Patočka, Jiří; Jakl, Jiří (2010). "Biomedically relevant chemical constituents of Valeriana officinalis". Journal of Applied Biomedicine. 8 (1): 11–18. doi:10.2478/v10136-009-0002-z.
^Bega D, Malkani R (2016). "Alternative treatment of restless legs syndrome: an overview of the evidence for mind-body interventions, lifestyle interventions, and neutraceuticals". Sleep Med. (Review). 17: 99–105. doi:10.1016/j.sleep.2015.09.009. PMID26847981.