Valerian

Valerian (Valeriana officinalis, Caprifoliaceae) is a perennial flowering plant native to Eurasia. It produces a catnip-like response in cats.

Crude extracts of valerian root may have sedative and anxiolytic effects; however, the clinical evidence is mixed and debated. It is commonly sold as dietary supplement to promote sleep. A dry ethanol extract of valerian root has been recognized as a medicine for adults with mild symptoms by the European Medicines Agency.

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 (though this originally meant zedoary, from which it is etymologically derived) and all-heal (which is also used for plants in the genus Stachys). Valeriana rubra, red valerian, often grown in gardens, is also sometimes referred to as "valerian", but is a different species. Valerian is also called cat's love for its catnip-like effects.

Description

The plant grows up to 2 metres (7 feet) tall and 1 m wide. The erect stems are unbranched, with pinnately divided, toothed leaves. The flowers are light pink, grouped in both compound and secondary clusters.

In the summer the mature plant can bear sweetly scented pink or white flowers.

Distribution and habitat

The plant is native to Europe and Asia. It is widespread in Britain.

Ecology

The flowers attract many fly species, especially hoverflies of the genus Eristalis. The plant is consumed as food by the larvae of some Lepidoptera (butterfly and moth) species, including the grey pug.

As an invasive species

Valerian is considered an invasive species in many locations outside its natural range, including the U.S. state of Connecticut where it is officially banned, and in New Brunswick, Canada, where it is listed as a plant of concern.

Effect on cats

Valerian root is a cat attractant, containing attractant semiochemicals in a way similar to catnip, which can affect cat behavior. Its roots and leaves are one of three alternatives for the one-third of domesticated or medium-sized cats who do not feel the effects of catnip. Valerian root has also been reported to be attractive to rats and used to attract members of the family Canidae to traps.

Valerian extract

Phytochemicals

Known compounds detected in valerian include:

• Alkaloids: actinidine, chatinine, shyanthine, valerianine, and valerine
• Isovaleramide may be created in the extraction process.
• Gamma-aminobutyric acid (GABA)
• Valeric acid
• Isovaleric acid
• Iridoids, including valepotriates
• Sesquiterpenes (contained in the volatile oil): valerenic acid, hydroxyvalerenic acid and acetoxyvalerenic acid
• Flavanones: hesperidin, 6-methylapigenin, and linarin

Preparation

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.

Traditional medicine

Valerian is a common traditional medicine used for treating insomnia. Some sources describe its effectiveness for this purpose as weak, ineffective, inconclusive, or low. Two meta-analyses concluded that valerian may improve sleep quality. A 2006 meta-analysis concluded that there was insufficient evidence to determine valerian’s effectiveness or safety for anxiety disorders. Another meta-analysis found that valerian may be safe and effective for improving sleep and reducing anxiety and that inconsistent results in past research likely stem from variability in extract quality.

In contrast, the European Medicines Agency (EMA) approved the health claim that valerian can be used as a traditional herb to relieve mild nervous tension and to aid sleep; the EMA’s Committee on Herbal Medicinal Products recognizes valerian dry ethanol extract as a well-established herbal medicine for relieving mild nervous tension and improving sleep, based on multiple randomized, controlled, double-blind clinical trials, expert reports, sleep-EEG studies, and traditional use demonstrating gradual improvements in sleep and mild nervous tension symptoms.

Germany’s Commission E, the scientific advisory board responsible for evaluating the safety and efficacy of herbal substances, has approved valerian as an effective mild sedative.

Valerian has not been shown to be helpful in treating restless leg syndrome.

Oral forms

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. For commonly used doses, valerian is generally recognized as safe in the U.S.

Adverse effects

Because the compounds in valerian produce central nervous system depression, they should not be used with other depressants, such as ethanol (drinking alcohol), benzodiazepines, barbiturates, opiates, kava, or antihistamine drugs.

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. Headache and diarrhea have occurred among subjects using valerian in clinical studies.

Other uses

The young leaves can be cooked and the roots can be infused in hot beverages like hot chocolate.

In culture

Valerian has been used in traditional herbal medicine since at least the times 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 a bridegroom to ward off the "envy" of the elves. In the 16th century, Pilgram Marpeck prescribed valerian tea for a sick woman.

John Gerard's Herball, or Generall Historie of Plantes, first published in 1597, 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, such that "no brothes, pottages or phisicalle meates are woorth [worth] anything if Setwall [valerian] were not at one end".

The 17th-century astrological botanist Nicholas 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."

Gallery

See also

• Orvietan
• Spikenard
• Corvalol

Notes

References

External links

• Valerian, National Center for Complementary and Integrative Health, US National Institutes of Health, October 2020