Valerian officinalis, Valerian root

  • Written by Simon Ido, Reviewed by Prof. Shoseyov Oded
  • 5 mins 21 secs
Highlights
  • Valerian root is a traditional herbal medicine which today is used as a sleep aid for mild insomnia[1, 3, 5].
  • Valerian is thought to possess sedative and tranquil- izing properties[1, 3, 5] as a result of its essential oils and other synergestic compounds[3, 4].
Background

Valerian officinalis, known as Valerian root, is a popular herbal medicine used as a sleep aid[5]. Historically, there has been much conflicting evidence regarding the efficacy of Valerian as a sleep aid[1, 2, 3, 6, 7], however, more up-to-date systematic reviews indicate that this is due to variable herbal quality of extracts as well as various combinations with other herbal compounds[1, 5].Valerian root is considered a safe herbal treatment[7], with very few recorded cases of overdose which presents itself as mild symptoms resolved within 24 hours[8].Valerian root has recorded use dating back to the first century AD, albeit for its metabolic stimulation rather than for its sedative properties[5]. Traditional herbal- ists have also used it as an anxiolytic, although scientific evidence supporting this use is minimal[3]. Today, sev- eral clinical studies have shown that Valerian is effective in the treatment of insomnia by reducing sleep latency, especially in continuous rather than acute use[3].It is believed that the sesquiterpene components of the volatile oil contained in the root are responsible for most of Valerian’s biological effects[3].

A review by the American Family Physician journal recommends a dosage of the root extract for insomnia to befrom300-600mg(or2-3gofdriedrootintea)30 minutes to two hours before bedtime[3]. It has also been observed that preparations consisting of both Valerian and Hops (Humulus lupulus) have shown a significant improvement in sleep quality[4].

Mode of Action

The chemical composition of Valerian root includes sesquiterpenes including valeric acid and bornyl acetate[4], iridoids, alkaloids, furanofuran lignans, and free amino acids such as GABA, tyrosine, arginine, and glutamine[3]. The sesquiterpene components are 

thought to be responsible for most of the biological ef- fects, however, it is entirely possible that all of the active constituents together are responsible for the clinical re- sponses seen [3].

The constituents of the volatile oil are extremely vari- able due to population differences in genetics and en- vironmental factors. Valerenic acid has been shown to inhibit the enzyme-induced breakdown of GABA in the brain, resulting in sedation[4]. Other kessane deriva- tives are also thought to contribute to Valerian’s sedative properties[2].

In mice, valerenic acid was shown to produce a sig- nificant decrease in motility[4]. Other polar compounds such as the valepotriates and lignans are thought to be associated with a suppression of CNS activity seen in mice trials[4]. Lignans are also thought to inhibit or an- tagonize 5-HTP depending on which part of the brain is observed[4]. The alkaloids and amino acids present are not thought to contribute to the biological effects as they are present in small amounts in the plant[4].

Additionally, aqueous extracts appear to be better than alcoholic extracts in achieving a pharmacological effects – the reason for this is unknown, and it thought that some compounds present in Valerian are more po- tent when freshly prepared or incorporated into solid oral dosage forms[4].

Some in-vitro studies have shown that high doses of valepotriates can cause damage to DNA and GI tract irritation through the muscle-relaxant properties of valepotriates[7]. However, in-vivo studies have shown no significant cytotoxic effects of valtrate on mouse bone marrow cells[2]. It is also thought that the valepotriates contribute to the synergestic effects of Valerian[2].

Contradictory findings regarding alcoholic and aque- ous extracts may be due to the hydrophilic and hy- drophobic components of Valerian acting in opposite di- rections at the adenosine receptors[5].

There is also little evidence on potential drug inter- actions, although it is recommended to express cau- tion with medications which are metabolized by the cy- tochrome P450 enzyme[7].

Pharmacological Effects

The most recent and up-to-date systemic review of Va- lerian root has shown that sleep promotion and anxi- olytic effects were the major therapeutic effects, how- ever, large differences were seen in effectiveness when herbal extracts were used[5]. Valerian root when used as a water-based extract is thought to contribute to sleep aid via reduced sleep latency and improving sleep qual- ity, especially when associated with anxiety, depression, and ADHD comorbidities[5].

One issue in studying the pharmacological effects of Valerian is the lack of standardization[7]. Some stud- ies show improvements in subjective sleep outcomes[1], while others show no improvements in both subjective and objective sleep outcomes[7]. Additionally, most ran- domized and controlled trials showed no improvements in sleep[1].

Although many reviews show contradictory effects, largely due to differences in herbal extract quality as dis- cussed above, a review in the American Family Physician journal concludes that Valerian is an effective and safe treatment in mild insomnia[3].

Valerian has been shown to have both sedative and tranquilizing activity, and is considered a classical ex- ample of a herbal drug where the overall effect is due to several types of constituents and modes of action[4] – which is one primary reason why literature is so conflict- ing.

It is also not known if prolonged use could result in toxicity, as side effects have been reported from chronic use including headaches, excitability, uneasiness, cardiac disturbances, and hepatoxicity and CNS depressant ef- fects (especially in combination with alcohol)[2, 8].

Potential Uses

As discussed above, Valerian root’s primary use is as a sleep aid for mild insomnia[1, 3, 4, 5], especially insomnia which is a result of anxiety, depression, or ADHD[5].

It is important to find a high-quality herbal prepara- tion of Valerian given the number of contradictory stud- ies seen in literature[5, 7]

References

[1]  S. Bent, A. Padula, D. Moore, M. Patterson, and W. Mehling. Valerian for sleep: A systematic re- view and meta-analysis. The American Journal of Medicine, 119(12):1005–1012, 2006. 

[2]  M. F. Caron and J. E. Riedlinger. Valerian: A prac- tical review for clinicians. Nutrition in Clinical Care, 2(4):250–257, 1999. 

[3]  S. Hadley and J. J. Petry. Valerian. Am Fam Physi- cian, 67(8):1755–1758, Apr 2003. 

[4]  P. J. Houghton. The Scientific Basis for the Reputed Activity of Valerian. Journal of Pharmacy and Phar- macology, 51

(5):505–512, 02 2010. [5]  N. Shinjyo, G. Waddell, and J. Green. Vale- rian root in treating sleep problems and associated disorders—a systematic review and meta-analysis. Journal of Evidence-Based Integrative Medicine, 25:2515690X20967323, 2020. PMID: 33086877. 

[6]  C. Stevinson and E. Ernst. Valerian for insomnia: a systematic review of randomized clinical trials. Sleep Medicine, 1(2):91–99, 2000. 

[7]  D. M. Taibi, C. A. Landis, H. Petry, and M. V. Vi- tiello. A systematic review of valerian as a sleep aid: Safe but not effective. Sleep Medicine Reviews, 11(3):209–230, 2007. [8]  L. Willey, S. Mady, D. Cobaugh, and P. Wax. Vale- rian overdose: a case report. Veterinary and human toxicology, 37(4):364—365, August 1995.

This document was created on November 2, 2021 and last up- dated on November 6, 2021.