Index
- Description of the plant: habitat and hints of botany
- Constituents of the drug and preparations
- Herbal use of valerian
- Drug interactions
- Side effects
- Conclusion
Questions and answers
Description of the plant: habitat and hints of botany
Valeriana officinalis L. (Fam. Caprifoliaceae) is a herbaceous plant native to Europe and Asia, but also widespread in North America. Its stem can reach a height of one meter, has opposite leaves with a toothed margin and blooms in the period of June, with white or pink flowers .
The preparation, commonly known as valerian , can be made from the underground organs of several species of Valerian. In other parts of the world, for example, Valeriana jatamansi Jones (Indian valerian) or Valeriana fauriei Briq (Japanese valerian) are used. Despite this, Valeriana officinalis L. remains the best known and most used speciesin Europe and is the only one officially considered by the European Pharmacopoeia.
Although the roots are the most used part of the plant for therapeutic purposes , the rhizome and the stolons also constitute the drug of Valeriana officinalis L .; they are harvested in the period between September and March and dried at temperatures below 40 ° C. Fresh drug is odorless, but once dried it develops a strong, nauseating odor due to the formation of short-chain fatty acids.
Constituents of the drug and preparations
The Valeriana officinalis drug contains a share of essential oil (0.3-1.0%) consisting of monoterpenic and sesquiterpenic compounds , such as valerenic acid, valerenal, valeranone and β-caryophyllene. In addition, it contains a percentage of iridoid compounds called valepotriates (0.1-2%), such as valtrate, isovaltrate and acevaltrate. Other identified components belong to the class of lignans and alkaloids, although present in smaller quantities.
The Official Pharmacopoeia of the Italian Republic describes the use of capsules containing a hydroalcoholic dry extractmade with ethanol (30-90% V / V) or methanol (40-55% V / V). As for the quality indices, the dry drug, according to the European Pharmacopoeia, must have an essential oil content greater than 0.4% (V / P) and a content of sesquiterpenic compounds (expressed as valerenic acid) greater than or equal at 0.17% (P / P).
Valerian preparations are indicated as mild sedatives in adults and children over 12 years of age. In Italy it is sold as a raw drug, food supplement or drug, the most used forms of which are dry, aqueous or ethanolic extracts, at doses between 45 and 300 mg.
On a qualitative level, the various preparations must in any case respect a minimum content of sesquiterpenic acids, greater than or equal to: 0.25% (P / P) for the hydroalcoholic extract, 0.02% (P / P) for the extract aqueous and 0.015% (W / W) for dyeing.
Herbal use of valerian
Valerian is traditionally used as a sedative and sedative , but some new studies suggest its use also in cases of dysmenorrhea and gastrointestinal disorders of nervous origin. Even today the drug is mainly used for its anxiolytic and sedative action , however the sleep-facilitating effects seem to manifest themselves only after a prolonged treatment period, of at least 14 days. The effects, initially attributed to valepotriates, were later associated with sesquiterpene compounds. In fact, today most products containing valerian are devoid of valepotriates , due to their potential mutagenic activity.
Valerian is the classic example of a drugwhose biological activity is linked to the action of different constituents, rather than to single components. Its extracts are able to influence the transmission of the neurotransmitter γ-aminobutyric acid (GABA), inhibiting its catabolism , reuptake at the presynaptic level and promoting its synthesis through the activation of the enzyme glutamate decarboxylase . Furthermore, other proposed mechanisms predict that some lignans contained in the drug may interact with adenosine and serotonin receptors.
In the monographs of the European Medicines Agency (EMA) the root (and its preparations) and essential oilValerian has been recognized as an established use in the treatment of mild anxiety and sleep disorders .
In the first case, the anxiolytic action is evidenced by some clinical studies which, although limited in the number of participants, seem to show a modest efficacy of the preparations. In the case of sedative action, a first systematic review in 2006 suggests on the basis of the studies analyzed, that the use of valerian can improve sleep quality., however, it is not possible to draw definitive conclusions due to methodological problems and great variability of the results, caused by different doses and treatment times. A second systematic review, published in 2015, pointed out that the effects of valerian on sleep duration, efficiency and latency time are similar to those induced by placebo , reporting in a single study the appearance of intestinal disorders , no longer confirmed by others. investigations. In summary, the literature data are often discordant and from observation it seems that the effects can occur in the case of chronic insomnia only after prolonged use.. To date, it can therefore be said that there is no decisive evidence on the sedative efficacy of Valeriana officinalis. Its traditional use is only partially confirmed by scientific data, making more targeted and rigorous studies necessary. To these data is added a clinical study that has shown how the association of a hop extract and valerian is able to diminish sleep latency, compared to the use of valerian alone.
Finally, two clinical trials evaluated the effectiveness of valerian in fighting menopausal symptoms . Both studies showed significant action in reducing the severity and frequency of hot flashesheat. A third study has shown that valerian is able to improve sleep in menopausal women and at the same time suffering from insomnia . Also in this context, the association of valerian with an extract of Melissa officinalis improved the quality of sleep, underlining the absence of side effects in the sample of 100 women in the study.
The data described here, while promising, need further research to confirm the positive effects in this specific condition of the female sphere .
Drug interactions
In some cases it has been hypothesized a possible interference of valerian with some anticancer drugs . A review of the literature published in 2014 stated that the in vitro studies, carried out until then, were not predictive of clinically relevant drug interactions. Furthermore, studies conducted both in humans and in animal models have not found interference with some of the main families of enzymes involved in drug metabolism. In conclusion, the authors do not highlight safety problems , even in the case of patients undergoing anticancer therapies.
Otherwise, when taken in combination with sedative drugs , a possible was observedpotentiation of effects , evidenced by the appearance of tremor and drowsiness.
Side effects
The use of valerian is generally believed to be safe . However, some gastrointestinal side effects (such as nausea, vomiting and abdominal pain), asthenia, tachycardia , headache , dizziness , drowsiness, tremors, as well as cases of itching and skin rash have been reported .
In case of overdose (20 g) it can cause mild symptoms, which disappear within 24 hours and include abdominal pain, fatigue, chest tightness, hand tremors and mydriasis. Use in children below 12 years of age is not recommended due to a lack of efficacy and safety data. Like other anxiolytic drugs , valerian may potentiate the effects of central depressants such as ethanol , and the use of machines or driving vehicles is not recommended during treatment.
Conclusion
The use of valerian in herbal medicine is considered safe, but to date there is still a need to conduct new and rigorous studies to support traditional use. The anxiolytic and sedative effects are subject to a high variability and seem to be linked to an individual sensitivity . Unfortunately, the data collected in this area are subject to several confounding factors and, often, in some studies a placebo was found to be sufficient to induce effects comparable to those of valerian. However, the presence of interesting results suggests continuing research to confirm the sedative effects associated with it. In the context of menopause, the first data are undoubtedly encouraging, but even in this case they need further confirmation.
BIBLIOGRAPHICAL REFERENCES
- Book: Pharmacognosy and phytotherapy: pharmacological bases and application aspects.
Authors: Mazzanti G, Dell’Agli M, Izzo A.
Publisher: Piccin
Year: 2020 - Book: Pharmaceutical biology and botany
Authors: Senatore F.
Publisher: Piccin
Year: 2011 - Book: Phytotherapy: rational use of plant drugs
Authors: Capasso F, Grandolini G, Izzo A.
Publisher: Springer
Year: 2006
Questions and answers
DOES THE USE OF VALERIAN FACILITATE SLEEP?
Valerian is traditionally used as a sedative, but to date the scientific data collected do not allow to confirm this activity, due to very variable results.
DOES TAKING VALERIAN HAVE RAPID EFFECTS ON ANXIETY AND SLEEP?
There is no clear evidence that valerian works in these areas, however the analysis of the data suggests that the effects occur only after prolonged use, exceeding 14 days.
CAN VALERIAN BE USED TO TREAT MENOPAUSAL SYMPTOMS?
The few studies that have been done tend to support this activity, showing a reduction in the frequency and severity of hot flashes. Unfortunately, the number of searches is still small to confirm its use in this area.
CAN VALERIAN BE USED IN COMBINATION WITH OTHER DRUGS TO FACILITATE SLEEP?
The use of valerian is generally thought to be safe, however there have been reports of side effects when taken in combination with sedative drugs, such as benzodiazepines. As a precaution, the association with other drugs is not recommended, as there are no data on possible interactions, in any case it is always important to contact your doctor to assess your condition.
