The nervous system is at the intersection between the mind and the physical body so maintaining it is of great importance. The nervine tonic herbs, otherwise known as the nervine trophorestoratives, are an important class of medicines that have an affinity for the nervous system and are said to support, repair, and strengthen its function (Hoffman, 1988). David Hoffman in his book, Holistic Herbal, writes, ‘The nervine tonics strengthen and feed the tissues directly… In many nerve problems, the aid of nervine tonics can be invaluable’. The nervine tonics are thought o work in the long term to nourish the nervous system, while in the short term often induce a feeling of relaxation and wellbeing. It is important to note, nervine tonics are not all equal and have additional actions (e.g. antidepressant, nootropic, relaxant, sedative, hypnotic, analgesic, adaptogen) and also energetics that require consideration (warming, cooling, drying, moistening).

From the North American and European system of herbalism, key examples of nervine tonics include; St. John’s wort, American skullcap, wood betony, milky oats, and blue vervain. From the Ayurvedic system of medicine, the medhya rasayana herbs possess similar properties and are said by Ayurvedic medicine to rejuvenate the brain and nervous system (Kulkarni et al., 2012). Medhya rasayana herbs are a sub division of the rasayana herbs which are more general in their action to most of the body (Winston, 2007). Many rasayana herbs also have an affinity for the nervous system. Examples of rasayana (or medhya rasayana) herbs which we can consider nervine tonics include; gotu kola, calamus, ashwagandha, bacopa, and holy basil. Additionally, herbalists consider ashwagandha and holy basil adaptogens, but adaptogens could also generally be considered nervine tonic in action as they can help relax and restore the nervous system. However, they are unique as they also have affinity for the endocrine system and adrenal glands. Their modulation of the stress response system appears to result in them having a tendency to energise as well as relax.

The adaptogens discussed in this article tend to be more calming in nature (ashwagandha, holy basil) in comparison with more stimulating adaptogens (rhodiola, Asian ginseng). The nervine tonic herbs from both Western herbalism and Ayurveda are variably indicated by traditional medicine for diverse conditions such as depression, anxiety, stress, headaches, various cognitive problems, epilepsy, nerve damage, and insomnia. This article will discuss these nervine tonic herbs in more detail as they are all of great importance in our materia medica.

St. John’s wort

stjohnswortwikicommons

Hypericum perforatum or St. John’s wort is native to Europe and produces distinctive bright five-petaled yellow flowers (Benzie, 2011). The name comes from its flowering around St John’s Day on the 24th June. St. John’s wort’s use as a medicine can be traced back to the ancient Greeks (Castleman, 2001) and the Greek physician Dioscorides (40-90 AD) recommended St. John’s wort internally as a treatment for sciatica and topically for burns. The herb is also associated with many folk traditions and the Romans and Greeks believed that St. John’s wort protected them against evil spells. Later, the Eclectics, America’s 19th century physicians, stated St. John’s wort to have, ‘undoubted power over the nervous and spinal cord’. In humans, St. John’s wort is a confirmed anti-depressant across many high quality scientific studies (Ng et al., 2017).

Despite its scientific categorisation as an anti-depressant, St. John’s wort is known by herbalists as one of the most important herbs for nerve pain in European and North American herbalism. It is also indicated in the treatment of anxiety. It is an important component of many formulas designed to improve nervous system health as it is considered an uplifting and nourishing tonic. Folk lore states, it may heal nerve damage if taken long term (Groves, 2016). St. John’s wort works best as a tincture made from fresh flowers and should have a deep red colour to indicate its medicinal potency. It may also be applied externally in oil form, with a similar colour, specifically for nerve pain. It will increase ones sensitivity to sunlight, so it is best to avoid excessive sun bathing.

American skullcap

skullcap-scutellaria-lateriflor-672x372

Scutellaria lateriflora or American skullcap is a perennial member of the mint family, it may be found growing in the meadows and swamps of North America (Awad et al., 2003). American skullcap was used by the Native Americans as a sedative (Barceloux, 2008). In his book, Holistic Herbal, David Hoffman states skullcap ‘relaxes nervous tension in the central nervous system and also has a renewing effect’ (Hoffman, 1988). In humans, skullcap has been found to have anti-anxiety and mild anti-depressant properties in double blind placebo controlled clinical trials (Brock et al., 2014; Wolfson et al., 2003).

Skullcap is indicated for insomnia, anxiety, stress, epilepsy, seizures, and painful tight muscles. It is one of the best herbs to help restore a normal sleep pattern with its notable sedative action that is stronger than St. John’s wort more gentle relaxant effect. It pairs very well with fresh milky oat seed for this purpose. American skullcap should be used as a fresh tincture, drying removes from its medicinal powers. In the correct form it is a potent addition to our nervine tonic materia medica.

Wood betony

Secondary_stemflower_Betonica_officinalis_high_mountain_variety_Orjen_-_Montenegro_wiki

Betonica officinalis or wood betony is native to Europe and was highly valued by both the ancient Greeks and Romans (Wood, 1997). Antonius Musa, physician to the Emperor Augustus, wrote a book claiming wood betony cured 47 diseases. Steeped in folk lore at the time, the Anglo-Saxon Herbal dramatically mentions betony as a shield against ‘frightful goblins that go by night and terrible sights and dreams’ (Watts, 2007). Next to vervain, wood betony was the most highly esteemed remedy for early European herbalists, and similar to vervain, unfortunately it has fallen into neglect in more modern times. It has been applied against headaches, fatigue, cognitive problems, weak digestion, sciatica, musculoskeletal conditions, CFS, and insomnia (Bartram, 2013). It has a relaxant action comparable with St. John’s wort in strength. Distinct to St. John’s wort and skullcap, it has a nootropic action and so may be useful in treating various cognitive problems.

Blue vervain

Verbena_hastata

Verbena hastata or blue vervain, is a direct descendent of ordinary European vervain. Vervain was used by the Greek physician, Hippocrates, he recommended it for plague and fevers (Castleman, 2001). It was also used by the Roman physician to Theodosius the Great for throat cancer. The Romans spread vervain around Europe and it became popular among the Druids of England in pagan times. Many years later, after introduction of European vervain into America, blue vervain was selected by Dr. O. Phelps Brown in New Jersey City as the most potent of several vervains he tested (Wood, 2004). In his book ‘The Complete Herbalist (1867)’, he writes, ‘the very great medicinal value of this plant was brought to my attention by an accidental knowledge of the good it had effected in a long-standing case of epilepsy’ (Wood, 1997).

I have noticed only a small dose of this potent herb (2-10 drops) is enough to induce a profound state of relaxation. Blue vervain may have uses in the treatment of fatigue, but also insomnia, epilepsy, anxiety, stress, weak digestion, and nerve pain. However, blue vervain is highly cooling and drying so is not the best herb for the vata constitution (cold and dry), it can be formulated with warming and moistening herbs to better suit vata or other herbs can be used instead. Blue vervain has a deep relaxing effect throughout the nervous system and is particuarly indicated in individuals prone to neck and shoulder tension.

Milky oats

Avena sativa or oats is an annual grass that has been cultivated for over 5000 years, while the mature seed is often eaten as a nutritious food, the immature fresh seed is used as a nervine (Singh et al., 2013). For just one week of the growing cycle of oats the developing oat seed is filled with fresh white milk, if the fresh seeds are harvested quickly then made into tincture, they make ‘the greatest nervous system trophorestorative’ (Winston, 2007). Fresh milky oats is a slow acting nervine tonic medicine that is subtle in its action, it may be used longer term to calm shattered nerves and stabilise emotions, and reduce symptoms of drug withdrawal. Energetically, milky oats is moistening and warming so it is quite unusual for a nervine.

Gotu kola

Gotu Kola (Centella Asiatica) Overview, Health Benefits, Side effects (3)

Centella asiatica or gotu kola is a creeping weedy herb that grows natively in tropical areas of India and Sri Lanka (Kuhn and Winston, 2000). The native Sinhalese of Ceylon observed in ancient times that elephants that appeared to be living unusually long periods of time enjoyed eating the leaves of gotu kola (Castleman, 2001). Ayurvedic practitioners consider gotu kola to be a medhya rasayana herb and nootropic (Kulkarni et al., 2012). Ex vivo and in vivo experiments have demonstrated the herb to possess anti-oxidant, neuroprotective, nerve regenerative, and anti-inflammatory properties (Kumar et al., 2003; George et al., 2009; Soumyanath et al., 2005). It is applied in various afflictions of the nerves including, anxiety, stress, cognitive problems, nerve damage, ADD, ADHD, but also in inflammatory or hot conditions such as rheumatoid arthritis and psoriasis (Winston, 2007; Groves, 2016). Gotu kola is considered to be a powerful tonic herb for the nervous and immune systems, so is well suited for a variety of disorders. It is cooling so it typically formulated alongside warming herbs like ashwagandha or calamus to treat the vata constitution (Frawley, 2000).

Calamus

acorus_wiki

Acorus calamus otherwise known as calamus or sweet flag is native to central Asia and eastern Europe (Rajput et al., 2014). The word, acorus, is derived from the Greek work ‘acoron’, and acorus calamus has been hypothesised to have been used by the ancient Greek physician, Dioscorides, in treating inflammation of the eye (Motley, 1994). The Charaka Samhita, an ancient Ayurvedic text, speaks of calamus as a substance that restores consciousness and promotes longevity. Historically, it has also been a popular remedy in Europe and the 17th century English physician Nicholas Culpepper, considered calamus root a ‘strengthener of the stomach and the head’ (Breverton, 2013).

In Ayurveda, it is considered a medhya rasayana herb, similar to gotu kola, and has a supportive role to play for the nervous system. Alongside gotu kola and ashwagandha, calamus is indicated in Ayurveda for neuropathic pain (Frawley, 2000). David Frawley also considers it as one of the best Ayurvedic herbs for depression alongside holy basil. There is some preliminary scientific support using experimental models that supports its role in nerve regeneration, reducing pain (Muthuraman et al., 2011) and reducing inflammation (Mehrotra et al., 2003).

There have been some safety concerns because of the identification of a compound called β-asarone in calamus, this causes cancer in mice when taken at high enough concentrations long term. However, there is no evidence in humans alcoholic based extracts of calamus cause cancer, and in fact, some studies show anti-cancer activity due to other compounds present in the extract (Rajput et al., 2014). Overall, calamus is an important nervine tonic herb in our materia medica with an ancient worldwide history of medicinal use.

Ashwagandha

Withania_somnifera_04_wiki

Withania somnifera or ashwagandha is a small shrub native to India, but also regions of the Middle East and East Africa (Castleman, 2001). Ashwagandha has been used in Ayurveda for some 3000 years (Castleman, 2001). It was mentioned in the Charaka Samhita as a whole body tonic for emancipation, reproductive ability, and longevity. Ashwagandha is relatively well studied for a medicinal plant and well-controlled human studies have found it effective in treating anxiety, osteoarthritis, and sub clinical hypothyroidism (Auddy et al., 2008; Ramakanth et al., 2016; Sharma et al., 2017). It also displays neuroprotective and neuro regenerative properties in various experimental models (Kurapati et al., 2013; Nakayama et al., 2007), which fits nicely with its nootropic action. Ashwagandha has affinities for the nervous, immune, and reproductive systems and may be useful in treating; anxiety, inflammatory arthritis, nerve pain, various autoimmune diseases, fatigue, and sexual debility. Arguably, the most important Ayurvedic herb, if we had to chose one.

Tulsi

Ocimum sanctum otherwise known as holy basil or tulsi, is a small fragrant herb with purple-green leaves. It is found growing wild in India and is also cultivated for widespread medicinal use in folk and Ayurvedic herbalism (Kuhn and Winston, 2000). Similar to calamus, tulsi is highly versatile in its action on the nervous system as it possesses nootropic, antidepressant, and nervine relaxant actions.

Maria Groves mentions this herb improves health of the immune system to fight infections, but also strengthens digestion, decreases inflammation, while relieving anxiety (Groves, 2016). A double-blind placebo controlled human study confirmed that tulsi is effective against anxiety (Saxena et al., 2011). Another renowned herbalist, David Winston writes, ‘I use holy basil to enhance cerebral circulation and memory’ (Winston, 2007). A well-controlled human clinical study found that tulsi has nootropic or cognitive boosting effects (Sampath et al., 2015), supporting David Winston’s work. Additionally, he reports success in treating brain trauma with a combination of holy basil, St. John’s wort, ginkgo, and bacopa (Groves, 2016).

Similar to ashwagandha and gotu kola, tulsi is a versatile nervine tonic herb with broad applicability as it also acts on the immune system.

Finding an energetic balance

It is often best to formulate the drying bitter tonics (e.g. blue vervain) with moistening herbs if taken long term, like hawthorn berry or milky oat seed. Hawthorn berry I have found to reduce the dryness caused by drying herbs particularly well and is mild and a well-suited addition to many formula. It will keep the digestive system moving (it is used in TCM for this purpose) and can moisten dry skin to some extent. Remember, long-term intake of drying herbs may lead to dry skin, constipation, and other problems especially in those people who tend towards dryness. It is also widely accepted that long-term intake of cooling nervines should be accompanied by warming ones, like valerian.

It is also good to study the energetic properties of the herbs in relation to an individual, for instance, gotu kola is a better nervine for pitta (hot constitution) as it is cooling, while ashwagandha is better for vata (cold constitution), as it is warming. They both may be combined together to make a more balanced compound.

Nervine tonic pair

This formula may have applications in restoring sleep, reducing anxiety, and has a renewing effect on the nervous system.

Fresh American skullcap (1 part) (cooling, drying)
Fresh St. John’s wort (1 part) (warming, drying)

Dose: 15-60 drops, 2-3 times daily
Contraindications: People taking SSRIs, St. John’s wort may decrease the effectiveness of pharmaceutical drugs. If on sedative medication be highly cautious regarding dose.

Conclusions

The nervine tonics are a very diverse class of herbs, in a way this is a strength because there is much to choose from, however, each herb requires studying in detail individually and also experiencing to gain a better idea of its specific indications. For instance; gotu kola is a nootropic and tends to be a little more energising to the nervous system, while skullcap is more of a sedative nervine tonic and helps improve sleep. While, milky oats is more nutritive and more subtle in its action than skullcap. A strength of a herbal formula is it may blend various herbs with different actions together for the same purpose.

There are also a variety of other very useful Western nervines that some herbalists consider nervine tonics I haven’t the time to discuss today, for example; lemon balm, lavender, and damiana. There are also a wide range of nervines from the Ayurvedic and Chinese systems that require discussing in more detail. Especially, herbs like reishi, lion’s mane, and bacopa. Perhaps there will be time in the future to write about them.

References

Auddy B, Hazra J, Mitra A, Abedon B, Ghosal S. A standardized Withania somnifera extract significantly reduces stress-related parameters in chronically stressed humans: A double-blind, randomized, placebo-controlled study. J Am Nutraceutical Assoc. 2008;11:50–6.

Awad, R., et al. “Phytochemical and biological analysis of skullcap (Scutellaria lateriflora L.): a medicinal plant with anxiolytic properties.” Phytomedicine 10.8 (2003): 640-649.

Barceloux, Donald G. Medical toxicology of natural substances: foods, fungi, medicinal herbs, plants, and venomous animals. John Wiley & Sons, 2008.

Bartram, Thomas. Bartram’s encyclopedia of herbal medicine. Hachette UK, 2013.

Benzie, Iris FF, and Sissi Wachtel-Galor, eds. Herbal medicine: biomolecular and clinical aspects. CRC Press, 2011.

Breverton, Terry. Breverton’s Complete Herbal. Quercus, 2013.

Brock, C., Whitehouse, J., Tewfik, I., & Towell, T. (2014). American Skullcap (Scutellaria lateriflora): A Randomised, Double‐Blind Placebo‐Controlled Crossover Study of its Effects on Mood in Healthy Volunteers. Phytotherapy Research, 28(5), 692-698.

Frawley, David. Ayurvedic healing: a comprehensive guide. Lotus Press, 2000.

George, Mathew, and Lincy Joseph. “Anti-allergic, anti-pruritic, and anti-inflammatory activities of Centella asiatica extracts.” African Journal of Traditional, Complementary and Alternative Medicines 6.4 (2009).

Groves, Maria. Body into Balance. Storey Publishing, 2016.

Hoffman, David. Holistic herbal. Element Books, 1988.

Kuhn, Merrily A., and David Winston. Herbal therapy and supplements: a scientific and traditional approach. Lippincott Williams & Wilkins, 2000.

Kulkarni, Reena, K. J. Girish, and Abhimanyu Kumar. “Nootropic herbs (Medhya Rasayana) in Ayurveda: an update.” Pharmacognosy reviews 6.12 (2012): 147.

Kurapati, Kesava Rao Venkata, et al. “Ashwagandha (Withania somnifera) reverses β-amyloid 1-42 induced toxicity in human neuronal cells: implications in HIV-associated neurocognitive disorders (HAND).” PLoS One 8.10 (2013): e77624.

 

Mehrotra, S., et al. “Anticellular and immunosuppressive properties of ethanolic extract of Acorus calamus rhizome.” International immunopharmacology 3.1 (2003): 53-61.

Motley, Timothy J. “The ethnobotany of sweet flag, Acorus calamus (Araceae).” Economic Botany 48.4 (1994): 397-412.

Muthuraman, Arunachalam, and Nirmal Singh. “Attenuating effect of Acorus calamus extract in chronic constriction injury induced neuropathic pain in rats: an evidence of anti-oxidative, anti-inflammatory, neuroprotective and calcium inhibitory effects.” BMC complementary and alternative medicine 11.1 (2011): 24.

Nakayama, Natsuki, and Chihiro Tohda. “Withanoside IV improves hindlimb function by facilitating axonal growth and increase in peripheral nervous system myelin level after spinal cord injury.” Neuroscience research 58.2 (2007): 176-182.

Ng, Qin Xiang, Nandini Venkatanarayanan, and Collin Yih Xian Ho. “Clinical use of Hypericum perforatum (St John’s wort) in depression: A meta-analysis.” Journal of Affective Disorders 210 (2017): 211-221.

Rajput, Sandeep B., Madan B. Tonge, and S. Mohan Karuppayil. “An overview on traditional uses and pharmacological profile of Acorus calamus Linn.(Sweet flag) and other Acorus species.” Phytomedicine 21.3 (2014): 268-276.

Ramakanth, G. S. H., et al. “A randomized, double blind placebo controlled study of efficacy and tolerability of Withaina somnifera extracts in knee joint pain.” Journal of Ayurveda and integrative medicine 7.3 (2016): 151-157.

Sampath, Suneetha, et al. “Holy basil (Ocimum sanctum Linn.) leaf extract enhances specific cognitive parameters in healthy adult volunteers: A placebo controlled study.” (2015).

Saxena, Ram Chandra, et al. “Efficacy of an extract of ocimum tenuiflorum (OciBest) in the management of general stress: A double-blind, placebo-controlled study.” Evidence-Based Complementary and Alternative Medicine 2012 (2011).

Sharma, Ashok Kumar, Indraneel Basu, and Siddarth Singh. “Efficacy and Safety of Ashwagandha Root Extract in Subclinical Hypothyroid Patients: A Double-Blind, Randomized Placebo-Controlled Trial.” The Journal of Alternative and Complementary Medicine (2017).

Singh, Rajinder, Subrata De, and Asma Belkheir. “Avena sativa (Oat), a potential neutraceutical and therapeutic agent: an overview.” Critical reviews in food science and nutrition 53.2 (2013): 126-144.

Soumyanath, Amala, et al. “Centella asiatica accelerates nerve regeneration upon oral administration and contains multiple active fractions increasing neurite elongation in‐vitro.” Journal of Pharmacy and Pharmacology 57.9 (2005): 1221-1229.

Veerendra Kumar, M. H., and Y. K. Gupta. “Effect of Centella asiatica on cognition and oxidative stress in an intracerebroventricular streptozotocin model of Alzheimer’s disease in rats.” Clinical and Experimental Pharmacology and Physiology 30.5‐6 (2003): 336-342.

Watts, Donald C. Dictionary of plant lore. Academic Press, 2007.

Winston, David, and Steven Maimes. Adaptogens: herbs for strength, stamina, and stress relief. Inner Traditions/Bear & Co, 2007.

Wolfson, P., and D. L. Hoffmann. “An investigation into the efficacy of Scutellaria lateriflora in healthy volunteers.” Alternative therapies in health and medicine 9.2 (2003): 74.

Wood, Matthew. The book of herbal wisdom: Using plants as medicine. North Atlantic Books, 1997.