O sleep, O gentle sleep,
Nature's soft nurse, how have I frighted thee,
That thou no more wilt weigh my eyelids down
And steep my senses in forgetfulness?

William Shakespeare, Henry IV

A good night's sleep is important to health. During sleep the body is in an anabolic state when energy conservation, tissue repair and growth take over. The body temperature drops, growth hormone is secreted and immune cell production is increased. Thus sleep is essential for a healthy body and a peaceful mind.

Insomnia is defined as difficulty falling asleep or staying asleep and affects roughly 50% of all adults. It may resolve and return intermittently or it may become chronic. As many as 10% of adults with sleep problems have chronic insomnia, defined as disrupted sleep occurring at least 3 nights per week and lasting 1-3 months. While there are numerous and varied reasons for sleep disturbances, a common denominator is physical, emotional or mental stress to the nervous system.

Nervines are the botanical world's answer to insomnia, with actions that have a beneficial, and sometimes tonic, effect on the nervous system. Some of the herbs promote relaxation supporting a natural sleep, while others act as a sedative or hypnotic (promotes deep sleep). Still other nervines nourish and restore balance to the nervous system. Nervines also have antispasmodic and analgesic properties, if muscle tension or pain is the reason for sleeplessness. While nervines act primarily on the nervous system there is a close interface with the adrenal glands. So nervines can also be a key component of adrenal support formulations.

California poppy

The California poppy (Eschscholtzia californica), considered a non-addictive alternative to its Papaveraceae family member, the opium poppy, is used for its anxiolytic, anodyne and sedative (hypnotic) properties. One of the oldest North American remedies for stress-induced maladies, Native Americans used the leaves to ease toothache and colic pains.

A German prescription drug, Phytonoxon N, containing California poppy was found to interact with opioid receptors which may explain some of the plant's medicinal actions. A specific indication of the poppy has been as a sedative and hypnotic (sleep promoter) for children where there is "over-excitability and sleeplessness." Another study showed a key alkaloidal constituent, chelerythrine, acting as an inhibitor to pain neurons in the spinal cord, significantly reducing nociceptive responses.

California poppy should be used cautiously, as the herb can interact with CNS depressant drugs and sedative medications such as benzodiazepines, potentiating the sedative effect.

German Chamomile

German Chamomile (Matricaria chamomilla) has been mainstreamed into several commercial tea formulations. In Mediterranean countries chamomile can be ordered in restaurants and bars in a concentrated 'espresso' form. Its reputation as a gentle sedative for children is well-known and commonly used for anxiety and insomnia. Having carminative properties, the herb is often used to settle the stomach in bouts of indigestion or gastritis.

Apigenin and luteolin, flavonoid constituents of chamomile, have demonstrated anti-anxiety and slight sedative activity without muscle relaxant effects in mice, likely due to modulating the GABA A receptor. The sedative effect may also be elicited due to very small concentrations of GABA found in the plant. Significant sleeping-time-potentiating effects were only observed at the two highest doses (160 and 320 mg/kg). A rat study also showed a reduction of stress-induced plasma ACTH after inhaling chamomile oil vapor, revealing a normalizing effect on cortisol production.

In a clinical trial chamomile extract produced a significant reduction in generalized anxiety disorder (GAD) symptoms over an 8-week period. The response rate using the herbal extract was comparable to conventional anxiolytic drugs without the adverse side effects.

Hops

The hop plant (Humulus lupulus) is in the Cannabaceae or Hemp family. In Europe hops have been grown commercially for beer brewing since the 11^th century, and in certain areas of the US brewing specialty beers using hops has become very popular. 

Traditionally hops, the flower of the Hop plant, were used to strengthen and stimulate the digestion, but also as a valuable remedy for sleeplessness and excitability. A sachet of hops placed inside a bed pillow releases an aroma thought to calm the mind. The herb is used extensively for the treatment of insomnia having a marked relaxing effect upon the central nervous system. It acts to ease tension and anxiety, especially where tension leads to restlessness, headache and possibly indigestion. In one study hops in combination with valerian has been found to improve sleep latency and quality of sleep. However, hops should be used cautiously in people with a marked degree of depression.

Kava

Kava (Piper methysticum) was discovered in the Pacific Islands. Traditionally the kava root was cut into pieces, chewed or ground up, then mixed with coconut milk or water and decanted into a community bowl or cups. Historically used for religious ceremonies to help worshippers reach higher states of consciousness, today the concoction is served at social gatherings. Its key constituents are resins known as kava lactones, kavain, and dihydrokavain (DHK). Primary effects of kava are a decrease in anxiety and relaxation of the body without loss of mental acuity. There is also a mild anesthetic effect specifically on the mucous membranes. While a remedy can be standardized for the lactones, often the total extract of the kava rootstock can have more activity than its isolated constituents.

Studies suggest kava lactones can bind to GABA-A receptors. Tissue studies imply kava lactones may have a mechanism of action via modulation of N-methyl-D-aspartate (NMDA) receptors. In a placebo-controlled trial, the efficacy of a kava extract to induce sleep was investigated. With kava extract (150-300 mg extract, containing 105 mg – 210 mg kava lactones respectively) the ability to fall asleep and the light sleep phase were shortened, the deep sleep phase was lengthened, the duration of REM sleep was not influenced and the duration of wakeful phases in sleep EEG recordings was decreased. Kava has also been shown to decrease anxiety and improve cognitive performance without causing sedation.¹

Some precautions with kava use include liver toxicity. However, investigations into the events have revealed toxicity is likely due to products made from parts of the kava plant other than the root and/or use of solvents to extract the lactones. Water extracts have not exhibited hepatotoxic effects in any of the products tested. Overdoses of kava aqueous extract has been reported in the Aboriginal communities, but doses ranged from 100-500 g/week. Long-term use of an equivalent dose of 400 mg or more of kava lactones per day may cause a scaly skin rash in some subjects.

Lavender

Lavender (Lavendula officinalis) is better known for its sweet-scented aroma than for its medicinal properties. It has a long history: it was popular during the late Middle Ages and was also one of the medicinal herbs taken to the New World by the Pilgrims. Its many volatile oils are key to its effectiveness.

As a gently strengthening nervous system tonic lavender is used to relieve states of nervous debility and exhaustion. Effective for headaches especially those related to stress, it also soothes and promotes natural sleep. One study compared the inhalation effects of lavender essential oil on the equality of sleep for shift nurses. Another study demonstrated improved feelings of well-being and energy as well as a statistically significant improvement in sleep quality in 79 college students with self-reported sleep issues. An animal research using an oral lavender extract at doses of 400-800 mg/kg were investigated for sleep onset and sleep duration. The extract was comparable to diazepam in reducing sleep onset latency, but was slightly less effective than the drug for increasing sleep duration. A human trial using 80 mg oral lavender oil showed beneficial effects on disturbed sleep and somatic complaints in patients with GAD. This same study's results also reported a significant anxiolytic effect.

Lemon balm

Lemon balm (Melissa officinalis) is a member of the mint family. A calming herb, it was historically used to reduce stress and anxiety and promote sleep. The herb has a long tradition as a tonic remedy that "raises the spirits and comforts the heart." People in the Middle Ages steeped lemon balm in wine to lift the spirits and help heal wounds. Like other members of the mint family, lemon balm aids digestion and can ease the pain and discomfort of indigestion or colic. Today its uses include insomnia, anxiety, GI complaints and menstrual cramps, with more recent research exhibiting lemon balm's effect in the treatment of cold sores (herpes simplex virus).

A 2011 pilot trial summarized the lemon balm extract as demonstrating a significant improvement in anxiety manifestations and associated symptoms and insomnia. After 15 days of treatment insomnia was reduced by 42%. In a study assessing an herbal combination for sleep disruption accompanying menopause, 100 women were evaluated.  Half were given placebo and half were given a remedy containing both lemon balm and valerian. The intervention group revealed a significant improvement in their sleep quality compared to the placebo group.

Oatstraw

Oatstraw (Avena sativa/officinalis) has been used historically as a remedy for nervous debility and exhaustion, where the nervous system needs 'feeding' or strengthening due to stress. As a tonic nervine it's almost nutritional in its effect and is considered to be extremely safe. Indicated for insomnia where "waking in the small hours of the night after going off to sleep easily" is the problem. Oats has a specific indication for fatigue in convalescence and neurasthenia.

Milky oats are the tops of the green oat plant. They are harvested in their milky stage, after flowering but before the seeds harden. Often made into a tincture milky oats are generally believed to work quickly in an acute situation. They have been used in withdrawal from nicotine and other addictive substances. Oatstraw is the stem of the plant and has more of a tonic effect, supporting the nervous system over time. Oatstraw is considered safe for everyday use; however, people with celiac disease should be cautious with its use due to possible cross-contamination with gluten cereals.

Passionflower

Passionflower (Passiflora incarnata) has a long history of use for insomnia, epilepsy and mania in Central and North America. It is considered by many herbalists as the herb of choice for unyielding insomnia and aids the transition into a restful sleep without a 'narcotic' hangover. Passionflower is useful as an anti-spasmodic when required for tension and effective for nerve pain such as neuralgia and shingles. 

Although regarded as an effective nervine, passionflower has not been well researched.  One study investigating its effects on sleep quality suggests consumption of an aqueous extract showed a benefit to sleep quality in those people with mild sleep problems. This herb often works synergistically when combined with other nervines.

Skullcap

Skullcap (Scutellaria laterifolia) is a classic nervine tonic, traditionally used for menstrual problems by Native Americans. In 19^th century America the herb became well known as a treatment for rabies and was assigned the common name of "mad dog." Its sedative and anti-spasmodic properties helps relax nervous tension while revitalizing the central nervous system. Useful for pre-menstrual tension, skullcap has a specific indication for the treatment of seizure disorders. While other varieties of the scutellaria family have been researched, there has been limited investigation on the laterifolia species. Though one study using skullcap indicated a significant enhancement of mood, the authors stated that further assessment of the herb’s anxiolytic effects was warranted to determine clinical value.

Valerian

Valerian (Valeriana officinalis) has a long been used as a mild sedative and is one of the most effective relaxing nervines. Valerian's medicinal value has been known since the 1^st century AD. Its distinctive odor is due to the volatile oil, valerenic acid and often described as "dirty socks." Valerian's actions include anxiolytic, mild sedative, hypnotic and spasmolytic effects. Traditionally used for certain kinds of epilepsy, valerian was also useful as a sedative in conditions of nervousness, stress and neuralgia. Viewed as a cerebral stimulant it was often used in conditions of mania with mental depression, despondency and nervous headache. For its sedative effect, Valerian can safely be used to reduce tension and anxiety, inducing a natural, healing sleep. Several studies have established valerian as a successful treatment for insomnia. In a German trial of over 11,000 patients, ingestion of an aqueous extract of the herb aided participants in falling asleep, improving the continuity of sleep and decreasing restlessness and tension.  Although outcomes were positive, best results were seen after 2 weeks of use.

Another trial showed improvement in sleep latency time and sleep quality in elderly patients with symptoms of sleep disturbance. Results indicated valerian increased slow-wave sleep (SWS) but did not alter REM sleep. For those people who have low baseline values valerian increases SWS and reduces stage 1 sleep, differentiating the mode of action from that of benzodiazepine-type drugs.

While sleep hygiene and lifestyle changes are sometimes necessary for treating insomnia, herbal remedies can be an integral part of the treatment plan. If you're interesting in testing for sleep-related difficulties, take a look at the Sleep Balance profile. 

• Blog: Adaptogens - Herbs for Healthy Living
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• The Encyclopedia of Medicinal Plants, by Andrew Chevallier
• The New Holistic Herbal, by David Hoffmann
• Principles and Practice of Phytotherapy, by Simon Mills and Kerry Bone
• Principles and Practice of Phytotherapy, 2^nd Edition, by Simon Mills and Kerry Bone
• 1. Emser W and Bartylla K. Improvement of sleep quality. Effect of kava extract WS 1490 on the sleep pattern in healthy subjects. Neurologie/Psychiatrie 1991;5(11):636-642.