Calm Down! Part 3

Calm Down! Part 3

Part 3 of a series

Herbal Agents

In part 1 we talked about minerals and how they can calm the horse. In part 2 we went over vitamins and amino acids and their actions for calming. In part 3 we focus on herbal agents.

Before we start lets talk about the word Nervine. Nervine is pronounced Nur-veen.

Officially it means “acting on or relieving disorders of the nerves; soothing the nerves.” There are lots of claims about many herbal products but I will limit this discussion to herbal ingredients as that are officially recognized as nervine agents.


You’ve probably herb of “Sleepy Time” it’s a tea for people made with chamomile leaves. Chamomile is known as “the calming herb,” although it has many uses both internally and externally in people and animals It is classified as a nervine because it is an herb with specific actions on the nervous system Because of its anti-spasm and anti-inflammatory properties, it is especially helpful for horses that process anxiety through their intestinal system (diarrhea, colic, weight loss).

Major chemical compounds present within chamomile include; Apigenin, Alpha-bisabolol, Sesquiterpenes, Terpenoids, Flavonoids, Coumarins, and Phenylpropanoids. These chemical compounds can have significant effect in the body.

  • Anticancer effect – Studies have shown that chamomile extracts have in vitro (in the laboratory) growth inhibitory effects on cancer cells in skin, prostate, breast, ovarian, prostate cancer cell lines with minimal effects on normal cells.
  • Anticoagulant effect – Coumarin compounds in chamomile such as herniarin and umbelliferone may have blood-thinning properties. However the mechanism is not well understood.
  • Anti-inflammatory effect – Several chemical constituents of chamomile such as bisabolol, chamazulene, apigenin, and loteolin possess anti-inflammatory properties although exact mechanism is not well characterized.
  • Antimicrobial effects – Chamazulene, alpha-bisabolol, flavonoids, and umbelliferone have antifungal activities. A number of in vitro studies showed chamomile’s anti-mycobacteria activity, inhibition of the growth of poliovirus and herpes virus, blockage of aggregation of Helicobacter pylori ( a bacterium linked to stomach ulcers in people) and numerous strains of Escherichia coli. Chamomile oil was demonstrated in studies to be effective against gram-positive bacteria such as Staphylococcus aureus, Streptococcus mutans, Streptococcus salivarius, and Bacillus species.
  • Antispasmodic/antidiarrheal effects – Bisabolol and flavonoids have demonstrated antispasmodic effects in animal experiments. In human studies, chamomile tea in combination with other herbs (vervain, licorice, fennel, balm mint) was shown to be effective in treating colic in children. Flavonoids and coumarins are considered smooth muscle relaxants.
  • CNS/sensory effects – Chemical compounds present within chamomile bind to GABA receptors, modulate monoamine neurotransmission, and have neuroendocrine effects.


Hops is most recognized as the flavoring agent in beer. However, this herb has also been used for centuries to relieve nervous tension, anxiety, irritability and other mood disturbances and therefore is classified as a nervine, or, an herb with specific actions on the nervous system. In humans, it has been shown to aid in sleep disturbances such as insomnia. In horses, it is most useful for those that process anxiety in the head and become distracted and unfocused.

Hops are also used in herbal medicine in a way similar to valerian, as a treatment for anxiety, restlessness, and insomnia.

A pillow filled with hops is a popular folk remedy for sleeplessness, and animal research has shown a sedative effect. The relaxing effect of hops may be due, in part, to the specific degradation product from alpha acids, 2-methyl-3-buten-2-ol, as demonstrated from nighttime consumption of non-alcoholic beer.

Hops are of interest for hormone replacement therapy and may have uses for potential relief of menstruation-related problems. Hops are also under study for potential activity against pasture-associated laminitis in horses.

Lemon Balm

Lemon Balm (Melissa officinalis) is an herb with actions on three main systems of the body: digestive, cardiovascular and nervous. Lemon Balm is reported to be “Excellent for hyperactive children, it is considered restorative to the cells and tissues of the brain, spinal cord and nerves and even has sedative effects”.

Lemon balm is also used medicinally as an herbal tea, or in extract form. It is used as an anxiolytic (anxiety reducing), mild sedative, or calming agent. At least one study has found it to be effective at reducing stress, although the study’s authors call for further research. Lemon balm extract was identified as a potent in vitro inhibitor of GABA transaminase, which explains anxiolytic effects. The major compound responsible for GABA transaminase inhibition activity in lemon balm was then found to be rosmarinic acid.

Lemon balm and preparations thereof also have been shown to improve mood and mental performance. These effects are believed to involve muscarinic and nicotinic acetylcholine receptors. Positive results have been achieved in a small clinical trial involving Alzheimer patients with mild to moderate symptoms.

Passion flower

Passion Flower (Passiflora incarnate) is an herb with gentle sedative properties producing a relaxing effect. It appears to be particularly effective when used in conjunction with a more dominant nervine such as chamomile, hops, valerian or vervain to assist in the rebalancing of a horse’s nervous system. Passion Flower is thought to act by breaking long-standing habits or nervous patterns and facilitating the development of new, more appropriate behaviors.

P. incarnata (maypop) leaves and roots have a long history of use among Native Americans in North America and were adapted by the European colonists. The fresh or dried leaves of maypop are used to make a tea that is used for insomnia, hysteria, and epilepsy, and is also valued for its analgesic properties. P. edulis (passion fruit) and a few other species are used in Central and South America for similar purposes. Once dried, the leaves can also be smoked.

The medical utility of only a few species of Passiflora has been scientifically studied. In initial study in 2001 for treatment of generalized anxiety disorder, maypop extract performed as well as oxazepam but with fewer short-term side effects. It was recommended to follow up with long-term studies to confirm these results.

A study performed on mice demonstrated that Passiflora alata has a genotoxic effect on cells, and suggested further research was recommended before this one species is considered safe for human consumption.

In genetics, genotoxicity describes the property of chemical agents that damages the genetic information within a cell causing mutations, which may lead to cancer. While genotoxicity is often confused with mutagenicity, all mutagens are genotoxic, however, not all genotoxic substances are mutagenic.

Passionflower is reputed to have sedative effects and has been used in sedative products in Europe, but in 1978, the U.S. Food and Drug Administration prohibited its use in over-the-counter sedative preparations because it had not been proven safe and effective. In 2011, the University of Maryland Medical Center reported that passionflower “… can trigger side effects and can interact with other herbs, supplements, or medications”. For these reasons, you should take herbs with care, under the supervision of a health care provider.”
Passionflower is classified as generally recognized as safe (GRAS) for use in foods in the US and is “possibly safe when used orally and appropriately for short-term medicinal purposes,” “possibly unsafe when used in excessive amounts,” but unsafe when used orally during pregnancy since “…passionflower constituents show evidence of uterine stimulation.” The database suggests it is possibly effective for adjustment disorder with anxious mood, anxiety, and opiate withdrawal, but it “can cause dizziness, confusion, sedation, and ataxia” and there are some reports of more severe side effects including vasculitis and altered consciousness. A 34-year-old woman required hospitalization for IV hydration and cardiac monitoring following use of passionflower for therapeutic purposes. Passionflower received a moderate rating for interaction with anti-hypertensive and depressant drugs.


Skullcap (Scutellaria lateriflora) is one of the most widely used herbs for the nervous system. It is a considered a “nervine, “or, an herb with specific actions on the nervous system. In humans, it is used for PMS, migraines, disturbed sleep, seizures, drug addictions and physical or mental stress. Its properties are said to include sedation, anti-spasmodic, anti-convulsive, and vasodilation (expanding blood vessels).

Skullcap is most often used as a sleep aid and as a mild sedative. It has similar properties as valerian root.

Skullcap is a widely used herb used for calming down people who are nervous. It’s used as a natural tranquilizer. It has the ability to relax the nervous system.

Valerian Root

Valerian is a “nervine,” or, an herb with specific actions on the nervous system Its sedating effects can be so potent that it should not be used by people or animals taking central nervous system (CNS) prescription medications or undergoing surgery using general anesthesia Valerian rebalances a nervous system struggling with restlessness, anxiety and, in humans, insomnia Because it also relieves muscle cramps and spasms associated with tension, it is especially helpful in horses that process anxiety through their muscles.

Because of valerian’s historical use as a sedative, antiseptic, anticonvulsant, migraine treatment, and pain reliever, most basic science research has been directed at the interaction of valerian constituents with the GABA receptor. Many studies remain inconclusive and all require clinical validation. The mechanism of action of valerian in general, and as a mild sedative in particular, has not been fully elucidated. However, some of the GABA-analogs, particularly valerenic acids as components of the essential oil along with other semi volatile sesquiterpenoids, generally are believed to have some affinity for the GABAA receptor, a class of receptors on which benzodiazepines (drugs such as Valium) are known to act. Valeric acid, which is responsible for the typical odor of mostly older valerian roots, does not have any sedative properties. Valeric acid is related to valproic acid, a widely-prescribed anticonvulsant; valproic acid is a derivative of valeric acid. Valproic acid is used to treat certain types of seizures (epilepsy). This medicine is an anticonvulsant that works in the brain tissue to stop seizures. Valproic acid is also used to treat the manic phase of bipolar disorder (manic-depressive illness), and helps prevent migraine headaches.


Verbena is a genus of plants containing over 250 different species of flowering plants. Characterized as a “nervine,” an herb with specific actions on the nervous system, several compounds have been isolated from the plant and shown to have actions on nerve cells. Vervain may help rebalance the nervous system of horses with nervous, excess energy, helping them slow down and concentrate.

Verbena has longstanding use in herbalism and folk medicine, usually as an herbal tea. Among other effects, it may act as a galactagogue (promotes lactation) and possibly sex steroid analogue. The plants are also sometimes used as an abortifacient.

The Take Home Message

  1. Herbal compounds can have serious effects and should be used as directed.
  2. Many herbal compounds can interact with other herbal components or drugs with undesirable effects.
  3. Many herbal compounds will result in a positive drug test for horses in competition.

The United States Equestrian Federation (USEF) currently lists chamomile, hops, lemon balm, passion flower, skullcap, valerian and vervain on the list of forbidden substances. If you are competing it is your responsibility to know the drugs and medications rule for your competition. Be aware that there is no such thing as “USEF Approved” seal.

Thank you for reading! In part 4 we’ll wrap up this subject with a discussion on drugs and products that are used for calming.