Vervain

Vervain (Verbena officinalis) is a flowering plant in the verbena family of herbs. While there are well over 250 species of verbena, vervain refers specifically to the types used for medicinal purposes. In addition to V. officinalis, less common varietals include blue vervain (V. hastata) and white vervain (V. urticifolia).

Verbena officinalis is a perennial plant with delicate, jagged leaves and small, five-petaled blossoms. Although vervain has no scent, alternative practitioners believe that vervain has anti-inflammatory, antibacterial, antispasmodic, and analgesic (pain-relieving) properties beneficial to one's health.

Vervain is also referred to as American blue verbena, simpler's joy, holy herb, mosquito plant, and wild hyssop. In traditional Chinese medicine, it is known as mǎ biān cǎo.

Verbena officinalis should not be confused with lemon verbena, a garden herb used for cooking that also has medicinal properties.

Health Benefits
The medicinal use of vervain can be traced back to the 18th century book "Sauer's Herbal Cure," where it was said to aid in the treatment of kidney stones. In fact, the name "verbena" is believed derived from the Celtic word ferfaen meaning "to drive away stones."

Vervain regained popularly in the 1930s as one of the 38 flowering plants used in a homeopathic tincture called Bach Flower Remedy, variations of which are still sold today. Among its purported benefits, vervain may help treat.

Headaches
General aches and pain
Insomnia
Digestive dysfunction
Upper respiratory tract symptoms
Urinary tract infections
Depression and anxiety

As with many homeopathic remedies, some of the health claims are better supported by research than others.

Pain Relief
A number of studies have looked into the anti-inflammatory and analgesic effects of Verbena officinalis, both in topical and oral formulations. Results have been largely mixed.

A 2006 study from Spain found that an extract of V. officinalis, applied topically in rats, was as effective in relieving edema (swelling) as traditional anti-inflammatory drugs, but it was far less able to relieve pain.1

Anxiety and Insomnia
Verbena tea has long been believed to have a calming effect that can help relieve stress and promote sleep. This effect was first described in the 1652 book The English Physician in which vervain was used as a tea to treat "over-enthusiasm."

Although there have been few studies investigating these effects in humans, there is evidence that V. officinalis not only reduces anxiety and insomnia but may prevent the occurrence of epileptic seizures. These effects are attributed to a sugar molecule in vervain, known as verbenalin, which is believed to have psychoactive properties.

A 2016 study published in the Frontiers of Pharmacology reported that an extract of V. officinalis, prescribed at a dose of 100 to 500 milligrams per kilogram, reduced the frequency and duration of tonic-clonic seizures in mice.2

Moreover, mice injected with the extract spent more time sleeping than those injected with a placebo. Anxiety, measured by movement through a maze, was also seen to improve.

While it is unclear if the same effect would be rendered in humans, it does suggest that V. officinalis may exert a positive influence on the central nervous system and adrenal glands (which produce stress hormones).

Infections
The treatment of infectious diseases, both common and severe, has become increasingly challenging in the face of growing antibiotic resistance. Vervain, long used to treat upper respiratory and urinary tract infections, is believed to exert antimicrobial effects that may help overcome these challenges.

This is evidenced in part by a 2016 study in which different parts of the V. officinalis were able to eradicate 24 strains of disease-causing bacteria.3

According to the research, extracts derived from the stem of V. officinalis were able to kill Staphylococcus aureus and Pseudomonas aeruginosa in the test tube more effectively that the antibiotic amoxicillin.

Similarly, the leaves of the plant showed considerable activity against Citrobacter freundii, while the root turned out to be highly effective against Bacillus subtilis.

While is unclear whether the same results would be seen outside of the test tube, the research does provide evidence of vervain's long-presumed effectiveness in treating minor cuts and skin infections.

Kidney Stones
Of all the conditions vervain is long presumed to treat, the prevention of kidney stones is one of the least supported by research. This is mostly because it is difficult to measure how effective a treatment is in not causing a medical condition. To date, there is little evidence to suggest it has any effect.

One study from China found that mice treated with verbenalin injections experienced no changes in either the structure or function of their kidneys compared to mice provided a placebo.4

What vervain does appear to do is increase urine output, which may, in fact, help prevent the formation of kidney stones. But it does so not by increasing the amount of water and sodium in the urinary tract—the way that most diuretics work—but rather by irritating the kidneys. This can actually hurt the kidneys more than help, especially over the long term.

Colorectal Cancer
One of the bolder claims made by herbalists is that vervain may aid in the treatment of colorectal cancer. These claims were largely fostered by research which showed that polysaccharides (a type of long-chain carbohydrate) in vervain altered the activity of colorectal cancer cells in test tubes.

A 2017 study from China reported that an extract of V. officinalis polysaccharides interrupted the spread of colorectal cells by preventing their adhesion to healthy cells.5

Without the means to bind to healthy cells, a tumor cannot metastasize and invade distant organs. This suggests that vervain polysaccharides may one day be used to help isolate and control tumors in people with colorectal cancer, improving survival.