What are goldenseal's therapeutic uses?

Overview

Although goldenseal root is one of the most popular herbs sold, it is taken almost entirely for the wrong reasons. Originally, it was used by Native Americans both as a dye and as a treatment for skin disorders, digestive problems, liver disease, diarrhea, and eye irritations. European settlers learned of the herb from the Iroquois and other tribes and quickly adopted goldenseal as a part of early colonial medical care.

In the early nineteenth century, herbalist Samuel Thompson created a wildly popular system of medicine that swept the country. Thompson spoke of goldenseal as a nearly magical cure for many conditions. His evangelism led to a dramatic upsurge in demand, followed by overcollection and decimation of the wild plant. Prices skyrocketed but then collapsed when Thompsonianism faded away.

Goldenseal has passed through several more booms and busts. Again in great demand, it is under intentional cultivation.

Therapeutic Dosages

When goldenseal is used as a topical treatment for minor skin wounds, a sufficient quantity of goldenseal cream, ointment, or powder should be applied to cover the wound. It is important to be sure to clean the wound at least once a day to prevent goldenseal particles from becoming trapped in the healing tissues.

For mouth sores and sore throats, goldenseal tincture is swished or gargled. Goldenseal may also be used as strong tea for this purpose, made by boiling 0.5 to 1 gram in a cup of water. The herb has a bitter taste. Goldenseal tea is also used as a douche for vaginal yeast infections.

Therapeutic Uses

Goldenseal contains a substance called berberine that has been found to inhibit
or kill many microorganisms, including fungi, protozoa, and bacteria. On this
basis, contemporary herbalists often use goldenseal as a topical antibiotic for
skin wounds, as well as to treat viral mouth sores and superficial fungal
infections, such as athlete’s foot. However, there is no
direct scientific evidence that goldenseal is effective for any of these
purposes.

Goldenseal is not likely to work as an oral antibiotic, because the blood levels of berberine that can be achieved by taking goldenseal orally are far too low to matter. However, goldenseal could theoretically be beneficial in treating sore throats and diseases of the digestive tract (such as infectious diarrhea) because it can contact the affected area directly. Since berberine is concentrated in the bladder, goldenseal could be useful for bladder infections. Nonetheless, there is no direct evidence that goldenseal is effective for these uses.

Extremely weak evidence (far too weak to rely upon) suggests that goldenseal or berberine may be helpful for various heart-related conditions, including arrhythmias, congestive heart failure, high cholesterol, diabetes, and high blood pressure. Similarly, infinitesimal evidence hints that goldenseal could be helpful for conditions in which spasms of smooth muscle play a role, such as dyspepsia (nonspecific stomach distress) and irritable bowel syndrome, as well as various forms of pain caused by inflammation.

Ironically, goldenseal’s most common uses are entirely inappropriate.
Goldenseal is frequently combined with the herb echinacea to
be taken as a “traditional immune booster” and “antibiotic” for the prevention and
treatment of colds. However, as the noted herbalist Paul Bergner has pointed out,
there are three things wrong with this packaging. First, there is no credible
evidence that goldenseal increases immunity. Only one study weakly hints at an
immune-strengthening effect. Second, colds are caused by viruses and do not
respond to antibiotics, even if goldenseal were an effective systemic
(whole-body) antibiotic, which it almost certainly is not. Third, goldenseal was
never used traditionally for the common cold.

The other myth that has helped drive the sales of goldenseal is the widespread belief that it can block a positive drug screen. The origin of this false idea dates back to a work of fiction published in 1900 by a pharmacist and author named John Uri Lloyd. In Stringtown on the Pike, a dead man is found to have traces of goldenseal in his stomach. In fact, he had taken goldenseal regularly as a digestive aid, but a toxicology expert mistakes the goldenseal for strychnine and deduces intentional murder.

This work of fiction sufficed to create a folkloric connection between goldenseal and drug testing. Although the goldenseal in the story actually made a drug test come out falsely positive, this has been turned around to become a belief that goldenseal can make urine drug screens come out negative. A word to the wise: It does not work.

Safety Issues

Although there are no reports of severe adverse effects attributed to use of goldenseal, this herb has not undergone much safety testing. One study suggests that topical use of goldenseal could cause photosensitivity (an increased tendency to react to sun exposure).

Goldenseal should not be used by pregnant women because the herb has been
reported to cause uterine contractions. In addition, berberine may increase levels
of bilirubin and cause genetic damage. The last of these
effects indicates that individuals with elevated bilirubin levels
(jaundice) also should avoid use of goldenseal. Safety in
young children, nursing women, or those with severe liver or kidney disease is
also not established.

Just as there are incorrect rumors regarding the benefits of goldenseal, there are popular but incorrect beliefs regarding its health risks. For example, it is often said that goldenseal can disrupt the normal bacteria of the intestines. However, there is no scientific evidence that this occurs. Another fallacy is that small overdoses of goldenseal are toxic, causing ulcerations of the stomach and other mucous membranes. This idea is based on a misunderstanding of old literature.

Some evidence suggests that goldenseal might interact with various medications
by altering the way they are metabolized in the liver. One study found that
berberine impairs metabolism of the drug cyclosporine,
thereby raising its levels. This could potentially cause toxicity. It is
important, therefore, to speak with a physician before taking goldenseal with
other medications.

Bibliography

Hubbard, M. A., et al. “Clinical Assessment of Cyp2d6-Mediated Herb-Drug Interactions in Humans: Effects of Milk Thistle, Black Cohosh, Goldenseal, Kava Kava, St. John’s Wort, and Echinacea.” Molecular Nutrition and Food Research 52, no. 7 (2008): 755-763.

Inbaraj, J. J., et al. “Photochemistry and Photocytotoxicity of Alkaloids from Goldenseal (Hydrastis canadensis L.).” Chemical Research in Toxicology 14 (2001): 1529-1534.

Scazzocchio, F., et al. “Antibacterial Activity of Hydrastis canadensis Extract and Its Major Isolated Alkaloids.” Planta Medica 67 (2001): 561-564.

Wu, X., et al. “Effects of Berberine on the Blood Concentration of Cyclosporin A in Renal-Transplanted Recipients: Clinical and Pharmacokinetic Study.” European Journal of Clinical Pharmacology 61, no. 8 (2005): 567-572.

Zhang, Y., et al. “Treatment of Type 2 Diabetes and Dyslipidemia with the Natural Plant Alkaloid Berberine.” Journal of Clinical Endocrinology and Metabolism 93, no. 7 (2008): 2559-2565.