Sunday, October 25, 2009

Goldenseal

Overview

Many people consider the main active constituent in goldenseal to be berberine, and most of the clinical studies have been done on the single compound. Berberine is an alkaloid that also comes from several other plants including Coptis chinensis (goldenthread), Berberis aquifolium (Oregon grape), B. vulgaris (barberry), and B. aristata (tree tumereic), which has a long history in folk medicine for diarrhea. Since goldenseal has had an endangered status, many herb companies have substituted it with other berberine-containing plants in formulas. Most commonly, goldenseal is used in immune support formulas (usually along with Echinacea), or for its antioxidant, anti-cancer effects, or for urinary tract infections.


Although goldenseal has a long traditional medicinal history among the Native Americans and later with the settlers, no clinical studies have been performed with the single herb in humans. However, there exists animal and in-vitro studies on goldenseal and both preclinical and clinical data on berberine. Preliminary animal models have shown goldenseal root to be immunostimulatory and to decrease an enzyme involved with tumor growth in colon cancer. Preliminary studies have found berberine to be of possible value for diarrhea, and liver cirrhosis (Choudhry et al, 1972; Gupte, 1975; Watanabe et al, 1982).


Comments

Goldenseal is often piggy-backed in immune support formulas with Echinacea, but little clinical evidence yet confirms this use.


Scientific Support

In a randomized controlled study, the effect of berberine sulfate (BS) was tested in 165 adults who were suffering from acute diarrhea due to either Escherichia coli or Vibrio cholerae. At the dosage of 400 mg of BS, patients with E. coli experienced a significant reduction in mean stool volume during three consecutive 8-hr periods after treatment. At 24 hrs past treatment, a significant number of E. coli patients treated with the BS were cured of their diarrhea than compared to control. In the cholera group, however, 1200 mgs were administered and found to only slightly decrease the stool volume, but when compared to the tetracycline only group (BS+ tetracycline vs. tetracycline only) did not show a significant difference in stool volume (Rabbani et al., ).


Khin-Maung-U et al. (1985) studied the effect of berberine, tetracycline, and the combiniation of berberine + tetracycline in 400 adult patients with diarrhea. In the 185 patients that suffered from diarrhea induced by cholera, there was a significant reduction in the frequency and volume of diarrheal stools in both treatment groups involving tetracycline, but not in the berberine alone group. Factoral design equations were able to show a 1 liter reduction of diarrheal stools and a reduction of cAMP concentrations in the berberine groups. In the 215 patients with non-cholera diarrhea, neither tetracycline or berberine showed benefit over placebo.


Safety / Dosage

Goldenseal is generally thought to be safe, but should not be used during pregnancy or lactation. Goldenseal is contraindicated for people with high blood pressure or other cardiovascular diseases.


Berberine is considered safe at goldenseal’s recommended dosages, however, they are contraindicated for pregnancy and may interfere with vitamin B metabolism. The LD(50) in rats for berberine is greater than 1,000 milligrams per kilogram of boy weight, indicating a low toxicity. Topical application of berberine may cause photosensitivity (Inbara et al., 2001; Kowalewski et al., 1975).


The typical dosage of goldenseal is 4 to 6 grams of the powdered root daily, 250-500 mg of the extracted root (usually standardized to 5% berberine content) three times daily (McKenna et al., 2002).


References

1.Choudhry VP, Sabir M, Bhide VN. Berberine in giardiasis. Indian Pediatr. 1972 Mar;9(3):143-6.

2.Gupte S. Use of berberine in treatment of giardiasis. Am J Dis Child. 1975 Jul;129(7):866.

3.Inbaraj JJ, Kukielczak BM, Bilski P, Sandvik SL, Chignell CF. Photochemistry and photocytotoxicity of alkaloids from Goldenseal (Hydrastis canadensis L.) 1. Berberine. Chem Res Toxicol. 2001 Nov;14(11):1529-34.

4.Khin-Maung-U, Myo-Khin, Nyunt-Nyunt-Wai, Aye-Kyaw, Tin-U. Clinical trial of berberine in acute watery diarrhoea. Br Med J (Clin Res Ed). 1985 Dec 7;291(6509):1601-5.

5.Kowalewski Z, Mrozikiewicz A, Bobkiewicz T, Drost K, Hladon B. [Toxicity of berberine sulfate] Acta Pol Pharm. 1975;32(1):113-20.

6.McKenna D, Jones K, Hughes K, Humphrey S. Botanical Medicines: The Desk Reference for Major Herbal Supplements, 2nd Ed. 2002 Haworth Press; Binghamton, NY

7.Rabbani GH, Butler T, Knight J, Sanyal SC, Alam K. Randomized controlled trial of berberine sulfate therapy for diarrhea due to enterotoxigenic Escherichia coli and Vibrio cholerae.

8.Watanabe A, Obata T, Nagashima H. Berberine therapy of hypertyraminemia in patients with liver cirrhosis. Acta Med Okayama. 1982 Aug;36(4):277-81.


EDITOR'S NOTE: This monograph can be found in The Health Professional's Guide to Dietary Supplements (Lippincott, Williams & Wilkins) by Shawn M. Talbott, PhD and Kerry Hughes, MS.

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