Oregon grape is an evergreen shrub which grows throughout the American northwest. It is somewhat misnamed, as the fruit are not actually grapes. It is, however, grown in Oregon (it is the official state flower). Oregon grape is a close relative of barberry(Berberis vulgaris), and shares many common uses and constituents. The root is used medicinally.
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For over a decade, our team has combed through thousands of research articles published in reputable journals. To help you make educated decisions, and to better understand controversial or confusing supplements, our medical experts have digested the science into these three easy-to-follow ratings. We hope this provides you with a helpful resource to make informed decisions towards your health and well-being.
3 StarsReliable and relatively consistent scientific data showing a substantial health benefit.
2 StarsContradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
1 StarFor an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support.
This supplement has been used in connection with the following health conditions:
Refer to label instructions
Berberine is an alkaloid found in various plants, including goldenseal, barberry, Oregon grape, and goldthread. Berberine exhibits a broad spectrum of antibiotic and antifungal activity in test tube, animal, and human studies.2, 3 Berberine has shown effective antidiarrheal activity in a number of diarrheal diseases,4, 5, 6 and it may offer the same type of relief for the diarrhea seen in patients with chronic candidiasis. Doctors familiar with the use of berberine-containing herbs sometimes recommend taking 2 to 4 grams of the dried root (or bark) or 250 to 500 mg of an herbal extract three times a day. While isolated berberine has been studied, none of these herbs has been studied in humans with chronic candidiasis.
Conjunctivitis and Blepharitis
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Goldenseal and Oregon grape contain the antibacterial constituent known as berberine. While topical use of berberine in eye drops has been clinically studied for eye infections,7 the use of the whole herbs has not been studied for conjunctivitis or blepharitis.
Refer to label instructions
Due to of its supposed antimicrobial activity, goldenseal has a long history of use for infectious diarrhea. Its major alkaloid, berberine (also found in barberry and Oregon grape), has been shown to improve infectious diarrhea in some double-blind trials.8 Negative studies have generally focused on people with cholera, while positive studies investigated viral diarrhea or diarrhea due to strains of E. coli. These studies generally used 400–500 mg berberine one to three times per day. Because of the low amount of berberine in most goldenseal products, it is unclear how effective the whole root or root extracts would be in treating diarrhea.
Indigestion, Heartburn, and Low Stomach Acidity
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Bitter herbs are thought to stimulate digestive function by increasing saliva production and promoting both stomach acid and digestive enzyme production.9 As a result, they are particularly used when there is low stomach acid but not in heartburn (where too much stomach acid could initially exacerbate the situation). These herbs literally taste bitter. Some examples of bitter herbs include greater celandine, wormwood, gentian,dandelion, blessed thistle, yarrow, devil’s claw, bitter orange, bitter melon, juniper, andrographis, prickly ash, and centaury.10. Bitters are generally taken either by mixing 1–3 ml tincture into water and sipping slowly 10–30 minutes before eating, or by making tea, which is also sipped slowly before eating.
Some bitters widely used in traditional medicine in North America include yarrow, yellow dock, goldenseal, Oregon grape, and vervain. Oregon grape’s European cousin barberry has also traditionally been used as a bitter. Animal studies indicate that yarrow, barberry, and Oregon grape, in addition to stimulating digestion like other bitters, may relieve spasms in the intestinal tract.11
Berberine is derived from several plants, including barberry, Oregon grape, goldenseal, and goldthread (Coptis chinensis). Preliminary trials have shown that berberine can be used successfully to treat giardia infections.12, 13 In addition, test tube studies show that berberine kills amoebae, although it is not known whether this effect occurs in humans.14 The amount required is approximately 200 mg three times per day for an adult—a level high enough to potentially cause side effects. Therefore, berberine should not be used without consulting a healthcare provider.
Refer to label instructions
An ointment containing Oregon grape (10% concentration) has been shown in a clinical trial to be mildly effective against moderate psoriasis but not more severe cases.15 Whole Oregon grape extracts were shown in one laboratory study to reduce inflammation often associated with psoriasis.16 In this study, isolated alkaloids from Oregon grape did not have this effect. This suggests that there are other active ingredients besides alkaloids in Oregon grape. Barberry, which is very similar to Oregon grape, is believed to have similar effects. An ointment, 10% of which contains Oregon grape or barberry extract, can be applied topically three times per day.
Urinary Tract Infection
Refer to label instructions
Goldenseal is reputed to help treat many types of infections. It contains berberine, an alkaloid that may prevent UTIs by inhibiting bacteria from adhering to the wall of the urinary bladder.17 Goldenseal and other plants containing berberine (such as Oregon grape) may help in the treatment of UTIs. These herbs have not, however, been studied for the treatment of UTIs in humans.
Traditional Use (May Not Be Supported by Scientific Studies)
Before European colonists arrived, the indigenous peoples of North America treated all manner of complaints with Oregon grape.1 The berries were used for poor appetite. A tea made from the root was used to treat jaundice, arthritis, diarrhea, fever, and many other health problems.
How It Works
How It Works
Alkaloids, including berberine, berbamine, canadine, and hydrastine, may account for the activity of Oregon grape. Isolated berberine has been shown to effectively treat diarrhea in patients infected with E. coli.18 One of the ways berberine may ease diarrhea is by slowing the transit time in the intestine.19 Berberine inhibits the ability of bacteria to attach to human cells, which helps prevent infections, particularly in the throat, intestines, and urinary tract.20 These actions, coupled with berberine’s ability to enhance immune cell function,21 make Oregon grape possibly useful for mild infections although clinical trials are lacking on the whole root.
In one clinical trial, an ointment of Oregon grape was found to be mildly effective for reducing skin irritation, inflammation and itching in people with mild to moderate psoriasis.22 Whole Oregon grape extracts were shown in one pharmacological study to reduce inflammation (often associated with psoriasis) and stimulate the white blood cells known as macrophages.23 In this study, isolated alkaloids from Oregon grape did not have these actions. This suggests that something besides alkaloids are important to the properties of Oregon grape responsible for reducing inflammation.
The bitter-tasting compounds as well as the alkaloids in Oregon grape root are thought to stimulate digestive function.
How to Use It
A tea can be prepared by boiling 1–3 teaspoons (5–15 grams) of chopped roots in 2 cups (500 ml) of water for fifteen minutes. After straining and cooling, 3 cups (750 ml) can be taken per day. Tincture, 1/2–3/4 teaspoon (3 ml) three times per day, can be used. Since berberine is not well absorbed, Oregon grape root might not provide adequate amounts of this compound to treat significant systemic infections. A physician should be consulted in the case of infection before attempting to use Oregon grape. An ointment made with 10% Oregon grape extract applied three or more times daily may be useful for psoriasis.
Interactions with Supplements, Foods, & Other Compounds
At the time of writing, there were no well-known supplement or food interactions with this supplement.
Berberine, a chemical extracted from goldenseal(Hydrastis canadensis),barberry(Berberis vulgaris), and Oregon grape(Berberis aquifolium), has been shown to have antibacterial activity. One double-blind study found that giving 100 mg of berberine at the same time as 500 mg of tetracycline four times daily led to a reduction of the efficacy of tetracycline in people with cholera.24 Berberine may have decreased the absorption of tetracycline in this study. Another double-blind trial did not find that berberine interfered with tetracycline in cholera patients.25 Until more studies are completed to clarify this issue, berberine-containing herbs should not be taken simultaneously with tetracycline.
Berberine is a chemical extracted from goldenseal(Hydrastis canadensis),barberry(Berberis vulgaris), and Oregon grape(Berberis aquifolium), which has antibacterial activity. However, one double-blind study found that 100 mg berberine given with tetracycline (a drug closely related to doxycycline) reduced the efficacy of tetracycline in people with cholera.26 In that trial, berberine may have decreased tetracycline absorption. Another double-blind trial found that berberine neither improved nor interfered with tetracycline effectiveness in cholera patients.27 Therefore, it remains unclear whether a significant interaction between berberine-containing herbs and doxycycline and related drugs exists.
The Drug-Nutrient Interactions table may not include every possible interaction. Taking medicines with meals, on an empty stomach, or with alcohol may influence their effects. For details, refer to the manufacturers’ package information as these are not covered in this table. If you take medications, always discuss the potential risks and benefits of adding a supplement with your doctor or pharmacist.
Oregon grape is thought to be safe in the recommended amounts. Long-term (more than two to three weeks) internal use is not recommended. Berberine alone has been reported to interfere with normal bilirubin metabolism in infants, raising a concern that it might worsen jaundice.28 For this reason, berberine-containing plants should be used with caution during pregnancy and breast-feeding.
10. Blumenthal M, Busse WR, Goldberg A, et al. (eds). The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Austin: American Botanical Council and Boston: Integrative Medicine Communications, 1998, 425–6.
11. Tewari JP, Srivastava MC, Bajpai JL. Pharmacologic studies of Achillea millefolium Linn. Indian J Med Sci 1994;28(8):331–6.
12. Gupte S. Use of berberine in treatment of giardiasis. Am J Dis Child 1975;129:866.
13. Choudhry VP, Sabir M, Bhide VN. Berberine in giardiasis. Indian Pediatr 1972;9:143–6.
14. Kaneda Y, Torii M, Tanaka T, Aikawa M. In vitro effects of berberine sulphate on the growth and structure of Entamoeba histolytica, Giardia lamblia and Trichomonas vaginalis. Ann Trop Med Parasitol 1991;85:417–25.
15. Wiesenauer M, Lüdtke R. Mahonia aquifolium in patients with psoriasis vulgaris—an intraindividual study. Phytomed 1996;3:231–5.
16. Galle K, Müller-Jakic B, Proebstle A, et al. Analytical and pharmacological studies on Mahonia aquifolium.Phytomed 1994;1:59–62.
17. Sun DX, Abraham SN, Beachey EH. Influence of berberine sulfate on synthesis and expression of pap fimbrial adhesin in uropathogenic Escherichia coli. Antimicrob Agents Chemother 1988;32:1274–7.
18. Rabbani GH, Butler T, Knight J, et al. Randomized controlled trial of berberine sulfate therapy for diarrhea due to enterotoxigenic Escherichia coli and Vibrio cholerae.J Infect Dis 1987;155:979–84.
19. Eaker EY, Sninsky CA. Effect of berberine on myoelectric activity and transit of the small intestine in rats. Gastroenterol 1989;96:1506–13.
20. Sun D, Courtney HS, Beachey EH. Berberine sulfate blocks adherence of Streptococcus pyogenes to epithelial cells, fibronectin, and hexadecane. Antimicrob Agents Chemother 1988;32:1370–4.
21. Kumazawa Y, Itagaki A, Fukumoto M, et al. Activation of peritoneal macrophages by berberine-type alkaloids in terms of induction of cytostatic activity. Int J Immunopharmacol 1984;6:587–92.
22. Wiesenauer M, Lüdtke R. Mahonia aquifolium in patients with psoriasis vulgaris—an intraindividual study. Phytomedicine 1996;3:231–5.
23. Galle K, Müller-Jakic B, Proebstle A, et al. Analytical and pharmacological studies on Mahonia aquifolium.Phytomedicine 1994;1:59–62.
24. Khin-Maung-U, Myo-Khin, Nyunt-Nyunt-Wai, et al. Clinical trial of berberine in acute watery diarrhoea. Br Med J 1985;291:1601–5.
25. Rabbani GH, Butler T, Knight J, et al. Randomized controlled trial of berberine sulfate therapy for diarrhea due to enterotoxigenic Escherichia coli and Vibrio cholerae. J Infect Dis 1987;155:979–84.
26. Khin-Maung-U, Myo-Khin, Nyunt-Nyunt-Wai, et al. Clinical trial of berberine in acute watery diarrhoea. BMJ 1985;291:160–5.
27. Rabbani GH, Butler T, Knight J, et al. Randomized controlled trial of berberine sulfate therapy for diarrhea due to enterotoxigenic Escherichia coli and Vibrio cholerae. J Infect Dis 1987;155:979–84.
28. Chan E. Displacement of bilirubin from albumin by berberine. Biol Neonate 1993;63:201–8.
The information presented in Aisle7 is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires June 2014.
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