Related Terms

• Aquifoline, aromaline, baluchistine, barberry, berbamine, Berberidaceae (family), berberine, Berberis aquifolium, Berberis piperiana, bisbenzylisoquinolines, blue barberry, California barberry, canadine, holly barberry, holly mahonia, hydrastine, Mahonia aquifolia, Mahonia aquifolium, Mahonia piperiana, mountain grape, obamegine, Odostemon aquifolium, Oregon grape, Oregon grape root, Oregon Hollygrape, Oregon-grape, Oregongrape, oxycanthine, palmatine, psorberine, RelievaTM, Rocky Mountain grape, sowberry, tall Oregon grape, trailing mahonia, wild oregon grape, woodsour.

Background

• Oregon grape (Mahonia aquifolium, Berberis aquifolium) is native to the west coast of North America, from British Columbia to northern California. It has yellow flowers, purple berries, and leathery leaves that resemble holly. It is not related to grape; however, the name "Oregon grape" originated from its purple clusters of berries that resemble grapes. It is a close relative of barberry (Berberis vulgaris).

• The rhizome (underground stem), root, and bark, which are odorless and bitter, are collected in autumn to be used medicinally. Native Americans have traditionally used Oregon grape to treat various ailments, including digestive problems and inflammatory skin conditions. Studies in humans have shown that it may be effective against atopic dermatitis and psoriasis. Substances found in Oregon grape have been studied for their anticancer and antibacterial effects, although these uses have not been well studied in humans.

Scientific Evidence

Tradition/Theory

The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious and should be evaluated by a qualified health care professional.

• Acne, antibacterial, antifungal, antimicrobial, antimutagenic, antioxidant, antiparasitic, antitumor, appetite stimulant, arthritis, bile flow improvement, blood purifier, cancer, colds, conjunctivitis (pinkeye), constipation, cough suppressant, diarrhea, digestion, diuretic (increases urination), dysentery, eye cleansing, eye inflammation, fever, flu, gastrointestinal disorders, general health maintenance, heart disease, hemorrhage, hepatitis, herpes, immune system regulation, infections, jaundice, skin diseases, sore throat, syphilis, tonic, urinary tract infections, vaginitis, yeast infection.

Dosing

The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.

Adults (18 years and older)

• There is no proven safe or effective dose for Oregon grape in adults. Oregon grape has been taken by mouth as an infusion and as a tincture. It has also been applied to the skin as an ointment.

• For psoriasis, the following has been applied to the skin: a 10% Oregon grape extract ointment applied three or more times daily; Oregon grape extract ointment (Relieva™) applied twice daily for 12 weeks and three times daily for four weeks; Oregon grape bark extract (10%) applied 2-3 times daily for an average of four weeks; a cream containing 10% Oregon grape applied for one month, 12 weeks, or up to six months.

• Use cautiously when taking by mouth for more than two or three weeks or in large doses, as consumption of large doses of berberine may cause poisoning or death.

Children (under 18 years old)

• There is no proven safe or effective dose of Oregon grape in children.

Safety

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

Allergies

• Avoid with known allergy or hypersensitivity to Oregon grape, its components, or members of the Berberidaceae family.

Side Effects and Warnings

• Oregon grape is generally well tolerated when used on the skin. Minor side effects, such as rash, a burning sensation, and clothing stains, were reported when Oregon grape was used on the skin.

• Berberine, a chemical found in Oregon grape, may cause jaundice (yellowing of the skin and eyes) in infants by interfering with normal bilirubin metabolism. Bilirubin is a brownish-yellow substance found in bile that is produced when the liver breaks down old red blood cells.

• Use cautiously, as other Berberis species have been identified as poisonous.

• Use cautiously when taking by mouth for more than two or three weeks or in large doses, as consumption of large doses of berberine may cause poisoning or death.

• Avoid with known allergy or hypersensitivity to Oregon grape, its constituents, or members of the Berberidaceae family.

Pregnancy and Breastfeeding

• There is a lack of available high quality scientific evidence on the use of Oregon grape during pregnancy or breastfeeding. Berberine, a chemical found in Oregon grape, may cause jaundice (yellowing of the skin and eyes) in infants by interfering with normal bilirubin metabolism and is therefore not recommended in jaundiced neonates and pregnant women.

Interactions

Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy.

Interactions with Drugs

• Oregon grape may interfere with the way the body processes certain drugs using the liver's cytochrome P450 enzyme system. As a result, the levels of these drugs may be increased in the blood and may cause increased effects or potential serious adverse reactions. Patients using any medications should check the package inserts, and speak with a qualified healthcare professional, including pharmacist, about possible interactions.

• Oregon grape may increase the amount of drowsiness caused by some drugs with sedative effects. Examples include benzodiazepine such as lorazepam (Ativan®) or diazepam (Valium®), barbiturates such as phenobarbital, narcotics such as codeine, some antidepressants, CNS depressants, and alcohol. Caution is advised while driving or operating machinery.

• Oregon grape may also interact with antibiotics, anticancer drugs, cardiovascular drugs, cyclosporine, drugs that affect the immune system, drugs that prevent or relieve seizures, gastrointestinal agents, and tetracycline.

Interactions with Herbs and Dietary Supplements

• Oregon grape may interfere with the way the body processes certain herbs using the liver's cytochrome P450 enzyme system. As a result, the levels of these drugs may be increased in the blood and may cause increased effects or potential serious adverse reactions. Patients using any medications should check the package inserts and speak with a qualified healthcare professional, including a pharmacist, about possible interactions.

• Oregon grape may increase the amount of drowsiness caused by some herbs or supplements with sedative effects.

• Oregon grape may also interact with antibacterials, anticancer agents, antioxidants, cardiovascular herbs or supplements, gastrointestinal herbs and supplements, herbs or supplements that affect the immune system, herbs or supplements that prevent or relieve seizures, licorice, and vitamin B.

Author Information

• This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

References

Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.

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2. Cernakova M, Kostalova D. Antimicrobial activity of berberine--a constituent of Mahonia aquifolium. Folia Microbiol (Praha) 2002;47(4):375-378. View Abstract

3. Chatterjee P, Franklin MR. Human cytochrome p450 inhibition and metabolic-intermediate complex formation by goldenseal extract and its methylenedioxyphenyl components. Drug Metab Dispos 2003;31(11):1391-1397. View Abstract

4. Donsky H, Clarke D. Relieva, a Mahonia aquifolium extract for the treatment of adult patients with atopic dermatitis. Am J Ther 2007;14(5):442-446. View Abstract

5. Gulliver WP, Donsky HJ. A report on three recent clinical trials using Mahonia aquifolium 10% topical cream and a review of the worldwide clinical experience with Mahonia aquifolium for the treatment of plaque psoriasis. Am J Ther 2005;12(5):398-406. View Abstract

6. Haupt H. [Poisonous and less poisonous plants. 63. Barberry (Berberidaceae) (Berberis vulgaris)]. Kinderkrankenschwester 2003;22(12):538-539. View Abstract

7. Klovekorn W, Tepe A, Danesch U. A randomized, double-blind, vehicle-controlled, half-side comparison with a herbal ointment containing Mahonia aquifolium, Viola tricolor and Centella asiatica for the treatment of mild-to-moderate atopic dermatitis. Int J Clin Pharmacol Ther 2007;45(11):583-591. View Abstract

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9. Rackova L, Oblozinsky M, Kostalova D, et al. Free radical scavenging activity and lipoxygenase inhibition of Mahonia aquifolium extract and isoquinoline alkaloids. J Inflamm (Lond) 2007;4:15. View Abstract

10. 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(5):979-984. View Abstract

11. Rohrer U, Kunz EM, Lenkeit K, et al. Antimicrobial activity of Mahonia aquifolium and two of its alkaloids against oral bacteria. Schweiz Monatsschr Zahnmed 2007;117(11):1126-1131. View Abstract

12. Slobodnikova L, Kost'alova D, Labudova D, et al. Antimicrobial activity of Mahonia aquifolium crude extract and its major isolated alkaloids. Phytother Res 2004;18(8):674-676. View Abstract

13. Vollekova A, Kost'alova D, Kettmann V, et al. Antifungal activity of Mahonia aquifolium extract and its major protoberberine alkaloids. Phytother Res 2003;17(7):834-837. View Abstract

14. Wu X, Li Q, Xin H, et al. Effects of berberine on the blood concentration of cyclosporin A in renal transplanted recipients: clinical and pharmacokinetic study. Eur J Clin Pharmacol 2005;61(8):567-572. View Abstract

15. Xu R, Dong Q, Yu Y, et al. Berbamine: a novel inhibitor of bcr/abl fusion gene with potent anti-leukemia activity. Leuk Res 2006;30(1):17-23. View Abstract