Botanical name: Berberis aquifolium
© Steven Foster
Parts used and where grown
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.
Oregon grape has been used
in connection with the following conditions (refer to the individual
health concern for complete information):
Historical or traditional use (may
or 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.
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.2 One of the ways berberine may ease diarrhea is by slowing the transit
time in the intestine.3 Berberine inhibits the ability of bacteria to attach to
human cells, which helps prevent infections,
particularly in the throat, intestines, and
urinary tract.4 These actions, coupled with berberine’s ability to
enhance immune cell function,5 make
Oregon grape possibly useful for mild infections although clinical trials are lacking on the
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.6 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.7 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
The bitter-tasting compounds as well as the alkaloids in Oregon grape root are thought to
stimulate digestive function.
How much is usually taken?
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.
Are there any side effects or interactions?
Oregon grape is thought to be safe in the amounts indicated above. 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.8 For this reason, berberine-containing plants should be used with caution
during pregnancy and breast-feeding.
Are there any drug
Certain medicines may interact with Oregon grape. Refer to drug interactions for a list of those medicines.
1. Duke JA. CRC Handbook of Medicinal Herbs. Boca Raton, FL: CRC
Press, 1985, 287–8.
2. 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.
3. Eaker EY, Sninsky CA. Effect of berberine on myoelectric activity and
transit of the small intestine in rats. Gastroenterol 1989;96:1506–13.
4. 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.
5. 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.
6. Wiesenauer M, Lüdtke R. Mahonia aquifolium in patients
with psoriasis vulgaris—an intraindividual study. Phytomedicine
7. Galle K, Müller-Jakic B, Proebstle A, et al. Analytical and
pharmacological studies on Mahonia aquifolium. Phytomedicine
8. Chan E. Displacement of bilirubin from albumin by berberine. Biol