Oregon Grape Overview

The roots and bark of the shrub Mahonia aquifolium(also called Oregon grape) have traditionally been used both orally and topically to treat skin problems. They were also used for other conditions such as gastritis, fever, hemorrhage, jaundice, gall bladder disease, and cancer. In addition, Mahoniawas used as a bitter tonic to improve appetite.

According to some experts, M. aquifoliumis identical to the plant named Berberis aquifolium, but others point to small distinctions. Berberis vulgaris, commonly called barberry , is a close relative of these herbs, but is not identical.

Evidence from two double-blind, placebo-controlled studies and one comparative trial suggest that cream made from the herb Oregon grape may help reduce symptoms of psoriasis, although it does not seem to be as effective as standard medications.

In a double-blind study published in 2006, two hundred people were given either a cream containing 10% Oregon grape extract or placebo twice a day for 3 months. ¹ The results indicate that the people using Oregon grape experienced greater benefits than those in the placebo group, and the difference was statistically significant. The treatment was well tolerated, though in a few people it caused rash or burning sensation.

Benefits were also seen in a double-blind, placebo-controlled study of 82 people with psoriasis. ² However, the study design had a significant flaw: the treatment salve was darker in color than the placebo, possibly allowing participants to guess which was which.

Another study found that dithranol, a conventional drug used to treat psoriasis symptoms, was more effective than Oregon grape. ³ Regrettably, the authors fail to state whether this study was double-blind. Forty-nine participants applied one treatment to their left side and the other to their right for 4 weeks. Skin biopsies were then analyzed and compared with samples taken at the beginning of the study. The physicians evaluating changes in skin tissue were unaware which treatments had been used on the samples. Greater improvements were seen in the dithranol group.

A large open study in which 443 participants with psoriasis used Oregon grape topically for 12 weeks found the herb to be helpful for 73.7% of the group. ⁴ Without a placebo group, it’s not possible to know whether Oregon grape was truly responsible for the improvement seen, but the trial does help to establish the herb's safety and tolerability. (See Safety Issues below.)

Laboratory research suggests Oregon grape has some effects at the cellular level that might be helpful in psoriasis, such as slowing the rate of abnormal cell growth and reducing inflammation. ⁵

Topical ointments or creams containing 10% Oregon grape extract are generally applied 3 times daily to the affected areas.

1. Bernstein S, Donsky H, Gulliver W, Hamilton D, Nobel S, Norman R. Treatment of mild to moderate psoriasis with Reliéva, a Mahonia aquifolium extract--a double-blind, placebo-controlled study. Am J Ther. 13(2):121-6.
2. Wiesenauer M, Ldtke R. Mahonia aquifolium in patients with Psoriasis vulgaris—an intraindividual study. Phytomedicine. 1996;3:231-235.
3. Augustin M, Andrees U, Grimme H, et al. Effects of Mahonia aquifolium ointment on the expression of adhesion, proliferation, and activation markers in the skin of patients with psoriasis. Forsch Komplementrmed. 1999;6(suppl 2):19-21.
4. Gieler U, von der Weth A, Heger M. Mahonia aquifolium—a new type of topical treatment for psoriasis. J Dermatol Treat. 1995;6:31-34.
5. Galle K, Mller-Jakic B, Proebstle A, et al. Analytical and pharmacological studies on Mahonia aquifolium. Phytomedicine. 1994;1:59-62.