Scientists at the Dermatology and Cosmetic Center in Rochester, New York, have found a natural treatment for mild-to-moderate cases of psoriasis: It’s a cream that contains extracts from a shrub called Mahonia aquifolium (also known as barberry, Oregon grape, or berberis). Actually, using Mahonia to treat psoriasis isn’t really new at all — the plant has been used as an oral medication to treat psoriasis for centuries. But now modern research is finally giving credibility to this powerful folk remedy.

In a double-blind, placebo-controlled trial, 200 people with moderate psoriasis applied a cream containing either Mahonia aquifolium extract or a placebo twice a day to the affected areas. After 12 weeks, the people who used the active cream showed a statistically significant improvement over those used the placebo cream. Another encouraging result from the study was that no one experienced significant side effects from the cream (a problem that’s all too common with current prescription medications for psoraisis).

If you’re interested in trying this for yourself, a number of online sources offer topical creams made from Mahonia.