Berberis aquifolium (formerly Mahonia aquifolium), commonly called Oregon grape or hollyleaved barberry, is an evergreen shrub native to western North America. It is distributed from Nebraska to the Pacific Ocean but it is especially abundant in northern California and Oregon, where the Oregon grape was adopted as its state flower in 1899. The flowers are yellow and born in erect clusters. The blue colored berries are edible but sour. Traditionally, Native Americans used the roots to make infusions as a tonic, a wash for the eyes, and a gargle for sore throats. The decoction of roots was taken for tuberculosis, arthritis, and syphilis.  

 

The root extract contains two representative alkaloids, protoberberine, and bisbenzylisoquinoline. The compounds belonging to those alkaloids found in Oregon grape root are berberine, jatrorrhizine, canadine, corypalmine, hydrastine, and isocorydine. It was reported that the crude extract and its alkaloid fractions exhibit free radical scavenging activities and lipoxygenase inhibition activities. The root extract and their constituents, berberine and jatrorrhizine, show anti-microbial activities against Propionibacterium acnes (P. acnes).