Berberis includes about 500 species of shrubs and subshrubs with sharp-toothed leaves and sometimes with spines on the stem; it includes the formerly segregate genus Mahonia (e.g., Oregon grape holly). Berberis vulgaris, a spiny shrub up to 3 meters tall, is one of only two species native to Europe. It also ranges into Asia and North Africa and has been naturalized in the United States, but because it is the alternate host for a pathogenic fungus of wheat, in many areas it has been eradicated and may not legally be planted. The reddish berries may be used to make jam and jelly. The plant was also formerly used as a source of dye; like other species of Berberis, it contains the antibacterial compound berberine, which has a strongly yellow color.

The bark and root bark of barberry have been used in European traditional medicine as a tonic and for a variety of conditions, ranging from dyspepsia, diarrhea and liver troubles to eye problems; other species are used for some similar purposes in Asia. Barberry fruits have been used in Iranian traditional medicine as an antiarrhythmic and sedative. Berberine has a number of biological activities in lab studies, including antimicrobial, antiplasmodial, antidiarrheal, anti-inflammatory, antidiabetic, cardioprotective, hepatoprotective, anticancer, and cholesterol-lowering effects. This does not indicate that crude barberry extracts would be effective for all of these uses, especially as the dosage of isolated berberine can be much higher than could be obtained from a crude extract. There have been relatively few animal or human studies of such extracts, most using other species. Related species are used for psoriasis in ointment form, and have been found to contain additional key active compounds. Barberry species have also been discovered to contain a compound that acts synergistically with berberine to prevent microbial drug resistance by disabling a molecular pump that bacteria would otherwise use to remove berberine.

Selected References

Fatehi-Hassanabad, Z., M. Jafarzadeh, A. Tarhini, and M. Fatehi. 2005. The antihypertensive and vasodilator effects of aqueous extract from Berberis vulgaris fruit on hypertensive rats. Phytother. Res. 19:222-225.

Kim, Y. D., S. H. Kim, and L. R. Landrum. 2004. Taxonomic and phytogeographic implications from ITS phylogeny in Berberis (Berberidaceae). J. Plant Res. 117:175-182.

Kong, W., J. Wei, P. Abidi, M. Lin, S. Inaba, C. Li, Y. Wang, Z. Wang, S. Si, H. Pan, S. Wang, J. Wu, Y. Wang, Z. Li, J. Liu, and J. D. Jiang. 2004. Berberine is a novel cholesterol-lowering drug working through a unique mechanism distinct from statins. Nat. Med. 10:1344-1351.

Stermitz, F. R., P. Lorenz, J. N. Tawara, L. A. Zenewicz, and K. Lewis. 2000. Synergy in a medicinal plant: antimicrobial action of berberine potentiated by 5?-methoxyhydnocarpin, a multidrug pump inhibitor. Proc Natl Acad Sci U S A 97:1433-1437.

Whittemore, A. T. 1997. Berberis. Pp. 276-286 in: Flora of North America Editorial Committee, eds. Flora of North America, vol. 3. Oxford University Press: New York.