Oregon grape is a holly-like shrub that exists as several distinct species. Berberis aquifolium is the traditional, 2- to 6-foot plant that most people envision when they hear the phrase “Oregon grape.” However, several other varieties of varying size and habitat are also described by the same common name. B. nervosa, B. repens, and B. pinnata round out the group, and all contain similar levels of isoquinolone alkaloids, the most prominent of which is berberine.
Berberine is the bright yellow compound that gives the rarer – and more expensive – goldenseal its name. In times past (and even now, in India), berberine was used to dye wool, leather and wood. Because it fluoresces in ultraviolet light, berberine is used to stain tissue specimens for specialized histological examination.
Traditionally, Oregon grape was used as a bitter tonic for stimulating salivary and gastric secretions and for improving liver function (the herbal simpler will appreciate the similarity between the vibrant hues of berberine and bile). Oregon grape has also been employed as an antimicrobial for the skin and gastrointestinal tract, and its alkaloids have been promoted for their antioxidant properties.
When used topically, infusions of Oregon grape may reduce colonization by methicillin-resistant staphylococcus aureus, or MRSA. A 2005 study published in “Journal of Medicinal Food” demonstrated that berberine, at relatively low concentrations, inhibited MRSA growth and reduced the organism’s ability to invade human fibroblasts. Further, berberine markedly enhanced the capacity of antibiotics – ampicillin and oxacillin – to eradicate MRSA, indicating both additive and synergistic effects. (1)
Viruses are also susceptible to berberine’s bug-killing properties. Infections caused by cytomegalovirus, or CMV, are troublesome complications in immunosuppressed transplant patients and individuals with HIV/AIDS. In 2007, Japanese scientists showed that berberine was comparable to ganciclovir, a commonly prescribed antiviral drug, for inhibiting CMV replication. (2)
A 2011 study in “Molecular Cancer” suggested that berberine could be useful for treating cervical cancer caused by human papillomavirus, or HPV. By blocking the expression of cancer-related proteins and transcription factors in HPV-infected cervical cells, berberine targets both viral and patient factors that contribute to cervical cancer’s development and growth. (3)
Another intriguing characteristic of berberine is its apparent ability to inhibit cyclooxygenase-2, an enzyme responsible for producing inflammatory molecules in your body. This same enzyme is the target of so-called COX-2 blockers, such as Vioxx and Celebrex. Berberine’s interference with COX-2 may have implications for people with certain inflammatory conditions, such as arthritis. Interestingly, icreased COX-2 activity has been detected in the cells of colon cancers, and a 2010 Chinese study demonstrated that berberine inhibited tumor formation in rat models of colon cancer. (4)
Like many plant-based compounds, berberine shows promise that has not yet been fully realized or demonstrated due to nuances in biomedical research (read: the patentable drugs get the research dollars). Conversely, its long-term safety has not been fully evaluated, even though herbalists routinely use berberine-rich preparations in their practices.
Oregon grape tinctures and extracts are commercially available, though you can make your own if you have some of this plant growing nearby. Remember to gather responsibly (i.e., leave the majority of the plant undisturbed, smooth over any upturned soil, and don’t gather on someone else’s property). Take 15 to 45 drops of a fresh root tincture up to three times daily.
- Yu HH, et al. Antimicrobial Activity of Berberine Alone and in Combination with Ampicillin or Oxacillin against Methicillin-Resistant Staphylococcus aureus. J Med Food. 2005;8(4):454-461
- Hayashi K, et al. Antiviral Activity of Berberine and Related Compounds against Human Cytomegalovirus. Bioorg Med Chem Lett. 2007;17(6):1562-1564
- Mahata S, et al. Berberine Modulates AP-1 Activity to Suppress HPV Transcription and Downstream Signaling to Induce Growth Arrest and Apoptosis in Cervical Cancer Cells. Mol Cancer. 2011;10(1):39
- Wu K, et al. Preventive Effects of Berberine on Experimental Colon Cancer and Relationship with Cyclooxygenase-2 Expression. Chin J Chin Mat Med. 2010;35(20):2768-2773