Barberry bark

During the early Middle Ages, European herbalists were guided by the Doctrine of Signatures, the belief that a plant's physical appearance revealed its therapeutic benefits. Barberry has yellow flowers, and its roots produce a yellow dye. These features were linked to the yellowing of the skin and the eyes during jaundice, a symptom of liver disease. As a result barberry was widely used to treat liver and gallbladder ailments and earned the nam "jaundice berry"

In addition to using barberry for liver and gallbladder problems, traditional Russian healers recommended it for inflammations, high blood pressure, and abnormal uterine bleeding.

When the colonists introduced barberry into North America, the Indians recognized it as a relative of the native Oregon Grape, a holly like plant that they considered a powerful healer. Many tribes adopted barberry enthusiastically and used it to treat dysentery, mouth ulcers, sore throat, wound infections, and intestinal complaints.

Most present-day herbalists limit their recommendations to gargling barberry decoction for sore throat and drinking it for diarrhea and constipation. But if they read the medical journals, they'd recommend if for a great deal more.

The berberine in barberry has a remarkable infection fighting properties. Studies around the world show it kills microorganisms that cause wound infections, diarrhea, dysentery, cholera, giardiasis, and urinary tract infections.

Berberine may also fight infection by stimulating the immune system. Studies show that it activates the macrophages, white blood cells that devour harmful microorganisms.

Barberry's traditional use in treating eye problems is alive and well in Germany, where a berberine preparation, Ophthiole, is used to treat sensitive eyes, inflamed lids, and pink eye (conjunctivitis). However this product is not available in the United States.