The Oregon Grape Plant and the Uses of Berberine
The Oregon Grape
Oregon grape is an attractive evergreen shrub that is native to the west coast of North America. Its fruits are blue berries that are borne in clusters and look somewhat like grapes. Despite its name, the plant is unrelated to the true grapes. The berries are edible, but they are very sour and have large seeds. They are flavourful, however, and can be used to make a delicious jam or jelly.
Oregon grape is often grown as an ornamental plant, since its shiny, holly-like leaves, bright yellow flowers, and blue berries are so beautiful. The plant is also valued because it attracts butterflies, bees, and birds. It's the state flower of Oregon.
The inner bark and roots of Oregon grape contain a bright yellow chemical called berberine. Berberine can act as a dye and is used to stain paper, silk, wool, leather, and wood. It may have health benefits as well. It kills bacteria in the lab and may be helpful for a range of health disorders.
I generally find Oregon grape at the edge of wooded areas, although it also grows inside forests. The plant seems to like semi-open and disturbed habitats.
The Leaves of an Oregon Grape Plant
The scientific name of the tall Oregon grape is Mahonia aquifolium. Some scientists prefer to call it Berberis aquifolium. The species name "aquifolium" means "spiny leaves" in Latin.
The stiff and leathery leaves of Oregon grape are technically leaflets, since the leaves are pinnately compound. The leaflets are flat and toothed. There are generally seven to nine of them in a leaf. They are arranged in two parallel rows and are joined to the leaf stem without a stalk. At the tip of the leaf there is a terminal leaflet that is joined to the stem with a stalk. There is a very noticeable vein down the centre of each leaflet.
The leaflets are usually medium to dark green in colour. They may have attractive red or bronze patches at times, such as when they are first produced, and they are often red in winter. The upper surface of each leaflet is waxy. The lower surface is not as shiny and is a paler green colour. The leaves are used in floral arrangements because they stay in good condition for a long time after they're picked.
Oregon Grape in Bloom
Flowers and Berries
The flowers and berries of Oregon grape are vividly coloured and beautiful. The plant is very noticeable when it's in bloom or when it bears berries. The flowers are bright yellow and are arranged in attractive clusters. Each flower has six yellow petals and six outer sepals of the same colour. Six stamens (the male reproductive structures) and one pistil (the female structure) are located in the centre of the flower.
Although the berries are tart, they taste good when sweetened. The correct identification of the plant is vital if the berries are being collected for food. It's also important that the berries are collected from an area that is free of pesticides or pollutants.
Differences Between Oregon Grape and Holly
The holly plant (Ilex aquifolium) isn't closely related to the Oregon grape, but it has the same species name because it has prickly leaves. When there are no flowers or fruit present, holly is sometimes confused with Oregon grape.
Holly leaves aren't compound and the spines on the leaves are more noticeable and less regular. Holly flowers are white and their berries are red. To confuse matters, though, Oregon grape is sometimes known as Oregon grape holly to distinguish it from true grapes.
A Chemical of Interest
Berberine is a yellow alkaloid found in a variety of plants in addition to Oregon grape. Goldenseal, another native North American plant, also contains the chemical. In addition, berberine is present in the barberry, which is found in many countries, and in the Amur cork tree (or Amur corktree), which is native to Asia.
Plants containing berberine are used in Chinese traditional medicine and in the Ayurvedic herbal medicine of India. Berberine is also used as a medicine by some people in the west.
Antibacterial Action of Berberine
There are claims that berberine helps many health problems, but at the moment there is insufficient scientific evidence for most of these claims. Multiple experiments suggest that the chemical is antibacterial, at least in lab equipment and lab animals, however. It hasn't been proven to work in humans yet, but the discoveries made so far are said to be "promising".
Although berberine does seem to kill bacteria, the methods by which it accomplishes this task are still being investigated. In some cases it's thought to interfere with bacterial reproduction. In other cases it seems to need the help of another substance in order to be effective.
The Importance of an MDR Inhibitor
A major problem for medicinal drug manufacturers is the fact that when antibacterial chemicals are absorbed by certain bacteria, the bacteria quickly release the chemicals before they are injured. This mechanism for removing the chemicals is known as a Multidrug Resistance Pump (MDR).
Researchers have found that berberine is quickly "pumped" from some bacteria after it enters them, so it never gets a chance to kill the bacteria. In animal and isolated bacteria tests, the scientists have found that administering an MDR inhibitor at the same time as berberine enables the berberine to stay in the bacterial cells and become an effective antibiotic.
Potential Medicinal Uses of Berberine
Berberine may be helpful for some diseases. For example, preliminary research suggests that it may kill fungi and parasites, lower the blood glucose level in diabetics, improve heart function, dilate blood vessels, reduce inflammation, and treat mild psoriasis (when used in a cream containing Oregon grape but not isolated berberine). In lab dishes, berberine has killed some types of cancer cells.
More research is needed to confirm whether berberine actually helps health disorders. Researchers sometimes discover that potentially medicinal chemicals work in lab equipment or in lab animals but not inside the human body. In cases where berberine does have a beneficial effect on a human health problem, researchers need to determine whether if it has harmful side effects.
Growing Oregon Grape in a Garden
Safety and Cautions
Oregon grape and berberine supplements are sold in health stores. Since the benefits of berberine inside the body are still uncertain, it may or may not be a waste of time taking the supplements. The fact that they are typically formulated without an MDR inhibitor may be significant.
Berberine is thought to be safe for most adults when taken in a moderate dose for a short period of time. If you are under a doctor's care, however, you should consult your doctor if you intend to take the supplement. It interferes with some prescribed medications, slowing their breakdown and elimination from the body. You should also check with your doctor if you have a serious pre-existing illness to see if he or she considers berberine to be safe for you.
Medicines from plants can be very useful, but we mustn't assume that because they are natural they are safe. Some plant chemicals can be dangerous inside the body.
Berberine in Pregnancy
Pregnant women should avoid taking berberine supplements because the chemical may travel through the placenta to the fetus. It may also be transferred to the baby when it feeds. In addition, berberine supplements should never be given to newborns.
Berberine can cause the buildup of bilirubin in a baby's body. Bilriubin is a yellow pigment made from the breakdown of hemoglobin (a red pigment) in old red blood cells. The liver normally eliminates bilirubin from the body, but berberine is believed to interfere with the liver's breakdown of the bilirubin. The bilirubin is then deposited in the skin, causing jaundice. In a baby, the excess bilirubin can cause a type of brain damage called kernicterus.
A Beautiful and Useful Plant
Oregon grape is a beautiful plant to observe in the wild or in a garden. The wild plant is one of my favourite sights in the area where I live. If you have the patience (and have positively identified the plant), the berries can be used to make a lovely jam or jelly.
Berberine is an interesting chemical, just like many other substances that have been discovered in plants. It might be very useful as a medical treatment once more information has been discovered about its action in our bodies. Further research is necessary, though. I hope this research is done. There are intriguing indications that berberine could be a very helpful substance.
Information about the Oregon grape plant from the Missouri Botanical Garden
Berberine and Multidrug Resistance Pump Inhibitors from the NIH (National Institutes of Health)
Action of a Berberine-Multidrug Resistant Pump Inhibitor Combination from the University of Wollongong in Australia
Safety of Berberine from WebMD
Questions & Answers
© 2012 Linda Crampton