Bioflavinoids in Autoimmune Disease

Posted by Elaine Moore Aug 30, 2006

Bioflavinoids, which are also known as flavonoids and flavinoids, are plant chemical with potent antioxidant properties. In autoimmune diseases, bioflavinoids are known to reduce inflammation and oxidative stress, promote healing of nerves and blood vessels and repair skin damage. Flavinoids have been referred to as "nature's biological response modifiers" or immunomodulators because of their ability to modify the immune system's reaction. Immunomodulators are used to strengthen the immune system and help it function properly. Flavinoids are also currently being researched for their role in preventing breast and colon cancers.

In 1935 Albert Szent-Gyorgyl was the first to describe bioflavinoids when he found that an extract he called citrin, made from lemon peels, was more effective in preventing scurvy than vitamin C. In 1936 Szent-Gyorgyl discovered that citrin contained a mixture of bioflavinoids, including hesperidine. Bioflavinoids represent a group of plant chemicals with several subtypes such as flavones, isoflavinoids, flavonones (catechins and naningin) and flavonols.

Bioflavinoid-Rich Foods

Foods rich in flavinoids include both black and green teas, red wines and dark chocolate, which are rich in epicatechin and catcechin bioflavinoids. Cocoa, the major active ingredient in dark chocolate, has been found to contain nearly twice as much antioxidant as red wine and three times as much antioxidant as green tea. Researchers as the National Center for Complementary and Alternative Medicine (NCCAM) at the National Institutes of Health (NIH) are also studying the effects of chocolate on insulin resistance. Several published studies show that dark chocolate may prevent insulin resistance and also lower blood pressure.

Other foods rich in bioflavinoids include the pulp and rind of citrus fruits, broccoli, eggplant, flaxseed, rose hips, berries, whole grains, soybeans and root vegetables. Bioflavinoids are also found in certain herbs, including feverfew, ginkgo biloba, licorice root, and St. John's Wort.

Major Bioflavinoids

The most important bioflavinoids, which can be found in foods or as extracts sold as dietary supplements include quercetin, rutin, hesperidine, anthocyanins, and proanthocyanidins,

Rutin is used in medicine to treat chronic venous insufficiency, glaucoma, hay fever, hemorrhoids, varicose veins, circulatory problems, oral herpes, cirrhosis, stress, low serum calcium and cataracts. Rutin also promotes healing in bruises and it is used to alleviate pain in rheumatic diseases such as gout, arthritis, systemic lupus erythematosuss (SLE), and ankylosing spondylitis. Food sources with high rutin content include apricots, buckwheat, cherries, prunes, rose hips, the white rind of citrus fruits and the core of green peppers.

Anthocyanins and proanthocyanidins are used to treat eye conditions, including cataracts, night blindness, diabetic retinopathy, and macular degeneration. Because these compounds help strengthen the wall of blood vessels, they may help prevent bruises, varicose veins and spider veins. In addition, they help in preventing blood clots and protect the brain from free radical damage. Anthocyanins also help reduce the risk of osteoporosis by stabilizing collagen production. Good sources include blackberries, cranberries, cherries, grapes, raspberries, black and green tea, red cabbage, elderberries and red wine.

The bioflavinoid quercetin is an excellent antihistamine and is known to reduce inflammation in gout, arthritis and asthma. Quercetin also stimulates detoxification in the liver, strengthens blood vessels and helps reduce elevated cholesterol levels. Quercetin is particularly important in reducing complications in patients with diabetes because it blocks the accumulation of sorbitol, a compound associated with nerve, eye and kidney damage in diabetes. Quercetin is found in green tea, onionskins, kale, red cabbage, tomatoes, lettuce, strawberries, cherries and grapes.

Other bioflavinoids, including the carotenoids and the catechins, will be described in future articles in September, 2006.

Resources

The Irresistible Treat That Might Help Resistance, CAM at the NIH, Volume XIII, Spring 2006.

Comalada M, Ballester J, Inhibition of pro-inflammatory markers in primary bone marrow-derived mouse macrophages by naturally occurring flavonoids: analysis of the structure-activity relationship, Biochem Pharmacology, Aug 23, 2006.