Flavonoids are organic compounds having a C6-C3-C6 carbon skeleton with over 2,000 reported occurring in the free state or as glycosides. They are responsible for the colors of many fruits and vegetables, are found also in grains, nuts, leaves and flowers, and studies suggest there value in the treatment of a number of disorders. They are considered one of the most common biological constituents in plants. They have a gentle, beneficial action on numerous physiological processes in the body and may benefit the heart, blood vessels, liver, immune system, connective tissue, adrenal glands, kidneys, musculature and nervous system. Flavonoids may act as anti-oxidants, "anti-allergics", anti-inflammatories, immunostimulating, anti-hepatotoxic, anti-neoplastic and hypoglycemic along with numerous other actions including stabilizing capillary permeability. Important herbs containing flavonoids include milk thistle, hawthorn, echinacea and bilberry. One possible chemical classification consists of PCO (proanthocyanidins), quercetin, citrus bioflavonoids and green tea polyphenols. The following is a description of three popular flavonoids; quercetin, grape seed extract and green tea extract.

INDICATIONS: Studies in experimental models indicate significant influence against diabetic complication (1), viral infection (2), inflammatory and allergic conditions (3) and cancer (4).

DOSAGE: 200 to 400 mg 20 minutes before meals, three times a day.

SIDE EFFECTS AND INTERACTIONS: Uncommon allergic reactions can occur, otherwise no significant side effects or interactions have been observed.

Quercetin serves as the backbone for other flavonoids, and is the most active of the flavonoids. Many medicinal plants have a significant quercetin content. It blocks mast cell and basophilic histamine degranulation, inhibits xanthine oxidase (the enzymes producing uric acid) and aldose reductase (the enzyme converting glucose into sorbitol), decreases neutrophil lysosomal enzyme secretion, and normalizes activity if phospholipase A2 and lipoxygenase. Although human studies are limited, its physiological actions explain its use in inflammatory and allergic conditions including asthma, hay fever, rheumatoid arthritis, lupus, diabetes and cancer. Sorbitol is implicated in the development of diabetic complications including cataracts, neuropathy and retinopathy. Studies show decreased cataract formation in the lens of diabetic animals. Its potential influence on diabetes may also relate to enhanced insulin secretion, protection of pancreatic beta cells from free-radical damage, and inhibition of platelet aggregation. Quercitin has anti-viral action against a number of different viruses, and inhibits a number of different cancers in experimental models.

1. Chaundry PS, et al., Inhibition of human lens aldose reductase by flavonoids, sulindac and indomethacin. Biochem and Phrmacol 32, 1995-1998, 1983
2. Kaul T, Middleton E, and Ogra P, Antiviral effects of flavonoids on human viruses. J Medi Virol 15, 71-79, 1985
3. Ferrandiz ML, and Alcaraz MJ, Anti-inflammatory activity and inhibition of arachidonic acid metabolism by flavonoids. Agents Action 32, 283-287, 1991
4. Stavric B, Quercetin in our diet: from potent mutagen to probable anticarcinogen. Clin Biochem 27, 245-248, 1994

INDICATIONS: venous insufficiency (1), varicose veins (2), capillary fragility (3) and diabetic retinopathy (4). Experimental studies suggest potential benefit in arteriosclerosis, heart disease and stroke.

DOSAGE: 50mg/day as antioxidant support and 150-300mg/day for conditions noted above.

SIDE EFFECTS AND INTERACTIONS: No side effects or significant drug interactions have been reported.

Proanthocyanidins (Procyanidins) is an important therapeutic class of flavonoids extracted from grape seeds and maritime (Landes) pine. When individual molecules bind together, the result is collectively called procyanidolic oligomers (PCO). They have a broad range of pharmacologic activity through increasing vitamin C levels, decreasing capillary permeability and fragility, scavenging free radicals and inhibiting destruction of collagen. The latter occurs through ability to cross-link collagen fibers, preventing free-radical damage, inhibiting enzymatic cleavage of collagen, and preventing the synthesis and release of inflammatory mediators. PCO has approximately 50 times the anti-oxidant activity of vitamin C or vitamin E. These influences, along with other mechanisms, explain there benefit in venous and capillary disorders, including venous insufficiency, capillary fragility, diabetic retinopathy and macular degeneration. Studies show that PCO also lowers cholesterol levels and can shrink arterial cholesterol deposits.

1. Henriet JP, Veno-lymphatic insufficiency: 4,729 patients undergoing hormonal and pro-cyanidol oligomer therapy. Phlebologie 46, 313-325, 1993
2. Gomez Trillo JT, Varicose veins of the lower extremities: Symptomatic treatment with a new vasculotrophic agent. Prensa Med Mex 38, 293-296, 1973
3. Lagrue G, Oliver-Martin F, and Grillot A, A study of the effects of procyanidol oligomers on capillary resistance in hypertension and in certain nephropathies. Sem Hosp Paris 57, 1399-1401, 1981
4. Soyeux A, et al., Endotelon: Diabetic retinopathy and hemorrheology (preliminary study). Bull Soc Ophtalmol Fr 87, 1441-1444, 1987

INDICATIONS: Epidemiologic and biochemical studies support an anti-carcinogenic (1) as well as anti-oxidant influence (2).

DOSAGE: 300 to 400mg/day of an extract standardized to 80% polyphenols and 55% epigallocatechin gallate.

SIDE EFFECTS AND INTERACTIONS: No definite side effects unless the tea with caffeine is consumed. There are no significant drug interactions.

Green tea is derived from the tea plant, Camellia sinensis, through light steaming of the leaves. Allowing the leaves to oxidize produces black tea. Green tea contains polyphenols, mainly flavonoids. They are potent anti-oxidants as well as anti-cancer substances. They inhibit the formation of carcinogenic substances such as nitrosamines, suppress their activation, and detoxify them.

1. Yang CS and Wang ZY, Tea and cancer. J Natl. Cancer Inst. 85(13), 327-335, 1993
2. Ho C, et al., Antioxidative effect of polyphenol extract prepared from various Chinese teas. Prev Med 21, 520-525, 1992

BIBLIOGRAPHY

Birdsall, Timothy, Miller, Alan and Kelly Greg, Thorne Research Product Book, Thorne Research Inc.; Sandpoint, Idaho, 1996
Brody, Tom Nutritional Biochemistry, Academic Press, San Diego, 1994
Hardman, Joel G. Ph.D. and Limbird, Lee L. Goodman and Gilman's The Pharmacological Basis of Therapeutics, McGraw-Hill, New York, New York, 1996
Hendler, Sheldon Saul M.D., Ph.D. The Doctor's Vitamin and Mineral Encyclopedia, Simon and Schuster; New York, 1990
Hoffmann, David Therapeutic Herbalism - A correspondence course in Phytotherapy
Johnson, Lois Syllabus for Advanced Clinical Herbalism, 1997
Kimball, Christopher Natural Health Handbook, Natural Health Ltd. Partnership, Brookline Village, Mass., 1994
Murray, Michael Encyclopedia of Nutritional Supplements, Prima Publishing; Rocklin, California, 1996
Murray, Michael and Pizzorno, Joseph, Encyclopedia of Natural Medicine, Prima Publishing Co.; Rocklin, California, 1998
Murray, Michael The Healing Power of Herbs, Prima Publishing; Rocklin, California, 1995
Robbers, James E. and Speedie, Marilyn K. and Tyler, Varro Pharmacognosy and Pharmacobiotechnology, Williams and Wilkins, Baltimore, 1966
Shils M.E., Olson, J.A. and Shike, M Modern Nutrition in Health and Disease, Lea and Febiger, Philadelphia, 1994
Werbach, Melvyn, Nutritional Influences on Illness, Third Line Press, Tarzana, California, 1993
Werbach, Melvyn R. and Murray, Michael T, Botanical Influences on Illness, Third Line Press; Tarzana, California, 1994
Werbach, Melvyn, Foundations of Nutritional Medicine, Third Line Press, Tarzana, California. 1997

phone: 707-528-4372 · toll-free: 1-800-896-1484
fax: 707-528-1015 · email: farmacopia@pacbell.net

Use of this site indicates you have agreed to the following User Agreement.