Bioflavonoids
Once known as "Vitamin P" and semi-essential nutrients
4000 flavonoid compounds have been characterized and classified
Group of plant pigments that are largely responsible for colors of many fruits and flowers
Useful in treatment and prevention of many health conditions
Four categories:
PCO (Proanthocyanidins)
most potent PCOs are those bound to other PCOs
exist in many plants and red wine
commercially available sources are from grape seeds and bark from the maritime pine
Quercetin
serves as backbone for other flavonoids such as citrus flavonoids: rutin, quercitrin, hesperidin
these derivatives have sugar molecules attached to the backbone
most active of the flavonoids
Citrus bioflavonoids
include rutin, quercitrin, hesperidin, naringin
standardized mixture of rutinosides known as hydroxyethylrutosides (HER)
clinical results have been obtained in treatment of capillary permeability, easy bruising, hemorrhoids, and varicose veins
Green Tea Polyphenols
derived from tea plant camellia sinensis
produced by steaming the fresh cut leaf
polyphenol indicates presence of phenolic ring in the chemical structure
polyphenols = flavonoids
polyphenols in green tea: catechin, epicatechin, epicatechin gallate, epigallocatechin gallate, and proanthocyanidins
epigallocatechin gallate = most significant active compound
Dietary Sources
Citrus fruits
Berries
Onions
Parsley
Legumes
Green Tea
Red Wine
Average Daily Intake = 150-200 mg
Beneficial Effects
referred to as "nature's biological response modifiers" - modify body's reaction to compounds such as allergens, viruses, and carcinogens
powerful antioxidants by giving protection versus oxidative and free radical damage
prevents formation of oxidized cholesterol through antioxidant effects
greater antioxidant effects than Vitamins C, E, Selenium, and Zinc
PCOs
increase intracellular Vitamin C levels
decrease capillary permeability and fragility
scavenge oxidants and free radicals
inhibit destruction of collagen
crosslinks collagen fibers to reinforce the natural crosslinking
prevents free radical damage
inhibits enzymatic cleavage of collagen by enzymes secreted by leukocytes in inflammation and microbes in infections
prevents release and synthesis and compounds that promote inflammation and allergies (histamines, prostaglandins, leukotrienes)
antioxidant effects are beneficial in:
aging process
chronic degenerative diseases (heart disease, arthritis, and cancer)
fat and cholesterol oxidation
antioxidants are produced by:
inhibiting xanthine oxidase noncompetitively(oxygen free radicals)
on the cellular level: PCOs are incorporated into the cell membranes along with the antioxidant effects offer great protection to cells against free radical damage.
Quercetin
anti-inflammatory activity due to inhibition of initial processes of inflammation
inhibits manufacture and release of histamine
potent antioxidant activity and Vitamin C sparing action
beneficial effects for diabetics
helps prevent diabetic cataracts, and retinopathy
enhances insulin secretion
protects pancreatic beta cells from free radical damage
antiviral activity
activity vs. herpes virus type 1, parainfluenzae3, polio virus type 1, and respiratory syncytial virus
in vivo, inhibits viral infection
may be of some benefit in the common cold
Citrus Bioflavonoids
antioxidant effects
increase intracellular Vitamin C, rutin, hesperidin, and HER
beneficial effects on capillary permeability and blood flow like PCOs
anti-allergy and anti-inflammatory effects like quercetin
Green Tea Polyphenols
potent antioxidant effects
increase activity of antioxidant enzymes in the small intestines, liver, lungs, and small bowel
inhibit formation of cancer causing compounds like nitrosamines in vitro
suppressing activation of carcinogens
trapping cancer causing agents
forms of cancer that green tea prevents best:
cancers of GI tract (stomach, small intestine, pancreas, colon)
cancer of the lungs
estrogen related cancers (inhibits estrogen interaction with its receptor)
consumption of green tea with meals inhibits formation of nitrosamines (nitrites combined with amino acids)
Principle Uses
PCOs
Treatment of venous and capillary disorders
venous insufficiency
varicose veins
capillary fragility
Diabetic retinopathy and macular degeneration
Prevention of heart disease and strokes
Lowers blood cholesterol levels
Shrinks size of cholesterol deposits in the artery
Inhibits platelet aggregation and vascular constriction
Quercetin
In vitro, helps virtually all inflammatory and allergic conditions
asthma
hay fever
rheumatoid arthritis
lupus
Beneficial in diabetes and cancer
Citrus Bioflavonoids
Venous insufficiency
Improve microvascular blood flow and clinical symptoms (pain, tired legs, night cramps, and restless legs)
Improve venous function
Relieve hemorrhoidal signs and symptoms in pregnant women
Green Tea Polyphenols
Used principally to prevent cancer
Available Forms
PCOs
Grape seed extract (92%-95%) and pine bark extract (80%-85%)
Used interchangeably, but grape seed extract is preferred
Grape seed extract is considered more potent and more effective than pine bark extract because only grape seed extract has gallic esters of proanthocyanidins which are the most active free radical scavenging PCOs
Quercetin
Available in powder and capsule forms
For anti-inflammatory effects, combination of Bromelain (pineapple enzyme) may provide additional benefit by enhancing absorption of quercetin
Amount of Bromelain should equal quercetin
Citrus Bioflavonoids
Mixed preparations are most widely used
Least active and quantified source of flavonoids
Green Tea Polyphenols
Commercial preparations that have been decaffeinated and concentrated for polyphenols (60%-80%)
1 cup = 300-400 mg of polyphenols
Downside = this dose also contains 50-100 mg of caffeine
Dosage Ranges
PCOs
Preventive and antioxidant=50 mg/day of grape seed extract or pine bark extract
Therapeutic purposes dose=150-300 mg/day of either extract
Quercetin
200-400 mg taken 20 minutes before meals three times a day
Citrus Bioflavonoids
2000-6000 mg/day
Green Tea Polyphenols
For green tea extract standardized for 80% polyphenols and 55 % epigallocatechin gallate, the dose=300-400 mg/day
*Look for level of epigallocatechin gallate and total content of polyphenol
Safety Issues
PCOs
safe, no toxicities, no side effects
Quercetin
Well-tolerated in humans
no side effects when taken in large quantities for long periods of time
safe for use in pregnancy
allergic reaction may occur-uncommon, but should result in discontinuation of product
Citrus Bioflavonoids
extremely safe
no side effects
safe in pregnancy
Green Tea Polyphenols
no side effects or toxicities
if product contains caffeine, overconsumption may result in a stimulant effect
Interactions
Do not interact with any drugs
citrus bioflavonoids containing naringin may interact with drugs
naringin is found in grapefruit juice
can increase oral bioavailability of drugs like nifedipine, felodipine, verapamil, and terfenadine
inhibits breakdown of various drugs including: caffeine, coumarins, and estrogens
Vitamin C-Bioflavonoids may enhance the effects of vitamin C
References
Evans CA and Miller NJ. "Antioxidant activities of flavonoids as bioactive components of food." Biochemical Society Transactions. 24(3):790-795, 1996.
Hertog Michael, et al. "Flavonoid Intake and Long-term Risk of Coronary Heart Disease and Cancer in the Seven Countries Study." Archives of Internal Medicine. 155:381-386, 1995.
Kandaswami Chithan, et al. "Ascorbic acid-enhanced antiproliferative effect of flavonoids on squamous cell carcinoma in vitro." Anti-Cancer Drugs. 4:91-95, 1993.
Lale A, Herbert JM, et al. "Ability of Different Flavonoids to Inhibit the Procoagulant Activity of Adherent Human Monocytes." Journal of Natural Products. 59:273-276, 1996.
Murray MT. "Flavonoids." Encyclopedia of Nutritional Supplements. p. 320-331.
So Felicia, et al. "Inhibition of proliferation of estrogen receptor positive MCF-7 human breast cancer cells by flavonoids in the presence and absence of excess estrogen." Cancer Letters. 112:127-133, 1997.
Wiseman H. "Role of dietary phyto-oestrogens in the protection against cancer and heart disease." Biochemical Society Transactions. 24(3):785-789, 1996.
Xiao-duo Ji, et al. "Interactions of Flavonoids and Other Phytochemicals with Adenosine Receptors." Journal of Medicinal Chemistry. 39:781-787, 1996.
Thanks to the University of North Carolina School of Pharmacy for the use of this article.
Source - http://www.chiro.org/
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