Quercetin

Description:

Glycosides are compounds that yield one or more sugars among the products of hydrolysis. Glycosides may be considered sugar ethers. The non sugar component is known as the aglycone, and the sugar component is called glycone. The flavonoid glycosides and their aglycones are generally termed flavonoids. Rutin, quercitrin, and the citrus bioflavonoids, including hesperidin, hesperetin, diosmin, and naringen, are among the best known flavonoid constituents. Quercetin is the aglycone of quercitrin, rutin and other flavonoids.

Plants/Food Which Contain Quercetin:

• Apple
• Asparagus
• Bearberry (Arctostaphylos uva-ursi)
• Bell Peppers
• Black Catechu (Acacia catechu)
• Boneset (Eupatorium perfoliatum)
• Brussel Sprouts
• Dill
• Elder flowers (Sambucus canadensis)
• Eucalyptus (Eucalyptus globullus)
• Euphorbia (Euphorbis piluifera)
• Fenugreek (Trigonella foenum-graecum)
• Hydrangea (Hydrangea arborescens)
• Kale
• Pale catechu (Uncaria gambir)
• Passionflower (Passiflora incarnata)
• Pear
• Podophyllum (Podophyllum peltatum)
• Onion
• Squill (Urginea maritima)
• Tarragon
• Tea
• Witch hazel (Hamamelis virginica)

Physiologic Therapeutics:

• Affects a variety of enzyme systems:
  
  Aldose reductase (an enzyme which promotes the synthesis and intracellular accumulation of sorbitol)
  Catechol-O-methyltransferase
  Cyclic nucleotide phosphodiesterases
  Cyclo-oxygenase
  Estrogen synthetase
  Histidine decarboxylase
  Hyaluronidase
  Phospholipase A2
  Protein kinases
  Transport ATPases
  Xanthine oxidase
• Anti-inflammatory - prevents mast cell and basophil degranulation
• Anti-oxidant
• Helps reduce the formation of leukotrienes
• Increases cyclic AMP
• Inhibits phospholipase A 2
• Inhibits platelet aggregation
• Prevents breakdown of collagen matrix of connective tissue and ground substance
• Protects pancreatic beta cells from damaging effects of free radicals
• Sparing effect on epinephrine
• Stabilizes membranes

Clinical Indications:

• Allergies
• Antiviral - herpes virus I, para-influenzae 3, polio virus I, respiratory syncytial virus
• Aphthous stomatitis
• Asthma
• Benign prostatic hypertrophy (BPH)
• Bronchitis
• Candidiasis
• Cataract prevention
- if diabetic
• Crohn's disease
• Diabetes mellitus
• Eczema
• Fibrocystic breast disease
• Fibromyalgia
• Gout
• Headaches
• Hemorrhoids
• Irritable bowel syndrome
• Otitis media
• Ovarian cancer - inhibition of tumor promotion (squamous cell carcinoma, ovarian carcinoma and estrogen receptor negative breast cancer)
• Psoriasis
• Psoriatic arthritis
• Rheumatoid arthritis
• Ulcerative colitis
• Atopic dermatitis
• Diabetic cataracts, neuropathy, retinopathy
• Inflammatory conditions

Dosage:

• 400 mg. 20 minutes before meals, TID

Drug/Nutrient Interaction:

• Bromelain may enhance quercetin absorption

Adverse Reactions and Toxicity:

• Well tolerated

Copyright 1998 - 2008 by L. Vicky Crouse, ND and James S. Reiley, ND. All rights reserved (ISSN 1527-0661).