QUERCETIN
The aerial part of Proustia pyrifolia has antiinflammatory, analgesic and antioxidant activities The extract of this
plant is found to contain beta-sitosterol, quercetin and dihydroquercetin. [30] Then what is quercetin?
Quercetin is a bioflavonoid. Quercetin is a natural antioxidant found mainly in red wine grapefruit, onions, apples
and black tea. Quercetin protects cells in the body from damage by free radicals, [12-14] quercetin might have
benefits against heart attacks and strokes. Quercetin may also help prevent immune cells from releasing
histamine, the chemical that initiates the itching, sneezing, and swelling of an allergic reaction. Thus, quercetin
benefits are more on allergies such as hay fever, hives, eczema and asthma.
______________________________________________________________________________________
Quercetin Benefits
Quercetin benefits on performance
Researchers found that quercetin intake led to changes in mitochondrial capacity in an animal study. These
changes in mitochondrial capacity were associated with an increase in both maximal endurance capacity and
voluntary wheel running activity. These quercetin benefits on fitness without exercise training may have important
implications for enhancement of athletic and military performance and may also extend to prevention and
treatment of chronic diseases. [A1]
Quercetin benefits against allergy, inflammnation and infection
Asthma incidence was lower at high quercetin intakes. [28] Quercetin may address the inflammatory component
of asthma. Quercetin prevents certain immune cells from releasing histamine. Histamine is a chemical that
triggers an allergic reaction. [1-4] One study shows quercetin might help prostatitis, an inflammation or infection
of the prostate gland. [5], while another study shows quercetin supplementation reduced symptoms of interstitial
cystitis [6] Quercetin even seems to be able to prevent certain viruses from infecting cells from cell studies. [22-
23]
Quercetin benefits on heart diseases, stroke and aggregation
Quercetin might help prevent heart diseases and stroke. [7-10] Quercetin has inhibitory properties of blood
platelet aggregation (clumping). [11]
Quercetin benefits on cancer
Quercetin might have cancer preventive properties, based on some in vitro and animal studies. [15-19]
Topotecan has cytotoxic activity against both of the breast cancer cell lines in vitro. A combination with Quercetin
increases efficacy of Topotecan in the treatment of breast cancers. [31]
Quercetin benefits on cancer, diabetes and cataracts.
A trend toward a reduction in risk of type 2 diabetes is associated with higher quercetin intake. [20] Further,
quercetin might protect rodents with diabetes from forming cataracts. [21]
__________________________________________________________________________________
Quercetin bromelain
Bromelain is an enzyme complex derived from the pineapple stem. Bromelain may assist the absorption of
quercetin in the G.I. tract. [25] Consequently there are two popular quercetin products - "quercetin bromelain"
and activated quercetin.
Quercetin and bromelain both have inhibitory properties of blood platelet aggregation (clumping). Consequently,
manufacturers are interesting to put them together in the product. [25-26]
ACTIVATED QUERCETIN Source Naturals Activated Quercetin is probably the most advertised quercetin product
over the internet. It is a blend of quercetin, magnesium ascorbate, and bromelain.
Activated Quercetin is actually a state-of-the-art quercetin complex. It is advertised that the additional ingredients
can maximize the absorption and benefits of quercetin. Thus, quercetin is thought to be a potent formula.
___________________________________________________________________________
Quecetin Side Effects
Most supplements have benefits and side effects. However, the severity and type of side effects vary from users
to users. Dr. Ray Sahelian says, "Quercetin side effects have not been reported in the medical literature...
Quercetin side effects with long term supplementation... is not known" (September 10, 2011).
According to Webmd.com, quercetin is probably safe up to dosage of 500 mg twice daily for 12 weeks. The
quecetin side effects may include headache and tingling of the arms and legs. Very high doses might cause
kidney damage. (September 10, 2011) While Sloan-Kettrering says, "No adverse effects have been reported with
single oral doses up to 4 grams." Papain and bromelain may support the absorption of quercetin in the intestine.
Drug interaction was also found with quercetin products. Quercetin raises the bioavailability of ditiazem
significantly. [24]
___________________________________________________________________________
Reference:
[1] Ogasawara H et al, Effect of selected flavonoids on histamine release (HR) and hydrogen peroxide (H2O2) generation by
human leukocytes [abstract]. J Allergy Clin Immunol. 1985;75(suppl):184. [2] Middleton E Jr. Effect of flavonoids on basophil
histamine release and other secretory systems. Prog Clin Biol Res. 1986;213:493–506.] [3] Knekt P et al, Flavonoid intake and
risk of chronic diseases. Am J Clin Nutr. 2002 Sep;76(3):560-8.] [4] Miller AL. The etiologies, pathophysiology, and
alternative/complementary treatment of asthma. Altern Med Rev. 2001 Feb;6(1):20-47. [5] Shoskes DA et al. Quercetin in men with
category III chronic prostatitis: a preliminary prospective, double-blind, placebo-controlled trial. Urology. 1999;54:960–963.][6]
Rodriguez LV et al. Treatment of interstitial cystitis with a quercetin containing compound: a preliminary, double-blind placebo
control trial. Presented at: American Urological Association 2001 Annual Meeting; June 2–7, 2001; Anaheim, Calif][7] Constant J.
Alcohol, ischemic heart disease, and the French paradox. Coron Artery Dis. 1997;8:645–649. [8] Hayek T et al, Reduced
progression of atherosclerosis in apolipoprotein E-deficient mice following consumption of red wine, or its polyphenols quercetin
or catechin, is associated with reduced susceptibility of LDL to oxidation and aggregation. Arterioscler Thromb Vasc Biol. 1997;17:
2744–2752. [9] Frankel EN et al Inhibition of human LDL oxidation by resveratrol. Lancet. 1993;341:1103–1104. Alliangana DM.
Effects of beta-carotene, flavonoid quercetin and quinacrine on cell proliferation and lipid peroxidation breakdown products in BHK-
21 cells. East Afr MedJ. 1996;73:752–757. [10] Keli SO et al. Dietary flavonoids, antioxidant vitamins, and incidence of stroke: the
Zupthen study. Arch Intern Med. 1996;156:637–642. [11] [Beretz, et al, “Role of cyclic AMP in the inhibition of human platelet
aggregation by quercetin, a flavonoid that potentiates the effect of prostacyclin.” Biochemical Pharmacology 1981;31(22):3597-600.
[12] Quercetin protects LDL from oxidation by lipid peroxides and transition metal ions. Oxidized LDL is absorbed by macrophages
and arterial endothelial cells, eventually leading to plaque deposits in arterial walls. [13] Afanas’ev, I.B. et. al., “Chelating and free
radical scavenging mechanisms of inhibitory action of rutin and quercetin in lipid peroxidation.” Biochemical Pharmacology 1989;
38(11):1763-69. [14] De Whalley, C.V., “Flavonoids inhibit the oxidative modification of low density lipoproteins by macrophages.”
Biochemical Pharmacology 39(11):1743-50.][15] Balasubramanian S, Govindasamy S. Inhibitory effect of dietary flavonol quercetin
on 7,12-dimethylbenz[a]anthracene-induced hamster buccal pouch carcinogenesis. Carcinogenesis. 1996;17:877–879. [16]
Cross HJ et al. Effect of quercetin on the genotoxic potential of cisplatin. Int J Cancer. 1996;66:404–408. [17] Hoffman R et al.
Enhanced anti-proliferative action of busulphan by quercetin on the human leukaemia cell line K562. Br J Cancer. 1989;59:347–
348. [18] ElAttar TM et al. Modulating effect of resveratrol and quercetin on oral cancer cell growth and proliferation. Anticancer
Drugs. 1999;10:187–193. [19] Yoshida M et al. Quercetin arrests human leukemic T-cells in late G1 phase of the cell cycle.
Cancer Res. 1992;52:6676–6681. [20] Knekt P., Flavonoid intake and risk of chronic diseases. Am J Clin Nutr. 2002 Sep;76(3):
560-8.] [21] Varma SD et al. Diabetic cataracts and flavonoids. Science. 1977;195:205–206] [22] Kaul TN et al. Antiviral effect of
flavonoids on human viruses. J Med Virol. 1985;15:71–79. [23] Musci I, Pragai BM. Inhibition of virus multiplication and alteration of
cyclic AMP level in cell cultures by flavonoids. Experientia. 1985;41:930–931.] [24] Choi JS. Enhanced diltiazem bioavailability after
oral administration of diltiazem with quercetin to rabbits. Int J Pharm. 2005 Jun 13;297(1-2):1-8. [25] Hollma, P. et. al., “Absorption
of dietary quercetin glycosides and quercetin in healthy ileostomy volunteers.” Am. J. Clin. Nutr. 1995;62:1276-82.][25] Beretz, et al,
“Role of cyclic AMP in the inhibition of human platelet aggregation by quercetin, a flavonoid that potentiates the effect
of prostacyclin.” Biochemical Pharmacology 1981;31(22):3597-600. [26] Heinicke et al “Effect of bromelain (Ananase®) on
human platelet aggregation. ”Experientia 1972;28(7):844] [27] Ebeler SE et al, Animal models and analytical approaches for
understanding the relationships between wine and cancer. Drugs Exp Clin Res. 2005;31(1):19-27.[30] Delporte C, Analgesic-
antiinflammatory properties of Proustia pyrifolia. J Ethnopharmacol. 2005 May 13;99(1):119-24.[31] Akbas SH et al, The effect of
quercetin on topotecan cytotoxicity in MCF-7 and MDA-MB 231 human breast cancer cells. J Surg Res. 2005 May 1;125(1):49-55.
[A1] Davis JM, Murphy EA, Carmichael MD, Davis B. Quercetin increases brain and muscle mitochondrial biogenesis and exercise
tolerance.Am J Physiol Regul Integr Comp Physiol. 2009 Feb 11.
__________________________________________________________________________________________________
The aerial part of Proustia pyrifolia has antiinflammatory, analgesic and antioxidant activities The extract of this
plant is found to contain beta-sitosterol, quercetin and dihydroquercetin. [30] Then what is quercetin?
Quercetin is a bioflavonoid. Quercetin is a natural antioxidant found mainly in red wine grapefruit, onions, apples
and black tea. Quercetin protects cells in the body from damage by free radicals, [12-14] quercetin might have
benefits against heart attacks and strokes. Quercetin may also help prevent immune cells from releasing
histamine, the chemical that initiates the itching, sneezing, and swelling of an allergic reaction. Thus, quercetin
benefits are more on allergies such as hay fever, hives, eczema and asthma.
______________________________________________________________________________________
Quercetin Benefits
Quercetin benefits on performance
Researchers found that quercetin intake led to changes in mitochondrial capacity in an animal study. These
changes in mitochondrial capacity were associated with an increase in both maximal endurance capacity and
voluntary wheel running activity. These quercetin benefits on fitness without exercise training may have important
implications for enhancement of athletic and military performance and may also extend to prevention and
treatment of chronic diseases. [A1]
Quercetin benefits against allergy, inflammnation and infection
Asthma incidence was lower at high quercetin intakes. [28] Quercetin may address the inflammatory component
of asthma. Quercetin prevents certain immune cells from releasing histamine. Histamine is a chemical that
triggers an allergic reaction. [1-4] One study shows quercetin might help prostatitis, an inflammation or infection
of the prostate gland. [5], while another study shows quercetin supplementation reduced symptoms of interstitial
cystitis [6] Quercetin even seems to be able to prevent certain viruses from infecting cells from cell studies. [22-
23]
Quercetin benefits on heart diseases, stroke and aggregation
Quercetin might help prevent heart diseases and stroke. [7-10] Quercetin has inhibitory properties of blood
platelet aggregation (clumping). [11]
Quercetin benefits on cancer
Quercetin might have cancer preventive properties, based on some in vitro and animal studies. [15-19]
Topotecan has cytotoxic activity against both of the breast cancer cell lines in vitro. A combination with Quercetin
increases efficacy of Topotecan in the treatment of breast cancers. [31]
Quercetin benefits on cancer, diabetes and cataracts.
A trend toward a reduction in risk of type 2 diabetes is associated with higher quercetin intake. [20] Further,
quercetin might protect rodents with diabetes from forming cataracts. [21]
__________________________________________________________________________________
Quercetin bromelain
Bromelain is an enzyme complex derived from the pineapple stem. Bromelain may assist the absorption of
quercetin in the G.I. tract. [25] Consequently there are two popular quercetin products - "quercetin bromelain"
and activated quercetin.
Quercetin and bromelain both have inhibitory properties of blood platelet aggregation (clumping). Consequently,
manufacturers are interesting to put them together in the product. [25-26]
ACTIVATED QUERCETIN Source Naturals Activated Quercetin is probably the most advertised quercetin product
over the internet. It is a blend of quercetin, magnesium ascorbate, and bromelain.
Activated Quercetin is actually a state-of-the-art quercetin complex. It is advertised that the additional ingredients
can maximize the absorption and benefits of quercetin. Thus, quercetin is thought to be a potent formula.
___________________________________________________________________________
Quecetin Side Effects
Most supplements have benefits and side effects. However, the severity and type of side effects vary from users
to users. Dr. Ray Sahelian says, "Quercetin side effects have not been reported in the medical literature...
Quercetin side effects with long term supplementation... is not known" (September 10, 2011).
According to Webmd.com, quercetin is probably safe up to dosage of 500 mg twice daily for 12 weeks. The
quecetin side effects may include headache and tingling of the arms and legs. Very high doses might cause
kidney damage. (September 10, 2011) While Sloan-Kettrering says, "No adverse effects have been reported with
single oral doses up to 4 grams." Papain and bromelain may support the absorption of quercetin in the intestine.
Drug interaction was also found with quercetin products. Quercetin raises the bioavailability of ditiazem
significantly. [24]
___________________________________________________________________________
Reference:
[1] Ogasawara H et al, Effect of selected flavonoids on histamine release (HR) and hydrogen peroxide (H2O2) generation by
human leukocytes [abstract]. J Allergy Clin Immunol. 1985;75(suppl):184. [2] Middleton E Jr. Effect of flavonoids on basophil
histamine release and other secretory systems. Prog Clin Biol Res. 1986;213:493–506.] [3] Knekt P et al, Flavonoid intake and
risk of chronic diseases. Am J Clin Nutr. 2002 Sep;76(3):560-8.] [4] Miller AL. The etiologies, pathophysiology, and
alternative/complementary treatment of asthma. Altern Med Rev. 2001 Feb;6(1):20-47. [5] Shoskes DA et al. Quercetin in men with
category III chronic prostatitis: a preliminary prospective, double-blind, placebo-controlled trial. Urology. 1999;54:960–963.][6]
Rodriguez LV et al. Treatment of interstitial cystitis with a quercetin containing compound: a preliminary, double-blind placebo
control trial. Presented at: American Urological Association 2001 Annual Meeting; June 2–7, 2001; Anaheim, Calif][7] Constant J.
Alcohol, ischemic heart disease, and the French paradox. Coron Artery Dis. 1997;8:645–649. [8] Hayek T et al, Reduced
progression of atherosclerosis in apolipoprotein E-deficient mice following consumption of red wine, or its polyphenols quercetin
or catechin, is associated with reduced susceptibility of LDL to oxidation and aggregation. Arterioscler Thromb Vasc Biol. 1997;17:
2744–2752. [9] Frankel EN et al Inhibition of human LDL oxidation by resveratrol. Lancet. 1993;341:1103–1104. Alliangana DM.
Effects of beta-carotene, flavonoid quercetin and quinacrine on cell proliferation and lipid peroxidation breakdown products in BHK-
21 cells. East Afr MedJ. 1996;73:752–757. [10] Keli SO et al. Dietary flavonoids, antioxidant vitamins, and incidence of stroke: the
Zupthen study. Arch Intern Med. 1996;156:637–642. [11] [Beretz, et al, “Role of cyclic AMP in the inhibition of human platelet
aggregation by quercetin, a flavonoid that potentiates the effect of prostacyclin.” Biochemical Pharmacology 1981;31(22):3597-600.
[12] Quercetin protects LDL from oxidation by lipid peroxides and transition metal ions. Oxidized LDL is absorbed by macrophages
and arterial endothelial cells, eventually leading to plaque deposits in arterial walls. [13] Afanas’ev, I.B. et. al., “Chelating and free
radical scavenging mechanisms of inhibitory action of rutin and quercetin in lipid peroxidation.” Biochemical Pharmacology 1989;
38(11):1763-69. [14] De Whalley, C.V., “Flavonoids inhibit the oxidative modification of low density lipoproteins by macrophages.”
Biochemical Pharmacology 39(11):1743-50.][15] Balasubramanian S, Govindasamy S. Inhibitory effect of dietary flavonol quercetin
on 7,12-dimethylbenz[a]anthracene-induced hamster buccal pouch carcinogenesis. Carcinogenesis. 1996;17:877–879. [16]
Cross HJ et al. Effect of quercetin on the genotoxic potential of cisplatin. Int J Cancer. 1996;66:404–408. [17] Hoffman R et al.
Enhanced anti-proliferative action of busulphan by quercetin on the human leukaemia cell line K562. Br J Cancer. 1989;59:347–
348. [18] ElAttar TM et al. Modulating effect of resveratrol and quercetin on oral cancer cell growth and proliferation. Anticancer
Drugs. 1999;10:187–193. [19] Yoshida M et al. Quercetin arrests human leukemic T-cells in late G1 phase of the cell cycle.
Cancer Res. 1992;52:6676–6681. [20] Knekt P., Flavonoid intake and risk of chronic diseases. Am J Clin Nutr. 2002 Sep;76(3):
560-8.] [21] Varma SD et al. Diabetic cataracts and flavonoids. Science. 1977;195:205–206] [22] Kaul TN et al. Antiviral effect of
flavonoids on human viruses. J Med Virol. 1985;15:71–79. [23] Musci I, Pragai BM. Inhibition of virus multiplication and alteration of
cyclic AMP level in cell cultures by flavonoids. Experientia. 1985;41:930–931.] [24] Choi JS. Enhanced diltiazem bioavailability after
oral administration of diltiazem with quercetin to rabbits. Int J Pharm. 2005 Jun 13;297(1-2):1-8. [25] Hollma, P. et. al., “Absorption
of dietary quercetin glycosides and quercetin in healthy ileostomy volunteers.” Am. J. Clin. Nutr. 1995;62:1276-82.][25] Beretz, et al,
“Role of cyclic AMP in the inhibition of human platelet aggregation by quercetin, a flavonoid that potentiates the effect
of prostacyclin.” Biochemical Pharmacology 1981;31(22):3597-600. [26] Heinicke et al “Effect of bromelain (Ananase®) on
human platelet aggregation. ”Experientia 1972;28(7):844] [27] Ebeler SE et al, Animal models and analytical approaches for
understanding the relationships between wine and cancer. Drugs Exp Clin Res. 2005;31(1):19-27.[30] Delporte C, Analgesic-
antiinflammatory properties of Proustia pyrifolia. J Ethnopharmacol. 2005 May 13;99(1):119-24.[31] Akbas SH et al, The effect of
quercetin on topotecan cytotoxicity in MCF-7 and MDA-MB 231 human breast cancer cells. J Surg Res. 2005 May 1;125(1):49-55.
[A1] Davis JM, Murphy EA, Carmichael MD, Davis B. Quercetin increases brain and muscle mitochondrial biogenesis and exercise
tolerance.Am J Physiol Regul Integr Comp Physiol. 2009 Feb 11.
__________________________________________________________________________________________________
| Quercetin side effects, quercetin benefits, quercetin bromelain September 10, 2011 Zhion@zhion.com |
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This website discusses the benefits and side effects of various supplements, herbs and drug products.
Different people may experience different side effects and benefits of a product. You are encouraged to report
adverse side effects to FDA, its website is www.fda.gov., or report the adverse side effects to the
manufacturer, you should be able to find the contact information on the label.
There are always new information. Please, send me an email (zhion@zhion.com) to correct my mistake(s).
Reasonable care has been taken in preparing this document and the information provided herein is believed
to be accurate. The information is not intended to be a substitute for professional medical advice. It is
important to seek the advice of a physician about any medical condition or symptom or the benefits and side
effects of a supplement or a drug product. Finally, please, do not transfer the article to other website. Thank
you. ALL RIGHTS RESERVED.
Different people may experience different side effects and benefits of a product. You are encouraged to report
adverse side effects to FDA, its website is www.fda.gov., or report the adverse side effects to the
manufacturer, you should be able to find the contact information on the label.
There are always new information. Please, send me an email (zhion@zhion.com) to correct my mistake(s).
Reasonable care has been taken in preparing this document and the information provided herein is believed
to be accurate. The information is not intended to be a substitute for professional medical advice. It is
important to seek the advice of a physician about any medical condition or symptom or the benefits and side
effects of a supplement or a drug product. Finally, please, do not transfer the article to other website. Thank
you. ALL RIGHTS RESERVED.
