Quercetin effects

Kaneider, N.C., Mosheimer, B., Reinisch, N., Patsch, J.R., and Wiedermann, C.J., Inhibition of thrombin-induced signaling by resveratrol and quercetin effects on adenosine nucleotide metabolism in endothelial cells and platelet-neutrophil interactions, Thromb. Res., 114, 185, 2004. 

DESCHNER E E, RUPERTO J F, WONG G Y and NEWMARK H L (1993) The effect of dietary quercetin and rutin on AOM-induced acute colonic epithelial abnormalities in mice fed a high-fat diet , Nutr Cancer, 20, 199-204. 

The effect of quercetin on cell cycle progression and growth of hiunan gastric cancer cells , Febs Lett, 260, 10-13. 

TERAO J, PiSKULA M and YAO Q (1994) Protective effect of epicatechin, epicatechin gallate, and quercetin on lipid peroxidation in phospholipid bilayers , Arch Biochem Biophys, 308, 278-84. 

Fig. 16.4 Interaction between quercetin (Quer) and iron and the balance between pro-oxidative and antioxidative effects. Quercetin may reduce Fe(H20) to yield Fe(H20) active in the Fenton region forming hydroxyl radicals ( OFI) or alkoxyl radicals ( OR), in effect being pro-oxidative. In contrast, quercetin may form a complex with iron(II), inactive in reducing FI2O2 to OFI, but rather oxidised in the quercetin ligand, in effect being antioxidative. Quer (-H) is the phenoxyl radical.

In the water-like solvent tert-butyl alcohol, a-tocopherol was found to prevent lipid oxidation, showing a distinct lag-phase for oxygen consumption. This was in contrast to quercetin or epicatechin, which were only weak retarders of lipid oxidation without any clear antioxidative effect. Quercetin or epicatechin, when combined with a-tocopherol, increased the lag-phase for oxygen consumption as seen for a-tocopherol alone. The stoichiometric factor for a-tocopherol, a-TOH, as chain-breaking antioxidant has the value n = 2 according to the well-established mechanism ... 

Flavonoids are chain-breaking antioxidants in lipid-like solvents like chlorobenzene, although the k(inh) is smaller than for a-tocopherol and the lag-phase accordingly less evident. For peroxidating lipids in chlorobenzene the clear lag-phase for a-tocopherol became longer when quercetin or catechin were present. The effect appears to be additive and a regeneration of a-tocopherol by quercetin or catechin in this lipid-like solvent should rather be termed a co-antioxidative effect (Pedrielli and Skibsted, 2002). 

PEDRiELLi p and SKIBSTED L H (2002) Antioxidant syneigy and regeneration effect of quercetin, (-)epicatechin, and (+)-catechin on a-tocopherol in homogeneous solutions of peroxidating methyl linoleate, JAgric Food Chem, 50, 7138-44. 

PEDRIELLI p, PEDULLi G F and SKIBSTED L H (2001a) Antioxidant mechanism of flavonoids. Solvent effect on rate constant for chain-braining reaction of quercetin and epicatechin in autoxidation of methyl linoleate, JAgric Food Chem, 49, 3034-40. 

Effects of Allelochemlcals on ATPases. Several flavonoid compounds inhibit ATPase activity that is associated with mineral absorption. Phloretin and quercetin (100 pM) inhibited the plasma membrane ATPase Isolated from oat roots (33). The naphthoquinone juglone was inhibitory also. However, neither ferulic acid nor salicylic acid inhibited the ATPase. Additional research has shown that even at 10 mM salicylic acid inhibits ATPase activity only 10-15% (49). This lack of activity by salicylic acid was substantiated with the plasma membrane ATPase Isolated from Neurospora crassa (50) however, the flavonols fisetln, morin, myricetin, quercetin, and rutin were inhibitory to the Neurospora ATPase. Flavonoids inhibited the transport ATPases of several animal systems also (51-53). Thus, it appears that flavonoids but not phenolic acids might affect mineral transport by inhibiting ATPase enzymes. 

The plant is known elaborate a series of quite unusual phenanthrene alkaloid derivatives, of which aristoliukine-C, aristofolin A and E, aristolochic acid-la methyl ester, and aristolochic acid. Other chemical constituents found in this plant are flavonoid glycosides such as kaempferol-3-O-rutinoside and quercetin kaempferol-3-O-rutinoside (3,4). Exposure to Aristolochiaceae family is associated with the development of cancer in humans. A significant advance is the toxicological effects of aristolochic acid has been provided by the work of Pezzuto et al. They showed that aristolochic acid is a mutagen... 

Mild extraction was also found to be effective in the analysis of extracts of Flaveria haumanii, l in which quercetin, kaempferol, isorhamnetin as well as their glycosides and sulfate esters were identified. The obtained results were useful in the identification of the colourants from fibres from pre-Columbian Andean textiles extracted with the use of water-methanol solution with formic or hydrochloric acid. The components of each extract were separated on a reversed phase HPLC column and the eluates were monitored at... 

Mertens-Talcott SU, Bomser JA, Romero C, Talcott ST and Percival SS. 2005. Ellagic acid potentiates the effect of quercetin on p21wafl/cipl, p53, and MAP-kinases without affecting intracellular generation of reactive oxygen species in vitro. J Nutr 135 609—614. 

Red wine contains quercetin, rutin, catechin, and epicatechin, among other flavonoids (Frankel and others 1993). Quercetin and other phenolic compounds isolated from wines were found to be more effective than a-tocopherol in inhibiting copper-catalyzed LDL oxidation. It has been determined that quercetin has also several anti-inflammatory effects it inhibits inflammatory cytokine production (Boots and others 2008), inducible NO synthase expression and activation of inflammatory transcription factors (Hamalainen and others 2007), and activity of cyclooxygenase and lipooxygenase (Issa 2006), among others. 

On patients with cancer, the effects of green tea catechins, soy isoflavones and quercetin as chemoprotective/chemotherapeutic agents have also been studied. Although results have not been entirely satisfactory, a partial response has been achieved in some trials. For example, small decreases in plasma concentration of prostate-specific antigen were observed in prostate cancer patients who consumed soy isoflavones. Nevertheless, results in individuals with premalignant disease who consumed green tea polyphenols support their advancement into phase III clinical intervention trials aimed at the prevention of PIN, leukoplakia, or premalignant cervical disease (Thomasset and others 2006). 

Balasubramanian S, Govindasamy S. 1996. Inhibitory effect of dietary flavonol quercetin on 7,12-dimethylbenz[a]anthracene-induced hamster buccal pouch carcinogenesis. Carcinogenesis 17(4) 877-879. 

Boots AW, Haenen GRMM and Bast A. 2008. Health effects of quercetin From antioxidant to nutraceutical. 

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