Quercetin dietary

A toxic component of braken fern, perhaps either quercetin (105) or ptaquiloside, a glucoside (106), has a mixed history of carcinogenicity. It is sometimes impHcated in an increased incidence of bladder cancer in animals and esophageal cancer in humans. Multiple other dietary components seem to either promote or interfere with its action, and the significance of braken fern in human carcinogenesis remains unproven. 

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. 

HOLLMAN P 0 H, DE VRIES J H M, VAN LEEUWEN S D, MENGELERS M J B and KATAN M B (1995) Absorption of dietary quercetin glycosides and quercetin in healthy ileostomy volunteers. Am J Clin Nutr 62, 1276-82. 

Walle, T. Vincent, T. S. Walle, U. K. Evidence of covalent binding of the dietary flavonoid quercetin to DNA and protein in human intestinal and hepatic cells. Biochem. Pharmacol. 2003, 65, 1603-1610. 

Complementary and alternative medicine therapies, such as acupuncture, biofeedback, chiropractic manipulation, dietary supplements, herbal therapy, and homeopathic preparations, are used by individuals with allergic rhinitis.29,30 Use of bromelain, gingko, ginseng, licorice, quercetin, and Urtica dioica has been reported, but large-scale studies documenting efficacy are lacking.31,32 Caregivers should inquire routinely about patients use of alternative therapies and counsel patients about the lack of validated data to support such practices.12... 

Hollman PC, van Trijp JM, Mengelers MJ, de Vries JH and Katan M B. 1997. Bioavailability of the dietary antioxidant flavonol quercetin in man. Cancer Lett 114(1—2) 139—140. 

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. 

The application of flavonoids for the treatment of various diseases associated with free radical overproduction is considered in Chapter 29. However, it seems useful to discuss here some studies describing the activity of flavonoids under certain pathophysiological conditions. Oral pretreatment with rutin of rats, in which gastric lesions were induced by the administration of 100% ethanol, resulted in the reduction of the area of gastric lesions [157]. Rutin was found to be an effective inhibitor of TBAR products in the gastric mucosa induced by 50%i ethanol [158]. Rutin and quercetin were active in the reduction of azoxymethanol-induced colonic neoplasma and focal area of dysplasia in the mice [159], Chemopreventive effects of quercetin and rutin were also shown in normal and azoxymethane-treated mouse colon [160]. Flavonoids exhibited radioprotective effect on 7-ray irradiated mice [161], which was correlated with their antioxidative activity. Dietary flavones and flavonols protected against the toxicity of the environmental contaminant dioxin [162], Rutin inhibited ovariectomy-induced osteopenia in rats [163],... 

Because of the advantageous dietary effects of flavonoids they have been vigorously investigated in food and food products. The objectives of these measurements were the separation and quantitation of well-known flavonoids in foods and the identification of new flavonoids. An HPLC-ESI MS method has been developed for the isolation and identification of new quercetin derivatives in the leaves of Eruca sativa (Mill). Fresh leaves (500g) were homogenized with 1 200 ml of methanol-water (7 3, v/v), the suspension was macerated for 24h at ambient temperature, then it was filtered, concentrated to 50 ml and diluted with water to 500 ml. The extract was applied to an Amberlite XAD-2 column (75 X 8cm i.d.) and was washed subsequently with 11 of water and 11 of diethyl ether. The glucoside fraction was eluted with 1.51 of methanol and the eluate was concentrated in vacuum and liophilized. 

Several dietary flavonoid intake studies have now been completed using the Dutch composition data often with additional estimates of flavonoid content of local food preferences such as berries (Table 4.14). Comparison of these intake studies indicates that quercetin is consistently the main contributor to flavonol and flavone intake. In the Netherlands, for example, quercetin accounts for 70% of the 23 mg/day total flavonol and flavone intake followed by kaempferol (17%), myricetin (6%), luteolin (4%), and apigenin (3%). ... 

The flavonoid database described in this chapter was applied to 4-day weighed food records obtained from healthy Scottish men n = 41) and women ( = 52) to provide a provisional estimate of flavonoid intake in Scotland. All subjects consumed foods containing flavonols, procyanidins, and catechins, dietary intakes of which are given in Table 4.15. The main flavonol consumed was quercetin, accounting for 66 and 63% of the total flavonol intake of 18.8 mg/day. Primary sources of flavonols were from black tea (42.7%), onions (14.3%), apples (10.2%i), and lager (7.2%i) (Table 4.16). 

Aral, Y. et al.. Dietary intakes of flavonols, flavones and isoflavones by Japanese women and the inverse correlation between quercetin intake and plasma LDL cholesterol concentration, J. Nutr., 130, 2243, 2000. 

Terao, J., Murota, K., and Moon, J.-H., Quercetin glucosides as dietary antioxidants in blood plasma modulation of their function by metabolic conbversion, in Free Radicals in Chemistry, Biology and Medicine, Yoshikawa, T., Toyokuni, Y., Yamamoto, Y., and Naito, Y., Eds., OIAC International, London, 2000, p. 50. 

Walgren, R.A., Lin, J.T., Kinne, R.K., and Walle, T., Cellular uptake of dietary flavonoid quercetin 4 -(3-glucoside by sodium-dependent glucose transporter SGLTl, J. Pharmacol Exp. Ther., 294, 837, 2000. 

Ciolino, H.P., Daschner, P.J., and Yeh, G.C., Dietary flavonoids quercetin and kaempferol are ligands of aryl hydrocarbon receptor that affect CYPlAl differentially, Biochem. J., 340, 715, 1999. 

Lesser, S., Cermak, R., Wolffram, S. (2004). Bioavailability of quercetin in pigs is influenced by the dietary fat content. Journal of Nutrition, 134, 1508-1511. 

We have recently analysed the effects of an oral dose of quercetin, the most abundant dietary flavonoid, on the hypertension, oxidant status and renal, cardiac and vascular alterations induced in rats by chronic inhibition of NO synthesis with N-nitro L-arginine methylester (L-NAME). Administration of this NO synthase inhibitor to rats for six weeks induced a progressive increase in systolic blood pressure, but concomitant administration of an oral daily dose of quercetin (10 mg Kg 1) inhibited the development of hypertension induced by L-NAME (Duarte et al, 1999, Meth. Find. Exp. Clin. Pharmacol. 21 (suppl. A), 40). Moreover, when... 

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