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Objective: This study was conducted to evaluate blood concentrations of inflammatory cytokines and oxidative stress-related biomarkers as risk factors of breast cancer and to determine the relation between these markers and antioxidant nutrient intake., Methods: Study subjects were 134 patients with breast cancer and 149 controls. Total antioxidant capacity and concentrations of 8-isoprostane, 8-hydroxy-2'-deoxyguanosine, interleukin (IL)-1β, IL-6, and IL-8 of blood samples were determined. A food-frequency questionnaire was used to assess nutrient intake., Results: Patients with breast cancer had significantly higher blood levels of oxidative stress markers compared with control subjects. Plasma concentrations of IL-1β and IL-6 were significantly higher in patients with breast cancer compared with those of control subjects. In the pooled analysis, total antioxidant capacity was significantly decreased with increasing quartiles of carbohydrate intake but was increased with increasing quartiles of total vitamin A intake and vitamin C intake. In addition, 8-hydroxy-2'-deoxyguanosine concentration was decreased with increasing quartiles of vitamin A and β-carotene. No significant association was found between nutrient intake and cytokine concentrations., Conclusions: These results suggest that oxidative stress and inflammation may be associated with the risk of breast cancer. Total vitamin A intake was negatively related to oxidative stresses, possibly modifying the risk of breast cancer., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Purpose: We investigated the effects of quercetin on renal tubular cell injury induced by oxalate and the inhibitory effects of quercetin on urinary crystal deposit formation in an animal model., Materials and Methods: MDCK cells (American Type Culture Collection, Manassas, Virginia) were incubated with different concentrations of oxalate with and without quercetin. MTT (Sigma) assays for cell viability, malondialdehyde and catalase activity were measured to investigate the antioxidant effect of quercetin. Male Sprague-Dawley rats were divided into 3 groups. Group 1 was fed standard rat chow. Groups 2 and 3 rats were fed standard chow supplemented with 3% sodium oxalate for 4 weeks. For the first 8 days in 4 weeks each rat in groups 2 and 3 also received gentamicin intramuscularly. Additionally, group 3 rats were administered quercetin for 4 weeks. Rats were sacrificed after 4 weeks, after which 24-hour urine collections and kidney removal were performed. In the renal tissue malondialdehyde, superoxide dismutase and catalase activity was measured. Bisected kidneys were examined under microscopy to determine the number of crystals., Results: The viability of MDCK cells significantly decreased and malondialdehyde production increased in the presence of oxalate. However, co-exposure to quercetin inhibited the decrease in cell viability and inhibited the lipid peroxidation production induced by oxalate. In the animal study malondialdehyde production in group 3 significantly decreased compared to that in group 2. Catalase and superoxide dismutase activity was increased in group 3 compared to that in group 2. The number of crystals in kidneys in group 3 was decreased significantly compared to that in group 2., Conclusions: Quercetin has an inhibitory effect on urinary crystal deposit formation.

Objective: Epidemiological studies have suggested beneficial effects of dietary polyphenols in reducing the risk of chronic diseases. This study was performed to investigate the effects of polyphenol-depleted and polyphenol-rich diets on blood oxidative stress markers and urinary excretions of major phenols., Methods: Nineteen healthy female non-smokers 19 to 21 years of age took part in the study, which consisted of two dietary intervention periods separated by three days. Experimental diets were composed of common foods selected to comply with low contents of polyphenols for phenol-depleted intervention and high contents of polyphenols for phenol-rich diets. Blood and urine samples were collected on day 0, 3 and 6 of each intervention. Duplicate portions of foods provided to the subjects were also collected. Blood oxidative stress markers included plasma antioxidant vitamins, erythrocyte superoxide dismutase (SOD) activity and lymphocyte DNA damage. Urinary excretions of major phenols were measured to affirm bioavailability of dietary phenols., Results: Plasma alpha-tocopherol and beta-carotene concentrations were slightly decreased on day 3 and 6 of the phenol-depleted dietary intervention period, although no change was observed with phenol-rich diets. The erythrocyte SOD activity was also slightly decreased during phenol-depleted dietary intervention. However, at day 6 of the phenol-rich intervention, the activity of SOD was significantly increased by 41%. Tail moment and tail length of lymphocyte DNA as markers of DNA damage were higher on day 6 of phenol-depleted intervention, although only tail moment showed a statistical significance. The average intakes of quercetin and kaempferol during the phenol-rich intervention were 21 mg/day and 9 mg/day, respectively. The average urinary excretion rates during phenol-rich intervention were 2.06% for quercetin and 0.46% for kaempferol. There were positive correlations between erythrocyte SOD activity and urinary concentration of quercetin or kaempferol., Conclusions: These results suggest that polyphenol-rich diets may decrease the risk of chronic diseases by reducing oxidative stress.

Abstract: Objective: This study was performed to evaluate the effects of high vegetable–fruit (high-VF) and low vegetable–fruit (low-VF) diet on surrogate biomarkers of adiposity-related metabolic disturbances. Methods: Overweight women (n=22, 19–29years) participated in the study between July and August, 2007 in Seoul, Korea. The intervention consisted of either high-VF diet (12 servings of VF/day) or low-VF diet (2 servings of VF/day). Plasma concentration of carotenoids and biomarkers of inflammation and oxidative stress were determined before and after each intervention period. Results: Study results indicated that body fat content is positively correlated with plasma interleukin (IL)-6, C-reactive protein (CRP), and leptin concentrations at baseline. Oxidative DNA damage and lipopolysaccharide (LPS)-activated production of IL-1β and IL-6 in peripheral blood mononuclear cells (PBMCs) were decreased with high-VF diet while low-VF diet increased those markers. Changes in the concentration of plasma total carotenoid and β-carotene were inversely correlated with change in plasma IL-1β concentration. Differences in IL-β production in LPS-activated PBMCs were inversely correlated with changes in plasma concentration of lutein–zeaxanthin. Also, changes in plasma total carotenoid and lycopene concentration were inversely correlated with the changes in IL-6 production in LPS-activated PBMCs. Conclusion: Daily intake of vegetables and fruits can modify adiposity-related metabolic disturbances. [Copyright &y& Elsevier]