1,721,051 research outputs found
O-GLcNACase as biomarker of antioxidant status in healty women under isoflavones supplementation
No full textConsumption of soy has been correlated to a lower incidence of chronic diseases, among which CVD characterized by a high oxidative stress, that has been partially attributed to isoflavone (IF) intake. We evaluated the antioxidant effects of 80 mg/d of total IF supplementation in 13 healthy women (age 29 ± 8) for 6 months followed by 2 months of suspension; blood samples were collected every two months (T=0, 1, 2, 3 and 4). Plasma concentrations of IF, RBC activities of O-GlcNAcase, considered good marker of cellular stress, and of cytosolic hesosaminidase (Hex-c), total plasma antioxidant capacity (Lag-time), RBC membrane fluidity (rs) and DNA oxidative damage (comet assay) were evaluated. Statistical analysis were performed by ANOVA for repeated measure (p<0.05).
IF plasma concentrations and Lag-time increased (p<0.05) according to dietary intervention and rs increased at T=2 vs. T=1 and T=4 (p<0.05). DNA damage (due to H2O2) significantly decreased during supplementation, with a significant inverse correlation with plasma IF concentration. OGlcNAcase and Hex-c activities did not change after 2 months of IF supplementation, while they increased at T=2 and T=3 vs. T=1 (p<0.05). Results suggest a positive effect of IF supplementation against oxidative stress and confirm previous studies indicating O-GlcNAcase as a good tool for monitoring antioxidant status
Effect of the ratio of casein phosphopeptides to calcium (w/w) on passive calcium transport in the distal small intestine of rats
No full textWe investigated the influence of different ratios between casein phosphopeptides and calcium (CPP/Ca) in intestinal lumen on passive Ca transport across the distal small intestine of rats in vitro
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
The consumption of soy products positively affects DNA resistance to oxidative stress in healthy subjects
No full textAntioxidant Effect of Daidzein and Genistein in Human Primary Lymphocytes
No full textDifferent epidemiological studies on eastern population have suggested an inverse correlation between consumption of soybean products, source of isoflavones such as daidzein (D) and genistein (G), and development of some chronic diseases. It has been supposed that the mechanism of D and G could be related to their estrogenic or antioxidant activities although the latter has not been extensively investigated.
The main objective of the present study was to evaluate the antioxidant activity of D and G in ex-vivo, using human primary lymphocytes separated from peripheric blood of healthy subjects. To this aim we supplemented cells with D and G at different concentrations between 0,01 μM and 2,5 μM, for 24 hours; we chose this range considering that plasma concentration of isoflavones, in not habitual consumers of soybeans products is 0,04 μM, while in habitual consumers it is 6 μM. After supplementation we induced oxidative stress to DNA by treatment with H2O2 500 μM, and to cellular membrane by treatment with Fe2+ 100 μM. DNA and lipid oxidative damages were evaluated by the Comet Assay and MDA quantification in HPLC, respectively.
The results obtained in our conditions demonstrated that the concentrations between 2,5 μM and 0,05 μM of D and between 2,5 μM and 0,1 μM of G significantly decreased oxidative damage to DNA with respect to control cells (P<0.05): the concentration of 2,5 μM D and G seemed to offer most protection. Differently, the preventive effect of D and G against oxidative damage to cellular membrane has been demonstrated only with supplementation of 2,5 μM (P<0.05).
In conclusion these findings are consistent with an antioxidant activity of D and G in human primary lymphocytes especially with respect to DNA oxidative damage. Furthermore, since the protective effect of these isoflavones has been found with concentrations reachable in plasma of not habitual consumers of soybeans, it seems possible suggest a functional role of these compounds also in western population
Influence of organic acids on aluminium absorption and storage in rat tissues
No full textSix groups of 16 rats each were fed a standard diet for 8 weeks. Aluminium (Al) complexed with organic anions (citrate, lactate, malate, or tartrate) was added to the diet of four of the groups and aluminium hydroxide to the diet of one group (control 'Al +'). Aluminium concentrations in the diets were 1500-2000 mg/kg. The sixth group (control 'Al -') served as control. Plasma, bone (femur), kidneys, cerebral cortex and cerebellum levels of aluminium were determined at 4 and 8 weeks. All the complexing agents increased tissue accumulations, compared with values in the two control groups, especially citrate in bone and kidneys and lactate in cerebral cortex. There were no significant differences (P < 0.05) in aluminium levels in the tissues considered between the 'Al +' and 'Al -' control groups. Our results show the ability of dietary organic acids to increase aluminium absorption and tissue accumulation and indicate that concurrent intake of aluminium and dietary organic acids is not appropriate
Rapid determination of sodium in milk and milk products by capillary zone electrophoresis
Full text linkA capillary zone electrophoresis method for the determination of Na in milk and milk products was developed and compared with an International Organization
for Standardization/International Dairy Federation standard method that is based on flame atomic absorption spectrometry. The adoption of a background electrolyte consisting of 10 mM imidazole adjusted to
pH 3.75 by the addition of oxalic acid allowed baseline separation of Na from other milk cations and from Li ion, which was adopted as an internal standard. Method validation was performed and the results for linearity, precision, limit of detection, limit of quantification, and recovery are presented. The procedure was tested on commercial milk samples differing in fat content (whole, semiskimmed, and skimmed) and processing conditions (pasteurization, UHT sterilization, and microfiltration).
The reliability of the method was confirmed for different varieties of cheese and other milk products. The
method enables the routine measurement of Na content by a rapid and accurate capillary zone electrophoresis
procedure
Phytate/calcium molar ratio does not predict accessibility of calcium in ready-to-eat dishes
No full textBACKGROUND: Phytic acid (PA), a naturally occurring compound of plant food, is generally considered to affect mineral
bioavailability. The aim of this study was to investigate the reliability of the PA/calcium molar ratio as a predictive factor of
calcium accessibility in composed dishes and their ingredients.
RESULTS: Dishes were chosen whose ingredients were rich in Ca (milk or cheese) or in PA (whole-wheat cereals) in order to
consider a range of PA/Ca ratios (from 0 to 2.4) and measure Ca solubility using an in vitro approach. The amounts of soluble
Ca in composed dishes were consistent with the sum of soluble Ca from ingredients (three out of five meals) or higher. Among
whole-wheat products, bread showed higher Ca accessibility (71%, PA/Ca=1.1) than biscuits (23%, PA/Ca=0.9) and pasta (15%,
PA/Ca=1.5), and among Ca-rich ingredients, semi-skimmed milk displayed higher Ca accessibility (64%) than sliced cheese
(50%) and Parmesan (38%). No significant correlation between the PA/Ca ratio and Ca accessibility was found (P = 0.077).
CONCLUSION: The reliability of the PA/Ca ratio for predicting the availability of calcium in composed dishes is unsatisfactory;
data emphasized the importance of the overall food matrix influence onmineral accessibility
Supplementation of Jurkat T cells with green tea extract decreases oxidative damage due to iron treatment
No full textRegular tea consumption has been associated with a reduced risk of cancer. As demonstrated in vitro, green tea contains catechins with antioxidant properties. We evaluated the effect of the supplementation of the Jurkat T-cell line with green tea extract on oxidative damage. Cells grown in medium with or without green tea extract (10 mg/L) were treated with Fe(2+) (100 micromol/L) as an oxidative stimulus for 2 h. Cell membrane lipid peroxidation was evaluated by fatty acids pattern analysis and malondialdehyde production in alpha-linolenic acid-loaded cells. Furthermore, oxidative DNA damage (single strand breaks) was detected in cells by the Comet assay and quantified as relative tail moment (RTM). Supplementation with green tea extract significantly decreased malondialdehyde production (1.6 +/- 0.3 vs. 0.6 +/- 0.1 nmol/mg protein, P < 0.05) and DNA damage (0.32 +/- 0.07 vs. 0.12 +/- 0.04 RTM, P < 0.05) after Fe(2+) oxidative treatment. In control cells, there was no effect on membrane distribution of (n-3) fatty acids due to Fe(2+) treatment. Cell enrichment with alpha-linolenic acid increased total membrane (n-3) fatty acids. However, the oxidative treatment did not modify the distribution of polyunsaturated fatty acids. It is likely that the observed protective effects can be attributed to epigallocatechin gallate, which is present mainly (670 g/kg) in green tea extract; however, we cannot exclude contributions by other catechins. These data support a protective effect of green tea against oxidative damage
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