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41.
Chromium(III) is often claimed to have a positive effect on body composition, while the responses in researches with supplementation
of different chemical form of chromium are various and inconsistent. We have studied the effects of 6 weeks of treatment with
three different forms of chromium (300 μg/kg) as chromium chloride, chromium tripicolinate, and chromium nanocomposite (CrNano)
on growth, body composition, serum parameters, and tissue chromium in rats. The supplementataion of CrNano significantly increased
average daily gain, food efficiency, and lean body mass and decreased fat mass and body fat proportion and serum levels of
glucose, urea nitrogen, triglyceride, and insulin. Chromium contents in liver, kidney, and hind leg muscle were increased
significantly with the addition of CrNano in diet. The results indicate that chromium nanocomposite has higher efficacy on
growth and body composition compared to the traditional chromium agents. 相似文献
42.
Chelation therapy and supplemental Cr have both been shown to lead to improved blood glucose, lipids, and insulin activity.
Chelation therapy leads to the removal of toxic as well as essential metals. To determine if chelation therapy leads to increased
urinary Cr losses and altered Cr homeostasis, 2 groups of subjects (1 group that had undergone only 1 or no chelation therapy
and 1 group in which all subjects had undergone at least 19 chelation sessions) were evaluated for differences in possible
Cr homeostasis based on urinary Cr losses. There were no significant differences in urinary Cr losses between the two groups
of subjects and there were no significant increases in urinary Cr losses resulting from chelation therapy. Increases in urinary
Cr losses were strongly influenced by supplementation but not chelation therapy. 相似文献
43.
E. Rodriguez R. Azevedo C. Remédios T. Almeida P. Fernandes C. Santos 《Journal of plant physiology》2013
Chromium (Cr), as a mutagenic agent in plants, has received less attention than other metal pollutants. To understand if Cr induces microsatellite instability (MSI), Pisum sativum seedlings were exposed for 28 days to different concentrations of Cr(VI) up to 2000 mg L−1, and the genetic instability of ten microsatellites (SSRs) was analyzed. In plants exposed to Cr(VI) up to 1000 mg L−1, MSI was never observed. However, roots exposed to 2000 mg L−1 displayed MSI in two of the loci analyzed, corresponding to a mutation rate of 8.3%. SSR2 (inserted in the locus for plastid photosystem I 24 kDa light harvesting protein) and SSR6 (inserted in the locus for P. sativum glutamine synthetase) from Cr(VI)-treated roots presented alleles with, respectively, less 6 bp and more 3 bp than the corresponding controls. This report demonstrates that: (a) SSRs technique is sensitive to detect Cr-induced mutagenicity in plants, being Cr-induced-MSI dose and organ dependent (roots are more sensitive); (b) two Cr-sensitive loci are related with thylakoid photophosphorylation and with glutamine synthetase, respectively; (c) despite MSI is induced by Cr(VI), it only occurs in plants exposed to concentrations higher than 1000 mg L−1 (values rarely found in real scenarios). Considering these data, we also discuss the known functional changes induced by Cr(VI) in photosynthesis and in glutamine synthetase activity. 相似文献
44.
45.
BackgroundChromium picolinate (CrPic) and vitamin D3 are known as two antioxidant micronutrients. Through inducing endothelial dysfunction, oxidants such as homocysteine (Hct) and malondialdehyde (MDA) lead to cardiovascular disease in type 2 diabetes mellitus (T2DM). No published data has directly examined the effects of these two antioxidants on improving the endothelial dysfunction in T2DM throughreducing homocysteine and oxidative stress.MethodsSubjects (n = 92) in this randomized, double blind, placebo-control study were randomly assigned to receive oral placebo (group I), D3 (group II: 50,000 IU/ week), chromium picolinate (CrPic) (group III: 500 μg/day), and both vitamin D3 and CrPic (group IV) for four months. Fasting blood samples were drawn at study baseline and following intervention to determine Hct, MDA, total antioxidant capacity (TAC), total thiol groups (SHs), vascular cell adhesion molecule- 1 (VCAM-1), and plasminogen activator inhibitor-1 (PAI-1).ResultsAfter intervention, MDA significantly decreased in groups II and IV; TAC significantly increased in group IV, and SHs significantly augmented in group III; Hct was significantly reduced in groups II, III, and IV; and VCAM-1 significantly decreased in groups III and IV and PAI-1 was significantly reduced in groups II, III, and IV.ConclusionOur findings suggest that through reducing homocysteine and oxidative stress and improving endothelial dysfunction, chromium and vitamin D3 co-supplementation might be predictive and preventive of cardiovascular diseasesassociated with T2DM.IRCT, IRCT20190610043852N1, registered 21 October 2019, https://fa.irct.ir/user/trial/42293/view 相似文献
46.
The high-energy intraconfigurational spin-forbidden bands expected in the region of 20 000 cm−1 have been uncovered in the spectra of a number of trans-diacidobis(ethylenediamine) chromium(III)complexes. These bands have been fitted to the quadrate components of the cubic transition 4A2g → 2T2g including spin-orbit interaction. Two interconfigurational spin-forbidden bands in the spectrum of trans-[Cr(en)2(dmf)2](ClO4)3 have been uncovered and interpretted. 相似文献
47.
Sinam G Behera SK Mishra RK Sinha S Mallick S Khare PB 《International journal of phytoremediation》2012,14(7):629-642
Study was undertaken to compare Cr accumulation in two ferns (Adiantum capillus-veneris Linn. and Microsorium punctatum (Linn.) Copel) and the role of antioxidants were also investigated towards metal tolerance in order to assess the use of ferns in phytomediation/ phytostabilization. Different concentrations (0, 50, 100, 150 microg g(-1) dw) of Cr were added to fern planted in pot containing 1 kg soil. In both the ferns, Cr accumulation increased with increase in metal concentration and maximum accumulation of 800.5 microg g(-1) (fronds) and 1457.4 microg g(-1) (roots) in M. punctatum and 660.8 microg g(-1) (fronds) and 1259.6 microg g(-1) (roots) in A. capillus-veneris was recorded. The increase in the levels of malondialdehyde, antioxidants and antioxidant enzymes (superoxide dismutase, glutathione peroxidase) in A. capillus-veneris was less pronounced than M. punctatum under Cr exposure as compared to their respective controls. In view of less decrease in chlorophyll content and antioxidants along with higher accumulation of Cr in the fronds M. punctatum, is indicative of its higher tolerance towards Cr. However, bioaccumulation factor (concentration of Cr in fronds/concentration of Cr in the soil) of both the ferns was recorded > 1 which qualifies the plants as potential Cr hyperaccumulator and suitable for phytoremediaton. 相似文献
48.
Hugh H. Harris Aviva Levina Carolyn T. Dillon Irma Mulyani Barry Lai Zhonghou Cai Peter A. Lay 《Journal of biological inorganic chemistry》2005,10(2):105-118
Chromium(VI) is a human carcinogen, primarily affecting the respiratory tract probably via active transport into cells, followed by the reduction to Cr(III) with the formation of DNA-damaging intermediates. Distribution of Cr and endogenous elements within A549 human lung adenocarcinoma epithelial cells, following treatment with Cr(VI) (100 M, 20 min or 4 h) were studied by synchrotron-radiation-induced X-ray emission (SRIXE) of single freeze-dried cells. After the 20-min treatment, Cr was confined to a small area of the cytoplasm and strongly co-localized with S, Cl, K, and Ca. After the 4-h treatment, Cr was distributed throughout the cell, with higher concentrations in the nucleus and the cytoplasmic membrane. This time-dependence corresponded to ~100% or 0% clonogenic survival of the cells following the 20-min or 4-h treatments, respectively, and could potentially be explained by a new cellular protective mechanism. Such processes may also be important in reducing the potential hazards of Cr(III) dietary supplements, for which there is emerging evidence that they exert their anti-diabetic effects via biological oxidation to Cr(VI). The predominance of Cr(III) was confirmed by micro-XANES spectroscopy of intracellular Cr hotspots. X-ray absorption spectroscopy (XANES and EXAFS, using freeze-dried cells after the 0–4-h treatments) was used to gain insight into the chemical structures of Cr(III) complexes formed during the intracellular reduction of Cr(VI). The polynuclear nature of such complexes (probably with a combination of carboxylato and hydroxo bridging groups and O-donor atoms of small peptides or proteins) was established by XAFS data analyses.Electronic Supplementary Material Supplementary material is available for this article at 相似文献
49.
Ramírez-Ramírez R Calvo-Méndez C Avila-Rodríguez M Lappe P Ulloa M Vázquez-Juárez R Gutiérrez-Corona JF 《Antonie van Leeuwenhoek》2004,85(1):63-68
A Cr(VI)-resistant yeast was isolated from tanning liquors from a leather factory in Leon, Guanajuato, Mexico. Based on morphological and physiological analyses and the D1/D2 domain sequence of the 26S rDNA, the yeast was identified as Candida maltosa. Resistance of the strain to high Cr(VI) concentrations and its ability to chemically reduce chromium was studied. When compared to the three laboratory yeasts Candida albicans, Saccharomyces cerevisiae and Yarrowia lipolytica, the C. maltosa strain was found to tolerate chromate concentrations as high as 100 micro g/ml. In addition to this phenotypic trait, the C. maltosa strain showed ability to reduce Cr(VI). Chromate reduction occurred both in intact cells (grown in culture medium or in soil containing chromate) as well as in cell-free extracts. NADH-dependent chromate reductase activity was found associated with soluble protein and, to a lesser extent, with the membrane fraction. 相似文献
50.
Bennett R Adams B French A Neggers Y Vincent JB 《Biological trace element research》2006,113(1):53-66
Chromium is generally believed to be an essential element and is often claimed to have value as a weight loss or muscle building
agent. Recent studies in humans and rats have failed to demonstrate effects on body composition, although recent studies with
pharmacological doses of the cation [Cr(III)3O(O2CCH2CH3)6(H2O)3]+ (or Cr3) (≤1 mg Cr/kg body mass) in rats have noted a trend toward body mass loss and fat mass loss. Thus, the effects of
large gavage doses of Cr3 (1–10 mg Cr/kg) on body mass, organ mass, food intake, and blood plasma variables (insulin, glucose,
leptin, cholesterol, and triglycerides) were examined over a 10-wk period using male Sprague-Dawley rats. No effects on body
composition were noted, although Cr3 administration lowered (p<0.05) plasma insulin, leptin, and triglycerides concentrations. As Cr3 is absorbed greater than 10-fold better than commercially
available nutritional supplements, the lack of an effect of the Cr(III) compound at these levels of administration clearly
indicates that Cr(III) supplements do not have an effect on body composition at any reasonable dosage. 相似文献