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Medical Forum / Diseases and Disorders / Diabetes / March 2008Kaempferol Attenuates Lipofuscin Accumulation
"Life prolonging activity of Kaempferol" Effects of the flavonoids kaempferol and fisetin on thermotolerance, oxidative stress and FoxO transcription factor DAF-16 in the model organism Caenorhabditis elegans by Andreas Kampkötter; Christiane Gombitang Nkwonkam; Ruben Felix Zurawski; Claudia Timpel; Yvonni Chovolou; Wim Wätjen; Regine Kahl (pp. 849-858). Flavonoids present in many herbal edibles possess a remarkable spectrum of biochemical and pharmacological actions and they are assumed to exert beneficial effects to human health. Although the precise biological mechanisms of their action has not been elucidated yet many of the protective properties of flavonoids are attributed to their antioxidative activity since oxidative stress is regarded as a main factor in the pathophysiology of various diseases and ageing. Oxidative stress results from excessive generation of reactive oxygen species (ROS) or diminished antioxidative defence and thus antioxidants are able to counteract such situations. We used the multicellular model organism Caenorhabditis elegans that is conserved in molecular and cellular pathways to mammals to examine the effects of the flavonoids kaempferol and fisetin with respect to their protective action in individual living worms. Both flavonoids increased the survival of C. elegans, reduced the intracellular ROS accumulation at lethal thermal stress, and diminished the extent of induced oxidative stress with kaempferol having a stronger impact. Kaempferol but not fisetin attenuated the accumulation of the ageing marker lipofuscin suggesting a life prolonging activity of this flavonoid. In addition to these effects that may be attributed to their antioxidative potential kaempferol and fisetin caused a translocation of the C. elegans FoxO transcription factor DAF-16 from the cytosol to the nucleus indicating a modulatory influence of both flavonoids on signalling cascade(s). Keywords: Caenorhabditis elegans ; Kaempferol; Fisetin; Stress resistance; DAF-16; Lipofuscin accumulation --------------------------------------------------- J. Phys. Chem. B, 112 (6), 1845 -1850, 2008. 10.1021/jp076881e S1520-6106(07)06881-2 Web Release Date: January 23, 2008 Copyright © 2008 American Chemical Society Complexation of Flavonoids with Iron: Structure and Optical Signatures Jun Ren, Sheng Meng, Ch. E. Lekka, and Efthimios Kaxiras* Department of Physics and School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, and Department of Materials Science and Engineering, University of Ioannina, Ioannina 45110, Greece Received: August 28, 2007 In Final Form: October 31, 2007 Abstract: Flavonoids exhibit antioxidant behavior believed to be related to their metal ion chelation ability. We investigate the complexation mechanism of several flavonoids, quercetin, luteolin, galangin, kaempferol, and chrysin, with iron, the most abundant type of metal ions in the body, through first-principles electronic structure calculations based on density functional theory (DFT). We find that the most likely chelation site for Fe is the 3-hydroxyl-4-carbonyl group, followed by 4-carbonyl-5-hydroxyl group and the 3'-4' hydroxyl (if present) for all of the flavonoid molecules studied. Three quercetin molecules are required to saturate the bonds of a single Fe ion by forming six orthogonal Fe-O bonds, though the binding energy per molecule is highest for complexes consisting of two quercetin molecules and one Fe atom, in agreement with experiment. Optical absorption spectra calculated with time-dependent DFT serve as signatures to identify various complexes. For the iron-quercetin complexes, we find a redshift of the first absorbance peak upon complexation in good agreement with experiment; this behavior is explained by the narrowing of the optical gap of quercetin because of Fe(d)-O(p) orbital hybridization. http://pubs.acs.org/cgi-bin/abstract.cgi/jpcbfk/2008/112/i06/abs/jp07... -------------------------------------------------------------------------------- From Wikipedia, the free encyclopedia Kaempferol Kaempferol is a natural flavonoid that has been isolated from tea,[1] broccoli, Delphinium, Witch-hazel, grapefruit, and other plant sources. Who loves ya. Tom Jesus Was A Vegetarian! http://jesuswasavegetarian.7h.com Man Is A Herbivore! http://tinyurl.com/a3cc3 DEAD PEOPLE WALKING http://tinyurl.com/zk9fk On Mar 10, 11:18 am, "ironjust...@aol.com" <ironjust...@aol.com> wrote: Kaempferol << Kaempferol and quercitrin effect on iron bioavailability in white and colored bean seeds (Phaseolus vulgaris L.) using an in vitro Digestion/ Human caco-2 cell modeljournal article Glahn, Raymond P. | Associate Professor Welch, Ross M. | Courtesy Professor | Crop & Soil Sciences profile | Agricultural Research Service profile Hu, Ying; Cheng, Zhiqiang; Heller, Larry; Glahn, Raymond P; Welch, Ross M | FASEB Journal, 2006; 20(4, Part 1): A197 Four different colored commercial beans (white, red, pinto and black beans) were investigated for factors affecting iron bioavailability. An in vitro digestion/human Caco-2 cell model was used to study the polyphenols from whole beans, de-hulled beans and their hulls and assess iron bioavailability. The results show that white beans contained higher levels of bioavailable iron compared to colored beans. These differences in bioavailable iron were not due to bean-iron and bean-phytate levels. Flavonoids in the colored bean hulls were found to be contributing to the low bioavailability of iron in the colored beans. White bean hulls contained no detectible flavonoids. The flavonoids, kaempferol and quercitrin, were identified in red and pinto bean hulls via HPLC. Some unidentified anthocyanins were also detected in the black bean hulls but not in the other colored bean hulls. Kaempferol and quercitrin were shown to inhibit iron bioavailability, with quercitrin being more inhibitory than kaempferol. Treatment of in vitro digestates with kaempferol and quercitrin inhibited iron bioavailability in a concentration dependent fashion. Thus, these flavonoids were found to be the main inhibitory factors affecting iron bioavailability in the red and pinto beans studied. This citation and abstract are made available courtesy of Thomson BIOSIS, 3501 Market Street, Philadelphia, PA 19104. ------------------------------ http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=2220047 Flavonoids are nonessential dietary factors, and humans consume about 1-2g of flavonoids daily. Flavonoids are abundantly present in fruits, vegetables, seeds, nuts, tea, and red wine, and the flavonoid mostly consumed is quercetin. Flavonoids are believed to act as health-promoting substances, and some of them have antioxidant and anti-inflammatory properties [10, 11]. Anti-inflammatory effects have also been found in vivo. For instance, genistein was reported to inhibit LPS-induced septic response in rat [21] and quercetin suppressed experimentally induced arthritis in rat. We compared the effects of 36 naturally occurring flavonoids and related polyphenolic compounds on LPS-induced NO production and iNOS expression in activated macrophages. The flavonoid classes containing the most effective compounds were isoflavones and flavonols. We identified eight compounds as being able to inhibit LPS-induced NO production and iNOS expression. Four compounds (genistein, kaempferol, quercetin, and daidzein) inhibited activation of both of the important transcription factors for iNOS, that is, STAT-1 and NF-B, whereas four compounds (flavone, isorhamnetin, naringenin, and pelargonidin) inhibited only NF-B. The results partly explain the anti-inflammatory effects of flavonoids. Who loves ya. Tom Jesus Was A Vegetarian! http://jesuswasavegetarian.7h.com Man Is A Herbivore! http://tinyurl.com/a3cc3 DEAD PEOPLE WALKING http://tinyurl.com/zk9fk > "Life prolonging activity of Kaempferol" > [quoted text clipped - 88 lines] > > DEAD PEOPLE WALKINGhttp://tinyurl.com/zk9fk On Mar 10, 1:34 pm, "ironjust...@aol.com" <ironjust...@aol.com> wrote:Kaempferol and quercitrin << ACTA CHROMATOGRAPHICA, NO. 13, 2003 HPLC-UV AND GC-MS CHARACTERIZATION OF THE FLAVONOL AGLYCONS QUERCETIN, KAEMPFEROL, AND MYRICETIN IN TOMATO PASTES AND OTHER TOMATO-BASED PRODUCTS Ö. Tokuşoğlu1,*, M. K. Ünal2, and Z. Yıldırım3 1Celal Bayar University, Akhisar M.Y.O.,45200, Akhisar, Manisa, Turkey 2Ege University, Department of Food Engineering, 35100,Bornova, İzmir, Turkey 3Ege University, Agricultural Faculty, Department of Field Crops, 35100 Bornova, Izmir, Turkey SUMMARY The amounts of three flavonoids, quercetin, kaempferol, and myri- cetin, in tomatoes (Solanum lycopersicum L.) and tomato-based products produced in Turkey has been determined by reversed phase high-perfor- mance liquid chromatography (RPHPLC) with UV detection. The HPLC profiles of five types of tomato, one commercial composite tomato juice, and three types of tomato paste, were obtained after acid hydrolysis and extraction. The presence of the flavonol aglycons was confirmed by gas chromatography with mass spectrometric detection (GC- MS). Tomatoes and tomato-based products contained primarily quercetin, kaempferol, and the minor flavonol myricetin. The total flavonol aglycon content of different varieties of tomato varied from 3.1 to 10.0 mg kg-1 of fresh weight. Tomato juice and tomato salsa were rich in total flavonols, containing 19.8 mg L-1 and 10.5-13.2 mg kg-1, respectively. The method enabled accurate and reproducible quantitative analysis of these flavonols in tomatoes and tomato-based products. CONCLUSIONS The tomato spreads and other tomato-based products consumed in Turkey are excellent dietary sources of quercetin and kaempferol. Who loves ya. Tom Jesus Was A Vegetarian! http://jesuswasavegetarian.7h.com Man Is A Herbivore! http://tinyurl.com/a3cc3 DEAD PEOPLE WALKING http://tinyurl.com/zk9fk > On Mar 10, 11:18 am, "ironjust...@aol.com" <ironjust...@aol.com> > wrote: Kaempferol << [quoted text clipped - 167 lines] > > - Show quoted text - |
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