B Halliwell

Summary

Affiliation: National University of Singapore
Country: Singapore

Publications

  1. ncbi request reprint How I became a biochemist
    Barry Halliwell
    Department of Biochemistry, National University of Singapore, Singapore
    IUBMB Life 56:569-70. 2004
  2. ncbi request reprint Mechanism of cell death induced by an antioxidant extract of Cratoxylum cochinchinense (YCT) in Jurkat T cells: the role of reactive oxygen species and calcium
    Soon Yew Tang
    Department of Biochemistry, Faculty of Medicine, National University of Singapore, Singapore
    Free Radic Biol Med 36:1588-611. 2004
  3. ncbi request reprint Cautions in the use of biomarkers of oxidative damage; the vascular and antioxidant effects of dark soy sauce in humans
    Chung Yung J Lee
    National University of Singapore, Yong Loo Lin School of Medicine, Department of Biochemistry, 8 Medical Drive, Singapore 117597, Singapore
    Biochem Biophys Res Commun 344:906-11. 2006
  4. pmc The antioxidant paradox: less paradoxical now?
    Barry Halliwell
    Department of Biochemistry, National University of Singapore, Singapore 119077, Singapore
    Br J Clin Pharmacol 75:637-44. 2013
  5. doi request reprint Free radicals and antioxidants: updating a personal view
    Barry Halliwell
    Department of Biochemistry, National University of Singapore, Singapore
    Nutr Rev 70:257-65. 2012
  6. ncbi request reprint Can oxidative DNA damage be used as a biomarker of cancer risk in humans? Problems, resolutions and preliminary results from nutritional supplementation studies
    B Halliwell
    Department of Biochemistry, National University of Singapore, Singapore
    Free Radic Res 29:469-86. 1998
  7. ncbi request reprint Plasma antioxidants: health benefits of eating chocolate?
    Barry Halliwell
    Department of Biochemistry, National University of Singapore, 8 Medical Drive, MD7 03 08, 117597 Singapore
    Nature 426:787; discussion 788. 2003
  8. ncbi request reprint Hypothesis: proteasomal dysfunction: a primary event in neurogeneration that leads to nitrative and oxidative stress and subsequent cell death
    Barry Halliwell
    Department of Biochemistry, Faculty of Medicine, National University of Singapore, Singapore
    Ann N Y Acad Sci 962:182-94. 2002
  9. pmc Measuring reactive species and oxidative damage in vivo and in cell culture: how should you do it and what do the results mean?
    Barry Halliwell
    Department of Biochemistry, Faculty of Medicine, National University of Singapore, MD 7 03 08, 8 Medical Drive, Singapore 117597, Singapore
    Br J Pharmacol 142:231-55. 2004
  10. doi request reprint Are polyphenols antioxidants or pro-oxidants? What do we learn from cell culture and in vivo studies?
    Barry Halliwell
    Department of Biochemistry, National University of Singapore, University Hall, Lee Kong Chian Wing, UHL 05 02G, 21 Lower Kent Ridge Road, Singapore 119077, Singapore
    Arch Biochem Biophys 476:107-12. 2008

Collaborators

Detail Information

Publications102 found, 100 shown here

  1. ncbi request reprint How I became a biochemist
    Barry Halliwell
    Department of Biochemistry, National University of Singapore, Singapore
    IUBMB Life 56:569-70. 2004
  2. ncbi request reprint Mechanism of cell death induced by an antioxidant extract of Cratoxylum cochinchinense (YCT) in Jurkat T cells: the role of reactive oxygen species and calcium
    Soon Yew Tang
    Department of Biochemistry, Faculty of Medicine, National University of Singapore, Singapore
    Free Radic Biol Med 36:1588-611. 2004
    ..Cell death has some features of apoptosis (propidium iodide staining, externalization of phosphatidylserine, limited caspase-3 and -9 activities), but there was no internucleosomal DNA fragmentation...
  3. ncbi request reprint Cautions in the use of biomarkers of oxidative damage; the vascular and antioxidant effects of dark soy sauce in humans
    Chung Yung J Lee
    National University of Singapore, Yong Loo Lin School of Medicine, Department of Biochemistry, 8 Medical Drive, Singapore 117597, Singapore
    Biochem Biophys Res Commun 344:906-11. 2006
    ..We conclude that DSS decreases lipid peroxidation in vivo. However, oxidative damage biomarkers changed after the placebo meal, a phenomenon to consider when designing interventional studies...
  4. pmc The antioxidant paradox: less paradoxical now?
    Barry Halliwell
    Department of Biochemistry, National University of Singapore, Singapore 119077, Singapore
    Br J Clin Pharmacol 75:637-44. 2013
    ..g. by supplying weak pro-oxidants) may be a more useful approach to treatment and prevention of diseases in which reactive oxygen species are important than is consumption of large doses of dietary antioxidants...
  5. doi request reprint Free radicals and antioxidants: updating a personal view
    Barry Halliwell
    Department of Biochemistry, National University of Singapore, Singapore
    Nutr Rev 70:257-65. 2012
    ..Increasing endogenous antioxidant levels (e.g., by supplying "pro-oxidants") may be a better approach to therapeutics and disease prevention than consuming large doses of "dietary antioxidants."..
  6. ncbi request reprint Can oxidative DNA damage be used as a biomarker of cancer risk in humans? Problems, resolutions and preliminary results from nutritional supplementation studies
    B Halliwell
    Department of Biochemistry, National University of Singapore, Singapore
    Free Radic Res 29:469-86. 1998
    ..It appears that such damage can be modulated by vegetable intake, although the effects of vegetables may be mediated by components different from the "classical" antioxidants vitamin C, alpha-tocopherol and beta-carotene...
  7. ncbi request reprint Plasma antioxidants: health benefits of eating chocolate?
    Barry Halliwell
    Department of Biochemistry, National University of Singapore, 8 Medical Drive, MD7 03 08, 117597 Singapore
    Nature 426:787; discussion 788. 2003
  8. ncbi request reprint Hypothesis: proteasomal dysfunction: a primary event in neurogeneration that leads to nitrative and oxidative stress and subsequent cell death
    Barry Halliwell
    Department of Biochemistry, Faculty of Medicine, National University of Singapore, Singapore
    Ann N Y Acad Sci 962:182-94. 2002
    ..Thus, agents that increase proteasome function may be generally neuroprotective, as may be NOS inhibitors. Proteasome inhibitors should be used with caution as therapeutic agents...
  9. pmc Measuring reactive species and oxidative damage in vivo and in cell culture: how should you do it and what do the results mean?
    Barry Halliwell
    Department of Biochemistry, Faculty of Medicine, National University of Singapore, MD 7 03 08, 8 Medical Drive, Singapore 117597, Singapore
    Br J Pharmacol 142:231-55. 2004
    ..The emphasis throughout is on the caution that is needed in applying these methods in view of possible errors and artifacts in interpreting the results...
  10. doi request reprint Are polyphenols antioxidants or pro-oxidants? What do we learn from cell culture and in vivo studies?
    Barry Halliwell
    Department of Biochemistry, National University of Singapore, University Hall, Lee Kong Chian Wing, UHL 05 02G, 21 Lower Kent Ridge Road, Singapore 119077, Singapore
    Arch Biochem Biophys 476:107-12. 2008
    ..Many studies of the biological effects of polyphenols in cell culture have been affected by their ability to oxidise in culture media, and awareness of this problem can avoid erroneous claims...
  11. ncbi request reprint Biochemistry of oxidative stress
    B Halliwell
    Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 8 Medical Drive, MD7 Level 2, Singapore 117597, Singapore
    Biochem Soc Trans 35:1147-50. 2007
    ..This brief review attempts to define them and to examine the ways in which oxidative stress and oxidative damage can affect cell behaviour both in vivo and in cell culture, using cancer as an example...
  12. ncbi request reprint Establishing biomarkers of oxidative stress: the measurement of hydrogen peroxide in human urine
    Barry Halliwell
    Department of Biochemistry, Faculty of Medicine, MD 7 03 08, 8 Medical Drive, Singapore 117597, Singapore
    Curr Med Chem 11:1085-92. 2004
    ..Work is underway to compare H(2)O(2) levels with variations in other biomarkers of oxidative damage, to test the possibility that there are daily or other periodic variations in oxidative damage rates...
  13. ncbi request reprint Vitamin E and thetreatment and prevention of diabetes: a case for a controlled clinical trial
    B Halliwell
    Department of Biochemistry, Faculty of Medicine, National University of Singapore, MD 7 03 15, 8 Medical Drive, Singapore 117597
    Singapore Med J 43:479-84. 2002
    ..Animal studies also support its usefulness. The weight of evidence available supports the suggestion that a major double-blind controlled clinical trial of antioxidants in prevention and treatment of type 2 diabetes should be undertaken...
  14. ncbi request reprint Oxidative stress in cell culture: an under-appreciated problem?
    Barry Halliwell
    Department of Biochemistry, Faculty of Medicine, MD 7 03 07, 8 Medical Drive, Singapore 117597, Singapore
    FEBS Lett 540:3-6. 2003
    ..Such artefacts may have affected many studies on the effects of ascorbate, thiols, flavonoids and other polyphenolic compounds on cells in culture...
  15. ncbi request reprint Psoralea corylifolia L. inhibits mitochondrial complex I and proteasome activities in SH-SY5Y cells
    Soon Yew Tang
    National University of Singapore, University Hall, Lee Kong Chian Wing, UHL 05 02G, 21 Lower Kent Ridge Road, Singapore
    Ann N Y Acad Sci 1100:486-96. 2007
    ..Our data show that the extract obtained from the seeds of Psoralea corylifolia L. decreased mitochondrial complex I and proteasome activities; and oxidative stress might be an early event...
  16. ncbi request reprint Oxidative stress and cancer: have we moved forward?
    Barry Halliwell
    Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 8 Medical Drive, MD7 Level 2 Singapore 117597
    Biochem J 401:1-11. 2007
    ..Chronic inflammation predisposes to malignancy, but the role of RS in this is likely to be complex because RS can sometimes act as anti-inflammatory agents...
  17. ncbi request reprint Dietary polyphenols: good, bad, or indifferent for your health?
    Barry Halliwell
    Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 8 Medical Drive, MD7 Level 2, 117597 Singapore, Singapore
    Cardiovasc Res 73:341-7. 2007
    ..The overall health benefit of flavonoids is uncertain, and consumption of large quantities of them in fortified foods or supplements should not yet be encouraged...
  18. ncbi request reprint Proteasomal dysfunction: a common feature of neurodegenerative diseases? Implications for the environmental origins of neurodegeneration
    B Halliwell
    Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
    Antioxid Redox Signal 8:2007-19. 2006
    ....
  19. ncbi request reprint Phagocyte-derived reactive species: salvation or suicide?
    Barry Halliwell
    Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 8 Medical Drive, MD7 Level 2, 117597 Singapore
    Trends Biochem Sci 31:509-15. 2006
    ..Recently, however, we have learned that they can also be anti-inflammatory by modulating the immune response. These data have implications for the proposed use of antioxidants to treat inflammation...
  20. ncbi request reprint Effect of diet on cancer development: is oxidative DNA damage a biomarker?
    Barry Halliwell
    Department of Biochemistry, National University of Singapore, Singapore 119260
    Free Radic Biol Med 32:968-74. 2002
    ....
  21. doi request reprint The wanderings of a free radical
    Barry Halliwell
    Department of Biochemistry, National University of Singapore, Singapore
    Free Radic Biol Med 46:531-42. 2009
    ..It was an exciting field when I started some 40 years ago, and it still is today, but some major challenges must be faced...
  22. ncbi request reprint Vitamin C: poison, prophylactic or panacea?
    B Halliwell
    Dept of Biochemistry, National University of Singapore, Kent Ridge Crescent, Singapore 119260
    Trends Biochem Sci 24:255-9. 1999
    ..Although there is no evidence that any of these effects are deleterious to humans, we might need to change our thinking about the mechanisms of the antioxidant action of ascorbate in vivo...
  23. ncbi request reprint Oxygen and nitrogen are pro-carcinogens. Damage to DNA by reactive oxygen, chlorine and nitrogen species: measurement, mechanism and the effects of nutrition
    B Halliwell
    Department of Biochemistry, National University of Singapore, Kent Ridge Crescent, Singapore 119260, Singapore
    Mutat Res 443:37-52. 1999
    ....
  24. ncbi request reprint Why and how should we measure oxidative DNA damage in nutritional studies? How far have we come?
    B Halliwell
    Department of Biochemistry, National University of Singapore
    Am J Clin Nutr 72:1082-7. 2000
    ..The available evidence suggests that in Western populations, intake of certain fruit and vegetables can decrease oxidative DNA damage, whereas ascorbate, vitamin E, and beta-carotene cannot...
  25. ncbi request reprint Hydrogen peroxide in the human body
    B Halliwell
    Department of Biochemistry, Faculty of Medicine, National University of Singapore
    FEBS Lett 486:10-3. 2000
    ..Urinary H(2)O(2) levels are influenced by diet, but under certain conditions might be a valuable biomarker of 'oxidative stress'...
  26. doi request reprint Free radicals and antioxidants - quo vadis?
    Barry Halliwell
    Department of Biochemistry, National University of Singapore, 8 Medical Drive, Singapore 117597
    Trends Pharmacol Sci 32:125-30. 2011
    ..This brief commentary highlights in broad terms the current status of the redox biology field and the major challenges it faces in the next decade...
  27. ncbi request reprint Vitamin C and genomic stability
    B Halliwell
    Department of Biochemistry, National University of Singapore, 10 Kent Ridge Crescent, 119260, Singapore, Singapore
    Mutat Res 475:29-35. 2001
    ....
  28. ncbi request reprint Role of free radicals in the neurodegenerative diseases: therapeutic implications for antioxidant treatment
    B Halliwell
    Department of Biochemistry, Faculty of Medicine, National University of Singapore, Singapore
    Drugs Aging 18:685-716. 2001
    ..Several agents already in therapeutic use might exert some of their effects by antioxidant action, including selegiline (deprenyl), apomorphine and nitecapone...
  29. ncbi request reprint Health promotion by flavonoids, tocopherols, tocotrienols, and other phenols: direct or indirect effects? Antioxidant or not?
    Barry Halliwell
    Department of Biochemistry, Faculty of Medicine, Singapore
    Am J Clin Nutr 81:268S-276S. 2005
    ..We argue that tocopherols and tocotrienols may also exert direct beneficial effects in the gastrointestinal tract and that their return to the gastrointestinal tract by the liver through the bile may be physiologically advantageous...
  30. pmc Reactive species and antioxidants. Redox biology is a fundamental theme of aerobic life
    Barry Halliwell
    Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597
    Plant Physiol 141:312-22. 2006
  31. ncbi request reprint Chronic exposure to U18666A is associated with oxidative stress in cultured murine cortical neurons
    Chor Hui Vivien Koh
    Department of Biochemistry, Faculty of Medicine, National University of Singapore, Singapore
    J Neurochem 98:1278-89. 2006
    ..The association of neuronal apoptosis with oxidative stress and Abeta accumulation may provide clues to the pathogenesis of Alzheimer's disease, as well as the role oxidative stress plays in other neurodegenerative diseases...
  32. ncbi request reprint Characterization of antioxidant and antiglycation properties and isolation of active ingredients from traditional chinese medicines
    Soon Yew Tang
    Department of Biochemistry, Faculty of Medicine, National University of Singapore, Singapore
    Free Radic Biol Med 36:1575-87. 2004
    ....
  33. ncbi request reprint Differential effects of calcium-dependent and calcium-independent phospholipase A(2) inhibitors on kainate-induced neuronal injury in rat hippocampal slices
    X R Lu
    Department of Anatomy, National University of Singapore, Singapore
    Free Radic Biol Med 30:1263-73. 2001
    ..This shows that cPLA(2) plays an important role in kainite-induced neurotoxicity and that cPLA(2) inhibitors can be used to protect hippocampal slices from damage induced by kainate...
  34. ncbi request reprint Lipid peroxidation in the postnatal rat brain. Formation of 4-hydroxynonenal in the supraventricular corpus callosum of postnatal rats
    Q Cao
    Department of Anatomy, National University of Singapore, Singapore 119260
    Exp Brain Res 137:205-13. 2001
    ..These results suggest that lipid peroxidation observed in the supraventricular corpus callosum at postnatal day 10 could result from an accumulation of iron in this region, at this time...
  35. ncbi request reprint Deciphering the mechanism of HNE-induced apoptosis in cultured murine cortical neurons: transcriptional responses and cellular pathways
    Zhao Feng Peng
    Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore
    Neuropharmacology 53:687-98. 2007
    ..Collectively, these might help to elucidate similar molecular mechanisms involved during cell death in neurodegenerative diseases...
  36. ncbi request reprint Distribution of hydroxynonenal-modified proteins in the kainate-lesioned rat hippocampus: evidence that hydroxynonenal formation precedes neuronal cell death
    W Y Ong
    Departments of Anatomy, National University of Singapore, 119260, Singapore
    Free Radic Biol Med 28:1214-21. 2000
    ..These observations suggest that HNE formation is an early event after this tissue injury, and may contribute to later cell death...
  37. ncbi request reprint The cytotoxicity of dopamine may be an artefact of cell culture
    Marie Veronique Clement
    Department of Biochemistry, Faculty of Medicine, National University of Singapore, Singapore
    J Neurochem 81:414-21. 2002
    ..These results suggest that caution needs to be employed when using cell culture studies to predict effects of L-DOPA and/or dopamine in vivo because of the extracellular generation of reactive species in the culture media...
  38. ncbi request reprint Oxidation and generation of hydrogen peroxide by thiol compounds in commonly used cell culture media
    L Hua Long
    Department of Biochemistry, Faculty of Medicine, National University of Singapore, Medical Drive, MD7 03-15, 10 Kent Ridge Crescent, Singapore, 119260
    Biochem Biophys Res Commun 286:991-4. 2001
    ....
  39. ncbi request reprint A mechanism of sulfite neurotoxicity: direct inhibition of glutamate dehydrogenase
    Xin Zhang
    Department of Biochemistry, Faculty of Medicine, National University of Singapore, 8 Medical Drive, Singapore 117597, Singapore
    J Biol Chem 279:43035-45. 2004
    ..Because glutamate is a major metabolite in the brain, inhibition of GDH by sulfite could contribute to the severe phenotype of sulfite oxidase deficiency in human infants...
  40. ncbi request reprint Oxidative stress and neurodegeneration: where are we now?
    Barry Halliwell
    Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
    J Neurochem 97:1634-58. 2006
    ..After a long lag period, therapeutic and other interventions based on a knowledge of redox biology are on the horizon for at least some of the neurodegenerative diseases...
  41. ncbi request reprint Flavonoids: a re-run of the carotenoids story?
    Barry Halliwell
    Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 8 Medical Drive, MD7 Level 2, Singapore 117597
    Novartis Found Symp 282:93-101; discussion 101-4, 212-8. 2007
    ..However, they may be able to help protect the gastro-intestinal tract against reactive oxygen species...
  42. ncbi request reprint Evidence for a trade-off between survival and fitness caused by resveratrol treatment of Caenorhabditis elegans
    Jan Gruber
    National University of Singapore University Hall, Lee Kong Chian Wing, UHL no 05 02G, 21 Lower Kent Ridge Road, Singapore
    Ann N Y Acad Sci 1100:530-42. 2007
    ..elegans, but did not affect the dying phase itself, suggesting that it did not act by directly affecting metabolism...
  43. doi request reprint Elevated oxidative stress, iron accumulation around microvessels and increased 4-hydroxynonenal immunostaining in zone 1 of the liver acinus in hypercholesterolemic rabbits
    Wei Yi Ong
    Department of Anatomy, National University of Singapore, Singapore
    Free Radic Res 43:241-9. 2009
    ..The results are suggestive of microvascular damage associated with iron accumulation and oxidative stress in the liver during hypercholesterolemia...
  44. ncbi request reprint Sulfite-mediated oxidative stress in kidney cells
    Annette S Vincent
    Department of Biochemistry, Faculty of Medicine, National University of Singapore, Singapore
    Kidney Int 65:393-402. 2004
    ..Administration of metabisulfite has also been shown to damage kidney cells...
  45. ncbi request reprint Lactacystin-induced apoptosis of cultured mouse cortical neurons is associated with accumulation of PTEN in the detergent-resistant membrane fraction
    N S Cheung
    Department of Biochemistry, National University of Singapore, 117597, Singapore, Singapore
    Cell Mol Life Sci 61:1926-34. 2004
    ..Taken together, our results suggest that truncation and accumulation of PTEN to the detergent-insoluble membrane fraction are two events associated with the apoptotic signals of the proteasome inhibitor in cortical neurons...
  46. ncbi request reprint Correlation of iron and zinc levels with lesion depth in newly formed atherosclerotic lesions
    Ren Minqin
    Department of Physics, Research Centre for Nuclear Microscopy, National University of Singapore, Singapore, Singapore
    Free Radic Biol Med 34:746-52. 2003
    ....
  47. ncbi request reprint Increased iron staining in the cerebral cortex of cholesterol fed rabbits
    Wei Yi Ong
    Department of Anatomy, National University of Singapore, Singapore 119260, Singapore
    Mech Ageing Dev 125:305-13. 2004
    ..Hypercholesterolaemia is known to be associated with increased plasma lipid peroxidation which might contribute to such damage...
  48. ncbi request reprint The mitochondrial free radical theory of ageing--where do we stand?
    Jan Gruber
    National University of Singapore, Department of Biochemistry, Centre for Life Sciences, 28 Medical Drive, 117456 Singapore
    Front Biosci 13:6554-79. 2008
    ..Implications for the prospect of successful interventions as well as evidence for and against efficacy of current therapeutic approaches are discussed...
  49. doi request reprint Different patterns of oxidized lipid products in plasma and urine of dengue fever, stroke, and Parkinson's disease patients: cautions in the use of biomarkers of oxidative stress
    Chung Yung J Lee
    Department of Biochemistry, National University of Singapore, Singapore
    Antioxid Redox Signal 11:407-20. 2009
    ....
  50. pmc A high-throughput and sensitive methodology for the quantification of urinary 8-hydroxy-2'-deoxyguanosine: measurement with gas chromatography-mass spectrometry after single solid-phase extraction
    Hai Shu Lin
    Department of Biochemistry, Faculty of Medicine, National University of Singapore, MD 7, Medical Drive, Singapore 117597, Singapore
    Biochem J 380:541-8. 2004
    ..Since this assay is simple, rapid, sensitive and reproducible, it seems suitable to be used as a routine methodology for the measurement of urinary excretion of 8OHdG in large population studies...
  51. ncbi request reprint Contribution of hydrogen peroxide to the cytotoxicity of green tea and red wines
    Phing Chian Chai
    Department of Biochemistry, Faculty of Medicine, National University of Singapore MD 7 03 08, 8 Medical Drive, Singapore 117597, Singapore
    Biochem Biophys Res Commun 304:650-4. 2003
    ..By contrast, H(2)O(2) was only responsible for part of the cytotoxicity of the red wines examined. Our data illustrate the danger of extrapolating from cell culture studies to predict the effects of complex beverages in vivo...
  52. doi request reprint Instability of, and generation of hydrogen peroxide by, phenolic compounds in cell culture media
    Lee Hua Long
    Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
    Arch Biochem Biophys 501:162-9. 2010
    ..Compound instability and generation of H2O2 must be taken into account in interpreting effects of phenolic compounds on cells in culture...
  53. ncbi request reprint Do mitochondria make nitric oxide? no?
    Yvonne Mei Sian Tay
    Department of Biochemistry, Faculty of Medicine, National University of Singapore, MD 7 02 07, 8 Medical Drive, Singapore 117597, Singapore
    Free Radic Res 38:591-9. 2004
    ..The implications for the putative mitochondrial NOS are discussed...
  54. doi request reprint Lack of effect of acute oral ingestion of vitamin C on oxidative stress, arterial stiffness or blood pressure in healthy subjects
    Ronan P Kelly
    Lilly NUS Centre for Clinical Pharmacology, Level 6, Clinical Research Centre MD 11, National University of Singapore, Singapore
    Free Radic Res 42:514-22. 2008
    ..068 (-0.009, 0.144)) or urinary or plasma total F(2)-isoprostanes (-0.005 ng/ml (-0.021, 0.010), -0.153 ng/mg (-0.319, 0.014), respectively)...
  55. ncbi request reprint Mechanism of clofibrate hepatotoxicity: mitochondrial damage and oxidative stress in hepatocytes
    B Qu
    Department of Biochemistry, Faculty of Medicine, National University of Singapore, Singapore, Singapore
    Free Radic Biol Med 31:659-69. 2001
    ..These results suggest that one action of clofibrate might be to impair mitochondrial function, so stimulating formation of ROS, which eventually contribute to cell death...
  56. ncbi request reprint A reassessment of the peroxynitrite scavenging activity of uric acid
    M Whiteman
    Department of Biochemistry, Faculty of Medicine, National University of Singapore, Singapore
    Ann N Y Acad Sci 962:242-59. 2002
    ..This study highlights the need to use several different assays in the presence of physiologically relevant concentrations of bicarbonate when assessing compounds for peroxynitrite scavenging, in order to avoid misleading results...
  57. ncbi request reprint Changes in glutathione in the hippocampus of rats injected with kainate: depletion in neurons and upregulation in glia
    W Y Ong
    Department of Anatomy, National University of Singapore
    Exp Brain Res 132:510-6. 2000
    ..One possibility is that the high content of glutathione is protective to reactive astrocytes. Another possibility is that the high glutathione concentration in reactive astrocytes may be protective to neurons around the glial scar...
  58. ncbi request reprint The in vitro cytotoxicity of ascorbate depends on the culture medium used to perform the assay and involves hydrogen peroxide
    M V Clement
    Oncology Research Institute, National University Medical Institutes, National University of Singapore, Singapore 117 597
    Antioxid Redox Signal 3:157-63. 2001
    ..The ability of ascorbate to interact with different cell culture media to produce H2O2 at different rates could account for many or all of the conflicting results obtained using ascorbate in cultured cell assays...
  59. doi request reprint Oxidative damage in dengue fever
    Raymond C S Seet
    Department of Medicine, Yong Loo Lin School of Medicine, National University Hospital, Singapore 119074
    Free Radic Biol Med 47:375-80. 2009
    ..01). Markers of oxidative damage are altered during the various stages of dengue infection...
  60. doi request reprint Ageing in nematodes: do antioxidants extend lifespan in Caenorhabditis elegans?
    Pamela Boon Li Pun
    Department of Biochemistry, Ageing Neurobiology Programme, Centre for Life Sciences, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
    Biogerontology 11:17-30. 2010
    ..Further studies into those extracts that produced significant lifespan extension indicated that a direct antioxidant effect is unlikely to be the main factor responsible for the modulation of nematode lifespan...
  61. ncbi request reprint Loss of oxidized and chlorinated bases in DNA treated with reactive oxygen species: implications for assessment of oxidative damage in vivo
    Matthew Whiteman
    Department of Biochemistry, Faculty of Medicine, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260, Singapore
    Biochem Biophys Res Commun 296:883-9. 2002
    ..This study emphasizes the need to examine more than one modified DNA base when assessing the role of reactive species in human disease...
  62. pmc Inhibition of hypochlorous acid-induced cellular toxicity by nitrite
    Matthew Whiteman
    Department of Biochemistry, Faculty of Medicine, National University of Singapore, 10 Kent Ridge Crescent, Republic of Singapore 119260
    Proc Natl Acad Sci U S A 99:12061-6. 2002
    ..NO are overproduced, may be cytoprotective against damage caused by HOCl. We propose that this is because HOCl is removed by reacting with NO(2-) to give nitryl chloride (NO2Cl), which is less damaging in our cell system...
  63. pmc Markers of oxidative damage are not elevated in otherwise healthy individuals with the metabolic syndrome
    Raymond C S Seet
    Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
    Diabetes Care 33:1140-2. 2010
    ..The role of oxidative damage in the pathogenesis of metabolic syndrome is poorly understood...
  64. ncbi request reprint Lack of tyrosine nitration by hypochlorous acid in the presence of physiological concentrations of nitrite. Implications for the role of nitryl chloride in tyrosine nitration in vivo
    Matthew Whiteman
    Department of Biochemistry, Faculty of Medicine, National University of Singapore, 8 Medical Dr, Singapore 117597, Republic of Singapore
    J Biol Chem 278:8380-4. 2003
    ..These data suggest that nitryl chloride formed from the reaction of nitrite with HOCl does not contribute to the elevated levels of 3-nitrotyrosine observed in human diseases...
  65. doi request reprint Limited antioxidant effect after consumption of a single dose of tomato sauce by young males, despite a rise in plasma lycopene
    Chung Yung Jetty Lee
    Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
    Free Radic Res 43:622-8. 2009
    ..05) significantly decreased at 48 h compared to 0 h after the tomato sauce meal. This study showed that a single dose of tomato sauce meal had only a limited antioxidant effect in vivo...
  66. doi request reprint Notopterygium forbesii boiss extract and its active constituents increase reactive species and heme oxygenase-1 in human fetal hepatocytes: mechanisms of action
    Soon Yew Tang
    Department of Biochemistry, Centre for Life Sciences, Yong Loo Lin School of Medicine, National University of Singapore, 28 Medical Drive, Singapore 117456
    Chem Res Toxicol 21:2414-23. 2008
    ..The induction of HO-1 protein in response to moderate oxidative stress may explain some of the beneficial pharmacological effects of NF...
  67. ncbi request reprint Factors affecting the ascorbate- and phenolic-dependent generation of hydrogen peroxide in Dulbecco's Modified Eagles Medium
    Liang Meng Wee
    Department of Biochemistry, Faculty of Medicine, National University of Singapore MD 7 03 08, 8 Medical Drive, Singapore 117597, Singapore
    Free Radic Res 37:1123-30. 2003
    ..Ascorbate prevented the loss of gallic acid incubated in DMEM. The role of metal ions and other constituents of the culture medium in promoting H2O2 generation is discussed...
  68. doi request reprint Artefacts in cell culture: pyruvate as a scavenger of hydrogen peroxide generated by ascorbate or epigallocatechin gallate in cell culture media
    Lee Hua Long
    Department of Biochemistry, National University of Singapore, Singapore
    Biochem Biophys Res Commun 388:700-4. 2009
    ....
  69. doi request reprint Is uric acid protective or deleterious in acute ischemic stroke? A prospective cohort study
    Raymond C S Seet
    Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
    Atherosclerosis 209:215-9. 2010
    ..No significant relationship was observed between urate and vascular outcomes. Depending on its level, serum urate may exhibit protective and deleterious effects on stroke outcomes...
  70. doi request reprint Deceptively simple but simply deceptive--Caenorhabditis elegans lifespan studies: considerations for aging and antioxidant effects
    Jan Gruber
    Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
    FEBS Lett 583:3377-87. 2009
    ..This review introduces C. elegans as a model organism, discusses aspects that make it attractive for aging and antioxidant research, and addresses some problems and potential artifacts...
  71. doi request reprint Oxidative damage in Parkinson disease: Measurement using accurate biomarkers
    Raymond C S Seet
    Department of Medicine, National University of Singapore, Singapore
    Free Radic Biol Med 48:560-6. 2010
    ..305, p= 0.023) and plasma total HETEs (r= -0.285, p= 0.043). Oxidative damage markers are systemically elevated in PD, which may give clues about the relation of oxidative damage to the onset and progression of PD...
  72. doi request reprint Using isoprostanes as biomarkers of oxidative stress: some rarely considered issues
    Barry Halliwell
    Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
    Antioxid Redox Signal 13:145-56. 2010
    ..We also discuss the controversial issue of whether and how F2-isoprostane levels in plasma should be standardized against lipids, and, if so, which lipids to use...
  73. doi request reprint Medicinal plants and antioxidants: what do we learn from cell culture and Caenorhabditis elegans studies?
    Soon Yew Tang
    Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Centre for Life Sciences, Kent Ridge, Singapore
    Biochem Biophys Res Commun 394:1-5. 2010
    ..This review summarizes the data we have obtained from in vitro and in vivo (Caenorhabditis elegans) studies examining the diverse effects of traditional medicinal plants and their modes of action...
  74. doi request reprint Notopterygium forbesii Boiss extract and its active constituent phenethyl ferulate attenuate pro-inflammatory responses to lipopolysaccharide in RAW 264.7 macrophages. A "protective" role for oxidative stress?
    Soon Yew Tang
    Department of Biochemistry, Centre for Life Sciences, Yong Loo Lin School of Medicine, National University of Singapore, 28 Medical Drive, Singapore 117456
    Chem Res Toxicol 22:1473-82. 2009
    ..These data add to the growing literature that ROS may sometimes be anti-inflammatory...
  75. ncbi request reprint Different cytotoxic and clastogenic effects of epigallocatechin gallate in various cell-culture media due to variable rates of its oxidation in the culture medium
    Lee Hua Long
    Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 8 Medical Drive, MD7 Level 2 Singapore, Singapore
    Mutat Res 634:177-83. 2007
    ..Thus, the culture medium, the cell type and the presence or absence of catalase (e.g. its variable amounts in S9 fractions) must be taken into account in in vitro genotoxicity testing...
  76. ncbi request reprint The novel neuromodulator hydrogen sulfide: an endogenous peroxynitrite 'scavenger'?
    Matthew Whiteman
    Department of Biochemistry, Faculty of Medicine, National University of Singapore, Republic of Singapore
    J Neurochem 90:765-8. 2004
    ....
  77. ncbi request reprint Potential artifacts in the measurement of DNA deamination
    Kok Seong Lim
    Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 8 Medical Drive, Singapore 117597
    Free Radic Biol Med 40:1939-48. 2006
    ..We also used it to measure levels in various rat tissues of both normal and endotoxin-treated rats, but could not find increased 2'-deoxyinosine formation in tissues even though *NO production was substantially increased...
  78. ncbi request reprint Iron, atherosclerosis, and neurodegeneration: a key role for cholesterol in promoting iron-dependent oxidative damage?
    Wei Yi Ong
    Department of Anatomy, National University of Singapore, Singapore 119260
    Ann N Y Acad Sci 1012:51-64. 2004
    ..This could explain why hypercholesterolemia is a risk factor for Alzheimer's disease. Further work is necessary to study the mechanism of increased iron transport across the blood brain barrier in atherosclerosis...
  79. ncbi request reprint Nitrite-mediated protection against hypochlorous acid-induced chondrocyte toxicity: a novel cytoprotective role of nitric oxide in the inflamed joint?
    Matthew Whiteman
    National University of Singapore, Republic of Singapore
    Arthritis Rheum 48:3140-50. 2003
    ..To examine the potential consequences of overproduction of nitric oxide (NO) and nitrite (NO(2) (-)) in the inflamed rheumatoid joint...
  80. ncbi request reprint Oxidative damage in mitochondrial DNA is not extensive
    Kok Seong Lim
    Department of Biochemistry, National University of Singapore, 8 Medical Drive, Singapore 117597
    Ann N Y Acad Sci 1042:210-20. 2005
    ..Using an improved GC-MS method and pure mtDNA, our analyses revealed that the damage level in mtDNA is not higher, and may be somewhat lower, than that in nDNA...
  81. ncbi request reprint Hypochlorous acid-mediated mitochondrial dysfunction and apoptosis in human hepatoma HepG2 and human fetal liver cells: role of mitochondrial permeability transition
    Matthew Whiteman
    Department of Biochemistry, Faculty of Medicine, National University of Singapore, 8 Medical Drive, Republic of Singapore 117597
    Free Radic Biol Med 38:1571-84. 2005
    ..For the first time, these results show that HOCl activates the MPT, which leads to the induction of apoptosis and provides a novel insight into the mechanisms of HOCl-mediated cell death at sites of chronic inflammation...
  82. ncbi request reprint The iron chelator desferrioxamine inhibits atherosclerotic lesion development and decreases lesion iron concentrations in the cholesterol-fed rabbit
    Ren Minqin
    Centre for Ion Beam Applications, Department of Physics, National University of Singapore, Singapore 117597
    Free Radic Biol Med 38:1206-11. 2005
    ..Our data strengthen the concept that iron contributes to the early stages of the development of atherosclerosis...
  83. ncbi request reprint Human fecal water content of phenolics: the extent of colonic exposure to aromatic compounds
    Andrew M Jenner
    Biochemistry Department, Faculty of Medicine, National University of Singapore, 8 Medical Drive, Singapore 117597
    Free Radic Biol Med 38:763-72. 2005
    ..This study is the first to measure the range of aromatic compounds in human fecal water and demonstrates that phenolic acid concentrations are high. The biological effects of phenolics may play an important role in colon function...
  84. ncbi request reprint Peroxynitrite mediates calcium-dependent mitochondrial dysfunction and cell death via activation of calpains
    Matthew Whiteman
    Department of Biochemistry, Faculty of Medicine, National University of Singapore, 8 Medical Dr, Republic of Singapore 117597
    FASEB J 18:1395-7. 2004
    ..Our data show, for the first time, that peroxynitrite induces mitochondrial dysfunction in cells via a calcium-dependent process that leads to caspase-independent apoptosis mediated by calpains...
  85. ncbi request reprint Inhibition of hypochlorous acid-induced oxidative reactions by nitrite: is nitrite an antioxidant?
    Matthew Whiteman
    Department of Biochemistry, Faculty of Medicine, National University of Singapore, Singapore
    Biochem Biophys Res Commun 303:1217-24. 2003
    ..These data suggest that NO(2)(-) may act in an antioxidant manner by removing HOCl at sites of inflammation where both HOCl and z.rad;NO are overproduced...
  86. ncbi request reprint The phospholipase A2 inhibitor quinacrine prevents increased immunoreactivity to cytoplasmic phospholipase A2 (cPLA2) and hydroxynonenal (HNE) in neurons of the lateral septum following fimbria-fornix transection
    X R Lu
    Department of Anatomy, National University of Singapore, Singapore
    Exp Brain Res 138:500-8. 2001
    ..We conclude that there is free-radical damage, as evidenced by HNE formation in neurons of the lateral septum after fimbria-fornix transection, and that this increase in HNE is dependent on phospholipase A2 activity...
  87. doi request reprint The effect of dichloroacetate on health- and lifespan in C. elegans
    S Schaffer
    Department of Biochemistry, Centre for Life Sciences, National University of Singapore, Singapore
    Biogerontology 12:195-209. 2011
    ..Our data illustrate the promise of a "metabolic tuning" intervention strategy, emphasize the importance of mitochondria in nematode aging and highlight operator bias as a potential confounder in lifespan studies...
  88. ncbi request reprint beta-Phenylethyl isothiocyanate-mediated apoptosis in hepatoma HepG2 cells
    P Rose
    Department of Community, Occupational and Family Medicine, MD3, National University of Singapore, 16 Medical Drive, 117597 Singapore
    Cell Mol Life Sci 60:1489-503. 2003
    ..Taken together, these results suggest that PEITC potently induces apoptosis and cell cycle arrest in HepG2 cells and that the generation of reactive oxygen species appears to be a secondary effect...
  89. ncbi request reprint Proteasome inhibition by lactacystin in primary neuronal cells induces both potentially neuroprotective and pro-apoptotic transcriptional responses: a microarray analysis
    Elaine Hau Jin Yew
    Department of Biochemistry, Faculty of Medicine, National University of Singapore, Singapore
    J Neurochem 94:943-56. 2005
    ....
  90. ncbi request reprint Effect of overexpression of wild-type or mutant parkin on the cellular response induced by toxic insults
    Dong Hoon Hyun
    Neurodegenerative Disease Research Centre, GKT School of Biomedical Sciences, King s College, London, United Kingdom
    J Neurosci Res 82:232-44. 2005
    ..The viability loss induced by all the insults showed apoptotic features. The presence of parkin mutations in substantia nigra in Parkinson's disease may increase neuronal vulnerability to a range of toxic insults...
  91. ncbi request reprint Proteasomal dysfunction induced by 4-hydroxy-2,3-trans-nonenal, an end-product of lipid peroxidation: a mechanism contributing to neurodegeneration?
    Dong Hoon Hyun
    Wolfson Centre for Age Related Diseases, GKT School of Biomedical Sciences, King s College, London, UK
    J Neurochem 83:360-70. 2002
    ..We propose that the proteasomal system is a significant target of HNE neurotoxicity in a wide range of neurodegenerative diseases, especially if abnormal proteins are being expressed...
  92. ncbi request reprint Interference with ubiquitination causes oxidative damage and increased protein nitration: implications for neurodegenerative diseases
    Dong Hoon Hyun
    Neurodegenerative Disease Research Centre, GKT School of Biomedical Sciences, King s College, London, UK
    J Neurochem 90:422-30. 2004
    ..We suggest that defects in this pathway at multiple points could produce the common features of neurodegenerative diseases, and that more such defects remain to be discovered...
  93. ncbi request reprint Zinc supplementation inhibits lipid peroxidation and the development of atherosclerosis in rabbits fed a high cholesterol diet
    Andrew Jenner
    Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, MD7, 8 Medical Drive, Singapore 117597
    Free Radic Biol Med 42:559-66. 2007
    ..Our data indicate that zinc has an antiatherogenic effect, possibly due to a reduction in iron-catalyzed free radical reactions...
  94. ncbi request reprint Proteasomal inhibition causes the formation of protein aggregates containing a wide range of proteins, including nitrated proteins
    Dong Hoon Hyun
    Wolfson Centre for Age Related Diseases, GKT School of Biomedical Sciences, King s College, London, UK
    J Neurochem 86:363-73. 2003
    ..The nitric oxide synthase inhibitor, l-NAME, decreased viability loss and aggregation, suggesting that nitration of proteins may play an important role in aggregation and in the cell death accompanying it...
  95. ncbi request reprint Increase in cholesterol and cholesterol oxidation products, and role of cholesterol oxidation products in kainate-induced neuronal injury
    Wei Yi Ong
    Department of Anatomy, National University of Singapore, Singapore
    Brain Pathol 13:250-62. 2003
    ....
  96. ncbi request reprint Oxidative DNA damage in peripheral leukocytes and its association with expression and polymorphisms of hOGG1: a study of adolescents in a high risk region for hepatocellular carcinoma in China
    Tao Peng
    Department of Hepatobiliary Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, Guangxi Zhuang Autonomous Region, China
    World J Gastroenterol 9:2186-93. 2003
    ..To study the oxidative DNA damage to adolescents of hepatocellular carcinoma (HCC) families in Guangxi Zhuang Autonomous Region, China...
  97. ncbi request reprint 5-s-Cysteinyl-conjugates of catecholamines induce cell damage, extensive DNA base modification and increases in caspase-3 activity in neurons
    Jeremy P E Spencer
    Wolfson Centre for Age Related Diseases, GKT School of Biomedical Sciences, King s College London
    J Neurochem 81:122-9. 2002
    ..Indeed, intracellular ROS were observed to rise sharply on exposure to the conjugates. These results suggest one mechanism by which oxidative stress may occur in the substantia nigra in Parkinson's disease...
  98. ncbi request reprint Effect of wild-type or mutant Parkin on oxidative damage, nitric oxide, antioxidant defenses, and the proteasome
    Dong Hoon Hyun
    Wolfson Centre for Age Related Diseases, GKT School of Biomedical Sciences, King s College London, London SE1 1UL, United Kingdom
    J Biol Chem 277:28572-7. 2002
    ..The presence of mutant Parkin in substantia nigra in juvenile parkinsonism may increase oxidative stress and nitric oxide production, sensitizing cells to death induced by other insults...
  99. ncbi request reprint Gender differences in steady-state levels of oxidative damage to DNA in healthy individuals
    Anna R Proteggente
    Antioxidant Research Group, Wolfson Centre for Age Related Diseases, GKT School of Biomedical Sciences, King s College London, UK
    Free Radic Res 36:157-62. 2002
    ..The role of gender in predisposition to oxidative damage to DNA needs to be addressed in future studies...
  100. ncbi request reprint Vitamin C protects against hypochlorous Acid-induced glutathione depletion and DNA base and protein damage in human vascular smooth muscle cells
    Andrew M Jenner
    Centre for Cardiovascular Biology and Medicine, Guy s, King s and St Thomas School of Biomedical Sciences, King s College, University of London, London, UK
    Arterioscler Thromb Vasc Biol 22:574-80. 2002
    ..Our findings suggest that physiological levels of vitamin C provide an important antioxidant defense against HOCl-mediated injury in atherosclerosis...
  101. ncbi request reprint Action of diclofenac on kidney mitochondria and cells
    Lin Eng Ng
    Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Kent Ridge, Singapore 119260, Singapore
    Biochem Biophys Res Commun 348:494-500. 2006
    ....