Carcinogenic Chromium(VI) Compounds Formed by Intracellular Oxidation of Chromium(III) Dietary Supplements by Adipocytes |
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| Authors: | Dr Lindsay E Wu Dr Aviva Levina Prof Hugh H Harris Dr Zhonghou Cai Dr Barry Lai Dr Stefan Vogt Prof David E James Prof Peter A Lay |
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| Institution: | 1. School of Chemistry, The University of Sydney, NSW, Australia;2. Garvan Institute of Medical Research, Darlinghurst, NSW, Australia;3. School of Medical Sciences, UNSW Australia, NSW, Australia;4. School of Chemistry and Physics, The University of Adelaide, SA, Australia;5. Advanced Photon Source, X-ray Science Division, Argonne National Laboratory, Argonne, IL, USA;6. Charles Perkins Centre, The University of Sydney, NSW, Australia |
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| Abstract: | Chromium(III) nutritional supplements are widely consumed for their purported antidiabetic activities. X‐ray fluorescence microscopy (XFM) and X‐ray absorption near‐edge structure (XANES) studies have now shown that non‐toxic doses of Cr3O(OCOEt)6(OH2)3]+ ( A ), a prospective antidiabetic drug that undergoes similar H2O2 induced oxidation reactions in the blood as other Cr supplements, was also oxidized to carcinogenic CrVI and CrV in living cells. Single adipocytes treated with A had approximately 1 μm large Cr hotspots containing CrIII, CrV, and CrVI (primarily CrVI thiolates) species. These results strongly support the hypothesis that the antidiabetic activity of CrIII and the carcinogenicity of CrVI compounds arise from similar mechanisms involving highly reactive CrVI and CrV intermediates, and highlight concerns over the safety of CrIII nutritional supplements. |
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| Keywords: | adipocytes cancer chromium oxidation X-ray fluorescence microscopy |
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