TY - JOUR
T1 - Ultrastructural damage in chromium picolinate-treated cells
T2 - A TEM study
AU - Manygoats, Kevin R.
AU - Yazzie, Monica
AU - Stearns, Diane M.
N1 - Funding Information:
Acknowledgements The authors acknowledge the excellent technical assistance of Marilee Sellers in the NAU Electron Microscope Facility. We thank Matthew Salanga and Dustin Grzesik for their assistance with the fluorescence microscopy. This work was supported by National Cancer Institute (NCI) grant CA75298 (D.M.S.), a National Institutes of Health (NIH) Research Supplement for Under Represented Minorities (K.R.M.), and the NIH Minority Student Development Program at NAU, grant MIGMS R25 GM56931 (K.R.M., M.Y.).
PY - 2002
Y1 - 2002
N2 - Chromium picolinate (CrPic) is a human dietary supplement that provides a bioavailable form of chromium(III). Its mechanism of action is unknown, and a number of toxic endpoints have been attributed to its use. Understanding the cellular effects of CrPic is important for confirmation or dismissal of these potential toxic effects. The purpose of this work was to characterize morphological damage caused by CrPic, picolinic acid, and chromic chloride in Chinese hamster ovary AA8 cells. A 48-h exposure to 80 μg/cm2 CrPic (0.44 mg/mL CrPic) produced 45% survival by colony formation. Transmission electron microscopy (TEM) showed 83% of analyzed cells having swollen mitochondria with degraded cristae. Apoptosis was identified by nuclear convolution and fragmentation, and cytoplasmic blebbing. Apoptosis was quantified by fluorescence microscopy with acridine orange/ethidium bromide staining. At the 80 μg/cm2 dose of CrPic, 37% of the cells were apoptotic cells at 48 h. An equivalent dose of picolinate, 3 mM, was much more cytotoxic and thus there was an inadequate cell number for TEM analysis. However, a lower dose of 1.5 mM induced 49% cell survival, and damaged 86% of the mitochondria, with 51% of the cells undergoing apoptosis. A dose of 1 mM chromic chloride produced 71% cell survival, and damaged 86% of the mitochondria, with 22% of the cells undergoing apoptosis. The amount of apoptosis correlated with overall cell survival by colony formation, but not with the amount of mitochondrial damage. The coordination of Cr(III) by picolinate ligands may alter the cellular chemistry of Cr(III) to make chromium picolinate a toxic form of Cr(III).
AB - Chromium picolinate (CrPic) is a human dietary supplement that provides a bioavailable form of chromium(III). Its mechanism of action is unknown, and a number of toxic endpoints have been attributed to its use. Understanding the cellular effects of CrPic is important for confirmation or dismissal of these potential toxic effects. The purpose of this work was to characterize morphological damage caused by CrPic, picolinic acid, and chromic chloride in Chinese hamster ovary AA8 cells. A 48-h exposure to 80 μg/cm2 CrPic (0.44 mg/mL CrPic) produced 45% survival by colony formation. Transmission electron microscopy (TEM) showed 83% of analyzed cells having swollen mitochondria with degraded cristae. Apoptosis was identified by nuclear convolution and fragmentation, and cytoplasmic blebbing. Apoptosis was quantified by fluorescence microscopy with acridine orange/ethidium bromide staining. At the 80 μg/cm2 dose of CrPic, 37% of the cells were apoptotic cells at 48 h. An equivalent dose of picolinate, 3 mM, was much more cytotoxic and thus there was an inadequate cell number for TEM analysis. However, a lower dose of 1.5 mM induced 49% cell survival, and damaged 86% of the mitochondria, with 51% of the cells undergoing apoptosis. A dose of 1 mM chromic chloride produced 71% cell survival, and damaged 86% of the mitochondria, with 22% of the cells undergoing apoptosis. The amount of apoptosis correlated with overall cell survival by colony formation, but not with the amount of mitochondrial damage. The coordination of Cr(III) by picolinate ligands may alter the cellular chemistry of Cr(III) to make chromium picolinate a toxic form of Cr(III).
KW - Apoptosis
KW - Chromium picolinate
KW - Electron microscopy
KW - Mitochondrial damage
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U2 - 10.1007/s00775-002-0357-z
DO - 10.1007/s00775-002-0357-z
M3 - Article
C2 - 12203015
AN - SCOPUS:0036940895
SN - 0949-8257
VL - 7
SP - 791
EP - 798
JO - Journal of Biological Inorganic Chemistry
JF - Journal of Biological Inorganic Chemistry
IS - 7-8
ER -