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Comparison of three forms of selenium as in vitro and in vivo antioxidants and comparison of human absorption and excretion
Author(s) -
Vinson Joe,
Dalal Sonak
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.5.a1070-a
Subject(s) - selenium , chemistry , antioxidant , glutathione peroxidase , yeast , in vivo , very low density lipoprotein , lipoprotein , biochemistry , endocrinology , medicine , superoxide dismutase , cholesterol , biology , microbiology and biotechnology , organic chemistry
Selenium has been recently shown to be protective for prostate cancer and epidemiology studies link consumption of Selenium to a decreased risk of heart disease. The mechanism of Selenium's action in the body is as an antioxidant in glutathione peroxidase. We have compared three forms of selenium (inorganic sodium selenite, organic selenomethione and a Selenium Yeast as antioxidants for the inhibition of lower density lipoprotein (LDL+VLDL) oxidation. We used our standard method at physiological pH and temperature [Methods Enzymol 335: 103–114 (2001)]. A dose‐response inhibition of lipoprotein oxidation was found for all forms and the concentration for 50% inhibition vs. a control was determined graphically. The IC 50 for selenite was > 100 μM, selenomethione 27 μM and the Yeast 0.42 μM. Thus only the Yeast was an antioxidant at physiological concentrations of ~ 1 μM. The lag time of LDL+VLDL oxidation was also measured for the three forms of Selenium at 1 μM and again the Yeast was superior to the other forms; lag time selenite 250 seconds longer than the control, selenomethione 170 seconds longer and the Yeast 18567 seconds longer. In the human study 200 μg of Se in each of the 3 forms was given randomly to 11 healthy subjects after an overnight fast. Blood was collected at baseline and periodically for 5 hours after taking the Selenium. Twenty four‐hour urines were taken before and after Selenium. Selenomethione and Yeast caused a greater Se concentration increase in the subjects’ plasma than selenite. The absorption of the Selenium Yeast was slower than selenite. Selenium from the Yeast was excreted less than the other two forms. Selenium Yeast is a superior in vitro antioxidant and was more absorbed than the other two forms.