The Absorption and Tissue Distribution of Selenium from High-Selenium Broccoli Are Different from Selenium from Sodium Selenite, Sodium Selenate, and Selenomethionine As Determined in Selenium-Deficient Rats

The absorption, tissue distribution, and body retention of selenium (Se) from hydroponically grown high-selenium broccoli were determined in rats. Animals were fed a Torula yeast based diet with no Se or supplemented with 0.1 mg Se/kg diet added as sodium selenate (controls) for six weeks. Selenium-deficient animals were then repleted with Se (0.1 mg/kg diet) supplied as either sodium selenate, sodium selenite, selenomethionine (SeMet), or high-Se broccoli. High-Se broccoli was grown hydroponically and contained 28 mg Se/kg (dry wt). Gross absorption of Se and absorption adjusted for urinary excretion of Se from high-Se broccoli were significantly lower than from other sources. Sodium selenite, sodium selenate, and SeMet were similarly effective in restoring most measures of Se status; high-selenium broccoli was much less effective. However, Se from high-selenium broccoli was nonsignificantly different from the other forms in restoring kidney and plasma Se concentrations. Similarly, Se from high-selenium broccoli was less effective than the other forms of Se in restoring glutathione peroxidase enzyme activity. We conclude that Se from high-selenium broccoli is absorbed, distributed, and retained in a different manner than Se from sodium selenite, sodium selenate and SeMet. These differences are probably because the metabolic pathway used by Se from high-selenium broccoli is different from the pathways used by the other forms of Se utilized in this study. Keywords: Selenium; broccoli; absorption; tissue distribution; sodium selenate; sodium selenite; selenomethionine