Biological availability of selenosugars in rats.

Area of Science:

• Biochemistry
• Toxicology
• Nutritional Science

Background:

• Selenium is an essential trace element with complex metabolism.
• Selenosugars represent a unique class of selenium compounds.
• Understanding selenosugar bioavailability is crucial for assessing their biological roles and potential toxicity.

Purpose of the Study:

• To investigate the biological availability and metabolism of two orally administered selenosugars in rats.
• To compare selenosugar metabolism with that of selenite and trimethylselenonium ion (TMSe).

Main Methods:

• Rats were exposed to sodium selenite, TMSe, selenosugar 1, or selenosugar 2 via drinking water for 48 hours.
• Urine samples were analyzed for total and specific selenium species concentrations using ICPMS and HPLC/ICPMS.
• Tissue samples (liver, kidney, small intestine, blood) were analyzed for total selenium concentrations.

Main Results:

• Selenosugar 1 was identified as a major metabolite in background urine.
• Rats exposed to selenite efficiently biotransformed it into selenosugars and TMSe.
• Rats exposed to selenosugars excreted significant amounts of TMSe, indicating partial bioavailability and biotransformation.
• Selenium accumulation was observed in tissues of selenite-exposed rats, but not significantly in other groups, except for minor increases in the small intestine of selenosugar-exposed rats.

Conclusions:

• Oral selenosugars are at least partly biologically available and can be metabolized to TMSe in rats.
• Selenite is readily biotransformed into various selenium species, including selenosugars and TMSe.
• TMSe appears to be excreted unchanged, with limited biotransformation in rats.