Keeping track to selenium metabolism

23-Mar-2012

J. Giner et al.

The technique allows for infinitesimal amounts of selenium to be quantified in their different chemical forms.

Spanish and Danish researchers have developed a method for the in vivo study of the unknown metabolism of selenium, an essential element for living beings. The technique can help clarify whether or not it possesses the anti-tumour properties that have been attributed to it and yet have not been verified through clinical trials.

"It is vox populi that doctors around the world recommend selenium supplements to complement traditional therapy against cancer and the AIDS virus but the truth is that the basics of these properties are not clear," explains to SINC Justo Giner, a chemist from the University of Oviedo (Spain).

"Even the general metabolism of selenium has not been completely cleared up," adds Giner who, along with other researchers at the same university and the University of Pharmaceutical Sciences of Copenhagen (Denmark), has developed a new methodology for discovering how this element moves around living organisms.

The in vivo study was carried out on laboratory rats, which were administered a stable metabolic tracer of enriched selenium (77Se). According to the researcher, "it opens the door for transferring this method to clinical trials on humans given that innocuous, non-radioactive isotopes are used."

In line with expected findings, the results reveal that selenium concentrations in biological tissue, blood and urine samples can indeed be analysed. Therefore, mass spectrometry techniques are employed along with a second isotopic tracer (74Se), which helps to quantify "with unequivocal precision" infinitesimal amounts of selenium in its different chemical forms that are distributed by the body.

Selenium is an antioxidant and plays an important role in the body's immune response. Understanding the path that it takes from the moment it is administered to when it is excreted could help to clarify its metabolism and its possible protecting effect against cancer and HIV.

The ideal dose of selenium

The main sources of selenium come from foods such as yeasts, animal products (meat, seafood, dairy products) and vegetables like broccoli, wheat-germ, nuts (especially Brazil nuts), oats, garlic and barley. The current recommended daily intake of selenium is approximately 55 micrograms for women and 70 micrograms for men.

Selenium deficiency is associated with different pathologies like endemic cardiomyopathy, cystic fibrosis, multiple sclerosis, rheumatoid arthritis, haemolysis and muscular dystrophy. Furthermore, thyroid metabolism is affected by selenium levels since the glands deiodinasa enzymes are in fact selenoproteins.

In contrast though, when intake is higher than nutritional requirements, selenium is considered a 'nutraceutical'. Mainly thanks to its antioxidant properties this means that it is beneficial for the health as long as it does not surpass the threshold in which it starts to become toxic.

Fundación Española para la Ciencia y la Tecnología (FECYT)

Request information now

Recommend news PDF version / Print

Share on

Facts, background information, dossiers
  • selenium
  • Fecyt
  • metabolism
More about FECYT
  • News

    Fluorescence method detects mercury contamination in fish

    Researchers from the University of Burgos (Spain) have developed a fluorescent polymer that lights up in contact with mercury that may be present in fish. High levels of the metal were detected in samples of swordfish and tuna. According to the conclusions of another Spanish study, mercury ... more

    Chemical fingerprints confirm the saffron fraud

    Saffron from Spain is one of the world's most superior varieties, but the majority of this product which is labelled and exported as such originates in other countries. Scientists from the Czech Republic and Spain confirmed this false labelling after analysing 44 commercial products. By usi ... more

    Some commercial coffees contain high levels of mycotoxins

    An analysis of one hundred coffees sold in Spain has confirmed the presence of mycotoxins -toxic metabolites produced by fungi. In addition, five of the samples that were tested were found to contain ochratoxin A, the only legislated mycotoxin, in amounts that exceeded maximum permitted lev ... more

Your browser is not current. Microsoft Internet Explorer 6.0 does not support some functions on Chemie.DE