Assessing the Bioavailability and Bioaccessibility of Selenium from Selenium-Rich Algae

Abstract

Many new selenium (Se) sources for supplementation use are emerging. The objective of this study was to test the Se bioaccessibility (BAC) and bioavailability (BA) of Se-rich algae. Algal samples were cultivated in media containing selenite or selenate then BAC and BA were compared to Se-salts and Se-amino acids from traditional supplementation. BAC was tested based on the Se solubility post in vitro digestion and BA by induction of cellular glutathione peroxidase activity (GPx) in a Se deficient Caco-2 cell model. Cells treated with algae grown in selenate and selenite had a mean GPx activity that was significantly less than the SeMet treatment (P<0.05). Overall, no algae samples grown in selenite were identified as superior since no significant differences were found among the algae samples. However, the algae grown in the higher concentration of selenate (200 ppm) with no sulfite appeared to have a better BA than all other algae samples. Although Se-rich algae did not increase GPx activity as well as traditional supplementation forms, the results gave an insight for the ways to improve Se BA from this novel source. In addition, evaluation of nutritional profile of the algae will give us a greater understanding of how it can offer other health benefits for future supplementation.