In vitro selenium bioaccessibility combined with in vivo bioavailability and bioactivity in Se-enriched microalga (Chlorella sorokiniana) to be used as functional food

Abstract

Speciation of seleno-metabolites and selenoproteins in Se-enriched Chlorella sorokiniana microalgae, in vitro and in vivo extracts has been performed by HPLC-ICP-MS. Selenium bioaccesibility in Se-enriched Chlorela sorokiniana evaluated by in vitro gastrointestinal digestion of the selenized microalga was 81% (79% as SeMet). Mice supplemeted with Se-enriched C. sorokiniana presented increased Se concentration in kidney, reflecting a potencial mechanism of excretion by urine. In addition, selenium bioavailavility, which was in the range of 3–15% depending on the diet was 1.13-fold higher in mice fed with Se-enriched microalgae against the basal diet, but decreased with higher amounts of selenium. Regarding bioactivity (∑Se as selenoproteins in serum/total Se in serum = 76–85% depending on the diet), selenium and selenoproteins (SeP) increased in serum from animals fed high supplemental Se levels. These results showed that Se-enriched algae can be considered as an alternative selenized food for humans, due to their high Se bioavailability.