Submitted to: Journal of Federation of American Societies for Experimental Biology
Publication Type: Abstract only
Publication Acceptance Date: 2/1/2003
Publication Date: 3/17/2003
Citation: Roberge, M., Borgerding, A., Finley, J.W. 2003. Specific selenium species from broccoli are transported differently across a caco-2 cell monolayer [abstract]. Journal of Federation of American Societies for Experimental Biology. 17(5):A1136. Interpretive Summary:
Technical Abstract: Biological actions of selenium (Se) depend in part on its specific chemical form. Reverse-phase HPLC coupled to an Inductively Coupled Plasma Mass Spectrometer (HPLC-ICP-MS) with known Se standards was used to characterize chemical forms of Se in biological matrices. High-Se broccoli contained multiple Se species including salts and Se-methyl selenocysteine (SeMSC), but many species were labile depending on the extraction conditions. Extractions at higher pH resulted in more highly oxidized compounds. Species of Se absorbed from high-Se broccoli across the gut epithelia were determined by exposing lyophilized broccoli to a simulated gastric and intestinal digestion. Digestates (Se concentrations of 0.1 to 15 ug/g) were applied to the apical surface of Caco-2 cells grown on permeable membranes and allowed to incubate 5 or 10h. Apical and basolateral media were collected and analyzed by HPLC-ICP-MS. Selenite, selenate and methylseleninic acid from broccoli extracts were evenly distributed after 5 h whereas SeMSC and selenomethionine required 10 h for equilibration. An unknown Se compound in broccoli extract was not detected on the basolateral side and mass balance indicated quantitative conversion to selenite, selenate or SeMSC. These data demonstrate that the intestinal cell is capable of absorbing some Se molecules from broccoli intact, whereas others are metabolized during absorption.