Permeability and Conjugative Metabolism of Flaxseed Lignans by Caco-2 Human Intestinal Cells

Abstract

Reports in the literature associate the dietary intake of flaxseed lignans with a number of health benefits. The major lignan found in flaxseed, secoisolariciresinol diglucoside (1), undergoes metabolism principally to secoisolariciresinol (2), enterodiol (3), and enterolactone (4) in the human gastrointestinal tract. Systemically, lignans are present largely as phase II enzyme conjugates. To improve understanding of the oral absorption characteristics, a systematic evaluation of the intestinal permeation was conducted and the conjugative metabolism potential of these lignans using the polarized Caco-2 cell system was analyzed. For permeation studies, lignans (100 μM) were added to acceptor or donor compartments and samples were taken at 2 h. For metabolism studies, lignans (100 μM) were incubated in Caco-2 for a maximum of 48 h. Cell lysates and media were treated with β-glucuronidase/sulfatase, and lignan concentrations were determined using HPLC. Apical-to-basal permeability coefficients for 2-4 were 8.0 ± 0.4, 7.7 ± 0.2, and 13.7 ± 0.2 (×10(-6)) cm/s, respectively, whereas efflux ratios were 0.8-1.2, consistent with passive diffusion. The permeation of compound 1 was not detected. The extent of conjugation after 48 h was <3%, ∼95%, ∼90%, and >99% for 1-4, respectively. These data suggest 2-4, but not 1 undergo passive permeation and conjugative metabolism by Caco-2 cells.

Further exploring the absorption and enterocyte metabolism of quercetin forms in the Caco-2 model using nano-LC-TOF-MS

“…In overall, our results pointed out the suitability of the proposed method that showed LODs, on column amount or injection volume requirements lower than for conventional HPLC methods using UV , fluorimetric , electrochemical , or MS detection . Furthemore, an environmental advantage is the lower solvent demand of the proposed nano‐LC method (flow rate of 300 nL/min), even in comparison with UHPLC methods (e.g.…”

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Comparative pharmacokinetics of purified flaxseed and associated mammalian lignans in male Wistar rats

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Dietary fibers and associated phytochemicals in cereals

“…) . The uptake is presumably by passive diffusion as indicated in vitro . While the plant lignans in the postabsorptive phase only represented 2% of the total lignans, the proportion after breakfast and lunch represented 21–32% of the total lignans and with a concomitant decrease in the concentration of enterolignans .…”