Assessment of absorption of four lignan constituents of JingNing particles in rat gut using in situ single-pass intestinal perfusion.

Purpose: To study small intestinal absorption of schisadrol A, schisandrol B, schizandrin A and schisandrin B in JingNing particles using in situ single-pass intestinal perfusion (SPIP). Methods: Absorption rate constant (Ka) and apparent permeability (Papp) of the drugs at different concentrations in various parts of rat small intestine (duodenum, jejunum and ileum) were determined using SPIP. JingNing particles were also perfused in situ at different pH in the entire rat intestine. Ethanol extract of Schisandra chinensis (standard) at low concentration was perfused in the duodenum for comparison with extract of JingNing particles. Results: The order of apparent permeability of the four lignans was schisandrol A < schisandrol B < schizandrin A < schisandrin B. Ka and Papp values of the four lignans in JingNing particles were concentration-dependent. Absorption increased in the rank order: ileum > duodenum > jejunum. Optimum absorption pH was 6.50. Polygala tenuifolia extract and volatile oil of Rhizoma acori tatarinowii significantly (p < 0.05) enhanced the absorption of the four lignans. Conclusion: The four lignans were well absorbed in the intestinal tract, particularly the ileum, probably through carrier-mediated transport. The alcohol extract of Polygala tenuifolia and volatile oil of Rhizoma acori graminei enhanced the absorption of the four lignans. [ABSTRACT FROM AUTHOR]