The PXR agonist and secondary bile acid LCA attenuates LPS-induced cytokine production in IEC-6 enterocytes. qRT-PCR showing (a) dose response of LCA treatment on IEC-6 enterocytes for the induction of PXR (i) and the PXR-responsive gene Mdr1a (ii). (b) Expression levels of transcripts for IL-6 (i) and TNFα (ii) in IEC-6 enterocytes treated with 100 μM of LCA followed by 2 h stimulation with LPS (1 μg/ml). Results shown are for IEC-6 cells in triplicate. Fold changes were calculated relative to untreated cells and normalized to β-actin. *P⩽0.05, **P⩽0.01 by unpaired t test. LCA, lithocholic acid; LPS, lipopolysaccharide; PXR, pregnane X receptor; qRT-PCR, quantitative real-time PCR.