Chenodeoxycholic acid (CDCA) is a bile acid, usually conjugated with either glycine or taurine. It acts as a detergent to solubilize fats for intestinal absorption and is reabsorbed by the small intestine. It is used as cholagogue, a choleretic laxative, and to prevent or dissolve gallstones.

Chenodeoxycholic acid （CDCA）和脱氧胆酸（DCA）均可抑制11 beta HSD2，其IC(50)值分别为22 mM和38 mM。Chenodeoxycholic acid 诱导皮质醇依赖性核内转位，增加矿物皮质激素受体（MR）的转录活性。[1] Chenodeoxycholic acid 通过激活膜G蛋白偶联受体（TGR5）依赖性通路，显著促进Ishikawa细胞生长，增加Cyclin D1蛋白和mRNA表达。[2] 在培养的人类肝母细胞瘤细胞系Hep G2中，Chenodeoxycholic acid 可使LDL受体mRNA水平提高近4倍，HMG-CoA还原酶和HMG-CoA合酶mRNA水平提高2倍。[3] Chenodeoxycholic acid 诱导的Isc被Bumetanide、BaCl2和囊性纤维化跨膜导电调节器（CFTR）抑制剂CFTRinh-172抑制（≥67%）。Chenodeoxycholic acid 激活的Isc被腺苷酸环化酶抑制剂MDL12330A降低43%，Chenodeoxycholic acid 增加细胞内cAMP浓度。[4] Chenodeoxycholic acid 通过增加其磷酸化、核内积聚来激活C/EBPβ。Chenodeoxycholic acid 增强了含有C/EBP响应元素（pGL-1651）的-1.65-kb GSTA2启动子结构的荧光素酶基因转录。Chenodeoxycholic acid 激活AMP激活的蛋白激酶（AMPK），促进细胞外信号调节激酶1/2（ERK1/2）的激活。[5]

Briefly, transfected HEK-293 cells, incubated in charcoal-treated Dulbecco's modified Eagle's medium for 24 h, are washed once with Hanks' solution and resuspended in a buffer containing 100 mM NaCl, 1 mM MgCl2, 1 mM EDTA, 1 mM EGTA, 250 mMsucrose, 20 mM Tris-HCl, pH 7.4. Cells are lysed by freezing in liquid nitrogen. Dehydrogenase activity is measured in a final volume of 20 μL containing the appropriate concentration of bile acid, 30 nCi of [3H]cortisol, and unlabeled cortisol to a final concentrations of 50 nM. The reaction is started by mixing cell lysate with the reaction mixture. Alternatively, endoplasmic reticulum microsomes are prepared from transfected HEK-293 cells and incubated with reaction mixture containing various concentrations of cortisol and CDCA. Incubation proceeded for 20 min, and the conversion of cortisol to cortisone is determined by thin layer chromatography (TLC). Because of the inaccuracy of the TLC method at low conversion rates and the end-product inhibition of 11βHSD2 at conversion rates higher than 60-70%, only conversion rates between 10 and 60% are considered for calculation. The inhibitory constant IC50 is evaluated using the curve-fitting program. Results are expressed as means±S.E. and consist of at least four independent measurements.

The cell viability is analyzed by incubating transfected HEK-293 cells and CHO cells for 1 h with the corresponding concentration of bile acid and staining with trypan blue. The toxicity of bile acids is analyzed using the tetrazolium salt MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) according to the cell proliferation kit I. No significant differences between control and bile acid-treated cells are obtained in both tests.