Bile acids are essential for solubilization and transport of dietary lipids, are the major products of cholesterol catabolism, and are physiological ligands for farnesoid X receptor (FXR), a nuclear receptor that regulates genes involved in lipid metabolism.1They are also inherently cytotoxic, as physiological imbalance contributes to increased oxidative stress.2,3Bile acid-controlled signaling pathways are promising novel targets to treat such metabolic diseases as obesity, type II diabetes, hyperlipidemia, and atherosclerosis.Guggulsterone, derived from resin of the guggul tree, is a competitive antagonist of FXR bothin vitroandin vivo.4Thecisstereoisomer of guggulsterone, (E)-guggulsterone, decreases chenodeoxycholic acid (CDCA)-induced FXR activation with an IC50value of 15 μM.5,6By inhibiting CDCA-induced transactivation of FXR, guggulsterone lowers low-density lipoprotein cholesterol and triglyceride levels in rodents fed a high cholesterol diet.4 1.Makishima, M., Okamoto, A.Y., Repa, J.J., et al.Identification of a nuclear receptor for bile acidsScience2841362-1365(1999) 2.Barbier, O., Torra, I.P., Sirvent, A., et al.FXR induces the UGT2B4 enzyme in hepatocytes: A potential mechanism of negative feedback control of FXR activityGastroenterology1241926-1940(2003) 3.Tan, K.P., Yang, M., and Ito, S.Activation of nuclear factor (erythroid-2 like) factor 2 by toxic bile acids provokes adaptive defense responses to enhance cell survival at the emergence of oxidative stressMol. Pharmacol.72(5)1380-1390(2007) 4.Urizar, N.L., Liverman, A.B., Dodds, D.T., et al.A natural product that lowers cholesterol as an anatagonist ligand for FXRScience296(5573)1703-1706(2002) 5.Cui, J., Huang, L., Zhao, A., et al.Guggulsterone is a farnesoid X receptor antagonist in coactivator association assays but acts to enhance transcription of bile salt export pumpThe Journal of Biological Chemisty278(12)10214-10220(2003) 6.Wu, J., Xia, C., Meier, J., et al.The hypolipidemic natural product guggulsterone acts as an antagonist of the bile acid receptorMolecular Endocrinology16(7)1590-1597(2002)
CAY10771 is a dual agonist of farnesoid X receptor (FXR) and peroxisome proliferator-activated receptor δ (PPARδ).1It activates FXR and PPARδ in reporter assays using HEK293T cells (EC50s = 0.94 and 1.5 μM, respectively) and is selective for these receptors over retinoic acid receptor α (RARα), retinoid X receptor α (RXRα), PPARα, PPARγ, and liver X receptor α (LXRα) at 10 μM. 1.Schierle, S., Neumann, S., Heitel, P., et al.Design and structural optimization of dual FXR/PPARδ activatorsJ. Med. Chem.63(15)8369-8379(2020)
Tauro-α-muricholic acid (TαMCA) is an antagonist of the farnesoid X receptor (FXR; IC50 = 28 μM) and a taurine-conjugated form of the murine-specific primary bile acid α-muricholic acid . TαMCA is common in rodents but has also been found in small amounts in human serum.
Cilofexor, also known as GS-9674, is a farnesoid X receptor (FXR) agonist. The nonsteroidal FXR agonist cilofexor (GS-9674) improves markers of cholestasis and liver injury in patients with PSC. In clinical study, cilofexor was well tolerated and led to significant improvements in liver biochemistries and markers of cholestasis in patients with PSC.