Obeticholic acid (also known as INT-747), is a potent, orally bioavailable farnesoid X receptor (FXR) agonist. The key role of the farnesoid X receptor (FXR) as a regulator of bile and cholesterol metabolism in the liver, with preclinical data from numerous studies providing strong rationale for the advancement of FXR agonists as hepatoprotective therapeutics in chronic liver disease. Obeticholic acid is marketed under the trade name Ocaliva. Ocaliva is specifically indicated for the treatment of primary biliary cholangitis (PBC) in combination with ursodeoxycholic acid (UDCA) in adults with an inadequate response to UDCA, or as monotherapy in adults unable to tolerate UDCA.

Cholic acid is a primary bile acid synthesized from cholesterol in the liver. Endogenous bile acids including cholic acid enhance bile flow and provide the physiologic feedback inhibition of bile acid synthesis. The mechanism of action of cholic acid has not been fully established; however, it is known that cholic acid and its conjugates are endogenous ligands of the nuclear receptor, farnesoid X receptor (FXR). FXR regulates enzymes and transporters that are involved in bile acid synthesis and in the enterohepatic circulation to maintain bile acid homeostasis under normal physiologic conditions. U.S. Food and Drug Administration approved Cholbam (cholic acid) capsules, the first FDA approved treatment for pediatric and adult patients with bile acid synthesis disorders due to single enzyme defects, and for patients with peroxisomal disorders (including Zellweger spectrum disorders).

Ursodiol tablets, USP are bile acids indicated for the treatment of patients with primary biliary cirrhosis. Ursodiol (Ursodeoxycholic acid), a naturally occurring hydrophilic bile acid, derived from cholesterol, is present as a minor fraction of the total human bile acid pool. Ursodeoxycholic acid reduces elevated liver enzyme levels by facilitating bile flow through the liver and protecting liver cells. The main mechanism if anticholelithic. Although the exact process of ursodiol's anticholelithic action is not completely understood, it is thought that the drug is concentrated in bile and decreases biliary cholesterol by suppressing hepatic synthesis and secretion of cholesterol and by inhibiting its intestinal absorption. The reduced cholesterol saturation permits the gradual solubilization of cholesterol from gallstones, resulting in their eventual dissolution. In addition to the replacement and displacement of toxic bile acids, other mechanisms of action include cytoprotection of the injured bile duct epithelial cells (cholangiocytes) against toxic effects of bile acids, inhibition of apotosis of hepatocytes, immunomodulatory effects, and stimulation of bile secretion by hepatocytes and cholangiocytes. Neither accidental nor intentional overdosing with ursodeoxycholic acid has been reported. Doses of ursodeoxycholic acid in the range of 16-20 mg/kg/day have been tolerated for 6-37 months without symptoms by 7 patients. The LD50 for ursodeoxycholic acid in rats is over 5000 mg/kg given over 7-10 days and over 7500 mg/kg for mice. The most likely manifestation of severe overdose with ursodeoxycholic acid would probably be diarrhea, which should be treated symptomatically.

Deoxycholic acid is a a bile acid which emulsifies and solubilizes dietary fats in the intestine, and when injected subcutaneously, it disrupts cell membranes in adipocytes and destroys fat cells in that tissue. In April 2015, deoxycholic acid was approved by the FDA for the treatment submental fat to improve aesthetic appearance and reduce facial fullness or convexity. It is marketed under the brand name Kybella by Kythera Biopharma and is the first pharmacological agent available for submental fat reduction, allowing for a safer and less invasive alternative than surgical procedures. As a bile acid, deoxycholic acid emulsifies fat in the gut. Synthetically derived deoxycholic acid, when injected, stimulates a targeted breakdown of adipose cells by disrupting the cell membrane and causing adipocytolysis. This results in an inflammatory reaction and clearing of the adipose tissue remnants by macrophages. Deoxycholic acid's actions are reduced by albumin and tissue-associated proteins, therefore its effect is limited to protein-poor subcutaneous fat tissue. Protein-rich tissues like muscle and skin are unaffected by deoxycholic acid, contributing to its safety profile. Deoxycholic acid is a cytolytic agent. The physiologic effect of deoxycholic acid is by means of decreased cell membrane integrity. Deoxycholic acid inhibits miR-21 expression in primary rat hepatocytes in a dose-dependent manner, and increases miR-21 pro-apoptotic target programmed cell death 4 (PDCD4) and apoptosis. Deoxycholic acid decreases NF-κB activity, shown to represent an upstream mechanism leading to modulation of the miR-21/PDCD4 pathway.

Turofexorate Isopropyl (XL335) is a potent, selective, and orally bioavailable FXR agonist. Binds to the ligand-binding domain (LBD) of human FXR. Turofexorate Isopropyl resides in a predominately hydrophobic pocket with only a few polar atoms making contact with WAY-362450. Turofexorate Isopropyl promotes transcription of the human BSEP, human SHP, and mouse IBABP genes utilizing reporter constructs with EC50 of 17, 230, and 33 nM, respectively in promoter assays. Turofexorate Isopropyl had been in phase I clinical trials for the treatment of hyperlipidemia. This compound was originally discovered by Exelixis Pharmaceuticals, then licensed to Wyeth (now a wholly-owned subsidiary of Pfizer). However, the studies were discontinued.

GW-4064 is a synthetic small molecule selective agonist of the orphan nuclear receptor FXR developed by GlaxoSmithKline. GW-4064-mediated FXR activation ameliorates diet-induced obesity, suppresses hepatic lipid accumulation, and maintains glucose and lipid homeostasis in C57BL/6 mice. GW-4064-treated tumors exhibited decreased levels of leptin-regulated proteins along with a strong staining intensity for SOCS3. Thus, FXR ligand GW-4064 might represent an emerging potential anti-cancer therapy able to block the tumor supportive role of activated fibroblasts within the breast microenvironment.

T0901317 is a potent, high affinity liver X receptors (LXRs) agonist. It upregulates expression of the ABCA1 gene associated with cholesterol efflux regulation and high-density lipoproteins metabolism. It also exhibits inverse agonist activity at constitutive androstane receptors (CARs). T0901317 activates bile acid farnesoid X receptors (FXRs), and it is 10-fold more potent than natural FXR ligand chenodeoxycholic acid.

Methyl cholate is a cholesterol biosynthesis inhibitor. It exhibited inhibitory effect on the later step of cholesterol biosynthesis, indicating that its action mode is different from that of statins that act on the HMG-CoA reductase.