Ursodeoxycholic acid ( INN, BAN and AAN), also known as ursodiol ( USAN) and the abbreviation UDCA, from the root-word for bear urso, as bear bile contains the substance, is one of the secondary bile acids, which are metabolic byproducts of intestinal bacteria.
Endogenous effectsPrimary bile acids are produced by the liver and stored in the gall bladder. When secreted into the intestine, primary bile acids can be metabolized into secondary bile acids by intestinal bacteria. Primary and secondary bile acids help the body digest fats. Ursodeoxycholic acid helps regulate cholesterol by reducing the rate at which the intestine absorbs cholesterol molecules while breaking up micelles containing cholesterol. Because of this property, ursodeoxycholic acid is used to treat (cholesterol) gallstones non-surgically. It is also used to relieve itching in pregnancy for some women who suffer obstetric cholestasis. While some bile acids are known to be colon tumor promoters (e.g. deoxycholic acid), others such as ursodeoxycholic acid are thought to be chemopreventive, perhaps by inducing cellular differentiation and/or cellular senescence in colon epithelial cells. It is believed to inhibit apoptosis. Ursodeoxycholic acid has also been shown experimentally to suppress immune response such as immune cell phagocytosis. Prolonged exposure and/or increased quantities of systemic (throughout the body, not just in the digestive system) ursodeoxycholic acid can be toxic.Material Safety Data Sheet on Ursodiol MSDS. https://fscimage.fishersci.com/msds/70916.htm
Medical usesAn incomplete list of the current uses is as follows:
- Reduction in gallstone formation, either in patients with gallstones unfit for cholecystectomy, or obese patients undergoing rapid weight loss to prevent gallstone formation.
- For the treatment of primary biliary cholangitis (also known as primary biliary cirrhosis, PBC).
- To aim to improve bile flow in patients with cystic fibrosis (controversial)
- In newborn infants with impaired bile flow
- After bariatric surgery, to prevent cholelithiasis due to the rapid weight loss with biliary cholesterol oversaturation and also biliary diskinesia secondary to abnormalities in cholecystokinin and biliary enervation.