Bile acids (BAs) are hormones which serve many different roles in the body’s digestive and metabolic systems. Their unique chemical composition contributes to their reported anti-inflammatory and antioxidant effects, explaining their historical use in traditional Chinese medicine (TCM) [1,2,3]. A total of forty-four different animal bile products isolated from both vertebrates and invertebrates have been used to treat ailments of the liver, skin, and biliary system. The earliest records suggest that bile salts from dog and ox were first used as therapeutics; however, the use of bear bile continues to be the most popular and of particular interest in today’s exploration of BA-based therapy [1,2]. Bile and gallbladders collected from black (Selenarctos thibetamus) and brown (Ursus arctos) bears have been used for thousands of years to remove toxins from the body, stop convulsions, and improve vision [1,3]. In TCM, as a medicine “cool” in nature, bear bile is used to treat “hot” diseases like fever, inflammation, swelling, and pain [1,3]. Modern analysis of bear bile shows that it contains relatively high levels of ursodeoxycholic acid (UDCA) and tauroursodeoxycholic acid (TUDCA) and has numerous pharmacological properties, such as: antimicrobial, anti-inflammatory, anti-convulsant, anti-hepatotoxic, and sedative [3,4,5,6]. The hepatoprotective, anti-gallstones and hypolipidemic effects of bear bile have led to its use as a therapeutic for liver disease and biliary cirrhosis in both TCM and modern Western medicine [2,3,7].
Current interest in BAs arose from the discovery of their signaling properties and ability to regulate the activity of many genes through the orphan nuclear receptor farnesoid X receptor (FXR) [8]. FXR agonists have shown potential as treatments for primary biliary cirrhosis and nonalcoholic steatohepatitis [8,9,10,11]. The Discovery of another BA receptor, transmembrane G-protein-coupled receptor 5 (TGR5), and its widespread distribution in the body, has brought on new explorations on BA-based therapies [8] and their extra-hepatic homeostatic functions on lipid, glucose, and energy metabolism [12,13,14,15]. Interestingly, more recent studies have shown that BAs are protective in neurodegenerative diseases, including a number of ocular afflictions. The aim of this review is to summarize the current knowledge of BA biosynthetic and functional pathways with a particular focus on their effects and therapeutic potential for ocular diseases.
www.ncbi.nlm.nih.gov
Current interest in BAs arose from the discovery of their signaling properties and ability to regulate the activity of many genes through the orphan nuclear receptor farnesoid X receptor (FXR) [8]. FXR agonists have shown potential as treatments for primary biliary cirrhosis and nonalcoholic steatohepatitis [8,9,10,11]. The Discovery of another BA receptor, transmembrane G-protein-coupled receptor 5 (TGR5), and its widespread distribution in the body, has brought on new explorations on BA-based therapies [8] and their extra-hepatic homeostatic functions on lipid, glucose, and energy metabolism [12,13,14,15]. Interestingly, more recent studies have shown that BAs are protective in neurodegenerative diseases, including a number of ocular afflictions. The aim of this review is to summarize the current knowledge of BA biosynthetic and functional pathways with a particular focus on their effects and therapeutic potential for ocular diseases.
Pharmacological and Metabolic Significance of Bile Acids in Retinal Diseases
Bile acids (BAs) are amphipathic sterols primarily synthesized from cholesterol in the liver and released in the intestinal lumen upon food intake. BAs play important roles in micellination of dietary lipids, stimulating bile flow, promoting biliary phospholipid ...
www.ncbi.nlm.nih.gov
