Bile-acid overview

An Overview of Bile-Acid Synthesis, Chemistry and Function... 

Many sites of exposure to bile in the body are associated with the development of cancer, e.g. the oesophagus, gallbladder and bile duct, pancreas, small intestine and colon (reviewed in ref. 2). One explanation for increased cancer at these sites could be that bile acids stimulate carcinogenesis via DNA-damaging effects. This chapter provides an overview of research conducted in relation to establishing the genotoxic and carcinogenic effects of bile acids. 

Hofmann, A.F., and A. Roda. 1984. Physicochemical properties of bile acids and their relationship to biological properties An overview of the problem. J Lipid Res 25 1477. 

This article focuses on specific dietary components—whether naturally occurring or added as food ingredients—known to interfere with the mechanisms of cholesterol absorption. An overview of cholesterol absorption is provided and emphasizes the critical role of bile acids and micelle formation in solubilizing cholesterol for transport to the brush border membrane of enterocytes. Where applicable, information is also included about commercial food ingredients that are specifically used as cholesterollowering agents. 

Schreiber, A.J. and Simon, F.R., Overview of clinical aspects of bile salt physiology, J. Pediatr. Gastroenterol. Nutr. 2, 337-345, 1983 Chiang, J.Y., Regulation of bile acid synthesis. Front. Biosci. 3, dll76-dll93, 1998 Cybulsky, M.I., Lichtman, A.H., Hajra, L., and liyama, K., Leukocyte adhesion molecules in atherogenesis, Clin. ChirtL Acta 286, 207-218, 1999. 

Fig. 1. Overview of the metabolic and transport pathways that control cholesterol levels in mammalian cells. Cholesterol is synthesized from acetyl-CoA and the four key enzymes that regulate cholesterol synthesis are indicated. Cells also obtain cholesterol by uptake and hydrolysis of LDL s cholesteryi esters (CE). End products derived from cholesterol or intermediates in the pathway include bile acids, oxysterols, cholesteryi esters, and non-steroidal isoprenoids. ACAT, acyl-CoA cholesterol acyltransferase.

B. S. Reddy, "Oncology Overview The Role of Bile Acids in the... 

The research areas covered by the Meeting are very wide, having to do with the liver and biliary pathophysiology, nutrition, gallstone disease and atherosclerosis prevention. Scientists from the major clinical and basic disciplines provided an update overview of the complex mechanisms regulating the biosynthesis and catabolism of cholesterol and the formation and metabolism of bile acids. 

Chiral micellar solubilization may involve the use of chiral surfactants, or a combination of achiral surfactants and a chiral selector. Terabe [26] and Bereuter [25] provide a comprehensive overview of applications involving chiral surfactants such as bile salts or synthetic amino acid surfactants. The use of cyclodextrins (CD) as the chiral selector in combination with MEKC was successful for the separation of neutral racemic nonsteroidal aromatase inhibitors and barbituates [38]. Further approaches to the separation of enantiomers utilizing a combination of CD-MEKC have been described in the review by Terabe [26]. 

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