ABSTRACT
The possibility that bile acids might be involved in the pathogenesis of colon cancer was proposed by P. Hill and co-workers. Hill and B. S. Drasar summarized the major reactions of the gut bacteria such as hydrolysis of glycine or taurine conjugates and 7α-dehydroxylation of primary bile acids, cholic, and chenodeoxycholic acid, to produce deoxycholic and lithocholic acids, respectively. R. H. Palmer has suggested that the molecular configuration of the bile acids nucleus is a major factor in explaining the toxic effects of bile acids. In studies of the effects of human bile and individual bile acids on cultured human fibroblasts, Trias found that the conjugates of deoxycholic acid were the most toxic, whereas, the conjugates of cholic and chenodeoxycholic acid were relatively nontoxic. The major bile acids, cholic, chenodeoxycholic, deoxycholic, and lithocholic acids, have been evaluated in the Syrian Hamster Embryo Cell Transformation system.
