The Role of Bile Acids in Natural Resistance: Physico-Chemical Host Defence

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ABSTRACT:

The toxic effects of endotoxin, the cell wall component-of Gram negative intestinal bacteria, under experimental conditions, can be induced only when they are administered.parenterally. However, in naturally occurring entero-endotoxaemic diseases (e.g., septic and various shocks, etc.), the endotoxin is absorbed from the intestinal tract. The cause and mode of translocation was unknown. The generally used experimental shock models differ from natural diseases only in the mode by which endotoxin enter the blood circulation. If the common bile duct of rats was chronically cannulated (bile deprived animals) orally administered endotoxin was absorbed from the intestinal tract into the blood circulation and provoked endotoxin shock. This translocation of endotoxins and the consequent shock can be prevented by sodium deoxycholate or natural biles. The bile acids split the endotoxin macromolecule into atoxic fragments. A similar detoxifying detergent action plays a significant role in host defence against infectious agents with a lipoprotein outer structure (e.g., so-called "big" viruses). This defence mechanism of macroorganisms based on the detergent activity of bile acids is called physico-chemical defence system. Since bile deficiency and the consequent endotoxaemia are important components in the pathogenesis of certain diseases (e.g., sepsis, intestinal syndrome of radiation disease, hepatorenal syndrome, parvovirus infection, herpes, psoriasis, atherosclerosis, etc.), bile acids may be used for the prevention and/or therapy of some clinical conditions such as the hepato-renal syndrome and psoriasis..

Source: Natural Immunity – 2005