Effect of Salmonella typhimurium enterotoxin (S-LT) on lipid peroxidation and cell viability levels of isolated rat enterocytes

Reactive oxygen species (ROS) are potent mediators of inflammatory disorder s and may be of pathophysiological importance in S. typhimurium induced tis sue damage. This study was carried out to investigate if ROS play a role in mediating the enterocyte damage during in vitro exposure to Salmonella typ himurium enterotoxin (S-LT). The ROS generation was detected by measuring t he changes in the enterocyte arachidonic acid (AA) metabolism (measured ind irectly by estimating the level of enterocyte damage in the absence and pre sence of the cyclooxygenase inhibitor, indomethacin) and xanthine oxidase a ctivity. The enterocyte damage was estimated by measuring the changes in th e level of lipid peroxidation and cell viability. The results obtained show ed that the exposure of isolated rat enterocytes to S-LT resulted in an inc reased XO activity; an increased arachidonic acid metabolism, dose and time dependent increase in the level of lipid peroxidation and decreased cell v iability. Lipid peroxidation decreased and cell viability increased in the presence of the antioxidant enzymes superoxide dismutase (SOD) or catalase. Thus the in vitro exposure of the enterocytes to S-LT is accompanied by an increased generation of ROS which may induce the lipid peroxidation of the enterocyte membrane thereby leading to a loss of cell viability.