Influence of lipoic acid on antioxidant capacity and lipid peroxidation in rats. The excessive production of reactive oxgen species (ROS), associated with inflammation, leads to oxidative stress, which is a major contributing factor to the high mortality in endotoxic shock. Lipoic acid is a potent antioxidant that can protect cells from oxidative damage by reactive oxygen species. Lipopolisaccharide stimulates synthesis and releasing from animal phagocytes, aggregating numbers of metabolites among them reactive oxygen species. They lead to inflammation and septic shock. Experiments were performed on male Wistar rats weighing 250-300 g. The administration of lipoic acid 0.5 h after LPS challenge resulted in increase in antioxidant capacity and decrease in plasma lipid peroxidation compared to LPS group.