Some enzymatic/nonenzymatic antioxidants as potential stress biomarkers of trichloroethylene, heavy metal mixture, and ethyl alcohol in rat tissues.

Enzymatic and nonenzymatic antioxidants serve as an important biological defense against environmental pollutants. Various enzymatic and nonenzymatic antioxidants as a stress biomarker in liver and kidney of rat were investigated. The antioxidant enzymes that were analyzed included superoxide dismutase (SOD), catalase, glutathione reductase (GR), glutathione-S-transferase (GST), and glutathione peroxidase. Levels of lipid peroxidation (LPO), reduced glutathione (GSH), as well as hydrogen peroxide (H(2)O(2)) were also measured in homogenates of the liver and kidney of the treated animals to determine oxidative stress induced by trichloroethylene (TCE), ethyl alcohol, and heavy metal mixture (H.M.M) individually and in different combinations. An increase up to the extent of 382% in malonaldehyde, a marker of LPO, was recorded in almost all the treatment groups in both the tissues. Similarly, a rise of 218% in GST activity was also recorded in kidney of TCE-treated animals. Although H.M.M ingestion resulted in significant change of 125% in SOD activity of hepatic tissue, the level of GR was increased by 93% in the renal tissue of the exposed rats. Solitary dose of alcohol in general did not show a significant change. Moreover, the changes in the levels of antioxidants were much more prominent when these toxicants were given in combination rather than alone. Overall, these results demonstrate the changes in the levels of antioxidant enzymes and GSH system, as well as alterations in the LPO and H(2)O(2) levels as a result of test toxicants.