Protective effect of N-acetylcysteine on rat liver cell membrane during methanol intoxication

Methanol is oxidized in-vivo to formaldehyde and then to formate, and these processes are accompanied by the generation of free radicals. We have stud ied the effect of N-acetylcysteine on liver cell membrane from rats intoxic ated with methanol (3.0 g kg(-1)). Evaluation of the effect was achieved by several methods. Lipid peroxidatio n and surface charge density were measured. An ultrastructural study of the liver cells was undertaken. The concentration of marker enzymes of liver d amage (alanine aminotransferase and aspartate aminotransferase) in blood se rum was measured. Methanol administration caused an increase in lipid peroxidation products ( approximately 30%) as well as in surface charge density (approximately 60%) . This might have resulted in the membrane liver cell damage visible under electron microscopy and a leak of alanine aminotransferase and aspartate am inotransferase into the blood (increase of approximately 70 and 50%, respec tively). Ingestion of N-acetylcysteine with methanol partially prevented th ese methanol-induced changes. Compared with the control group, lipid peroxi dation was increased by approximately 3% and surface charge density by appr oximately 30%. Alanine aminotransferase and aspartate aminotransferase acti vity increased by 9 and 8%, respectively, compared with the control group. The results suggested that N-acetylcysteine was an effective antioxidant in methanol intoxication. It may have efficacy in protecting free radical dam age to liver cells following methanol intoxication.