Reversal of methylmercury-induced oxidative stress, lipid peroxidation, and DNA damage by the treatment of N-acetyl cysteine: a protective approach.

This study was designed to evaluate the protective effect of N-acetyl cysteine in reducing methylmercury (MeHg)-induced oxidative stress, lipid peroxidation, DNA damage in liver, kidney, and brain, and their ability to restore altered hepatic, renal, and other biochemical variables. Male Sprague-Dawley rats (150±10 g) were randomly divided into three groups. Group 1 served as the control. Groups 2 and 3 were administered methylmercury (1 mg kg⁻¹ orally, 5 days/week) for 12 weeks, and group 2 served as the experimental control. Group 3 received N-acetyl cysteine (0.6 mg kg⁻¹ intraperitoneally, two days/week) for 12 weeks after methylmercury exposure. Methylmercury exposure caused a significant rise in bilirubin, gamma-glutamyl transpeptidase, protein, triglycerides, cholesterol, urea, creatinine, uric acid, and blood urea nitrogen, with a concomitant decrease in albumin content, reduced glutathione level and acetyl cholinesterase activity, antioxidant enzymes such as glutathione reductase, glutathione peroxidase, glucose-6-phosphate dehydrogenase, and adenosine triphosphatase. However, lipid peroxidation level, metallothionein expression, and DNA damage with increment of tail length were observed after methylmercury intoxication. N-acetyl cysteine, a widely available, nontoxic amino acid derivative, is a promising antioxidant with a wide spectrum of biological functions. The ability of N-acetyl cysteine to enhance mercury excretion and its wide availability in clinical use indicate that it may be an ideal therapeutic agent against methylmercury poisoning.