Neuroprotective Effects of the Glutathione Precursor N-Acetylcysteine against Rotenone-Induced Neurodegeneration
In this study, the neuroprotective potential of the glutathione precursor N-acetylcysteine in the rotenone-induced Parkinson’s disease (PD) was investigated. Rats were administered rotenone (1.5 mg/kg/day) once every other day for 2 weeks by subcutaneous injection. Starting from the first day of rotenone treatment, rats received the vehicle control or N-acetylcysteine (NAC) at doses of 10 and 30 mg/kg orally given at time of rotenone injection. Rats were evaluated for brain malondialdehyde (MDA), reduced glutathione (GSH), nitric oxide content, and paraoxonase-1 (PON-1) activity in the striatum, cerebral cortex, and the rest of the brain tissue. The level of the anti-apoptotic Bcl-2 was also determined in the striatum. In addition, histopathological examination and the expression of cycloxygenase-2 (COX-2) in the striatum and cerebral cortex were performed. Rotenone treatment caused a significant increase in MDA and nitric acid content in the striatum, cerebral cortex, and the rest of the brain tissue. It also significantly decreased brain GSH content and PON-1 activity in these regions and decreased striatal Bcl-2 level compared to control values. Rotenone treatment caused neuronal necrosis, apoptosis, and vacuolization, and increased the expression of COX-2 in both the striatum and cerebral cortex. NAC given at doses of 10 and 30 mg/kg to rotenone-treated rats caused a dose-dependent significant decrease in MDA levels in the cortex and the rest of the brain tissue and at the dose of 30 mg/kg significantly decreased the striatal MDA level. It also significantly decreased the nitric oxide level, increased GSH content and PON-1 activity in the striatum, cerebral cortex, and the rest of the brain when given at doses of 10 and 30 mg/kg. Additionally, there was a significant increase in the striatal Bcl-2 level by NAC at 30 mg/kg. NAC decreased neuronal necrosis and apoptosis as well as COX-2 immunostaining in both the striatum and cerebral cortex in a dose-dependent manner. These findings suggest a potential benefit for NAC in alleviating brain oxidative stress, neuroinflammation, and neurodegeneration in the rotenone model of PD in rats. NAC could thus be a useful adjunct in the treatment of patients with PD.
Submission of an original manuscript to the Journal will be taken to mean that it represents original work not previously published; that it is not being considered elsewhere for publication; that the author(s) agrees to assign copyright to the Journal upon acceptance for publication in the Journal, and if accepted for publication, it will be published in the digital format (PDF) and/or in print and it will not be published elsewhere in the same form, for commercial purposes, in any language, without the consent of the Publisher.