Abstract
Background: Parkinson's disease (PD) is a neurodegenerative disorder for which no curative therapies currently exist. Experimental models employing 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) reproduce PD features such as striatal dopaminergic dysfunction and motor deficits. Various MPTP dosing regimens are used to screen drug candidates for PD, but their validity is limited because of the predominant use of young male animals. Sex bias is another issue that is underrepresented in PD research, since females are more susceptible to this pathology. Here, we studied the model of bolus administration of MPTP (30 mg/kg) in aged female mice and assessed its sensitivity to the antioxidants fullerene C(60) and fullerenol C(60)(OH)(24), given that oxidative stress is a key contributor to PD. Methods: 12-month-old female C57BL/6 mice received fullerene (0.1 mg/kg/day, via diet) or fullerenol (0.15 mg/kg/day, via drinking water). On day 10, mice were injected with MPTP. We studied tremor, piloerection, and behavior in the pole test, rotarod, pole test, and open field. High-performance liquid chromatography (HPLC) was employed to study dopaminergic neurotransmission, and the expression levels of its molecular regulators and nitric oxide synthase (NOS)-related targets were investigated using RT-PCR in the striatum and cortex. Results: MPTP-challenged mice displayed profound impairment in markers of dopaminergic neurotransmission and cellular distress, and showed disrupted motor behavior and vegetative functions. Antioxidant-treated animals that received a bolus injection of MPTP demonstrated partial preservation of tremor response, dopaminergic parameters, and iNOS and nNOS gene expression, although motor performance in the pole test was only modestly improved. Fullerenol appeared more effective in decreasing MPTP-induced neurochemical changes. Conclusions: The applied MPTP model showed its validity in mimicking PD features and was sensitive to low doses of antioxidants, suggesting its usefulness for screening drugs that target oxidative and nitrosative stress. The neuroprotective effects of fullerene-based compounds suggest their potential utility in the treatment of PD.