Neuroprotective effects of Physical Activity in an Animal Model of Parkinson's Disease Induced by Paraquat and Maneb in Wistar Rats

Abstract

Neurodegenerative Parkinson's disease (PD) due to loss of nigrostriatal dopaminergic (DA) cells is strongly associated with non-motor and primarily motor symptoms. Therefore, a non-pharmacological approach based on physical exercise could be used to reduce the risk of PD incidence. The aim of the present study was to test the neuroprotective effect of physical activity (PA) in an animal model of Parkinson's disease in the Wistar rat. The animal model of PD was induced in rats by twice-weekly (i.p.) intraperitoneal injection of a mixture of 5 mg/kg parquat (PQ) and 0.05 mg/kg maneb (MB) for 6 weeks. Two groups of six rats each were subjected to PD induction. One of the two groups and a third group were subjected to exercise and forced to undergo rotarod gait training for 4 weeks. A fourth control group received only the vehicle solution (distilled water (dw) + dimethyl sulfoxide (DMSO) à 0,1 %). Catalepsy, akinesia and motor coordination were measured by the catalepsy bar test (CBT), beam walking test (BWT) and rotarod, respectively, to assess motor impairments. Non-motor impairments (anxiety levels, depressive states and cognitive performance) were assessed using the elevated plus maze (EPM), forced swim test (FST) and the object recognition test (NOR), respectively. Biochemical parameters malondialdehyde (MDA), catalase (CAT), superoxide dismutase SOD) were assessed to determine the level of oxidative stress (OS) in the prefrontal cortex (PFC) and striatum (ST). Our results show that rotarod walking exercise, a motor learning modality, improves motor disorders (muscle rigidity, akinesia, and motor coordination) and reduces anxiety and depressive behaviors in rats with improved memory abilities. In addition, exercise attenuates markers of PQMB-induced oxidation.