Neuroprotective effects of Wharton’s jelly-derived mesenchymal stem cells on motor deficits due to Parkinson’s disease

Human Wharton’s jelly-derived mesenchymal stem cells (hWJ-MSCs) have been recognized as a potential tool to replace damaged cells by improving the survival of the dopaminergic cells in Parkinson’s disease (PD). In this study, we examined the effects of hWJ-MSCs and associated with L-dopa/carbidopa on motor disturbances in the PD model. Materials and Methods: PD was induced by injection of 6-hydroxydopamine (6-OHDA) (16 μg/2 μl into medial forebrain bundle (MFB)). Sham group received a vehicle instead of 6-OHDA. PD+C group received hWJ-MSCs twice on the 14th and 28th days post PD induction. PD+C+D group received hWJ-MSCs and also L-dopa/carbidopa (10/30 mg/kg). PD+D group received L-dopa/carbidopa alone. Four months later, motor activities (the parameters of locomotor and muscle stiffness) were evaluated, dopaminergic neurons were counted in substantia nigra pars compacta (SNc), the level of dopamine (DA), and tyrosine hydroxylase (TH) were measured in the striatum. Results: Data indicated that motor activities, the number of dopaminergic neurons, and levels of DA and TH activities were significantly reduced in PD rats as compared to the sham group (P<0.001). However, the same parameters were improved in the treated groups when compared with the PD group (P<0.001 and P<0.01, respectively). Conclusion: The chronic treatment of PD rats with hWJ-MSCs and L-dopa/carbidopa, improved motor activity, which may be the result of increased TH activity and due to released DA from dopaminergic neurons.