Therapeutic Effects of Selenium on Alpha-Synuclein Accumulation in Substantia Nigra Pars Compacta in a Rat Model of Parkinson's Disease: Behavioral and Biochemical Outcomes.

Parkinson's disease (PD) is the second most common progressive neurodegenerative disorder characterized by the accumulation of accumulated alpha-synuclein (α-Syn) in substantia nigra. Research has shown that selenium (Se) can protect neural cells through the actions of selenoproteins, including selenoprotein P (SelP) and selenoprotein S (SelS), which participate in endoplasmic reticulum-associated protein degradation (ERAD). In this study, we investigated the potential protective role of Se in a pre-clinical PD rat model.We aimed to evaluate the therapeutic effects of Se administration in the 6-hydroxydopamine (6-OHDA) induced unilateral rat PD model. Male Wistar rats were utilised for unilateral PD animal model which were subjected to stereotaxic surgery and injected with 20 µg 6-OHDA/5 µl 0.2% ascorbate saline. After confirming the model, the rats were intraperitoneally injected with 0.1, 0.2, and 0.3 mg/kg of sodium selenite for 7 days. We then performed behavioral tests, including apomorphine-induced rotation, hanging, and rotarod tests. Following sacrifice, we analysed the substantia nigra area of the brain and serum for protein quantification, element analysis, and gene expression analysis.Our results indicate that the administration of 0.3 mg/kg of Se improved the motor deficiency in hanging, rotarod, and apomorphine-induced rotational tests. While there was no significant improvement in the expression of α-Syn, Se increased the expression of selenoproteins. Additionally, levels of selenoproteins, Se, and α-Syn both brain and serum were re-established by the treatment, suggesting the role of Se on the α-Syn accumulation. Furthermore, Se improved PD-induced biochemical deficits by increasing the levels of SelS and SelP (p<0.005).In conclusion, our findings suggest that Se may have a protective role in PD. 0.3 mg/kg dosage of Se increased the expression of selenoproteins, reduced the accumulation of α-Syn in the brain, and improved PD-induced motor deficits. These results suggest that Se may be a potential therapeutic option for PD treatment.

Neuroprotective effect of combined therapy with hyperbaric oxygen and madopar on 6-hydroxydopamine-induced Parkinson's disease in rats.

Parkinson's disease (PD) is a common movement disorder in the elderly. In the present study, we examined whether the combination of hyperbaric oxygen (HBO) and madopar therapy provided a neuroprotective effect on dopaminergic neurons in the substantia nigra using a rat model of PD. Rotational assessments revealed that both HBO and combination therapy significantly attenuated apomorphine-induced turning in PD rats. Our results indicated that the combination therapy increased glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) activities and reduced the malondialdehyde (MDA) content in the SN. Furthermore, the combination therapy resulted in significant protection against the loss of neurons, and specifically tyrosine hydroxylase (TH)-positive neurons, in the SN and also alleviated the production of glial fibrillary acidic protein (GFAP). The levels of Bcl-2 were increased and Bax were decreased following the HBO or combination therapy. In brief, the neuroprotective effect of combined therapy with HBO and madopar against 6-OHDA-induced PD rats may rely on its ability to reduce oxidative stress and protect against Bax/Bcl-2-mediated apoptosis.