• Biomolecules & Therapeutics
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• v.32 no.5
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• pp.523-530
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• 2024

Parkinson's disease (PD) is a neurodegenerative disease caused by the death of dopaminergic neurons in the nigrostriatal pathway, leading to motor and non-motor dysfunctions, such as depression, olfactory dysfunction, and memory impairment. Although levodopa (L-dopa) has been the gold standard PD treatment for decades, it only relieves motor symptoms and has no effect on non-motor symptoms or disease progression. Prior studies have reported that 6-shogaol, the active ingredient in ginger, exerts a protective effect on dopaminergic neurons by suppressing neuroinflammation in PD mice. This study investigated whether cotreatment with 6-shogaol and L-dopa could attenuate both motor and non-motor symptoms and dopaminergic neuronal damage. Both 6-shogaol (20 mg/kg) and L-dopa (80 mg/kg) were orally administered to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine/probenecid-induced PD model mice for 26 days. The experimental results showed that L-dopa alleviated motor symptoms, but had no significant effect on non-motor symptoms, loss of dopaminergic neuron, or neuroinflammation. However, when mice were treated with 6-shogaol alone or in combination with L-dopa, an amelioration in both motor and non-motor symptoms such as depression-like behavior, olfactory dysfunction and memory impairment was observed. Moreover, 6-shogaol-only or co-treatment of 6-shogaol with L-dopa protected dopaminergic neurons in the striatum and reduced neuroinflammation in the striatum and substantia nigra. Overall, these results suggest that 6-shogaol can effectively complement L-dopa by improving non-motor dysfunction and restoring dopaminergic neurons via suppressing neuroinflammation.

• Journal of Korean Neurosurgical Society
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• v.38 no.6
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• pp.456-464
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• 2005

Objective : The authors investigated whether rotenone induces cellular death also in non-dopaminergic neurons and high concentration of potassium ion can show protective effect for non-dopaminergic neuron in case of rotenone-induced cytotoxicity. Methods : Neuro 2A cells was treated with rotenone, and their survival as well as cell death mechanism was estimated using 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium[MTT] assay, Lactate dehydrogenase[LDH] release assay, fluorescence microscopy, and agarose gel electrophoresis. The changes in rotenone-treated cells was also studied after co-treatment of 50mM KCl. And the protective effect of KCl was evaluated by mitochondrial membrane potential assay and compared with the effects of various antioxidants. Results : Neuro 2A cells treated with rotenone underwent apoptotic death showing chromosome condensation and fragmentation as well as DNA laddering. Co-incubation of neuro 2A cells with 50mM KCl prevented it from the cytotoxicity induced by rotenone. Intracellular accumulation of reactive oxygen species[ROS] resulting by rotenone were significantly reduced by 50mM KCl. Potassium exhibited significantly similar potency compared to the antioxidants. Conclusion : The present findings showed that potassium attenuated rotenone-induced cytotoxicity, intracellular accumulation of ROS, and fragmentation of DNA in Neuro 2A cells. These findings suggest the therapeutic potential of potassium ion in neuronal apoptosis, but the practical application of high concentration of potassium ion remains to be settled.

• The Korean Journal of Nuclear Medicine
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• v.39 no.6
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• pp.421-429
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• 2005

Purpose: It has been postulated that dopamine release in the striatum underlies the reinforcing properties of nicotine. Substantial evidence in the animal studies demonstrates that nicotine interacts with dopaminergic neuron and regulates the activation of the dopaminergic system. The aim of this study was to visualize the dopamine release by smoking in human brain using PET scan with $[^{11}C]raclopride$. Materials and Methods: Five male non-smokers or ex-smokers with an abstinence period longer than 1 year (mean age of $24.4{\pm}1.7$ years) were enrolled in this study $[^{11}C]raclopride$, a dopamine D2 receptor radioligand, was administrated with bolus-plus-constant infusion. Dynamic PET was performed during 120 minutes ($3{\times}20s,\;2{\times}60s,\;2{\times}120s,\;1{\times}180s\;and\;22{\times}300s$). following the 50 minute-scanning, subjects smoked a cigarette containing 1 mg of nicotine while in the scanner. Blood samples for the measurement of plasma nicotine level were collected at 0, 5, 10, 15, 20, 25, 30, 45, 60, and 90 minute after smoking. Regions for striatal structures were drawn on the coronal summed PET images guided with co-registered MRI. Binding potential, calculated as (striatal-cerebellar)/cerebellar activity, was measured under equilibrium condition at baseline and smoking session. Results: The mean decrease in binding potential of $[^{11}C]raclopride$ between the baseline and smoking in caudate head, anterior putamen and ventral striatum was 4.7%, 4.0% and 7.8%, respectively. This indicated the striatal dopamine release by smoking. Of these, the reduction in binding potential in the ventral striatum was significantly correlated with the cumulated plasma level of the nicotine (Spearman's rho=0.9, p=0.04). Conclusion: These data demonstrate that in vivo imaging with $[^{11}C]raclopride$ PET could measure nicotine-induced dopamine release in the human brain, which has a significant positive correlation with the amount or nicotine administered bt smoking.