scholarly journals Neuroprotective Effect of Curcumin on the Nigrostriatal Pathway in a 6-Hydroxydopmine-Induced Rat Model of Parkinson’s Disease is Mediated by α7-Nicotinic Receptors

2020 ◽  
Vol 21 (19) ◽  
pp. 7329
Author(s):  
Eslam El Nebrisi ◽  
Hayate Javed ◽  
Shreesh K Ojha ◽  
Murat Oz ◽  
Safa Shehab

Parkinson’s disease (PD) is a common neurodegenerative disorder, characterized by selective degeneration of dopaminergic nigrostriatal neurons. Most of the existing pharmacological approaches in PD consider replenishing striatal dopamine. It has been reported that activation of the cholinergic system has neuroprotective effects on dopaminergic neurons, and human α7-nicotinic acetylcholine receptor (α7-nAChR) stimulation may offer a potential therapeutic approach in PD. Our recent in-vitro studies demonstrated that curcumin causes significant potentiation of the function of α7-nAChRs expressed in Xenopus oocytes. In this study, we conducted in vivo experiments to assess the role of the α7-nAChR on the protective effects of curcumin in an animal model of PD. Intra-striatal injection of 6-hydroxydopmine (6-OHDA) was used to induce Parkinsonism in rats. Our results demonstrated that intragastric curcumin treatment (200 mg/kg) significantly improved the abnormal motor behavior and offered neuroprotection against the reduction of dopaminergic neurons, as determined by tyrosine hydroxylase (TH) immunoreactivity in the substantia nigra and caudoputamen. The intraperitoneal administration of the α7-nAChR-selective antagonist methyllycaconitine (1 µg/kg) reversed the neuroprotective effects of curcumin in terms of both animal behavior and TH immunoreactivity. In conclusion, this study demonstrates that curcumin has a neuroprotective effect in a 6-hydroxydopmine (6-OHDA) rat model of PD via an α7-nAChR-mediated mechanism.

2015 ◽  
Vol 26 (24) ◽  
pp. 4478-4491 ◽  
Author(s):  
BK. Binukumar ◽  
Varsha Shukla ◽  
Niranjana D. Amin ◽  
Philip Grant ◽  
M. Bhaskar ◽  
...  

Parkinson’s disease (PD) is a chronic neurodegenerative disorder characterized by the loss of dopamine neurons in the substantia nigra, decreased striatal dopamine levels, and consequent extrapyramidal motor dysfunction. Recent evidence indicates that cyclin-dependent kinase 5 (Cdk5) is inappropriately activated in several neurodegenerative conditions, including PD. To date, strategies to specifically inhibit Cdk5 hyperactivity have not been successful without affecting normal Cdk5 activity. Previously we reported that TFP5 peptide has neuroprotective effects in animal models of Alzheimer’s disease. Here we show that TFP5/TP5 selective inhibition of Cdk5/p25 hyperactivation in vivo and in vitro rescues nigrostriatal dopaminergic neurodegeneration induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP/MPP+) in a mouse model of PD. TP5 peptide treatment also blocked dopamine depletion in the striatum and improved gait dysfunction after MPTP administration. The neuroprotective effect of TFP5/TP5 peptide is also associated with marked reduction in neuroinflammation and apoptosis. Here we show selective inhibition of Cdk5/p25 ­hyperactivation by TFP5/TP5 peptide, which identifies the kinase as a potential therapeutic target to reduce neurodegeneration in Parkinson’s disease.


2020 ◽  
Author(s):  
Junqiang Yan ◽  
Hongxia Ma ◽  
Xiaoyi Lai ◽  
Jiannan Wu ◽  
Anran Liu ◽  
...  

Abstract Background Parkinson's disease (PD) is the second most common neurodegenerative disease after Alzheimer's. The drugs currently used to treat PD cannot inhibit the development of PD, and long-term use produces severe drug resistance and adverse reaction. Artemisinin (ART) is an active ingredient of Artemisia annua and has a neuroprotective effect, but the mechanism is still unclear. This study was designed to investigate the neuroprotective effect of ART in MPP+-treated SH-SY5Y cells. Results There was no significant cytotoxicity when the ART concentration was under. 40μM. The 20μM ART for 24h could increase the cell viability by reducing oxidative stress and cell apoptosis in MPP+-treated SH-SY5Y cell. In addition, immunoblot and immunofluorescence results showed that MPP+ treatment increased the expression of Beclin1, LC3II/LC3I and decreased the expression of P62, while ART can reverse the changes caused by MPP+. Discussion More and more researches reported that ART and its derivates have neuroprotective effects through anti-oxidant and anti-apoptosis. we found that pre-treated cells with 20μM ART for 4h could significantly increase the viability in Parkinson's disease cell model. The oxidative stress and apoptosis were the main reason for the degeneration of dopaminergic neurons, while artemisinin can attenuate oxidative stress and apoptosis in MPP+-lesioned dopaminergic neurons. The levels of autophagy proteins LC3II/I, Beclin1 and P62 also showed that MPP+ increased the autophagy level, and pre-treatment with ART decreased the autophagy level, which may be the pathological mechanism for artemisinin to reduce oxidative stress damage and apoptosis. Conclusions These results indicate that ART exerts a positive effect on MPP+-treated SH-SY5Y cells in terms of anti-oxidative stress and anti-apoptosis. These effects may be related to autophagy. These findings contribute to a better understanding of the critical role of ART in PD treatment.


2021 ◽  
Author(s):  
Xiao Yan Sheng ◽  
Shui Yuan Yang ◽  
Xiao Min Wen ◽  
Xin Zhang ◽  
Yong Feng Ye ◽  
...  

Abstract Background: Shende’an tablet (SDA) is a newly capsuled Chinese herbal formula derived from the Chinese traditional medicine Zhengan Xifeng Decoction which is approved for the treatment of neurasthenia and insomnia in China. This study aimed to investigate the neuroprotective effects of SDA against Parkinson’s disease (PD) in vitro and in vivo.Methods: In the present work, the neuroprotective effects and mechanism of SDA were evaluated in the cellular PD model. Male C57BL/6J mice were subject to a partial MPTP lesion alongside treatment with SDA. Behavioural test and tyrosine-hydroxylase immunohistochemistry were used to evaluate nigrostriatal tract integrity. HPLC analysis and Western blotting were used to assess the effect of SDA on dopamine metabolism and the expression of HO-1, PGC-1α and Nrf2, respectively.Results: Our results demonstrated that SDA had neuroprotective effect in dopaminergic PC12 cells with 6-OHDA lesion. It had also displayed efficient dopaminergic neuronal protection and motor behavior alleviation properties in MPTP-induced PD mice. In the PC12 cells and MPTP-induced Parkinson’s disease animal models, SDA was highly efficacious in α-synuclein clearance associated with the activation of PGC-1α/Nrf2 signal pathway.Conclusion: SDA demonstrated potential as a future therapeutic modality in PD through protecting dopamine neurons and alleviating the motor symptoms, mediated by the activation of PGC-1α/Nrf2 signal pathway.


2020 ◽  
Vol 19 (8) ◽  
pp. 572-583
Author(s):  
Helle Bogetofte ◽  
Arezo Alamyar ◽  
Morten Blaabjerg ◽  
Morten Meyer

Parkinson’s Disease (PD) is a neurodegenerative disorder characterized by a preferential degeneration of dopaminergic neurons in the substantia nigra pars compacta. This results in a profound decrease of striatal dopamine (DA) levels, which in turn leads to the cardinal motor symptoms of PD; muscle rigidity, hypo- and bradykinesia and resting tremor. Even 50 years after its initial use, the DA precursor levodopa (L-dopa), is still the most effective medical therapy for the symptomatic treatment of PD. Long-term L-dopa treatment is however, unfortunately associated with undesirable side effects such as motor fluctuations and dyskinesias. Furthermore, despite the disease alleviating effects of L-dopa, it is still discussed whether L-dopa has a neurotoxic or neuroprotective effect on dopaminergic neurons. Here we review the history of L-dopa, including its discovery, development and current use in the treatment of PD. We furthermore review current evidence of the L-dopa-induced side effects and perspectives of L-dopa treatment in PD compared to other established treatments such as DA-agonists and the inhibitors of catechol-o-methyltransferase and monoamine oxidase B.


PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3933 ◽  
Author(s):  
Justin Y.D. Lu ◽  
Ping Su ◽  
James E.M. Barber ◽  
Joanne E. Nash ◽  
Anh D. Le ◽  
...  

Clinical evidence points to neuroprotective effects of smoking in Parkinson’s disease (PD), but the molecular mechanisms remain unclear. We investigated the pharmacological pathways involved in these neuroprotective effects, which could provide novel ideas for developing targeted neuroprotective treatments for PD. We used the ETC complex I inhibitor methylpyridinium ion (MPP+) to induce cell death in SH-SY5Y cells as a cellular model for PD and found that nicotine inhibits cell death. Using choline as a nicotinic acetylcholine receptor (nAChR) agonist, we found that nAChR stimulation was sufficient to protect SH-SY5Y cells against cell death from MPP+. Blocking α7 nAChR with methyllycaconitine (MLA) prevented the protective effects of nicotine, demonstrating that these receptors are necessary for the neuroprotective effects of nicotine. The neuroprotective effect of nicotine involves other pathways relevant to PD. Cleaved Poly (ADP-ribose) polymerase-1 (PARP-1) and cleaved caspase-3 were decreased by nicotine in 6-hydroxydopamine (6-OHDA) lesioned mice and in MPP+-treated SH-SY5Y cells. In conclusion, our data indicate that nicotine likely exerts neuroprotective effects in PD through the α7 nAChR and downstream pathways including PARP-1 and caspase-3. This knowledge could be pursued in future research to develop neuroprotective treatments for PD.


Biomolecules ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1421 ◽  
Author(s):  
Hayate Javed ◽  
M. F. Nagoor Meeran ◽  
Sheikh Azimullah ◽  
Lujain Bader Eddin ◽  
Vivek Dhar Dwivedi ◽  
...  

Rotenone (ROT), a plant-derived pesticide is a well-known environmental neurotoxin associated with causation of Parkinson’s disease (PD). ROT impairs mitochondrial dysfunction being mitochondrial complex-I (MC-1) inhibitor and perturbs antioxidant-oxidant balance that contributes to the onset and development of neuroinflammation and neurodegeneration in PD. Due to the scarcity of agents to prevent the disease or to cure or halt the progression of symptoms of PD, the focus is on exploring agents from naturally occurring dietary phytochemicals. Among numerous phytochemicals, α-Bisabolol (BSB), natural monocyclic sesquiterpene alcohol found in many ornamental flowers and edible plants garnered attention due to its potent pharmacological properties and therapeutic potential. Therefore, the present study investigated the neuroprotective effects of BSB in a rat model of ROT-induced dopaminergic neurodegeneration, a pathogenic feature of PD and underlying mechanism targeting oxidative stress, inflammation and apoptosis. BSB treatment significantly prevented ROT-induced loss of dopaminergic neurons and fibers in the substantia nigra and striatum respectively. BSB treatment also attenuated ROT-induced oxidative stress evidenced by inhibition of MDA formation and GSH depletion as well as improvement in antioxidant enzymes, SOD and catalase. BSB treatment also attenuated ROT-induced activation of the glial cells as well as the induction and release of proinflammatory cytokines (IL-1β, IL-6 and TNF-α) and inflammatory mediators (iNOS and COX-2) in the striatum. In addition to countering oxidative stress and inflammation, BSB also attenuated apoptosis of dopaminergic neurons by attenuating downregulation of anti-apoptotic protein Bcl-2 and upregulation of pro-apoptotic proteins Bax, cleaved caspases-3 and 9. Further, BSB was observed to attenuate mitochondrial dysfunction by inhibiting mitochondrial lipid peroxidation, cytochrome-C release and reinstates the levels/activity of ATP and MC-I. The findings of the study demonstrate that BSB treatment salvaged dopaminergic neurons, attenuated microglia and astrocyte activation, induction of inflammatory mediators, proinflammatory cytokines and reduced the expression of pro-apoptotic markers. The in vitro study on ABTS radical revealed the antioxidant potential of BSB. The results of the present study are clearly suggestive of the neuroprotective effects of BSB through antioxidant, anti-inflammatory and anti-apoptotic properties in ROT-induced model of PD.


Author(s):  
Swati Sharan ◽  
Pravir Kumar ◽  
Rashmi K Ambasta

Aim: To screen zinc database for structurally similar molecules to compound 23 that targets DJ1 for use as a neuroprotective agent for Parkinson’s disease. Background: Parkinson’s disease (PD), the second most common chronic neurodegenerative disorder characterized by progressive loss of dopaminergic neurons of the substantia nigra. To date, several proteins account for the recessive familial PD-forms, namely, Parkin, PINK-1, DJ-1, SNCA, PARK2, and LRRK2 Genes. DJ1 is one of the important central points that may be targeted for PD therapy. Recently, Compound 23 has been observed to exert the neuroprotective effect against neurodegeneration in PD model, but due to its toxic substructure, the hunt for better nontoxic compound continues. Objective: The overall objective of our work is to apply in silico approaches to screen structure similar compounds that interacts potentially with DJ1 and may serve as a good therapeutic molecule for PD. Method: Initial data mining was done from zinc database and then screened compounds were additionally screened with toxicity checker, carcinopred, ADMET analysis and docking analysis. Results: The basic screening of database for structurally similar chemicals to compound 23 resulted in 50 compounds, which were further screened to twenty-three and finally seven compounds have been screened based on the toxicity and carcinopred test. Later, the seven compounds were docked and analysed for its docking efficiency with DJ1. Our result of molecular docking and molecular simulation analysis highlights Molecule 42(SS2), to exhibit best binding affinity against DJ-1 protein target and can be proposed to be used as a therapeutic agent to modulate neurodegenerative proteins. Conclusion: Therefore, we conclude discovery of novel, non-toxic, non-carcinogenic; ADMET investigated capable of crossing BB barrier but structurally similar compounds of Compound-23, specifically molecule 42(SS2) and potentially molecule 34(SS1) to be used as a neuroprotective agent for Parkinson’s disease.


2020 ◽  
Author(s):  
Junqiang Yan ◽  
Hongxia Ma ◽  
Xiaoyi Lai ◽  
Jiannan Wu ◽  
Anran Liu ◽  
...  

Abstract Background Parkinson's disease (PD) is the second most common neurodegenerative disease after Alzheimer's. The drugs currently used to treat PD cannot inhibit the development of PD, and long-term use produces severe drug resistance and adverse reaction. Artemisinin (ART) is an active ingredient of Artemisia annua and has a neuroprotective effect, but the mechanism is still unclear. This study was designed to investigate the neuroprotective effect of ART in MPP+-treated SH-SY5Y cells. Results There was no significant cytotoxicity when the ART concentration was under. 40 µM. The 20 µM ART for 24 h could increase the cell viability by reducing oxidative stress and cell apoptosis in MPP+-treated SH-SY5Y cell. In addition, immunoblot and immunofluorescence results showed that MPP+ treatment increased the expression of Beclin1, LC3II/LC3I and decreased the expression of P62, while ART can reverse the changes caused by MPP+. Discussion More and more researches reported that ART and its derivates have neuroprotective effects through anti-oxidant and anti-apoptosis. we found that pre-treated cells with 20 µM ART for 4 h could significantly increase the viability in Parkinson's disease cell model. The oxidative stress and apoptosis were the main reason for the degeneration of dopaminergic neurons, while artemisinin can attenuate oxidative stress and apoptosis in MPP+-lesioned dopaminergic neurons. The levels of autophagy proteins LC3II/I, Beclin1 and P62 also showed that MPP + increased the autophagy level, and pre-treatment with ART decreased the autophagy level, which may be the pathological mechanism for artemisinin to reduce oxidative stress damage and apoptosis. Conclusions These results indicate that ART exerts a positive effect on MPP+-treated SH-SY5Y cells in terms of anti-oxidative stress and anti-apoptosis. These effects may be related to autophagy. These findings contribute to a better understanding of the critical role of ART in PD treatment.


Marine Drugs ◽  
2019 ◽  
Vol 17 (4) ◽  
pp. 221 ◽  
Author(s):  
Chunhui Huang ◽  
Zaijun Zhang ◽  
Wei Cui

Parkinson’s disease (PD) is a neurodegenerative disorder caused by the loss of dopaminergic neurons, leading to the motor dysfunctions of patients. Although the etiology of PD is still unclear, the death of dopaminergic neurons during PD progress was revealed to be associated with the abnormal aggregation of α-synuclein, the elevation of oxidative stress, the dysfunction of mitochondrial functions, and the increase of neuroinflammation. However, current anti-PD therapies could only produce symptom-relieving effects, because they could not provide neuroprotective effects, stop or delay the degeneration of dopaminergic neurons. Marine-derived natural compounds, with their novel chemical structures and unique biological activities, may provide anti-PD neuroprotective effects. In this study, we have summarized anti-PD marine-derived natural products which have shown pharmacological activities by acting on various PD targets, such as α-synuclein, monoamine oxidase B, and reactive oxygen species. Moreover, marine-derived natural compounds currently evaluated in the clinical trials for the treatment of PD are also discussed.


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