scholarly journals Tocotrienols Ameliorate Neurodegeneration and Motor Deficits in the 6-OHDA-Induced Rat Model of Parkinsonism: Behavioural and Immunohistochemistry Analysis

Nutrients ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1583
Author(s):  
Mangala Kumari ◽  
Premdass Ramdas ◽  
Ammu Kutty Radhakrishnan ◽  
Methil Kannan Kutty ◽  
Nagaraja Haleagrahara

Parkinson’s disease (PD) is a debilitating neurodegenerative disease, which progresses over time, causing pathological depigmentation of the substantia nigra (SN) in the midbrain due to loss of dopaminergic neurons. Emerging studies revealed the promising effects of some nutrient compounds in reducing the risk of PD. One such nutrient compound that possess neuroprotective effects and prevents neurodegeneration is tocotrienol (T3), a vitamin E family member. In the present study, a single dose intracisternal injection of 250 µg 6-hydroxydopamine (6-OHDA) was used to induce parkinsonism in male Sprague Dawley (SD) rats. Forty-eight hours post injection, the SD rats were orally supplemented with alpha (α)- and gamma (γ)-T3 for 28 days. The neuroprotective effects of α- and γ-T3 were evaluated using behavioural studies and immunohistochemistry (IHC). The findings from this study revealed that supplementation of α- and γ-T3 was able to ameliorate the motor deficits induced by 6-OHDA and improve the neuronal functions by reducing inflammation, reversing the neuronal degradation, and preventing further reduction of dopaminergic neurons in the SN and striatum (STR) fibre density.

2020 ◽  
Author(s):  
Chenyu Zhang ◽  
Miao Zhao ◽  
Bingwei Wang ◽  
Zhijie Su ◽  
Bingbing Guo ◽  
...  

Abstract Background: Parkinson’s disease (PD) is characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta (SNc), accompanied by chronic neuroinflammation, oxidative stress, and widespread accumulation of α-synuclein. Celastrol (Cel), a potent anti-inflammatory and anti-oxidative pentacyclic triterpene, has emerged as a neuroprotective agent. However, the mechanisms by which celastrol is neuroprotective in PD has not yet been elucidated. Methods: The MPTP and AAV-mediated human wild-type α-syn overexpression within SNc induced PD mouse models were employed in this study. By using multiple genetically modified mice (Nrf2-KO, NLRP3-KO and Caspase1-KO), we identified that celastrol effectively inhibited the NLRP3 inflammasome activation, mitigated motor deficits and nigrostriatal dopaminergic degeneration through Nrf2-NLRP3-Caspase1 pathway. Results: Here we show that celastrol protected against the loss of dopaminergic neurons, mitigated the neuroinflammation and motor deficits in both MPTP-induced PD mouse model and AAV-mediated human α-syn overexpression PD model. Whole-genome deep sequencing analysis reveals that Nrf2, NLRP3 and Caspase1 in SNc may be associated with the neuroprotective actions of celastrol in PD. Conclusions: These findings suggest that Nrf2-NLRP3-Caspase1 axis may be a key target of celastrol in PD treatment, and highlight the favorable properties linked to neuroprotection of celastrol, making celastrol as a promising disease-modifying agent for PD.


2019 ◽  
Vol 20 (23) ◽  
pp. 5832 ◽  
Author(s):  
Kwon ◽  
Lee ◽  
Park ◽  
Ra ◽  
Lee ◽  
...  

In our ongoing research to discover natural products with neuroprotective effects, hyperoside (quercetin 3-O-galactoside) was isolated from Acer tegmentosum, which has been used in Korean traditional medicine to treat liver-related disorders. Here, we demonstrated that hyperoside protects cultured dopaminergic neurons from death via reactive oxygen species (ROS)-dependent mechanisms, although other relevant mechanisms of hyperoside activity remain largely uncharacterized. For the first time, we investigated the neuroprotective effects of hyperoside on 6-hydroxydopamine (6-OHDA)-induced neurotoxicity in neurons, and the possible underlying mechanisms. Hyperoside significantly ameliorated the loss of neuronal cell viability, lactate dehydrogenase release, excessive ROS accumulation and mitochondrial membrane potential dysfunction associated with 6-OHDA-induced neurotoxicity. Furthermore, hyperoside treatment activated the nuclear erythroid 2-related factor 2 (Nrf2), an upstream molecule of heme oxygenase-1 (HO-1). Hyperoside also induced the expression of HO-1, an antioxidant response gene. Remarkably, we found that the neuroprotective effects of hyperoside were weakened by an Nrf2 small interfering RNA, which blocked the ability of hyperoside to inhibit neuronal death, indicating the vital role of HO-1. Overall, we show that hyperoside, via the induction of Nrf2-dependent HO-1 activation, suppresses neuronal death caused by 6-OHDA-induced oxidative stress. Moreover, Nrf2-dependent HO-1 signaling activation represents a potential preventive and therapeutic target in Parkinson′s disease management.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ryo Kikuoka ◽  
Ikuko Miyazaki ◽  
Natsuki Kubota ◽  
Megumi Maeda ◽  
Daiki Kagawa ◽  
...  

AbstractMirtazapine, a noradrenergic and specific serotonergic antidepressant (NaSSA), is known to activate serotonin (5-HT) 1A receptor. Our recent study demonstrated that stimulation of astrocytic 5-HT1A receptors promoted astrocyte proliferation and upregulated antioxidative property in astrocytes to protect dopaminergic neurons against oxidative stress. Here, we evaluated the neuroprotective effects of mirtazapine against dopaminergic neurodegeneration in models of Parkinson’s disease (PD). Mirtazapine administration attenuated the loss of dopaminergic neurons in the substantia nigra and increased the expression of the antioxidative molecule metallothionein (MT) in the striatal astrocytes of 6-hydroxydopamine (6-OHDA)-injected parkinsonian mice via 5-HT1A receptors. Mirtazapine protected dopaminergic neurons against 6-OHDA-induced neurotoxicity in mesencephalic neuron and striatal astrocyte cocultures, but not in enriched neuronal cultures. Mirtazapine-treated neuron-conditioned medium (Mir-NCM) induced astrocyte proliferation and upregulated MT expression via 5-HT1A receptors on astrocytes. Furthermore, treatment with medium from Mir-NCM-treated astrocytes protected dopaminergic neurons against 6-OHDA neurotoxicity, and these effects were attenuated by treatment with a MT-1/2-specific antibody or 5-HT1A antagonist. Our study suggests that mirtazapine could be an effective disease-modifying drug for PD and highlights that astrocytic 5-HT1A receptors may be a novel target for the treatment of PD.


2011 ◽  
Vol 3 (1) ◽  
pp. 22-30 ◽  
Author(s):  
T. C. H. Leung ◽  
C. N. P. Lui ◽  
L. W. Chen ◽  
W. H. Yung ◽  
Y. S. Chan ◽  
...  

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Chung-Che Lu ◽  
Tee-Tau Eric Nyam ◽  
Jinn-Rung Kuo ◽  
Yao-Lin Lee ◽  
Chung-Ching Chio ◽  
...  

Abstract Background The aim of this study was to investigate whether AMN082 exerts its neuroprotective effect by attenuating glutamate receptor-associated neuronal apoptosis and improving functional outcomes after traumatic brain injury (TBI). Methods Anesthetized male Sprague–Dawley rats were divided into the sham-operated, TBI + vehicle, and TBI + AMN082 groups. AMN082 (10 mg/kg) was intraperitoneally injected 0, 24, or 48 h after TBI. In the 120 min after TBI, heart rate, mean arterial pressure, intracranial pressure (ICP), and cerebral perfusion pressure (CPP) were continuously measured. Motor function, the infarct volume, neuronal nitrosative stress-associated apoptosis, and N-methyl-d-aspartate receptor 2A (NR2A) and NR2B expression in the pericontusional cortex were measured on the 3rd day after TBI. Results The results showed that the AMN082-treated group had a lower ICP and higher CPP after TBI. TBI-induced motor deficits, the increase in infarct volume, neuronal apoptosis, and 3-nitrotyrosine and inducible nitric oxide synthase expression in the pericontusional cortex were significantly improved by AMN082 therapy. Simultaneously, AMN082 increased NR2A and NR2B expression in neuronal cells. Conclusions We concluded that intraperitoneal injection of AMN082 for 3 days may ameliorate TBI by attenuating glutamate receptor-associated nitrosative stress and neuronal apoptosis in the pericontusional cortex. We suggest that AMN082 administration in the acute stage may be a promising strategy for TBI.


2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Ruru Li ◽  
Jianzong Chen

Parkinson’s disease (PD) is a common neurodegenerative disease characterized by the degeneration of nigrostriatal dopaminergic (DA) neurons. Our previous studies have suggested that salidroside (Sal) might play neuroprotective effects against PD by preserving mitochondrial Complex I activity. However, the exact mechanism of the neuroprotective effect of Sal remains unclear. Growing evidence indicates that PINK1/Parkin-mediated mitophagy is involved in the development of PD. In this study, we investigated whether Sal exerts a neuroprotective effect by modulating PINK1/Parkin-mediated mitophagy. Results showed that Sal alleviated MPTP-induced motor deficits in pole test. Moreover, Sal diminished MPTP-induced degeneration of nigrostriatal DA neurons as evidenced by upregulated TH-positive neurons in the substantia nigra, increased DAT expression, and high dopamine and metabolite levels in the striatum. Furthermore, in comparison with the MPP+/MPTP group, Sal considerably increased the mitophagosome and mitophagy flux. Moreover, in comparison with the MPP+/MPTP group, Sal evidently enhanced the mitochondrial expression of PINK1 and Parkin, accompanied by an increase in the colocalization of mitochondria with Parkin. However, transfection of MN9D cells with PINK1 siRNA reversed Sal-induced activated mitophagy and cytoprotective effect. In conclusion, Sal may confer neuroprotective effects by enhancing PINK1/Parkin-mediated mitophagy in MPP+/MPTP-induced PD models.


Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5478
Author(s):  
Joana Silva ◽  
Alice Martins ◽  
Celso Alves ◽  
Susete Pinteus ◽  
Helena Gaspar ◽  
...  

Parkinson’s disease (PD) is the second most common neurodegenerative disorder, and is characterized by a progressive degeneration of the dopaminergic neurons in the substantianigra. Although not completely understood, several abnormal cellular events are known to be related with PD progression, such as oxidative stress, mitochondrial dysfunction and apoptosis. Accordingly, the aim of this study was to evaluate the neuroprotective effects of Codium tomentosum enriched fractions in a neurotoxicity model mediated by 6-hydroxydopamine (6-OHDA) on SH-SY5Y human cells, and the disclosure of their mechanisms of action. Additionally, a preliminary chemical screening of the most promising bioactive fractions of C. tomentosum was carried out by GC-MS analysis. Among the tested fractions, four samples exhibited the capacity to revert the neurotoxicity induced by 6-OHDA to values higher or similar to the vitamin E (90.11 ± 3.74% of viable cells). The neuroprotective effects were mediated by the mitigation of reactive oxygen species (ROS) generation, mitochondrial dysfunctions and DNA damage, together with the reduction of Caspase-3 activity. Compounds belonging to different chemical classes, such as terpenes, alcohols, carboxylic acids, aldehydes, esters, ketones, saturated and unsaturated hydrocarbons were tentatively identified by GC-MS. The results show that C. tomentosum is a relevant source of neuroprotective agents, with particular interest for preventive therapeutics.


Author(s):  
Miao Zhao ◽  
Bingwei Wang ◽  
Chenyu Zhang ◽  
Zhijie Su ◽  
Bingbing Guo ◽  
...  

AbstractThe pathogenesis of Parkinson’s disease (PD) remains unclear, and there is no disease-modifying agent for PD. Withaferin A (WA), a naturally occurring compound, has emerged as a neuroprotective agent. However, the mechanisms by which WA is neuroprotective in PD are unknown. Here we show that WA protected against loss of dopaminergic neurons, neuroinflammation, and motor deficits in MPTP-induced PD mouse models. Whole-genome deep sequencing analysis combined with Meta-analysis of human PD studies reveal that DJ1, Nrf2, and STING in substantia nigra pars compacta (SNc) are linked to anti-PD effect of WA. We found that WA activated DJ1 and Nrf2, and suppressed STING within SNc; and overexpression of STING in SNc dampened the effect of WA. Using genetically modified mice (DJ1-KO, Nrf2-KO, STINGgt/gt and STING-KO) and immunolabeling technique, we identified that WA targeted DJ1-Nrf2-STING pathway in dopaminergic neurons; and we demonstrate that STING might be an important factor in PD pathogenesis. In addition, WA alleviated accumulation of phosphorylated α-synuclein (p-α-syn) and insoluble α-syn within SNc in adeno-associated virus (AAV)-mediated human α-syn overexpression PD model. Our comparative analysis on whole-genome transcriptome profiles suggests that STING might be a key target of WA and amantadine in PD treatment. This study highlights a multifaceted role for WA in neuroprotection, and suggests that WA can be a potential candidate for treatment of PD.


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