scholarly journals An Insight of Vitamin E as Neuroprotective Agents

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Hui-Min Yap ◽  
Kwan-Liang Lye

Nervous system is the network of nerve cells that transmits nerve impulses throughout the body. It is rich in both unsaturated fats and irons, making it predominantly susceptible to oxidative stress and damage. Oxidative stress reflects the disruption of the redox balance between the formation and clearance of highly free radicals, for instance reactive oxygen species (ROS) and reactive nitrogen species (RNS). Oxidative stress will further damage the cell lipid, protein and DNA. Oxidative stress has a role in the modulation of critical cellular functions, such as apoptosis program activation, ion transport and calcium mobilization which lead to cell death. Many studies were conducted to prevent neuronal cell death caused by oxidative stress through administration of free radical scavenging antioxidant, such as vitamin E. Vitamin E is known as a chain-breaking antioxidant that showed the capability to increase the viability of neuronal cells that had undergone glutamate injury by inhibiting glutamate-induced pp60 (c-Src) kinase activation. Vitamin E occurs in 8 forms, namely ?-, ?-, ?- and ?-tocopherols and ?-, ?-, ?-and ?-tocotrienols. Tocotrienols differ from tocopherols by possessing an unsaturated isoprenoid side chain instead of a saturated phytyl tail. Tocotrienols, compared to tocopherols, are lightly studied due to the abundance of ?-tocopherol in the human body and its antioxidant properties. Nevertheless, recent studies showed that ?-tocotrienol is more effective in preventing lipid peroxidation compared to ?-tocopherol. Furthermore, tocotrienol was discovered to protect neuronal cell through antioxidant-independent activities. The tocotrienol-rich fraction (TRF) is an extract that consists of 75% tocotrienol and 25% ?-tocopherol. TRF was reported to possess potent antioxidant, anti-inflammation, anticancer and cholesterol-lowering properties. Thus, this writing highlights the significant neuroprotective effects of tocotrienol and tocopherol.

2018 ◽  
Vol 19 (10) ◽  
pp. 3252 ◽  
Author(s):  
Yan-Rou Tsai ◽  
Cheng-Fu Chang ◽  
Jing-Huei Lai ◽  
John Wu ◽  
Yen-Hua Chen ◽  
...  

Due to its high oxygen demand and abundance of peroxidation-susceptible lipid cells, the brain is particularly vulnerable to oxidative stress. Induced by a redox state imbalance involving either excessive generation of reactive oxygen species (ROS) or dysfunction of the antioxidant system, oxidative stress plays a central role in a common pathophysiology that underpins neuronal cell death in acute neurological disorders epitomized by stroke and chronic ones such as Alzheimer’s disease. After cerebral ischemia, for example, inflammation bears a key responsibility in the development of permanent neurological damage. ROS are involved in the mechanism of post-ischemic inflammation. The activation of several inflammatory enzymes produces ROS, which subsequently suppress mitochondrial activity, leading to further tissue damage. Pomalidomide (POM) is a clinically available immunomodulatory and anti-inflammatory agent. Using H2O2-treated rat primary cortical neuronal cultures, we found POM displayed neuroprotective effects against oxidative stress and cell death that associated with changes in the nuclear factor erythroid derived 2/superoxide dismutase 2/catalase signaling pathway. POM also suppressed nuclear factor kappa-light-chain-enhancer (NF-κB) levels and significantly mitigated cortical neuronal apoptosis by regulating Bax, Cytochrome c and Poly (ADP-ribose) polymerase. In summary, POM exerted neuroprotective effects via its anti-oxidative and anti-inflammatory actions against H2O2-induced injury. POM consequently represents a potential therapeutic agent against brain damage and related disorders and warrants further evaluation.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Anne Christmann ◽  
Manuela Gries ◽  
Patrik Scholz ◽  
Pascal L. Stahr ◽  
Jessica Ka Yan Law ◽  
...  

Abstract Motoric disturbances in Parkinson’s disease (PD) derive from the loss of dopaminergic neurons in the substantia nigra. Intestinal dysfunctions often appear long before manifestation of neuronal symptoms, suggesting a strong correlation between gut and brain in PD. Oxidative stress is a key player in neurodegeneration causing neuronal cell death. Using natural antioxidative flavonoids like Rutin, might provide intervening strategies to improve PD pathogenesis. To explore the potential effects of micro (mRutin) compared to nano Rutin (nRutin) upon the brain and the gut during PD, its neuroprotective effects were assessed using an in vitro PD model. Our results demonstrated that Rutin inhibited the neurotoxicity induced by A53T α-synuclein (Syn) administration by decreasing oxidized lipids and increasing cell viability in both, mesencephalic and enteric cells. For enteric cells, neurite outgrowth, number of synaptic vesicles, and tyrosine hydroxylase positive cells were significantly reduced when treated with Syn. This could be reversed by the addition of Rutin. nRutin revealed a more pronounced result in all experiments. In conclusion, our study shows that Rutin, especially the nanocrystals, are promising natural compounds to protect neurons from cell death and oxidative stress during PD. Early intake of Rutin may provide a realizable option to prevent or slow PD pathogenesis.


2019 ◽  
Vol 62 (1) ◽  
Author(s):  
Jee-Yun Park ◽  
Khulan Amarsanaa ◽  
Yanji Cui ◽  
Ji-Hyung Lee ◽  
Jinji Wu ◽  
...  

Abstract Oxidative stress causes neuronal cell death in various neurodegenerative diseases, such as Alzheimer’s disease, ischemia, and Parkinson’s disease. Therefore, reducing intracellular reactive oxygen species (ROS) has been evaluated as an effective treatment strategy for neurodegenerative disorders. Methyl lucidone (MLC) extracted from Lindera erythrocarpa Makino (Lauraceae) has been previously reported to exhibit microglial-mediated neuroprotective effects via inhibiting neuroinflammation. However, the antioxidant effects of MLC are still unclear. The aim of this study was to determine the neuroprotective mechanism of MLC in HT-22 neurons against oxidative stress induced by glutamate. In results, the pretreatment of MLC significantly enhanced the viability of HT-22 cells under glutamate-induced oxidative conditions, suggesting that MLC has a neuronal mechanism to protect neurons without microglial regulation. Also, the glutamate effect to increase ROS production was effectively blocked by MLC without any free radical scavenging activity. To induce this antioxidant effect, MLC upregulated the expression of heme oxygenase 1 (HO-1) and nuclear translocation of nuclear factor-E2-related factor 2 (Nrf-2), known as an intracellular antioxidant enzyme, and its transcription factor. Additionally, Akt phosphorylation regulating Nrf-2 was confirmed to be involved in the neuroprotective signaling activated by MLC. These results indicate that MLC may play a role as an antioxidant agent to inhibit neurodegenerative processes via activating antioxidant signaling pathways that include Nrf-2 and phosphatidylinositol 3-kinase (PI3K).


2021 ◽  
Vol 12 (1) ◽  
pp. 210-217
Author(s):  
Yibiao Wang ◽  
Min Xu

Abstract Background This study aimed to explore the role of miR-380-5p in cerebral ischemia/reperfusion (CIR) injury-induced neuronal cell death and the potential signaling pathway involved. Methodology Human neuroblastoma cell line SH-SY5Y cells were used in this study. Oxygen and glucose deprivation/reperfusion (OGD/R) model was used to mimic ischemia/reperfusion injury. CCK-8 assay and flow cytometry were used to examine cell survival. Quantitative real time PCR (RT-qPCR) assay and Western blotting were used to measure the change of RNA and protein expression, respectively. TargetScan and Luciferase assay was used to confirm the target of miR-380-5p. Malondialdehyde (MDA) superoxide dismutase (SOD) and glutathione peroxidase (GSHPx) were measured using commercial kits. Results miR-380-5p was downregulated in SH-SY5Y cells after OGD/R. Cell viability was increased by miR-380-5p, while cell apoptosis was reduced by miR-380-5p mimics. MDA was reduced by miR-380-5p mimics, while SOD and GSHPx were increased by miR-380-5p. Results of TargetScan and luciferase assay have showed that BACH1 is the direct target of miR-380-5p. Expression of NRF2 was upregulated after OGD/R, but was not affected by miR-380-5p. mRNA expression of HO-1 and NQO1 and ARE activity were increased by miR-380-5p. Overexpression of BACH1 reversed the antioxidant and neuroprotective effects of miR-380-5p. Conclusion miR-380-5p inhibited cell death induced by CIR injury through target BACH1 which also facilitated the activation of NRF2, indicating the antioxidant and neuroprotective effects of miR-380-5p.


2021 ◽  
Vol 22 (13) ◽  
pp. 6946
Author(s):  
Weishun Tian ◽  
Suyoung Heo ◽  
Dae-Woon Kim ◽  
In-Shik Kim ◽  
Dongchoon Ahn ◽  
...  

Free radical generation and oxidative stress push forward an immense influence on the pathogenesis of neurodegenerative diseases such as Alzheimer’s disease and Parkinson’s disease. Maclura tricuspidata fruit (MT) contains many biologically active substances, including compounds with antioxidant properties. The current study aimed to investigate the neuroprotective effects of MT fruit on hydrogen peroxide (H2O2)-induced neurotoxicity in SH-SY5Y cells. SH-SY5Y cells were pretreated with MT, and cell damage was induced by H2O2. First, the chemical composition and free radical scavenging properties of MT were analyzed. MT attenuated oxidative stress-induced damage in cells based on the assessment of cell viability. The H2O2-induced toxicity caused by ROS production and lactate dehydrogenase (LDH) release was ameliorated by MT pretreatment. MT also promoted an increase in the expression of genes encoding the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT). MT pretreatment was associated with an increase in the expression of neuronal genes downregulated by H2O2. Mechanistically, MT dramatically suppressed H2O2-induced Bcl-2 downregulation, Bax upregulation, apoptotic factor caspase-3 activation, Mitogen-activated protein kinase (MAPK) (JNK, ERK, and p38), and Nuclear factor-κB (NF-κB) activation, thereby preventing H2O2-induced neurotoxicity. These results indicate that MT has protective effects against H2O2-induced oxidative damage in SH-SY5Y cells and can be used to prevent and protect against neurodegeneration.


Antioxidants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1702
Author(s):  
Sereen Sandouka ◽  
Tawfeeq Shekh-Ahmad

Epilepsy is a chronic disease of the brain that affects over 65 million people worldwide. Acquired epilepsy is initiated by neurological insults, such as status epilepticus, which can result in the generation of ROS and induction of oxidative stress. Suppressing oxidative stress by upregulation of the transcription factor, nuclear factor erythroid 2-related factor 2 (Nrf2) has been shown to be an effective strategy to increase endogenous antioxidant defences, including in brain diseases, and can ameliorate neuronal damage and seizure occurrence in epilepsy. Here, we aim to test the neuroprotective potential of a naturally occurring Nrf2 activator sulforaphane, in in vitro epileptiform activity model and a temporal lobe epilepsy rat model. Sulforaphane significantly decreased ROS generation during epileptiform activity, restored glutathione levels, and prevented seizure-like activity-induced neuronal cell death. When given to rats after 2 h of kainic acid-induced status epilepticus, sulforaphane significantly increased the expression of Nrf2 and related antioxidant genes, improved oxidative stress markers, and increased the total antioxidant capacity in both the plasma and hippocampus. In addition, sulforaphane significantly decreased status epilepticus-induced neuronal cell death. Our results demonstrate that Nrf2 activation following an insult to the brain exerts a neuroprotective effect by reducing neuronal death, increasing the antioxidant capacity, and thus may also modify epilepsy development.


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