scholarly journals Krill Oil Attenuates Cognitive Impairment by the Regulation of Oxidative Stress and Neuronal Apoptosis in an Amyloid β-Induced Alzheimer’s Disease Mouse Model

Molecules ◽  
2020 ◽  
Vol 25 (17) ◽  
pp. 3942
Author(s):  
Ji Hyun Kim ◽  
Hui Wen Meng ◽  
Mei Tong He ◽  
Ji Myung Choi ◽  
Dongjun Lee ◽  
...  

In the present study, we investigated the cognitive improvement effects and its mechanisms of krill oil (KO) in Aβ25–35-induced Alzheimer’s disease (AD) mouse model. The Aβ25–35-injected AD mouse showed memory and cognitive impairment in the behavior tests. However, the administration of KO improved novel object recognition ability and passive avoidance ability compared with Aβ25–35-injected control mice in behavior tests. In addition, KO-administered mice showed shorter latency to find the hidden platform in a Morris water maze test, indicating that KO improved learning and memory abilities. To evaluate the cognitive improvement mechanisms of KO, we measured the oxidative stress-related biomarkers and apoptosis-related protein expressions in the brain. The administration of KO inhibited oxidative stress-related biomarkers such as reactive oxygen species, malondialdehyde, and nitric oxide compared with AD control mice induced by Aβ25–35. In addition, KO-administered mice showed down-regulation of Bax/Bcl-2 ratio in the brain. Therefore, this study indicated that KO-administered mice improved cognitive function against Aβ25–35 by attenuations of neuronal oxidative stress and neuronal apoptosis. It suggests that KO might be a potential agent for prevention and treatment of AD.

Antioxidants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2011
Author(s):  
Alaa Sirwi ◽  
Nesrine S. El Sayed ◽  
Hossam M. Abdallah ◽  
Sabrin R. M. Ibrahim ◽  
Gamal A. Mohamed ◽  
...  

Alzheimer’s disease (AD) is the most common type of dementia and is characterized by advanced cognitive deterioration, deposition of Aβ (amyloid-beta), and the formation of neurofibrillary tangles. Administration of streptozotocin (STZ) via the intracerebroventricular (ICV) route is a reliable model resembling sporadic AD (SAD) associated neuropathological changes. The present study was undertaken to explore the neuroprotective effects of the methoxy flavonoid, umuhengerin, in an STZ-induced SAD mouse model as a potential therapy for AD. Mice were injected once with STZ (3 mg/kg, ICV), followed by daily administration of umuhengerin (orally, 30 mg/kg) or the positive control donepezil (orally, 2.5 mg/kg) for 21 days. The pharmacological activity of umuhengerin was assessed through estimation of oxidative stress and inflammatory markers via mouse ELISA kits, Western blot analysis, and brain histopathological examination. Morris water maze test was also conducted to investigate umuhengerin-induced cognitive enhancement. The results showed that umuhengerin attenuated STZ-produced neuroinflammation and oxidative stress with a notable rise in the expression of Nrf2 (nuclear factor erythroid 2-related factor 2). In contrast, it downregulated Keap-1 (Kelch-like ECH associated protein 1), as well as elevated brain contents of GSH (reduced glutathione) and HO-1 (heme oxygenase-1). STZ-injected animals receiving umuhengerin showed marked downregulation of the nuclear factor kappa beta (NF-Kβp65) and noticeable increment in the expression of its inhibitor kappa beta alpha protein (IKβα), as well as prominent reduction in malondialdehyde (MDA), H2O2 (hydrogen peroxide), and TNF-α (tumor-necrosis factor-alpha) contents. Β-secretase protein expression and acetylcholinesterase (AchE) activity were also diminished upon umuhengerin injection in the STZ group, leading to decreased Aβ formation and cognitive improvement, respectively. In conclusion, umuhengerin neuroprotective effects were comparable to the standard drug donepezil; thus, it could be an alternative approach for AD management.


2017 ◽  
pp. 1049-1056 ◽  
Author(s):  
Z. CHMATALOVA ◽  
M. VYHNALEK ◽  
J. LACZO ◽  
J. HORT ◽  
R. POSPISILOVA ◽  
...  

Increased oxidative stress in the brain during the course of Alzheimer’s disease (AD) leads to an imbalance of antioxidants and formation of free radical reaction end-products which may be detected in blood as fluorescent lipofuscin-like pigments (LFPs). The aim of this study was to evaluate and compare LFPs with plasma selenium concentrations representing an integral part of the antioxidant system. Plasma samples from subjects with AD dementia (ADD; n=11), mild cognitive impairment (MCI; n=17) and controls (n=12), were collected. The concentration of selenium was measured using atomic absorption spectroscopy. LFPs were analyzed by fluorescence spectroscopy and quantified for different fluorescent maxima and then correlated with plasma selenium. Lower levels of selenium were detected in MCI and ADD patients than in controls (P=0.003 and P=0.049, respectively). Additionally, higher fluorescence intensities of LFPs were observed in MCI patients than in controls in four fluorescence maxima and higher fluorescence intensities were also observed in MCI patients than in ADD patients in three fluorescence maxima, respectively. A negative correlation between selenium concentrations and LFPs fluorescence was observed in the three fluorescence maxima. This is the first study focused on correlation of plasma selenium with specific lipofuscin-like products of oxidative stress in plasma of patients with Alzheimer´s disease and mild cognitive impairment.


Molecules ◽  
2021 ◽  
Vol 26 (17) ◽  
pp. 5342
Author(s):  
Aslina Pahrudin Arrozi ◽  
Zulzikry Hafiz Abu Bakar ◽  
Hiroyasu Taguchi ◽  
Daijiro Yanagisawa ◽  
Ikuo Tooyama

Thioredoxin-interacting protein (TXNIP) is involved in multiple disease-associated functions related to oxidative stress, especially by inhibiting the anti-oxidant- and thiol-reducing activity of thioredoxin (TXN). Shiga-Y5 (SY5), a fluorine-19 magnetic resonance probe for detecting amyloid-β deposition in the brain, previously showed therapeutic effects in a mouse model of Alzheimer’s disease; however, the mechanism of action of SY5 remains unclear. SY5 passes the blood–brain barrier and then undergoes hydrolysis to produce a derivative, Shiga-Y6 (SY6), which is a TXNIP-negative regulator. Therefore, this study investigates the therapeutic role of SY5 as the prodrug of SY6 in the thioredoxin system in the brain of a mouse model of Alzheimer’s disease. The intraperitoneal injection of SY5 significantly inhibited TXNIP mRNA (p = 0.0072) and protein expression (p = 0.0143) induced in the brain of APP/PS1 mice. In contrast, the levels of TXN mRNA (p = 0.0285) and protein (p = 0.0039) in the brain of APP/PS1 mice were increased after the injection of SY5. The ratio of TXN to TXNIP, which was decreased (p = 0.0131) in the brain of APP/PS1 mice, was significantly increased (p = 0.0072) after the injection of SY5. These results suggest that SY5 acts as a prodrug of SY6 in targeting the thioredoxin system and could be a potential therapeutic compound in oxidative stress-related diseases in the brain.


2022 ◽  
Vol 2022 ◽  
pp. 1-11
Author(s):  
Qi Qi Pang ◽  
Ji-Hyun Kim ◽  
Ji Myung Choi ◽  
Jia-Le Song ◽  
Sanghyun Lee ◽  
...  

Abnormal production and degradation of amyloid beta (Aβ) in the brain lead to oxidative stress and cognitive impairment in Alzheimer’s disease (AD). Cirsium japonicum var. maackii (CJM) is widely used as an herbal medicine and has antibacterial and anti-inflammatory properties. This study focused on the protective effect of the ethyl acetate fraction from CJM (ECJM) on Aβ25-35-induced control mice. In the T-maze and novel object recognition test, ECJM provided higher spatial memory and object recognition compared to Aβ25-35 treatment alone. In the Morris water maze test, ECJM-administered mice showed greater learning and memory abilities than Aβ25-35-induced control mice. Additionally, ECJM-administered mice experienced inhibited lipid peroxidation and nitric oxide production in a dose-dependent manner. The present study indicates that ECJM improves cognitive impairment by inhibiting oxidative stress in Aβ25-35-induced mice. Therefore, CJM may be useful for the treatment of AD and may be a potential material for functional foods.


Author(s):  
Ravinder Kaur ◽  
Kudrat Randhawa ◽  
Sanimardeep Kaur ◽  
Richa Shri

AbstractBackgroundAn earlier study demonstrated significant antioxidant and anticholinesterase activities of hydromethanol extract (HME) of Allium cepa. The aim of the study was to investigate the component responsible for these activities followed by an in vivo study.MethodsIn vitro antioxidant and anticholinesterase activities of standardized ethylacetate fraction (EAF) of HME were assessed. Bioactivity-guided fractionation showed that, as compared with its subfractions, EAF had most significant activity in 2,2-diphenyl-1-picrylhydrazyl and Ellman assays. Thus, EAF was further examined using a streptozotocin (STZ)-induced model of Alzheimer’s disease in mice. STZ was injected intracerebroventricularly on days 1 and 3 (3 mg/kg) in mice. EAF was thereafter administered (42, 84, and 168 mg/kg b.w./day p.o.) from days 9 to 22. The Morris water maze test was used to evaluate learning and memory in mice. Acetylcholinesterase (AChE) activity and oxidative stress markers were assessed in the brain homogenates of mice. Additionally, histopathological studies were performed to observe effects in the brain at the cellular level. EAF was standardized based on quercetin and quercetin 4′-O-glucoside content using a validated thin layer chromatography densitometric method.ResultsSTZ produced significant (p < 0.05) memory impairment along with oxidative stress and a cholinergic deficit in mice. EAF treatment ameliorated STZ-induced behavioral deficits and biochemical alterations in mice in a significant and dose-dependent manner.ConclusionsOur results show that EAF is efficacious in improving memory and learning via AChE inhibition and antioxidant activity in the mice brain. Thus, AC could be explored further to find out a lead candidate for Alzheimer’s disease.


2015 ◽  
Vol 12 (9) ◽  
pp. 860-869 ◽  
Author(s):  
Yu Zhang ◽  
Furong Wang ◽  
Xianwen Luo ◽  
Li Wang ◽  
Peng Sun ◽  
...  

2021 ◽  
Vol 22 (1) ◽  
pp. 461
Author(s):  
Sónia C. Correia ◽  
Nuno J. Machado ◽  
Marco G. Alves ◽  
Pedro F. Oliveira ◽  
Paula I. Moreira

The lack of effective disease-modifying therapeutics to tackle Alzheimer’s disease (AD) is unsettling considering the actual prevalence of this devastating neurodegenerative disorder worldwide. Intermittent hypoxic conditioning (IHC) is a powerful non-pharmacological procedure known to enhance brain resilience. In this context, the aim of the present study was to investigate the potential long-term protective impact of IHC against AD-related phenotype, putting a special focus on cognition and mitochondrial bioenergetics and dynamics. For this purpose, six-month-old male triple transgenic AD mice (3×Tg-AD) were submitted to an IHC protocol for two weeks and the behavioral assessment was performed at 8.5 months of age, while the sacrifice of mice occurred at nine months of age and their brains were removed for the remaining analyses. Interestingly, IHC was able to prevent anxiety-like behavior and memory and learning deficits and significantly reduced brain cortical levels of amyloid-β (Aβ) in 3×Tg-AD mice. Concerning brain energy metabolism, IHC caused a significant increase in brain cortical levels of glucose and a robust improvement of the mitochondrial bioenergetic profile in 3×Tg-AD mice, as mirrored by the significant increase in mitochondrial membrane potential (ΔΨm) and respiratory control ratio (RCR). Notably, the improvement of mitochondrial bioenergetics seems to result from an adaptative coordination of the distinct but intertwined aspects of the mitochondrial quality control axis. Particularly, our results indicate that IHC favors mitochondrial fusion and promotes mitochondrial biogenesis and transport and mitophagy in the brain cortex of 3×Tg-AD mice. Lastly, IHC also induced a marked reduction in synaptosomal-associated protein 25 kDa (SNAP-25) levels and a significant increase in both glutamate and GABA levels in the brain cortex of 3×Tg-AD mice, suggesting a remodeling of the synaptic microenvironment. Overall, these results demonstrate the effectiveness of the IHC paradigm in forestalling the AD-related phenotype in the 3×Tg-AD mouse model, offering new insights to AD therapy and forcing a rethink concerning the potential value of non-pharmacological interventions in clinical practice.


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