NO synthase and NO-dependent signal pathways in brain aging and neurodegenerative disorders: the role of oxidant/antioxidant balance

Exercise to prevent the negative effects of sleep deprivation: A systematic review and meta-analysis

Ample sleep is an important basis for maintaining health, however with the pace of life accelerating in modern society, more people are using sacrificial sleep to cope with these social changes. Sleep deprivation can have negative effects on cognitive performance and psychosomatic health. It is well known that exercise, as a beneficial intervention strategy for human health, has been increasingly used in the clinic. But it's not clear if it can prevent the negative effects of sleep deprivation. In this meta-analysis, we reviewed 23 articles from PubMed and Web of Science to investigate whether moderate physical exercise can prevent the negative effects of sleep deprivation in rodents. Our findings suggest that exercise can prevent sleep deprivation-induced cognitive impairment and anxiety-like behaviors through multiple pathways. We also discuss possible molecular mechanisms involved in this protective effect, highlighting the potential of exercise as a preventive or therapeutic strategy for sleep deprivation-induced negative effects.

Neurotoxicity of 4-nonylphenol in adult zebrafish: Evaluation of behaviour, oxidative stress parameters and histopathology of brain

Nonylphenol and its derivatives use as plasticizer or additives in manufacturing industries. Effluents originated from industrial areas are being added to soil, ground water, river and marine water intentionally or unintentionally. Complex mixture of these contaminants enter the food chain and produce sub-lethal deleterious effects mainly on nervous and reproductive systems of aquatic animals and human beings. The information pertaining to oxidative stress-mediated alterations in brain of zebrafish would be helpful to understand the toxicity potential of such compounds in aquatic animals. The aim of the present study was to evaluate the behavioural changes, status of oxidative stress markers; sod, cat, and NF-E2-related factor 2 (nrf2) mRNA gene expression profile; and histopathological changes in the brain of adult zebrafish exposed to 4-nonylphenol (4NP) at concentration of 100 and 200 μg/L of water for 21 days. Zebrafish were divided into four groups viz; control (C1), vehicle (C2, ethanol 10 μg/L of water), treatment 1 (T1, 4-NP, 100 μg/L) and treatment 2 (T2, 4-NP, 200 μg/L). Both exposure levels of 4-NP adversely affected the exploratory behaviour of zebrafish and produced anxiety-like symptom. Concentration-dependent reduction in activity of superoxide dismutase and catalase; and glutathione level, with increased level of malondialdehyde recorded in the brain of exposed zebrafish. Gene expression analysis showed down regulation of sod, cat, nrf2 genes in brain of zebrafish from toxicity groups indicating 4-NP induced oxidative stress in brain. However, noticeable histological alterations were not observed in 4-NP exposed brain of zebrafish.

A story of the potential effect of non-steroidal anti-inflammatory drugs (NSAIDs) in Parkinson's disease: beneficial or detrimental effects

Parkinson's disease (PD) is an advanced neurodegenerative disease (NDD) caused by the degeneration of dopaminergic neurons (DNs) in the substantia nigra (SN). As PD is an age-related disorder, the majority of PD patients are associated with musculoskeletal disorders with prolonged use of analgesic and anti-inflammatory agents, such as non-steroidal anti-inflammatory drugs (NSAIDs). Therefore, NSAIDs can affect PD neuropathology in different ways. Thus, the objective of the present narrative review was to clarify the potential role of NSAIDs in PD according to the assorted view of preponderance. Inhibition of neuroinflammation and modulation of immune response by NSAIDs could be an effective way in preventing the development of NDD. NSAIDs affect PD neuropathology in different manners could be beneficial or detrimental effects. Inhibition of cyclooxygenase 2 (COX2) by NSAIDs may prevent the development of PD. NSAIDs afforded a neuroprotective role against the development and progression of PD neuropathology through the  modulation of neuroinflammation. Though, NSAIDs may lead to neutral or harmful effects by inhibiting neuroprotective prostacyclin (PGI2) and accentuation of pro-inflammatory leukotrienes (LTs). In conclusion, there is still a potential conflict regarding the effect of NSAIDs on PD neuropathology.

Honey and Alzheimer's Disease-Current Understanding and Future Prospects

Alzheimer's disease (AD), a leading cause of dementia, has been a global concern. AD is associated with the involvement of the central nervous system that causes the characteristic impaired memory, cognitive deficits, and behavioral abnormalities. These abnormalities caused by AD is known to be attributed by extracellular aggregates of amyloid beta plaques and intracellular neurofibrillary tangles. Additionally, genetic factors such as abnormality in the expression of APOE, APP, BACE1, PSEN-1, and PSEN-2 play a role in the disease. As the current treatment aims to treat the symptoms and to slow the disease progression, there has been a continuous search for new nutraceutical agent or medicine to help prevent and cure AD pathology. In this quest, honey has emerged as a powerful nootropic agent. Numerous studies have demonstrated that the high flavonoids and phenolic acids content in honey exerts its antioxidant, anti-inflammatory, and neuroprotective properties. This review summarizes the effect of main flavonoid compounds found in honey on the physiological functioning of the central nervous system, and the effect of honey intake on memory and cognition in various animal model. This review provides a new insight on the potential of honey to prevent AD pathology, as well as to ameliorate the damage in the developed AD.

Protective effects of verbenalin and (+)-eudesmin against 6-hydroxydopamine-induced oxidative/nitrosative stress in SH-SY5Y cells

BACKGROUND

The purpose of this research was to study whether verbenalin, an iridoid glucoside, and (+)-eudesmin, a furofuran lignan isolated from different plant families, can attenuate cell damage and death induced by 6-hydroxydopamine (6-OHDA) in human neuroblastoma SH-SY5Y cells.

METHODS

SH-SY5Y cells were incubated with 6-OHDA (35 µM) for 1 day. Verbenalin and (+)-eudesmin were administrated with various concentrations (1, 2.5, 5, 10, 20, and 50 µM) one hour before the 6-OHDA treatment. After 1 day, cell viability and neuroprotective effect were investigated with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays. Nitrosative stress was determined with measurements of nitric oxide (NO) and 3-nitrotyrosine (3-NT), a biomarker of peroxynitrite formation.

RESULTS

We observed that 6-OHDA declined viability and augmented LDH leakage in SH-SY5Y cells. MTT analyses showed that pretreatment with verbenalin and (+)-eudesmin markedly prevented the toxicity due to 6-OHDA (P < 0.05). Verbenalin and (+)-eudesmin suppressed LDH release induced by 6-OHDA (P < 0.01). Although 6-OHDA treatment produced no marked effects on NO levels, (+)-eudesmin at high concentrations (10-50 µM) markedly attenuated NO levels (P < 0.01). There was a significant increase in 3-NT levels with 6-OHDA exposure in cells. Pretreatment with verbenalin, but not (+)-eudesmin, diminished 3-NT levels at low concentrations (1-20 µM) and prevented the cytotoxic effect of 6-OHDA (P < 0.01).

CONCLUSION

These results indicated that verbenalin and (+)-eudesmin exert potent cytoprotective activities against cytotoxicity triggered by 6-OHDA in neuroblastoma cells. This is the first report demonstrating that verbenalin may act as a peroxynitrite scavenger.

Pharmacological evaluation of bromelain in mouse model of Alzheimer's disease

The current study elucidates pharmacological evaluation of bromelain as a bioactive compound obtain from pineapple stem belongs to family Bromeliaceae in AlCl3 and D - galactose induced mice. In mice, co-administration of AlCl3 at dose 5 mg/kg b.w., via the oral route, and D - galactose at dose 60 mg/kg b.w., via intraperitoneal route for 90 days resulted in cognitive impairment, spatial learning, and memory deficits, as well as neurotoxicity. However, 30 consecutive days, treatments via an intraperitoneal route with bromelain low dose (Brm L) at dose 10 mg/kg b.w., bromelain high dose (Brm H) at dose 20 mg/kg b.w., donepezil (Dnpz) at dose 2 mg/kg b.w., and Brm L + Dnpz at doses 10, 2 mg/kg b.w. were considerably reversed the effect of AlCl3 and D - galactose induced AD mice. Consequences of behavioral parameters (Morris water maze, elevated plus maze and locomotor), biochemical estimation (MDA, GSH, SOD, CAT, Nitrite and AChE), and ELISA tests (mouse BACE, Aβ1 - 42, TNF-α, IL-6, and BDNF) confirmed significant (p < 0.05) neuroprotective effect of treatments in AlCl3 and D - galactose induced mice. Additionally, hematoxylin and eosin staining of the cerebral cortex and the hippocampus exposed eosinophilic lesions and hyperchromatic nuclei in AD mice, but these neurodegenerative effects were eliminated by Brm L, Brm H, Dnpz, and Brm L + Dnpz treatments. Thus, bromelain alone and in combination with donepezil prevent AlCl3 and D - galactose induced spatial learning and memory deficits, as well as cognitive impairment, by increasing cholinergic activity and synaptic plasticity, as well as reducing oxidative damage, neuroinflammation, Aβ 1-42 aggregations, and histopathological damage, according to our findings. The present study consequences indicate that bromelain alone and in combination with donepezil appears to have neuroprotective properties. Henceforward, this may be a promising treatment option for Alzheimer's disease.

Ameliorative effect of myrcene in mouse model of Alzheimer's disease

Myrcene (Myr) has been reported to show neuroprotective effects in cerebral ischemia. In this research work, we investigated the Myr effect on neurobehavioural, and neuropathological alteration in mice induced by Aluminium trichloride (AlCl₃) and D - galactose. The administration of AlCl₃ (5 mg/kg; p. o.), and D - galactose (60 mg/kg; i. p.) for 90 days in mice resulted in spatial learning and memory deficits, cognitive decline, as well as neurotoxicity. The treatments with Myr low dose (100 mg/kg), Myr high dose (200 mg/kg), donepezil (2 mg/kg), and Myr low dose + donepezil (100 + 2 mg/kg) were administered via intraperitoneal route for 30 days significantly reversed the neurobehavioral, and neuropathological effects of AlCl₃ and D - galactose in mice. The results of behavioural tests such as Morris water maze, elevated plus maze, and locomotor; biochemical analysis such as malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), nitrite, and acetylcholinesterase (AChE); and ELISA tests such as mouse β - secretase (BACE), amyloid-beta peptide_1-42 (Aβ_{1 - 42}), tumor necrosis factor - α (TNF-α), interleukin - 6 (IL-6), and brain-derived neurotrophic factor (BDNF) demonstrated a significant (p < 0.05) neuroprotective effect of the Myr and donepezil co-treatments. In addition, hematoxylin and eosin staining of the cerebral cortex and hippocampus revealed eosinophilic lesions and hyperchromatic nuclei in Alzheimer's disease mice, but treatments with Myr low dose, Myr high dose, donepezil, and Myr low dose + donepezil reversed these neurodegenerative effects. Myr showed these activities by enhancing synaptic plasticity and cholinergic activity, as well as reducing oxidative damage, neuroinflammation, Aβ_1-42 aggregations, and histopathological damage. Myr alone and in combination with donepezil may serve as a potential candidate for the treatment of Alzheimer's disease.

Copper induces oxidative stress and apoptosis of hippocampal neuron via pCREB/BDNF/ and Nrf2/HO-1/NQO1 pathway

Disordered copper metabolism has been suggested to occur to several neurological conditions, including Alzheimer's disease and Parkinson's disease. However, the underlying mechanism was still unclear. This might link to copper-induced hippocampal neuronal apoptosis and decrease in neurons viability. Our vitro experiment showed copper exposure induced oxidative stress and promoted apoptosis of HT22 murine hippocampal neuronal cell. Mechanistically, we found copper, on the one hand, prevented phosphorylation of cAMP response element binding protein (CREB) to decrease expression its downstream target protein Brain-derived neurotrophic factor (BDNF), and to decrease mitochondrial membrane potential and Bcl-2/Bax ratio; on the other hand, copper-induced reactive oxygen species (ROS), promoted lipid peroxidation, reduced antioxidant enzyme activity of GSH-Px. Copper-induced oxidative damage further decreased the phosphorylation of CREB, decreased expression of Bcl-2, enhanced expression of Bax, and accelerated the dissociation of keap1-Nrf2 complex, promoted the nuclear translocation of Nrf2, stimulate the expression of antioxidant molecules HO-1 and NQO1. In conclusion, we found copper inhibited pCREB/BDNF signaling pathway by prevent CREB from phosphorylation, further found that oxidative damage not only inhibited neuroprotective signaling pathways and induced apoptosis, but activated antioxidant protection signals Nrf2/HO-1/NQO1 signaling pathway.

Exercise-Induced Benefits for Alzheimer's Disease by Stimulating Mitophagy and Improving Mitochondrial Function

Neurons are highly specialized post-mitotic cells that are inherently dependent on mitochondria due to their higher bioenergetic demand. Mitochondrial dysfunction is closely associated with a variety of aging-related neurological disorders, such as Alzheimer’s disease (AD), and the accumulation of dysfunctional and superfluous mitochondria has been reported as an early stage that significantly facilitates the progression of AD. Mitochondrial damage causes bioenergetic deficiency, intracellular calcium imbalance and oxidative stress, thereby aggravating β-amyloid (Aβ) accumulation and Tau hyperphosphorylation, and further leading to cognitive decline and memory loss. Although there is an intricate parallel relationship between mitochondrial dysfunction and AD, their triggering factors, such as Aβ aggregation and hyperphosphorylated Tau protein and action time, are still unclear. Moreover, many studies have confirmed abnormal mitochondrial biosynthesis, dynamics and functions will present once the mitochondrial quality control is impaired, thus leading to aggravated AD pathological changes. Accumulating evidence shows beneficial effects of appropriate exercise on improved mitophagy and mitochondrial function to promote mitochondrial plasticity, reduce oxidative stress, enhance cognitive capacity and reduce the risks of cognitive impairment and dementia in later life. Therefore, stimulating mitophagy and optimizing mitochondrial function through exercise may forestall the neurodegenerative process of AD.

The Aging Liver: Redox Biology and Liver Regeneration

Significance: During aging, excessive production of reactive species in the liver leads to redox imbalance with consequent oxidative damage and impaired organ homeostasis. Nevertheless, slight amounts of reactive species may modulate several transcription factors, acting as second messengers and regulating specific signaling pathways. These redox-dependent alterations may impact the age-associated decline in liver regeneration. Recent Advances: In the last few decades, relevant findings related to redox alterations in the aging liver were investigated. Consistently, recent research broadened understanding of redox modifications and signaling related to liver regeneration. Other than reporting the effect of oxidative stress, epigenetic and post-translational modifications, as well as modulation of specific redox-sensitive cellular signaling, were described. Among them, the present review focuses on Wnt/β-catenin, the nuclear factor (erythroid-derived 2)-like 2 (NRF2), members of the Forkhead box O (FoxO) family, and the p53 tumor suppressor. Critical Issues: Even though alteration in redox homeostasis occurs both in aging and in impaired liver regeneration, the associative mechanisms are not clearly defined. Of note, antioxidants are not effective in slowing hepatic senescence, and do not clearly improve liver repopulation after hepatectomy or transplant in humans. Future Directions: Further investigations are needed to define mutual redox-dependent molecular pathways involved both in aging and in the decline of liver regeneration. Preclinical studies aimed at the characterization of these pathways would define possible therapeutic targets for human trials. Antioxid. Redox Signal. 35, 832-847.

Role of heat shock proteins in aging and chronic inflammatory diseases

Advanced age is associated with a decline in response to stress. This contributes to the establishment of chronic inflammation, one of the hallmarks of aging and age-related disease. Heat shock proteins (HSP) are determinants of life span, and their progressive malfunction leads to age-related pathology. To discuss the function of HSP on age-related chronic inflammation and illness. An updated review of literature and discussion of relevant work on the topic of HSP in normal aging and chronic inflammatory pathology was performed. HSP contribute to inflamm-aging. They also play a key role in age-associated pathology linked to chronic inflammation such as autoimmune disorders, neurological disease, cardiovascular disorder, and cancer. HSP may be targeted for control of their effects related to age and chronic inflammation. Research on HSP functions in age-linked chronic inflammatory disorders provides an opportunity to improve health span and delay age-related chronic disorders.

Protective effect of chronic administration of pelargonidin on neuronal apoptosis and memory process in amyloid-beta-treated rats

OBJECTIVE

Alzheimer's disease (AD) is a progressive neurodegenerative disorder associated with impaired cognitive skills and learning and memory dysfunctions.  It has been suggested that pelargonidin (PG), as an antioxidant agent, has a neuroprotective effect. PG could prevent damaging effects of amyloid-beta (Aβ) deposition. The aim of this study was to determine the chronic effect of PG on hippocampal neurons and memory processes in a rat model of AD.

MATERIALS AND METHODS

Twenty-eight male adult rats were divided into sham, AD, AD+PG (5 μg, intracerebroventricular), and PG (5 μg, intracerebroventricular) groups. Intracerebroventricular (ICV) injection of Aβ peptides (6 μg) was done using stereotaxic surgery. ICV administration of PG or saline was performed daily for 28 consecutive days. Behavioral analysis was performed using the novel object recognition (NOR) and passive avoidance tests. Neuronal apoptosis was detected using TUNEL assay in the hippocampus.

RESULTS

The ICV injection of Aβ reduced step-through latency and discrimination index in behavioral tests (p<0.001). Aβ increased the number of apoptotic neurons (p<0.001). PG treatment decreased the time spent in the dark compartment and neuronal apoptosis in the AD+PG rats (p<0.001). PG increased the discrimination index in the NOR test (p<0.001). Although PG did not change behavioral variables, it decreased cell death in the PG group.

CONCLUSION

PG attenuated neuronal apoptosis and improved cognition and memory deficiency in AD rats. The protective effect of PG against Aβ may be due to its anti-apoptotic property. It is suggested that PG can be useful to treat AD.

Molecular and cellular pathways contributing to brain aging

Aging is the leading risk factor for several age-associated diseases such as neurodegenerative diseases. Understanding the biology of aging mechanisms is essential to the pursuit of brain health. In this regard, brain aging is defined by a gradual decrease in neurophysiological functions, impaired adaptive neuroplasticity, dysregulation of neuronal Ca2+ homeostasis, neuroinflammation, and oxidatively modified molecules and organelles. Numerous pathways lead to brain aging, including increased oxidative stress, inflammation, disturbances in energy metabolism such as deregulated autophagy, mitochondrial dysfunction, and IGF-1, mTOR, ROS, AMPK, SIRTs, and p53 as central modulators of the metabolic control, connecting aging to the pathways, which lead to neurodegenerative disorders. Also, calorie restriction (CR), physical exercise, and mental activities can extend lifespan and increase nervous system resistance to age-associated neurodegenerative diseases. The neuroprotective effect of CR involves increased protection against ROS generation, maintenance of cellular Ca2+ homeostasis, and inhibition of apoptosis. The recent evidence about the modem molecular and cellular methods in neurobiology to brain aging is exhibiting a significant potential in brain cells for adaptation to aging and resistance to neurodegenerative disorders.

Regional Differences in Heat Shock Protein 25 Expression in Brain and Spinal Cord Astrocytes of Wild-Type and SOD1 G93A Mice

Heterogeneity of glia in different CNS regions may contribute to the selective vulnerability of neuronal populations in neurodegenerative conditions such as amyotrophic lateral sclerosis (ALS). Here, we explored regional variations in the expression of heat shock protein 25 in glia under conditions of acute and chronic stress. Hsp27 (Hsp27; murine orthologue: Hsp25) fulfils a number of cytoprotective functions and may therefore be a possible therapeutic target in ALS. We identified a subpopulation of astrocytes in primary murine mixed glial cultures that expressed Hsp25. Under basal conditions, the proportion of Hsp25-positive astrocytes was twice as high in spinal cord cultures than in cortical cultures. To explore the physiological role of the elevated Hsp25 expression in spinal cord astrocytes, we exposed cortical and spinal cord glia to acute stress, using heat stress and pro-inflammatory stimuli. Surprisingly, we observed no stress-induced increase in Hsp25 expression in either cortical or spinal cord astrocytes. Similarly, exposure to endogenous stress, as modelled in glial cultures from SOD1 G93A-ALS mice, did not increase Hsp25 expression above that observed in astrocytes from wild-type mice. In vivo, Hsp25 expression was greater under conditions of chronic stress present in the spinal cord of SOD1 G93A mice than in wild-type mice, although this increase in expression is likely to be due to the extensive gliosis that occurs in this model. Together, these results show that there are differences in the expression of Hsp25 in astrocytes in different regions of the central nervous system, but Hsp25 expression is not upregulated under acute or chronic stress conditions.

Preventive and Therapeutic Potential of Physical Exercise in Neurodegenerative Diseases

Significance: The prevalence and incidence of age-related neurodegenerative diseases (NDDs) tend to increase along with the enhanced average of the world life expectancy. NDDs are a major cause of morbidity and disability, affecting the health care, social and economic systems with a significant impact. Critical Issues and Recent Advances: Despite the worldwide burden of NDDs and the ongoing research efforts to increase the underlying molecular mechanisms involved in NDD pathophysiologies, pharmacological therapies have been presenting merely narrow benefits. On the contrary, absent of detrimental side effects but growing merits, regular physical exercise (PE) has been considered a prone pleiotropic nonpharmacological alternative able to modulate brain structure and function, thereby stimulating a healthier and "fitness" neurological phenotype. Future Directions: This review summarizes the state of the art of some peripheral and central-related mechanisms that underlie the impact of PE on brain plasticity as well as its relevance for the prevention and/or treatment of NDDs. Nevertheless, further studies are needed to better clarify the molecular signaling pathways associated with muscle contractions-related myokines release and its plausible positive effects in the brain. In addition, particular focus of research should address the role of PE in the modulation of mitochondrial metabolism and oxidative stress in the context of NDDs.

Potentiation of the apoptotic signaling pathway in both the striatum and hippocampus and neurobehavioral impairment in rats exposed chronically to a low-dose of cadmium

Cadmium (Cd) is a highly toxic heavy metal. It accumulates in biological tissues, especially in fish which constitutes a first rank food for humans, particularly in the coastal areas. This study investigates the effect of long-term exposure to low Cd concentration (17 μg/kg/day) in rat striatum and hippocampus. In this study, the neurobehavioral ability changes were assessed by applying cognitive standard testing at the end of the rats' exposure period. In addition, the examination of mitochondrial swelling was performed at the same time of evaluation of its redox status in the brain regions studied through stress parameters (GSH, MDA, GST, and CAT). This study examined also whether this long-term exposure can modify the apoptotic signaling pathway via assessment of apoptotic markers (caspase-8 and 9, Bax, Bcl-2, and Cyt-c) in cell lysates. The results of this study showed changes in neurobehavioral abilities of animals and a stronger mitochondrial swelling associated with a significant decrease in antioxidant systems (GSH, GST, and CAT) and conversely an increase in the lipoperoxidation end product (MDA) in both the striatal and hippocampal mitochondria. In addition, the results revealed a significant increase in pro-apoptotic intracellular components such as caspase-9, Cyt-c, and Bax, and showed also an evident decrease in Bcl-2 levels. In conclusion, our results reported that chronic exposure to Cd produces behavioral and cognitive perturbations, enhances oxidative stress associated with mitochondrial edema and Cyt-c leakage, and, ultimately, potentiates apoptosis signaling pathway in both brain regions in rats.

Restoring pars intermedia dopamine concentrations and tyrosine hydroxylase expression levels with pergolide: evidence from horses with pituitary pars intermedia dysfunction

Background

Pituitary pars intermedia dysfunction (PPID) develops slowly in aged horses as degeneration of hypothalamic dopaminergic neurons leads to proliferation of pars intermedia (PI) melanotropes through hyperplasia and adenoma formation. Dopamine (DA) concentrations and tyrosine hydroxylase (TH) immunoreactivity are markedly reduced in PI tissue of PPID-affected equids and treatment with the DA receptor agonist pergolide results in notable clinical improvement. Thus, we hypothesized that pergolide treatment of PPID-affected horses would result in greater DA and TH levels in PI tissue collected from PPID-affected horses versus untreated PPID-affected horses.

To test this hypothesis, pituitary glands were removed from 18 horses: four untreated PPID-affected horses, four aged and four young horses without signs of PPID, and six PPID-affected horses that had been treated with pergolide at 2 µg/kg orally once daily for 6 months. DA concentrations and TH expression levels in PI tissues were determined by high performance liquid chromatography with electrochemical detection and Western blot analyses, respectively.

Results

DA and TH levels were lowest in PI collected from untreated PPID-affected horses while levels in the pergolide treated horses were similar to those of aged horses without signs of PPID.

Conclusions

These findings provide evidence of restoration of DA and TH levels following treatment with pergolide. Equine PPID is a potential animal model of dopaminergic neurodegeneration, which could provide insight into human neurodegenerative diseases.

Hederagenin Modulates M1 Microglial Inflammatory Responses and Neurite Outgrowth

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder. Neurite atrophy and synaptic loss initiate the onset of neuronal death, while the activated M1 microglia-induced neuroinflammatory microenvironment inhibits neurite regeneration and exacerbates neuronal loss. Thus, optimizing the brain microenvironment using small compounds through suppressing activated M1 microglia and promoting neurite regrowth might be an effective therapeutic strategy for AD. We found that hederagenin (HED), a naturally occurring triterpene compound, inhibited lipopolysaccharide-induced nitric oxide generation and downregulated expression of proinflammatory cytokines, such as tumor necrosis factor-α, interleukin-1β (IL-1β), and IL-6. Further investigation of primary microglia confirmed that HED inhibited Iba-1 positive M1 microglia. However, no changes were seen in CD206 positive M2 microglia polarization. HED remarkably suppressed phosphorylated nuclear factor kappa-light-chain-enhancer of activated B cells subunit p65 signaling. In addition, HED ameliorated Aβ25-35-induced neuritic atrophy and neuronal death. Therefore, HED might be a therapeutic candidate for AD.

The role of CD47 in pathogenesis and treatment of renal ischemia reperfusion injury

Ischemia reperfusion (IR) injury is a process defined by the temporary loss of blood flow and tissue perfusion followed later by restoration of the same. Brief periods of IR can be tolerated with little permanent deficit, but sensitivity varies for different target cells and tissues. Ischemia reperfusion injuries have multiple causes including peripheral vascular disease and surgical interventions that disrupt soft tissue and organ perfusion as occurs in general and reconstructive surgery. Ischemia reperfusion injury is especially prominent in organ transplantation where substantial effort has been focused on protecting the transplanted organ from the consequences of IR. A number of factors mediate IR injury including the production of reactive oxygen species and inflammatory cell infiltration and activation. In the kidney, IR injury is a major cause of acute injury and secondary loss of renal function. Transplant-initiated renal IR is also a stimulus for innate and adaptive immune-mediated transplant dysfunction. The cell surface molecule CD47 negatively modulates cell and tissue responses to stress through limitation of specific homeostatic pathways and initiation of cell death pathways. Herein, a summary of the maladaptive activities of renal CD47 will be considered as well as the possible therapeutic benefit of interfering with CD47 to limit renal IR.

Platycodigenin as Potential Drug Candidate for Alzheimer's Disease via Modulating Microglial Polarization and Neurite Regeneration

Neuroinflammatory microenvironment, regulating neurite regrowth and neuronal survival, plays a critical role in Alzheimer’s disease (AD). During neuroinflammation, microglia are activated, inducing the release of inflammatory or anti-inflammatory factors depending on their polarization into classical M1 microglia or alternative M2 phenotype. Therefore, optimizing brain microenvironment by small molecule-targeted microglia polarization and promoting neurite regeneration might be a potential therapeutic strategy for AD. In this study, we found platycodigenin, a naturally occurring triterpenoid, promoted M2 polarization and inhibited M1 polarization in lipopolysaccharide (LPS)-stimulated BV2 and primary microglia. Platycodigenin downregulated pro-inflammatory molecules such as interleukin (IL)-1β, tumor necrosis factor (TNF)-α, IL-6 and nitric oxide (NO), while upregulated anti-inflammatory cytokine IL-10. Further investigation confirmed that platycodigenin inhibited cyclooxygenase-2 (Cox2) positive M1 but increased Ym1/2 positive M2 microglial polarization in primary microglia. In addition, platycodigenin significantly decreased LPS-induced the hyperphosphorylation of mitogen-activated protein kinase (MAPK) p38 and nuclear factor-κB (NF-κB) p65 subunits. Furthermore, the inactivation of peroxisome proliferators-activated receptor γ (PPARγ) induced by LPS was completely ameliorated by platycodigenin. Platycodigenin also promoted neurite regeneration and neuronal survival after Aβ treatment in primary cortical neurons. Taken together, our study for the first time clarified that platycodigenin effectively ameliorated LPS-induced inflammation and Aβ-induced neurite atrophy and neuronal death.

Sp1-regulated expression of p11 contributes to motor neuron degeneration by membrane insertion of TASK1

Disruption in membrane excitability contributes to malfunction and differential vulnerability of specific neuronal subpopulations in a number of neurological diseases. The adaptor protein p11, and background potassium channel TASK1, have overlapping distributions in the CNS. Here, we report that the transcription factor Sp1 controls p11 expression, which impacts on excitability by hampering functional expression of TASK1. In the SOD1-G93A mouse model of ALS, Sp1-p11-TASK1 dysregulation contributes to increased excitability and vulnerability of motor neurons. Interference with either Sp1 or p11 is neuroprotective, delaying neuron loss and prolonging lifespan in this model. Nitrosative stress, a potential factor in human neurodegeneration, stimulated Sp1 expression and human p11 promoter activity, at least in part, through a Sp1-binding site. Disruption of Sp1 or p11 also has neuroprotective effects in a traumatic model of motor neuron degeneration. Together our work suggests the Sp1-p11-TASK1 pathway is a potential target for treatment of degeneration of motor neurons.

The adaptor protein p11 and K+ channel TASK1 have overlapping distributions in the CNS. Here, the authors demonstrate that the transcription factor Sp1 regulates p11 levels, which in turn affects intrinsic membrane properties and can contribute to degeneration of motor neurons in disease and injury models.

NQO1: A target for the treatment of cancer and neurological diseases, and a model to understand loss of function disease mechanisms

NAD(P)H quinone oxidoreductase 1 (NQO1) is a multi-functional protein that catalyses the reduction of quinones (and other molecules), thus playing roles in xenobiotic detoxification and redox balance, and also has roles in stabilising apoptosis regulators such as p53. The structure and enzymology of NQO1 is well-characterised, showing a substituted enzyme mechanism in which NAD(P)H binds first and reduces an FAD cofactor in the active site, assisted by a charge relay system involving Tyr-155 and His-161. Protein dynamics play important role in physio-pathological aspects of this protein. NQO1 is a good target to treat cancer due to its overexpression in cancer cells. A polymorphic form of NQO1 (p.P187S) is associated with increased cancer risk and certain neurological disorders (such as multiple sclerosis and Alzheimer´s disease), possibly due to its roles in the antioxidant defence. p.P187S has greatly reduced FAD affinity and stability, due to destabilization of the flavin binding site and the C-terminal domain, which leading to reduced activity and enhanced degradation. Suppressor mutations partially restore the activity of p.P187S by local stabilization of these regions, and showing long-range allosteric communication within the protein. Consequently, the correction of NQO1 misfolding by pharmacological chaperones is a viable strategy, which may be useful to treat cancer and some neurological conditions, targeting structural spots linked to specific disease-mechanisms. Thus, NQO1 emerges as a good model to investigate loss of function mechanisms in genetic diseases as well as to improve strategies to discriminate between neutral and pathogenic variants in genome-wide sequencing studies.

A Hydrolyzed Chicken Extract CMI-168 Enhances Learning and Memory in Middle-Aged Mice

There has been increasing evidence that consumption of dietary supplements or specific nutrients can influence cognitive processes and emotions. A proprietary chicken meat extraction, Chicken Meat Ingredient-168 (CMI-168), has previously been shown to enhance cognitive function in humans. However, the mechanism underlying the CMI-168-induced benefits remains unclear. In this study, we investigated the effects of CMI-168 on hippocampal neuroplasticity and memory function in middle-aged (9⁻12 months old) mice. The mice in the test group (termed the "CMI-168 group") were fed dietary pellets produced by mixing CMI-168 and normal laboratory mouse chow to provide a daily CMI-168 dose of 150 mg/kg of body weight for 6 weeks. The control mice (termed the "Chow group") were fed normal laboratory mouse chow pellets. CMI-168 supplementation did not affect the body weight gain, food intake, or exploratory behavior of the mice. In the novel object recognition test, the CMI-168 group showed better hippocampus-related non-spatial memory compared to the control Chow group. However, spatial memory examined by the Morris Water Maze test was similar between the two groups. There was also no significant difference in the induction and maintenance of long-term potentiation and dendritic complexity of the hippocampal cornu ammonis region 1 (CA1) neurons, as well as the levels of neuroplasticity-related proteins in the hippocampi of the CMI-168 and Chow groups. Interestingly, we observed that CMI-168 appeared to protect the mice against stress-induced weight loss. In conclusion, dietary supplementation of CMI-168 was found to improve learning and memory in middle-aged mice, independent of structural or functional changes in the hippocampus. The resilience to stress afforded by CMI-168 warrants further investigation.

Pesticide toxicity: a mechanistic approach

Pesticides are known for their high persistence and pervasiveness in the environment, and along with products of their biotransformation, they may remain in and interact with the environment and living organisms in multiple ways, according to their nature and chemical structure, dose and targets. In this review, the classifications of pesticides based on their nature, use, physical state, pathophysiological effects, and sources are discussed. The effects of these xenobiotics on the environment, their biotransformation in terms of bioaccumulation are highlighted with special focus on the molecular mechanisms deciphered to date. Basing on targeted organisms, most pesticides are classified as herbicides, fungicides, and insecticides. Herbicides are known as growth regulators, seedling growth inhibitors, photosynthesis inhibitors, inhibitors of amino acid and lipid biosynthesis, cell membrane disrupters, and pigment biosynthesis inhibitors, whereas fungicides include inhibitors of ergosterol biosynthesis, protein biosynthesis, and mitochondrial respiration. Insecticides mainly affect nerves and muscle, growth and development, and energy production. Studying the impact of pesticides and other related chemicals is of great interest to animal and human health risk assessment processes since potentially everyone can be exposed to these compounds which may cause many diseases, including metabolic syndrome, malnutrition, atherosclerosis, inflammation, pathogen invasion, nerve injury, and susceptibility to infectious diseases. Future studies should be directed to investigate influence of long term effects of low pesticide doses and to minimize or eliminate influence of pesticides on non-target living organisms, produce more specific pesticides and using modern technologies to decrease contamination of food and other goods by pesticides.

Moutan Cortex Radicis inhibits the nigrostriatal damage in a 6-OHDA-induced Parkinson's disease model

The traditionally used oriental herbal medicine Moutan Cortex Radicis [MCR; Paeonia Suffruticosa Andrews (Paeoniaceae)] exerts anti-inflammatory, anti-spasmodic, and analgesic effects. In the present study, we investigated the therapeutic effects of differently fractioned MCR extracts in a 6-hydroxydopamine (OHDA)-induced Parkinson's disease model and neuro-blastoma B65 cells. Ethanol-extracted MCR was fractionated by n-hexane, butanol, and distilled water. Adult Sprague-Dawley rats were treated first with 20 μg of 6-OHDA, followed by three MCR extract fractions (100 or 200 mg·kg^-1) for 14 consecutive days. In the behavioral rotation experiment, the MCR extract-treated groups showed significantly decreased number of net turns compared with the 6-OHDA control group. The three fractions also significantly inhibited the reduction in tyrosine hydroxylase-positive cells in the substantia nigra pars compacta following 6-OHDA neurotoxicity. Western blotting analysis revealed significantly reduced tyrosine hydroxylase expression in the substantia nigra pars compacta in the 6-OHDA-treated group, which was significantly inhibited by the n-hexane or distilled water fractions of MCR. B65 cells were exposed to the extract fractions for 24 h prior to addition of 6-OHDA for 30 min; treatment with n-hexane or distilled water fractions of MCR reduced apoptotic cell death induced by 6-OHDA neurotoxicity and inhibited nitric oxide production and neuronal nitric oxide synthase expression. These results showed that n-hexane- and distilled water-fractioned MCR extracts inhibited 6-OHDA-induced neurotoxicity by suppressing nitric oxide production and neuronal nitric oxide synthase activity, suggesting that MCR extracts could serve as a novel candidate treatment for the patients with Parkinson's disease.

Dysregulation of Mesenchymal Stromal Cell Antioxidant Responses in Progressive Multiple Sclerosis

The potential of autologous cell-based therapies including those using multipotent mesenchymal stromal cells (MSCs) is being investigated for multiple sclerosis (MS) and other neurological conditions. However, the phenotype of MSC in neurological diseases has not been fully characterized. We have previously shown that MSC isolated from patients with progressive MS (MS-MSC) have reduced expansion potential, premature senescence, and reduced neuroprotective potential in vitro. In view of the role of antioxidants in ageing and neuroprotection, we examined the antioxidant capacity of MS-MSC demonstrating that MS-MSC secretion of antioxidants superoxide dismutase 1 (SOD1) and glutathione S-transferase P (GSTP) is reduced and correlates negatively with the duration of progressive phase of MS. We confirmed reduced expression of SOD1 and GSTP by MS-MSC along with reduced activity of SOD and GST and, to examine the antioxidant capacity of MS-MSC under conditions of nitrosative stress, we established an in vitro cell survival assay using nitric oxide-induced cell death. MS-MSC displayed differential susceptibility to nitrosative stress with accelerated senescence and greater decline in expression of SOD1 and GSTP in keeping with reduced expression of master regulators of antioxidant responses nuclear factor erythroid 2-related factor 2 and peroxisome proliferator-activated receptor gamma coactivator 1-α. Our results are compatible with dysregulation of antioxidant responses in MS-MSC and have significant implications for development of autologous MSC-based therapies for MS, optimization of which may require that these functional deficits are reversed. Furthermore, improved understanding of the underlying mechanisms may yield novel insights into MS pathophysiology and biomarker identification. Stem Cells Translational Medicine 2018;7:748-758.

Redox Signaling in Neurotransmission and Cognition During Aging

SIGNIFICANCE

Oxidative stress increases in the brain with aging and neurodegenerative diseases. Previous work emphasized irreversible oxidative damage in relation to cognitive impairment. This research has evolved to consider a continuum of alterations, from redox signaling to oxidative damage, which provides a basis for understanding the onset and progression of cognitive impairment. This review provides an update on research linking redox signaling to altered function of neural circuits involved in information processing and memory. Recent Advances: Starting in middle age, redox signaling triggers changes in nervous system physiology described as senescent physiology. Hippocampal senescent physiology involves decreased cell excitability, altered synaptic plasticity, and decreased synaptic transmission. Recent studies indicate N-methyl-d-aspartate and ryanodine receptors and Ca²⁺ signaling molecules as molecular substrates of redox-mediated senescent physiology.

CRITICAL ISSUES

We review redox homeostasis mechanisms and consider the chemical character of reactive oxygen and nitrogen species and their role in regulating different transmitter systems. In this regard, senescent physiology may represent the co-opting of pathways normally responsible for feedback regulation of synaptic transmission. Furthermore, differences across transmitter systems may underlie differential vulnerability of brain regions and neuronal circuits to aging and disease.

FUTURE DIRECTIONS

It will be important to identify the intrinsic mechanisms for the shift in oxidative/reductive processes. Intrinsic mechanism will depend on the transmitter system, oxidative stressors, and expression/activity of antioxidant enzymes. In addition, it will be important to identify how intrinsic processes interact with other aging factors, including changes in inflammatory or hormonal signals. Antioxid. Redox Signal. 28, 1724-1745.

Anti-neuroinflammatory effects of Ginkgo biloba extract EGb761 in LPS-activated primary microglial cells

BACKGROUND

Neuroinflammation is a key factor of Alzheimer's disease (AD) and other neurodegenerative conditions. Microglia are the resident mononuclear immune cells of the central nervous system (CNS). They play an essential role in the maintenance of homeostasis and responses to neuroinflammation. Ginkgo biloba extract EGb 761 is one of the most commonly used natural medicines owing to its established efficacy and remarkable biological activities especially in respect to CNS diseases. However, only few studies have addressed the effects and mechanisms of Ginkgo biloba extract in microglia activation.

METHODS

We measured the production of pro-inflammatory mediators and cytokines by ELISA and analyzed gene expressions by qRT-PCR and Western Blot in LPS treated cultured primary rat microglia.

RESULTS

The Ginkgo biloba extract EGb 761 significantly inhibited the release of prostaglandin E₂ (PGE₂) and differentially regulated the levels of pro-inflammatory cytokines. The inhibition of LPS-induced PGE₂ release in primary microglia was partially dependent on reduced protein synthesis of mPGES-1 and the reduction in the activation of cytosolic phospholipase A2 (cPLA2) without altering COX-2 enzymatic activity, inhibitor of kappa B alpha (IkappaBalpha) degradation, and the activation of multiple mitogen activated protein kinases (MAPKs). Altogether, we showed that EGb 761 reduces neuro-inflammatory activation in primary microglial cells by targeting PGE₂ release and cytokines.

CONCLUSION

Ginkgo biloba extract EGb 761 displayed anti-neuroinflammatory activity in LPS-activated primary microglia cells. EGb 761 was able to reduce neuroinflammatory activation by targeting the COX/PGE₂ pathway. This effect might contribute to the established clinical cognitive efficacy in Alzheimer's disease, vascular and mixed dementia.

Whey protein concentrate supplementation protects rat brain against aging-induced oxidative stress and neurodegeneration

Whey protein concentrate (WPC) is a rich source of sulfur-containing amino acids and is consumed as a functional food, incorporating a wide range of nutritional attributes. The purpose of this study is to evaluate the neuroprotective effect of WPC on rat brain during aging. Young (4 months) and old (24 months) male Wistar rats were supplemented with WPC (300 mg/kg body weight) for 28 days. Biomarkers of oxidative stress and antioxidant capacity in terms of ferric reducing antioxidant potential (FRAP), lipid hydroperoxide (LHP), total thiol (T-SH), protein carbonyl (PC), reactive oxygen species (ROS), nitric oxide (NO), and acetylcholinesterase (AChE) activity were measured in brain of control and experimental (WPC supplemented) groups. In addition, gene expression and histopathological studies were also performed. The results indicate that WPC augmented the level of FRAP, T-SH, and AChE in old rats as compared with the old control. Furthermore, WPC-treated groups exhibited significant reduction in LHP, PC, ROS, and NO levels in aged rats. WPC supplementation also downregulated the expression of inflammatory markers (tumor necrosis factor alpha, interleukin (IL)-1β, IL-6), and upregulated the expression of marker genes associated with autophagy (Atg3, Beclin-1, LC3B) and neurodegeneration (neuron specific enolase, Synapsin-I, MBP-2). The findings suggested WPC to be a potential functional nutritional food supplement that prevents the progression of age-related oxidative damage in Wistar rats.

Effects of Antioxidant Supplements on the Survival and Differentiation of Stem Cells

Although physiological levels of reactive oxygen species (ROS) are required to maintain the self-renewal capacity of stem cells, elevated ROS levels can induce chromosomal aberrations, mitochondrial DNA damage, and defective stem cell differentiation. Over the past decade, several studies have shown that antioxidants can not only mitigate oxidative stress and improve stem cell survival but also affect the potency and differentiation of these cells. Further beneficial effects of antioxidants include increasing genomic stability, improving the adhesion of stem cells to culture media, and enabling researchers to manipulate stem cell proliferation by using different doses of antioxidants. These findings can have several clinical implications, such as improving neurogenesis in patients with stroke and neurodegenerative diseases, as well as improving the regeneration of infarcted myocardial tissue and the banking of spermatogonial stem cells. This article reviews the cellular and molecular effects of antioxidant supplementation to cultured or transplanted stem cells and draws up recommendations for further research in this area.

Complementary proteomic approaches reveal mitochondrial dysfunction, immune and inflammatory dysregulation in a mouse model of Gulf War Illness

Purpose

Long‐term consequences of combined pyridostigmine bromide (PB) and permethrin (PER) exposure in C57BL6/J mice using a well‐characterized mouse model of exposure to these Gulf War (GW) agents were explored at the protein level.

Experimental design

We used orthogonal proteomic approaches to identify pathways that are chronically impacted in the mouse CNS due to semiacute GW agent exposure early in life. These analyses were performed on soluble and membrane‐bound protein fractions from brain samples using two orthogonal isotopic labeling LC‐MS/MS proteomic approaches—stable isotope dimethyl labeling and iTRAQ.

Results

The use of these approaches allowed for greater coverage of proteins than was possible by either one alone and revealed both distinct and overlapping datasets. This combined analysis identified changes in several mitochondrial, as well as immune and inflammatory pathways after GW agent exposure.

Conclusions and clinical relevance

The work discussed here provides insight into GW agent exposure dependent mechanisms that adversely affect mitochondrial function and immune and inflammatory regulation. Collectively, our work identified key pathways which were chronically impacted in the mouse CNS following acute GW agent exposure, this may lead to the identification of potential targets for therapeutic intervention in the future.

Long‐term consequences of combined PB and PER exposure in C57BL6/J mice using a well‐characterized mouse model of exposure to these GW agents were explored at the protein level. Expanding on earlier work, we used orthogonal proteomic approaches to identify pathways that are chronically impacted in the mouse CNS due to semiacute GW agent exposure early in life. These analyses were performed on soluble and membrane‐bound protein fractions from brain samples using two orthogonal isotopic labeling LC‐MS/MS proteomic approaches—stable isotope dimethyl labeling and iTRAQ. The use of these approaches allowed for greater coverage of proteins than was possible by either one alone and revealed both distinct and overlapping datasets. This combined analysis identified changes in several mitochondrial, as well as immune and inflammatory pathways after GW agent exposure. The work discussed here provides insight into GW agent exposure dependent mechanisms that adversely affect mitochondrial function and immune and inflammatory regulation at 5 months postexposure to PB + PER.

The use of non-steroidal anti-inflammatory drugs in neurological diseases

Non-steroidal anti-inflammatory drugs (NSAIDs) have been in use for many years and constitute a large part of prescriptions issued in daily practice. Although NSAIDs are used for many diseases in neurology, they have also been tested as a new therapeutic option for various other diseases. While their effects on headache and cerebrovascular diseases are well known, little is known about their impact on neurodegenerative diseases. This review discusses the use, effects and safety of NSAIDs in neurological diseases.

Chemical basis for the disparate neuroprotective effects of the anthocyanins, callistephin and kuromanin, against nitrosative stress

Oxidative and nitrosative stress are major factors in neuronal cell death underlying neurodegenerative disease. Thus, supplementation of antioxidant defenses may be an effective therapeutic strategy for diseases such as amyotrophic lateral sclerosis, Parkinson's disease, and Alzheimer's disease. In this regard, treatment with nutraceutical antioxidants has garnered increasing attention; however, the differential neuroprotective effects of structurally similar nutraceuticals, which may affect their suitability as therapeutic agents, has not been directly examined. In this study we compare the ability of two anthocyanins, callistephin (pelargonidin-3-O-glucoside) and kuromanin (cyanidin-3-O-glucoside) to protect cerebellar granule neurons from damage induced by either oxidative or nitrosative stress. These anthocyanins differ by the presence of a single hydroxyl group on the B-ring of kuromanin, forming a catechol moiety. While both compounds protected neurons from oxidative stress induced by glutamate excitotoxicity, a stark contrast was observed under conditions of nitrosative stress. Only kuromanin displayed the capacity to defend neurons from nitric oxide (NO)-induced apoptosis. This protective effect was blocked by addition of Cu, Zn-superoxide dismutase, indicating that the neuroprotective mechanism is superoxide dependent. Based on these observations, we suggest a unique mechanism by which slight structural variances, specifically the absence or presence of a catechol moiety, lend kuromanin the unique ability to generate superoxide, which acts as a scavenger of NO. These findings indicate that kuromanin and compounds that share similar chemical characteristics may be more effective therapeutic agents for treating neurodegenerative diseases than callistephin and related (non-catechol) compounds.

Assessment of Serum Nitrogen Species and Inflammatory Parameters in Relapsing-Remitting Multiple Sclerosis Patients Treated with Different Therapeutic Approaches

The role of nitric oxide and its reactive derivatives (NO _x ) is well known in the pathogenesis of multiple sclerosis, which is an inflammatory disease while NO _x seems to be important in coordinating inflammatory response. The purpose of the present study was to assess serum NO _x as one of the nitrogen species and inflammatory parameters in relapsing-remitting multiple sclerosis patients and to compare the effectiveness of various types of disease-modifying therapies that reduce nitric oxide and inflammatory biomarkers. Elevated NO _x level was observed in patients who received the first-line disease-modifying therapy (interferons beta-1a and beta-1b) in comparison with the subjects treated with the second-line disease-modifying therapy (natalizumab; fingolimod) and healthy controls without significant differences in C-reactive protein and interleukin-1 beta. A negative correlation was observed between serum NO _x level and the duration of multiple sclerosis confirmed in the whole study population and in subjects treated with the first-line agents. Only serum NO _x , concentration could reveal a potential efficacy of disease-modifying therapy with a better reduction in NO _x level due to the second-line agents of disease-modifying therapy.

Nutrition- and Virus-Induced Stress Represses the Expression of Manganese Superoxide Dismutase in Vitro

The relationship between oxidative stress and neuronal cell death has been suggested for many years. To understand the influence of oxidative stress on neuronal cell death, we investigated the influence of oxidative stress on DEV cells, a human glial cell line. Using enterovirus infection and/or malnutrition to induce oxidative stress, our results demonstrate that those stressors severely influence the antioxidant defense system in DEV cells. Although the expression of mitochondrial manganese superoxide dismutase (MnSOD) in DEV cells was significantly increased in acute infection with viral and nutritional stress, in persistent infection and nutritional stress, the expression of the MnSOD was drastically downregulated. We believe that this downregulation of MnSOD expression in the chronic stress model is due to repression of antioxidant defense. The downregulation of the MnSOD expression may lead to an increase of free-radical production and thus explain why the cells in the chronic stress model were more vulnerable to other oxidative stress influences. The vulnerability of DEV cells to additional stress factors resulted in progressive cell death, which may be analogous to the cell death in neurodegenerative diseases.

Major pathogenic mechanisms in vascular dementia: Roles of cellular stress response and hormesis in neuroprotection

Vascular dementia (VaD), considered the second most common cause of cognitive impairment after Alzheimer disease in the elderly, involves the impairment of memory and cognitive function as a consequence of cerebrovascular disease. Chronic cerebral hypoperfusion is a common pathophysiological condition frequently occurring in VaD. It is generally associated with neurovascular degeneration, in which neuronal damage and blood-brain barrier alterations coexist and evoke beta-amyloid-induced oxidative and nitrosative stress, mitochondrial dysfunction, and inflammasome- promoted neuroinflammation, which contribute to and exacerbate the course of disease. Vascular cognitive impairment comprises a heterogeneous group of cognitive disorders of various severity and types that share a presumed vascular etiology. The present study reviews major pathogenic factors involved in VaD, highlighting the relevance of cerebrocellular stress and hormetic responses to neurovascular insult, and addresses these mechanisms as potentially viable and valuable as foci of novel neuroprotective methods to mitigate or prevent VaD. © 2016 Wiley Periodicals, Inc.

Modulatory Effects of Ferulic Acid on Cadmium-Induced Brain Damage

Studies have shown the pharmacological relevance of phenolics like ferulic acid (FA) in promoting health. This study sought to investigate the modulatory effects of FA on cadmium-induced brain damage in rats. Brain damage was induced in Wistar strain rats by oral administration of cadmium (5 mg/kg body weight) for 21 days. Assays for malondialdehyde (MDA) content, acetylcholinesterase (AChE), butyrylcholinesterase (BChE), monoamine oxidase (MAO), and Na+/K+-ATPase activities were carried out. The study revealed significant ( P < .05) increases in the MDA content and all enzymes’ (AChE, BChE, MAO, and Na+/K+-ATPase) activity investigated following cadmium administration. However, rats administered FA (10 and 20 mg/kg body weight) alongside cadmium significantly ( P < .05) protected the brain by reversing the level of lipid peroxidation as measured by the MDA content as well as the enzymes’ activity. This study, therefore, substantiates the neuroprotective potentials of FA especially in the management of cadmium-induced toxicity.

Lignans from Schisandra chinensis ameliorate cognition deficits and attenuate brain oxidative damage induced by D-galactose in rats

The aim of this study was to explore the neuroprotective effects of active compounds from Schisandra chinensis (Trucz.) Baill. (Magnoliaceae) against the D-galactose (D-gal)-induced neurotoxicity in rat. The Wistar rats were subcutaneously injected with D-gal (150 mg/(kg day)) for six weeks and orally administered with water extract or 95 % ethanol extract (partitioned with petroleum ether (PE), chloroform (CF), ethyl acetate (EA) and n-Butanol (NB), respectively) of the fruits of Schisandra chinensis simultaneously. The alteration of cognitive functions was assessed by using Morris water maze and Step-down type passive avoidance test. The results demonstrated that PE fraction was the most effective fraction to ameliorate cognitive deficits. Further biochemical examination indicated that PE could attenuate the activities decreasing of superoxide dismutase (SOD), catalase (CAT), the total antioxidant (T-AOC) induced by D-gal, and maintain the normal levels of glutathione (GSH), malondialdehyde (MDA) and nitric oxide (NO) in the serum, prefrontal cortex, striatum and hippocampus of the brain of related rat, selectively. Meanwhile, the compounds of PE fraction were also identified as mainly lignans, thus, these results suggest that lignans from the PE fraction of Schisandra chinensis represented a potential source of medicine for the treatment of the aging-associated neurodegenerative diseases.

Silicon Reverses Lipid Peroxidation but not Acetylcholinesterase Activity Induced by Long-Term Exposure to Low Aluminum Levels in Rat Brain Regions

Aluminum (Al) is the most widely distributed metal in the environment and is extensively used in daily life leading to easy exposure to human beings. Besides not having a recognized physiological role, Al may produce adverse effects through the interaction with the cholinergic system contributing to oxidative stress. The present study evaluated, in similar conditions of parenteral nutrition, whether the reaction of silicon (SiO2) with Al(3+) to form hydroxyaluminosilicates (HAS) reduces its bioavailability and toxicity through intraperitoneal administrations of 0.5 mg Al/kg/day and/or 2 mg Si/kg/day in Wistar rats. Al and Si concentrations were determined in rat brain tissue and serum. Acetylcholinesterase (AChE) activity and lipid peroxidation (LPO) were analyzed in the cerebellum, cortex, hippocampus, striatum, hypothalamus, and blood. An increase in the Al concentration was verified in the Al + Si group in the brain. All the groups demonstrated enhanced Si compared to the control animals. Al(3+) increased LPO measured by thiobarbituric acid reactive substances (TBARS) in cerebellum and hippocampus, whereas SiO2 reduced it when compared with the control group. An increase of AChE activity was observed in the Al-treated group in the cerebellum whereas a decrease of this enzyme activity was observed in the cortex and hippocampus in the Al and Al + Si groups. Al and Si concentrations increased in rat serum; however, no effect was observed in blood TBARS levels and AChE activity. SiO2 showed a protective effect in the hippocampus and cerebellum against cellular damage caused by Al(3+)-induced lipid peroxidation. Thus, SiO2 may be considered an important protector in LPO induced by Al(3+).

Luminescent Rhenium(I) and Iridium(III) Polypyridine Complexes as Biological Probes, Imaging Reagents, and Photocytotoxic Agents

Although the interactions of transition metal complexes with biological molecules have been extensively studied, the use of luminescent transition metal complexes as intracellular sensors and bioimaging reagents has not been a focus of research until recently. The main advantages of luminescent transition metal complexes are their high photostability, long-lived phosphorescence that allows time-resolved detection, and large Stokes shifts that can minimize the possible self-quenching effect. Also, by the use of transition metal complexes, the degree of cellular uptake can be readily determined using inductively coupled plasma mass spectrometry. For more than a decade, we have been interested in the development of luminescent transition metal complexes as covalent labels and noncovalent probes for biological molecules. We argue that many transition metal polypyridine complexes display triplet charge transfer ((3)CT) emission that is highly sensitive to the local environment of the complexes. Hence, the biological labeling and binding interactions can be readily reflected by changes in the photophysical properties of the complexes. In this laboratory, we have modified luminescent tricarbonylrhenium(I) and bis-cyclometalated iridium(III) polypyridine complexes of general formula [Re(bpy-R(1))(CO)3(py-R(2))](+) and [Ir(ppy-R(3))2(bpy-R(4))](+), respectively, with reactive functional groups and used them to label the amine and sulfhydryl groups of biomolecules such as oligonucleotides, amino acids, peptides, and proteins. Additionally, using a range of biological substrates such as biotin, estradiol, and indole, we have designed luminescent rhenium(I) and iridium(III) polypyridine complexes as noncovalent probes for biological receptors. The interesting results generated from these studies have prompted us to investigate the possible applications of luminescent transition metal complexes in intracellular systems. Thus, in the past few years, we have developed an interest in the cytotoxic activity, cellular uptake, and bioimaging applications of these complexes. Additionally, we and other research groups have demonstrated that many transition metal complexes have facile cellular uptake and organelle-localization properties and that their cytotoxic activity can be readily controlled. For example, complexes that can target the nucleus, nucleolus, mitochondria, lysosomes, endoplasmic reticulum, and Golgi apparatus have been identified. We anticipate that this selective localization property can be utilized in the development of intracellular sensors and bioimaging reagents. Thus, we have functionalized luminescent rhenium(I) and iridium(III) polypyridine complexes with various pendants, including molecule-binding moieties, sugar molecules, bioorthogonal functional groups, and polymeric chains such as poly(ethylene glycol) and polyethylenimine, and examined their potentials as biological reagents. This Account describes our design of luminescent rhenium(I) and iridium(III) polypyridine complexes and explains how they can serve as a new generation of biological reagents for diagnostic and therapeutic applications.

Cytotoxic effect of nanosilver particles on testicular tissue: Evidence for biochemical stress and Hsp70-2 protein expression

Lastly, there are growing evidences that nanosilver (NS) particles highly induce cytotoxic impacts in vitro and in vivo. Here, we analyzed the dose dependent effect of NS on histological changes, biochemical alterations and endocrine statuses, sperm parameters as well as chaperone Hsp70-2 expression. NS particles (50-60nm) were administrated in 3 doses of 0.5, 1 and 5mg/kg, intraperitoneally, for 35 days. The 0.3mL normal saline was administrated in control-sham group. Histological alterations, sperm parameters, serum levels of LH, FSH and testosterone were evaluated. Germinal and Leydig cells RNA damage, Leydig cells steroidogenic foci, the testicular and sperm total antioxidant capacity (TAC), malondialdehyde (MDA), nitric oxide (NO) levels, immunohistochemical (IHC) expression and mRNA level of Hsp70-2 were analyzed. The NS, dose dependently, resulted in enhanced germinal cells degeneration, necrosis, seminiferous tubules atrophy and decreased serum levels of LH, FSH and testosterone. Elevated germinal and Leydig cells RNA damage associated with increased sperm abnormalities were observed in NS-treated groups. Expression of Hsp70-2 was up-regulated in 0.5mg/kg, while its expression was decreased in 1 and 5mg/kg NS-treated groups. Testicular and sperm TAC levels reduced. However, the MDA and NO levels significantly (P<0.05) increased in all NS-treated groups. No histological and biochemical changes were detected in control-sham group. In conclusion, the NS particles exert their pathological impact via affecting testicular antioxidant and endocrine statuses, which in turn lead to diminished expression of Hsp70-2. Ultimately, by this mechanism NS particles adversely impact the cellular RNA, DNA and protein contents.

Oral treatment with herbal formula B307 alleviates cardiac failure in aging R6/2 mice with Huntington's disease via suppressing oxidative stress, inflammation, and apoptosis

Cardiac failure is often observed in aging patients with Huntington’s disease (HD). However, conventional pharmacological treatments for cardiac failure in HD patients have rarely been studied. Chinese herbal medicines, especially combined herbal formulas, have been widely used to treat cardiac dysfunctions over the centuries. Thus, we assess whether oral treatment with herbal formula B307 can alleviate cardiac failure in transgenic mice with HD. After oral B307 or vehicle treatment for 2 weeks, cardiac function and cardiomyocytes in 12-week-old male R6/2 HD mice and their wild-type littermate controls (WT) were examined and then compared via echocardiography, immunohistochemistry, and Western blotting. We found that cardiac performance in aging R6/2 HD mice had significantly deteriorated in comparison with their WT (P<0.01). Cardiac expressions of superoxide dismutase 2 (SOD2) and B-cell lymphoma 2 (Bcl-2) in aging R6/2 HD mice were significantly lower than their WT (P<0.01), but cardiac expressions of tumor necrosis factor alpha (TNF-α), neurotrophin-3 (3-NT), 4-hydroxynonenal (4-HNE), Bcl-2-associated X protein (Bax), calpain, caspase 12, caspase 9, and caspase 3 of aging R6/2 HD mice were significantly higher than their WT (P<0.05). Furthermore, we found that cardiac performance in aging R6/2 HD mice had significantly improved under oral B307 treatment (P<0.05). Cardiac expressions of SOD2 and Bcl-2 of aging R6/2 HD mice were significantly higher under oral B307 treatment (P<0.01), but cardiac expressions of TNF-α, 3-NT, 4-HNE, Bax, calpain, caspase 12, caspase 9, and caspase 3 of aging R6/2 HD mice were significantly reduced under oral B307 treatment (P<0.05). Oral B307 treatment may briefly alleviate cardiac failure in aging HD R6/2 mice via suppressing cardiac oxidative stress, inflammation, and apoptosis. We suggested that the herbal formula B307 may be further developed as a potential health supplement for ameliorating cardiac failure associated with aging.

Oxidative stress and depressive symptoms in older adults: A magnetic resonance spectroscopy study

Major depression is common in older adults and associated with greater health care utilisation and increased risk of poor health outcomes. Oxidative stress may be implicated in the pathophysiology of depression and can be measured via the neurometabolite glutathione using proton magnetic resonance spectroscopy ((1)H-MRS). This study aimed to examine the relationship between glutathione concentration and depressive symptom severity in older adults 'at-risk' of depression. In total, fifty-eight older adults considered 'at-risk' of depression (DEP) and 12 controls underwent (1)H-MRS, medical and neuropsychological assessments. Glutathione was measured in the anterior cingulate cortex (ACC), and calculated as a ratio to creatine. Depressive and anxiety symptoms were assessed using the Hospital Anxiety and Depression Scale (HADS). Compared to controls, DEP patients had increased glutathione/creatine ratios in the ACC (t=2.7, p=0.012). In turn, these increased ratios were associated with greater depressive symptoms (r=0.28, p=0.038), and poorer performance on a verbal learning task (r=-0.28, p=0.040). In conclusion, depressive symptoms in older people are associated with increased glutathione in the ACC. Oxidative stress may be pathophysiologically linked to illness development and may represent an early compensatory response. Further research examining the utility of glutathione as a marker for depressive symptoms and cognitive decline is now required.