In vitro and in vivo effects of genistein on murine alveolar macrophage TNF alpha production

The Role of Oxidative Stress in Early Brain Injury after Subarachnoid Hemorrhage

This review focuses on the problem of oxidative stress in early brain injury (EBI) after spontaneous subarachnoid hemorrhage (SAH). EBI involves complex pathophysiological mechanisms, including oxidative stress. In the first section, we describe the main sources of free radicals in EBI. There are several sources of excessive generation of free radicals from mitochondrial free radicals’ generation and endoplasmic reticulum stress, to hemoglobin and enzymatic free radicals’ generation. The second part focuses on the disruption of antioxidant mechanisms in EBI. The third section describes some newly found molecular mechanisms and pathway involved in oxidative stress after EBI. The last section is dedicated to the pathophysiological mechanisms through which free radicals mediate early brain injury.

Effects of sub-concussion on neuropsychological performance and its potential mechanisms: A narrative review

Concussion and mild traumatic brain injury (mTBI) are recognised as serious medical events that are relatively common in contact sports. Recently, the seemingly non-injurious phenomenon of sub-concussion has gained interest among neuroscience researchers and early studies are showing that there may be some acute and chronic effects on brain health and function with repeated sub-concussive events of the type seen in soccer, where players strike the ball with the head, and collision sports like the rugby codes. The aim of this narrative review is to describe sub-concussion and the current understanding of short and long term effects of repeated minor impacts that have been found to occur in human and animal models. Here, potential mechanisms for cognitive dysfunction following sub-concussion and recommend directions for future research are discussed. The Potential mechanisms of injuries resulting from sub-concussion such as changes in blood brain barrier integrity, neuroinflammation, cognitive impairment, and oxidative stress damage, among other changes in central nervous system function vary considerably making understanding of the underlying causative mechanism challenging for researchers. Some evidence suggests a link between impaired cerebrovascular function and cognitive impairment which poses a potential mechanism linking the two. It is hoped that this review helps guide researchers toward a potential direction of investigations.

Ponatinib-induced ischemic stroke in larval zebrafish for drug screening

Conventional mammalian ischemic stroke models for drug screening are technically challenging, laborious and time-consuming. In this study, using Ponatinib as an inducer, we developed and characterized a zebrafish ischemic stroke model. This zebrafish ischemic stroke had the cerebral vascular endothelial injury, thrombosis, reduced blood flow, inflammation and apoptosis as well as the reduced motility. The zebrafish ischemic stroke model was validated with 6 known human therapeutic drugs of ischemic stroke (Aspirin, Clopidogrel, Naoxintong capsules, Edaravone, Xingnaojing injection, Shuxuening injection). The mRNA levels of the neovascularization-related gene (vegfaa) and vascular endothelial growth factor receptor gene (VEGFR), neurodevelopment related genes (mbp and α1-tubulin), brain-derived neurotrophic factor (BDNF) and glial cell derived neurotrophic factor (GDNF) were significantly downregulated; whereas apoptosis-related genes (caspase-3, caspase-7, caspase-9 and bax/bcl-2), and inflammatory factor genes (IL-1β, IL-6, IL-10, TNF-α and NF-κB) were remarkably upregulated in the model. These results suggest that the pathophysiology of Ponatinib-induced zebrafish ischemic stroke is similar to that of human ischemic stroke patients and this whole animal model could be used to study the complex cellular and molecular pathogenesis of ischemic stroke and to rapidly identify therapeutic agents.

Hydrogen Inhalation Attenuates Oxidative Stress Related Endothelial Cells Injury After Subarachnoid Hemorrhage in Rats

Background: Subarachnoid hemorrhage (SAH) is a devastating cerebrovascular disease with poor clinical outcome. Nucleotide binding and oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome serves a key role in inflammatory response, which may lead to endothelial cell injury and blood-brain barrier (BBB) disruption. Hydrogen (H₂) is considered a neuroprotective antioxidant. This study was set out to explore whether hydrogen inhalation protects against SAH induced endothelial cell injury, BBB disruption, microthrombosis and vasospasm in rats.

Methods: One hundred eighty-two male SD rats were used for the study. SAH was induced by endovascular perforation. H2 at a concentration of 3.3% was inhaled beginning at 0.5 h after SAH for duration of 30, 60 or 120 min, followed by single administration or once daily administration for 3 days. The temporal expression of NLRP3 and ASC in the brain was determined, with the effect of hydrogen inhalation evaluated. In addition, brain water content, oxidative stress markers, inflammasome, apoptotic markers, microthrombosis, and vasospasm were evaluated at 24 or 72 h after SAH.

Results: The expression of NLRP3 and ASC were upregulated after SAH associated with elevated expression of MDA, 8-OHdG, 4-HNE, HO-1, TLR4/NF-κB, inflammatory and apoptotic makers. Hydrogen inhalation reduced the expression of these inflammatory and apoptotic makers in the vessels, brain edema, microthrombi formation, and vasospasm in rats with SAH relative to control. Hydrogen inhalation also improved short-term and long-term neurological recovery after SAH.

Conclusion: Hydrogen inhalation can ameliorate oxidative stress related endothelial cells injury in the brain and improve neurobehavioral outcomes in rats following SAH. Mechanistically, the above beneficial effects might be related to, at least in part, the inhibition of activation of ROS/NLRP3 axis.

The Toxicity of Nonaged and Aged Coated Silver Nanoparticles to Freshwater Alga Raphidocelis subcapitata

The transformation of coated silver nanoparticles (AgNPs) and their impacts on aquatic organisms require further study. The present study investigated the role of aging on the transformation of differently coated AgNPs and their sublethal effects on the freshwater alga Raphidocelis subcapitata. The stability of AgNPs was evaluated over 32 d, and the results indicated that transformation of AgNPs occurred during the incubation; however, coating-specific effects were observed. Fresh AgNPs increased reactive oxygen species (ROS) formation, whereas aged AgNPs induced excessive ROS generation compared with their fresh counterparts. Increased ROS levels caused increased lipid peroxidation (LPO) in treatment groups exposed to both fresh and aged NPs, although LPO was comparatively higher in algae exposed to aged AgNPs. The observed increase in catalase (CAT) activity of algal cells was attributed to early stress responses induced by excessive intracellular ROS generation, and CAT levels were higher in the aged NP treatment groups. In conclusion, AgNPs increased ROS levels and LPO in algae and caused the activation of antioxidant enzymes such as CAT. Overall, the results suggest that aging and coating of AgNPs have major impacts on AgNP transformation in media and their effects on algae. Environ Toxicol Chem 2019;38:2371-2382. © 2019 SETAC.

Total Antioxidant Capacity Predicts Outcome in Acute Ischemic Stroke Subtypes in Egyptian Patients

BACKGROUND

Oxidative stress after ischemic stroke contributes to neuronal cell injury. We tried to demonstrate an association between total antioxidant capacity (TAC) levels and outcomes after acute ischemic stroke (AIS).

METHODS

We enrolled 60 patients (36 females and 24 males) who were admitted to our hospital due to AIS, in addition to 30 age and sex-matched healthy controls. TAC levels were measured on day 1 of stroke onset, the relationships between TAC levels, stroke subtypes, and clinical outcomes based on the National Institutes of Health Stroke Scale and modified Rankin scale upon discharge were evaluated.

RESULTS

TAC levels were significantly lower in AIS patients than control (P < .001) being much lower in patients with large-vessel cerebral infarction than in those with small-vessel infarction. We investigated whether TAC concentrations reflected the severity and outcome of ischemic stroke and we found a significantly lower concentration of TAC in the poor outcome group than in the good outcome group (P < .001).

CONCLUSIONS

Our findings suggested that the biochemical changes related to TAC and oxidative stress may be considered a marker of ischemic brain injury and clinical outcome of ischemic stroke.

Mesenchymal Stem Cells (MSCs) Coculture Protects [Ca2+]i Orchestrated Oxidant Mediated Damage in Differentiated Neurons In Vitro

Cell-therapy modalities using mesenchymal stem (MSCs) in experimental strokes are being investigated due to the role of MSCs in neuroprotection and regeneration. It is necessary to know the sequence of events that occur during stress and how MSCs complement the rescue of neuronal cell death mediated by [Ca²⁺]_i and reactive oxygen species (ROS). In the current study, SH-SY5Y-differentiated neuronal cells were subjected to in vitro cerebral ischemia-like stress and were experimentally rescued from cell death using an MSCs/neuronal cell coculture model. Neuronal cell death was characterized by the induction of proinflammatory tumor necrosis factor (TNF)-α, interleukin (IL)-1β and -12, up to 35-fold with corresponding downregulation of anti-inflammatory cytokine transforming growth factor (TGF)-β, IL-6 and -10 by approximately 1 to 7 fold. Increased intracellular calcium [Ca²⁺]_i and ROS clearly reaffirmed oxidative stress-mediated apoptosis, while upregulation of nuclear factor NF-κB and cyclo-oxygenase (COX)-2 expressions, along with ~41% accumulation of early and late phase apoptotic cells, confirmed ischemic stress-mediated cell death. Stressed neuronal cells were rescued from death when cocultured with MSCs via increased expression of anti-inflammatory cytokines (TGF-β, 17%; IL-6, 4%; and IL-10, 13%), significantly downregulated NF-κB and proinflammatory COX-2 expression. Further accumulation of early and late apoptotic cells was diminished to 23%, while corresponding cell death decreased from 40% to 17%. Low superoxide dismutase 1 (SOD1) expression at the mRNA level was rescued by MSCs coculture, while no significant changes were observed with catalase (CAT) and glutathione peroxidase (GPx). Interestingly, increased serotonin release into the culture supernatant was proportionate to the elevated [Ca²⁺]_i and corresponding ROS, which were later rescued by the MSCs coculture to near normalcy. Taken together, all of these results primarily support MSCs-mediated modulation of stressed neuronal cell survival in vitro.

The Effects of a Combination of Ion Channel Inhibitors in Female Rats Following Repeated Mild Traumatic Brain Injury

Following mild traumatic brain injury (mTBI), the ionic homeostasis of the central nervous system (CNS) becomes imbalanced. Excess Ca²⁺ influx into cells triggers molecular cascades, which result in detrimental effects. The authors assessed the effects of a combination of ion channel inhibitors (ICI) following repeated mTBI (rmTBI). Adult female rats were subjected to two rmTBI weight-drop injuries 24 h apart, sham procedures (sham), or no procedures (normal). Lomerizine, which inhibits voltage-gated calcium channels, was administered orally twice daily, whereas YM872 and Brilliant Blue G, inhibiting α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and P2X₇ receptors, respectively, were delivered intraperitoneally every 48 h post-injury. Vehicle treatment controls were included for rmTBI, sham, and normal groups. At 11 days following rmTBI, there was a significant increase in the time taken to cross the 3 cm beam, as a sub-analysis of neurological severity score (NSS) assessments, compared with the normal control (p < 0.05), and a significant decrease in learning-associated improvement in rmTBI in Morris water maze (MWM) trials relative to the sham (p < 0.05). ICI-treated rmTBI animals were not different to sham, normal controls, or rmTBI treated with vehicle in all neurological severity score and Morris water maze assessments (p > 0.05). rmTBI resulted in increases in microglial cell density, antioxidant responses (manganese-dependent superoxide dismutase (MnSOD) immunoreactivity), and alterations to node of Ranvier structure. ICI treatment decreased microglial density, MnSOD immunoreactivity, and abnormalities of the node of Ranvier compared with vehicle controls (p < 0.01). The authors' findings demonstrate the beneficial effects of the combinatorial ICI treatment on day 11 post-rmTBI, suggesting an attractive therapeutic strategy against the damage induced by excess Ca²⁺ following rmTBI.

Protective effects of hydroxytyrosol against α-synuclein toxicity on PC12 cells and fibril formation

There is a considerable consensus that the increased production and/or aggregation of α-synuclein (αsyn) plays a central role in the pathogenesis of Parkinson's disease (PD). Therefore, a method of identifying molecules that block αsyn aggregation and prevent the loss of dopaminergic neurons is urgently needed in order to treat or slow the progression of PD. Hydroxytyrosol (HT), a well-known bioactive food compound present in olive oil, olives and wine, possesses demonstrated antioxidant and anti-inflammatory properties that can cross the Blood Brain Barrier (BBB). In the present work, the role of HT, tyrosol (TYR) and other tyrosine metabolites (hydroxyphenyl acetic acid (HPAA)) against αsyn aggregation, destabilisation and toxicity was evaluated through the use of different in vitro tests (Thioflavin T (ThT), Transmission Electronic Microscopy (TEM), electrophoresis and MTT assay). Results show that HT presents a strong inhibitory effect preventing αsyn aggregation and exercising a destabilising effect by disaggregating αsyn fibrils. Moreover, HT is able to counteract αsyn-induced toxicity. This is the first time that the effect of HT against αsyn toxicity and aggregation is evaluated. Thus, HT can be considered a promising compound for further approaches to tackling PD.

Se@SiO2 nanocomposites suppress microglia-mediated reactive oxygen species during spinal cord injury in rats

Selenium (Se) is an essential trace element with strong antioxidant activity, showing a great prospect in the treatment of spinal cord injury (SCI). However, the narrow gap between the beneficial and toxic effects has limited its further clinical application. In this experiment, we used porous Se@SiO2 nanocomposites (Se@SiO2) modified by nanotechnology as a new means of release control to investigate the anti-oxidative effect in SCI. In vitro Se@SiO2 toxicity, anti-oxidative and anti-inflammatory effects on microglia were assayed. In vivo we investigated the protective effect of Se@SiO2 to SCI rats. Neurological function was evaluated by Basso, Beattie and Bresnahan (BBB). The histopathological analysis, microglia activation, oxidative stress, inflammatory factors (TNF-α, IL-1β and IL-6) and apoptosis were detected at 3 and 14 days after SCI. The favorable biocompatibility of Se@SiO2 suppressed microglia activation, which is known to be associated with oxidative stress and inflammation in vivo and in vitro. In addition, Se@SiO2 improved the rat neurological function and reduced apoptosis via caspase-3, Bax and Bcl-2 pathways in SCI. Se@SiO2 was able to treat SCI and reduce oxidative stress, inflammation and apoptosis induced by microglia activation, which may provide a novel and safe strategy for clinical application.

Complexes of arzanol with a Cu2+ ion: a DFT study

Arzanol (C₂₂H₂₆O₇) is a naturally occurring acylphloroglucinol largely responsible for the anti-inflammatory, anti-oxidant, antibiotic and antiviral activities of Helichrysum italicum. Like all acylphloroglucinols, the molecule contains a carboxylic substituent (-COR group); for arzanol, this is a -COCH₃ group. The molecule is further characterized by the presence of an α-pyrone ring bonded in meta to -COR through a methylene bridge, and of a prenyl chain bonded to the other meta position. The molecule can form up to three intramolecular hydrogen bonds (IHB) simultaneously, and their presence and patterns are the major stabilizing factors. This work considers complexes of representative conformers of arzanol with a Cu²⁺ ion, taking into account the different possibilities for the binding of the Cu²⁺ ion to the electron-density rich sites of the molecule and including simultaneous coordination to two geometrically suitable sites. Calculations were performed at the DFT/B3LYP level, using the 6-31+G(d,p) basis set for the C, O and H atoms and the LANL2DZ pseudopotential for the Cu²⁺ ion. Interaction energies show preference for simultaneous binding of Cu²⁺ to two sites. Simultaneous binding to the O of a phenol OH neighboring the prenyl chain and to the π bond of the prenyl chain appears to be the most favorable option, followed by simultaneous binding to the sp² O of the α-pyrone ring and the O of the phenol OH ortho to -COR on the side of the α-pyrone ring. The charge of the Cu²⁺ ion is reduced to +1 or slightly less in the complexes, which is consistent with the molecules' antioxidant (reducing) ability. Graphical abstract The copper ion prefers to attach to two sites of the arzanol molecule simultaneously. The arzanol molecule reduces the charge of the copper ion from +2 to +1 by transferring an electron to it; it becomes a radical molecular cation. The distribution of the unpaired electron in the molecule (as highlighted by the spin density maps) depends on the site/s to which the Cu²⁺ ion binds and on the molecule's conformer.

Intramolecular Hydrogen Bonding and Conformational Preferences of Arzanol-An Antioxidant Acylphloroglucinol

Arzanol is a naturally-occurring prenylated acylphloroglucinol isolated from Helichrysum italicum and exhibiting anti-oxidant, antibiotic and antiviral activities. The molecule contains an α-pyrone moiety attached to the phloroglucinol moiety through a methylene bridge. The presence of several hydrogen bond donor or acceptor sites makes intramolecular hydrogen bonding patterns the dominant stabilising factor. Conformers with all the possible different hydrogen bonding patterns were calculated at the HF/6-31G(d,p) and DFT/B3LYP/6-31+G(d,p) levels with fully relaxed geometry in vacuo and in three solvents—chloroform, acetonitrile and water (these levels being chosen to enable comparisons with previous studies on acylphloroglucinols). Calculations in solution were performed with the Polarisable Continuum Model. The results show that the lowest energy conformers have the highest number of stronger intramolecular hydrogen bonds. The influence of intramolecular hydrogen bonding patterns on the other molecular properties is also analysed.

Chlorogenic acid protects against aluminium-induced cytotoxicity through chelation and antioxidant actions in primary hippocampal neuronal cells

Chlorogenic acid (CGA), a major polyphenolic component of many plants, displays antioxidant and neuroprotective properties in neurodegenerative diseases. To investigate whether CGA may influence aluminium (Al) induced cytotoxicity, aluminium chloride (50 μM Al) was administered in primary hippocampal neuronal cells presupplemented with CGA (10, 50 and 100 μM). Our study shows that the exposure to Al caused cell death, Al³⁺ accumulation, reactive oxygen species generation and mitochondrial damage in cells. The administration of CGA (50 μM) increased cell viability by 37.5%, decreased the levels of Al³⁺ by 26.0%, together with significantly weakening the oxidative damage compared with Al treatment alone. CGA protected neurons against Al-induced oxidative stress by increasing the expression of nuclear factor-E2-related factor 2 and its target phase 2 enzymes. The administration of CGA remarkably promoted the activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione S-transferase, creatine kinase and acetylcholinesterase and attenuated the rate of ATP hydrolysis. Our finding shows that CGA has neuroprotective effects against Al-induced cytotoxicity by chelation and antioxidant activation.

The Protective Effect of Omeprazole Against Traumatic Brain Injury: An Experimental Study

BACKGROUND

The development of secondary brain injury via oxidative stress after traumatic brain injury (TBI) is a well-known entity. Consequently, the aim of the present study was to evaluate the role of omeprazole (OM) on rat model of TBI.

METHODS

A total of 24 male rats were used and divided into 4 groups as follows; control, trauma, OM, and methylprednisolone (MP). The trauma, OM, and MP groups were subjected to closed-head contusive weight-drop injuries. Rats received treatment with saline, OM, or MP, respectively. All the animals were sacrificed at 24 hours after trauma and brain tissues were extracted. The oxidant/antioxidant parameters (malondialdehyde, glutathione peroxidase, superoxide dismutase, nitric oxide) and caspase-3 in the cerebral tissue were analyzed, and histomorphologic evaluation of the cerebral tissue was performed.

RESULTS

Levels of MDA and activity of caspase-3 were significantly reduced in the OM and MP groups compared with the trauma group. Glutathione peroxidase and superoxide dismutase levels were increased both in the OM and MP groups compared with the trauma group. The pathology scores were statistically lower in the OM and MP groups than the trauma group.

CONCLUSIONS

The results of the present study showed that OM was as effective as MP in protecting brain from oxidative stress, and apoptosis in the early phase of TBI.

Protein aggregation into insoluble deposits protects from oxidative stress

Protein misfolding and aggregation have been associated with the onset of neurodegenerative disorders. Recent studies demonstrate that the aggregation process can result in a high diversity of protein conformational states, however the identity of the specific species responsible for the cellular damage is still unclear. Here, we use yeast as a model to systematically analyse the intracellular effect of expressing 21 variants of the amyloid-ß-peptide, engineered to cover a continuous range of intrinsic aggregation propensities. We demonstrate the existence of a striking negative correlation between the aggregation propensity of a given variant and the oxidative stress it elicits. Interestingly, each variant generates a specific distribution of protein assemblies in the cell. This allowed us to identify the aggregated species that remain diffusely distributed in the cytosol and are unable to coalesce into large protein inclusions as those causing the highest levels of oxidative damage. Overall, our results indicate that the formation of large insoluble aggregates may act as a protective mechanism to avoid cellular oxidative stress.

The Enhancement of Radiation Sensitivity in Nasopharyngeal Carcinoma Cells via Activation of the Rac1/NADPH Signaling Pathway

We reported in an earlier study that using mass spectrometry and bioinformatic analysis demonstrated Rac1 protein might be mostly mitochondrial target in the radiosensitization process of nasopharyngeal carcinoma CNE-1 cells. The goal of our current study was to reveal the relationship between Rac1/NADPH pathway and radiosensitization in CNE-1 cells using Rac1 activator, phorbol 12-myristate 13-acetate (PMA) and Rac1 inhibitor NSC23766. The Rac1-GTP expression was determined using a pulldown assay, the Rac1 location using a immunofluorescence with a laser scanning confocal microscope, the NADPH oxidase activity with NBT assay and the reactive oxygen species with DCFH-DA probe. The apoptosis rate was analyzed by flow cytometry, and the expressions of p67(phox) and NFκB-p105/p50 were analyzed by Western blot. After treatment with PMA and 2 Gy radiation (compared to the control), Rac1-GTP was activated and translocated to the cell membrane. NADPH oxidase activity, reactive oxygen species of intracellular concentration and the apoptosis rate increased significantly. The expression of p67(phox) and NFκB-p50 protein also increased. However, in the cells treated with NSC23766 alone or NSC23766 combined with 2 Gy irradiation, the results were just the opposite. Overall, these results indicate that the Rac1 protein may be the key target involved in the radiosensitization of nasopharyngeal carcinoma cells. The activated Rac1/NADPH pathway combined with radiation can increase the radiosensitivity of nasopharyngeal carcinoma cells, and the Rac1/NADPH pathway may be the signaling pathway involved in the radiosensitization process.

Mitigation of sensory and motor deficits by acrolein scavenger phenelzine in a rat model of spinal cord contusive injury

Currently there are no effective therapies available for the excruciating neuropathic pain that develops after spinal cord injuries (SCI). As such, a great deal of effort is being put into the investigation of novel therapeutic targets that can alleviate this pain. One such target is acrolein, a highly reactive aldehyde produced as a byproduct of oxidative stress and inflammation that is capable of activating the transient receptor potential ankyrin 1 (TRPA1) cation channel, known to be involved in the transmission and propagation of chronic neuropathic pain. One anti-acrolein agent, hydralazine, has already been shown to reduce neuropathic pain behaviors and offer neuroprotection after SCI. This study investigates another acrolein scavenger, phenelzine, for its possible role of alleviating sensory hypersensitivity through acrolein suppression. The results show that phenelzine is indeed capable of attenuating neuropathic pain behaviors in acute, delayed, and chronic administration schedules after injury in a rat model of SCI. In addition, upon the comparison of hydralazine to phenelzine, both acrolein scavengers displayed a dose-dependent response in the reduction of acrolein in vivo. Finally, phenelzine proved capable of providing locomotor function recovery and neuroprotection of spinal cord tissue when administered immediately after injury for 2 weeks. These results indicate that phenelzine may be an effective treatment for neuropathic pain after SCI and likely a viable alternative to hydralazine. We have shown that phenelzine can attenuate neuropathic pain behavior in acute, delayed, and chronic administration in post-SCI rats. This was accompanied by a dose-dependent reduction in an acrolein metabolite in urine and an acrolein adduct in spinal cord tissue, and the suppression of TRPA1 over-expression in central and peripheral locations post-trauma. Acrolein scavenging might be a novel therapeutic strategy to reduce post-SCI neuropathic pain.

Neuroprotective effects of (-)-linalool against oxygen-glucose deprivation-induced neuronal injury

(-)-Linalool, a major component of many essential oils, is widely used in cosmetics and flavoring ingredients as well as in traditional medicines. Although various in vitro and in vivo studies have shown that (-)-linalool has anti-convulsant, anti-nociceptive, anti-inflammatory and anti-oxidative properties, its anti-ischemic/hypoxic effects have yet to be determined. This study assessed the neuroprotective effects of (-)-linalool against oxygen-glucose deprivation/reoxygenation (OGD/R)-induced cortical neuronal injury, an in vitro model of ischemic stroke. (-)-Linalool significantly attenuated OGD/R-evoked cortical neuronal injury/death, although it did not inhibit N-methyl-D-aspartate (NMDA)-induced excitotoxicity. (-)-Linalool significantly reduced intracellular oxidative stress during OGD/R-induced injury, as well as scavenging peroxyl radicals (Trolox equivalents or TE = 3.8). This anti-oxidant effect was found to correlate with the restoration of OGD/R-induced decreases in the activities of SOD and catalase. In addition, (-)-linalool inhibited microglial migration induced by monocyte-chemoattractant protein-1 (MCP-1), a chemokine released by OGD/R. These findings show that (-)-linalool has neuroprotective effects against OGD/R-induced neuronal injury, which may be due to its anti-oxidant and anti-inflammatory activities. Detailed examination of the anti-ischemic mechanisms of (-)-linalool may indicate strategies for the development of drugs to treat cerebral ischemic injury.

Nose to brain delivery of astaxanthin-loaded solid lipid nanoparticles: fabrication, radio labeling, optimization and biological studies

Astaxanthin nanoformulation was found appropriate in all measures with strong antioxidant activity against H₂O₂induced oxidative stress in PC12 cells. Biodistribution and brain delivery was also found to be superior to conventional dosage form.

Evaluation of the antiradical activity of hyperjovinol-A utilizing donor-acceptor maps

Hyperjovinol-A ((2-methyl-1-(2,4,6-trihydroxy-3-(3-hydroxy-3,7-dimethyloct-6-enyl)phen yl)propan-1-one) is an acylated phloroglucinol isolated from Hypericum Jovis and exhibiting good antioxidant activity. The study investigates the compound’s antiradical ability on the basis of the electron-donor and electron-acceptor abilities of its conformers, deriving donor and acceptor indexes and mapping them in terms of donor-acceptor maps (DAM). The DAMs of vitamins C and E and of carotene astaxantine are used as comparison references. Calculations were performed at the DFT/BPW91/6-311+G(d,p) level, with optimizations on fully relaxed geometries to obtain the conformers of the neutral molecule in vacuo, and single point calculations to obtain the energies of the cationic and anionic species in vacuo and of the neutral, cationic, and anionic species in water, ethanol, and pentylethanoate. The calculations in solution utilized the polarizable continuum model (PCM). The results indicate that hyperjovinol-A may have better antiradical activity than vitamin C. This is in agreement with experimental results, showing that the antioxidant activity of hyperjovinol-A is comparable with that of the best drugs currently in clinical use. The activity is maintained in solution. The Fukui function f(·) was also calculated for all the conformers of hyperjovinol-A, to identify the regions of highest reactivity.

Sevoflurane preconditioning improving cerebral focal ischemia-reperfusion damage in a rat model via PI3K/Akt signaling pathway

In this study, we aimed to assess the neuroprotective effect of sevoflurane preconditioning in a cerebral focal ischemia-reperfusion rat model. Sixty Sprague Dawley rats were divided into six groups: sham operated group, cerebral focal ischemia-reperfusion (CIR) group, CIR+sevoflurane preconditioning (SP) (2%) group, CIR+sevoflurane preconditioning (2.5%) group, CIR+sevoflurane preconditioning (3%) group, and CIR+sevoflurane preconditioning (3.5%) group. All subjects were euthanized 2days post-surgery and their hippocampus tissues were removed. Tissue malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH) and glutathione peroxidase (GSH-Px) levels were measured and hippocampus tissue samples were examined histopathologically. Results showed that significant difference in antioxidant, immunity indexes, and apoptosis-related protein expression was detected in hippocampus tissue between sham-operated control and CIR groups. Sevoflurane preconditioning significantly dose-dependently reduced MDA, IL-1β, IL-6, IL-10 and TNF-α levels and enhanced antioxidant enzyme activities in hippocampus tissue of CIR+SP groups compared to CIR group. In addition, sevoflurane preconditioning significantly dose-dependently upregulated PI3K, p-Akt and Bcl-2 levels and downregulated caspase-3 and Bax levels in hippocampus tissue of CIR+SP groups compared to CIR group. It can be concluded that sevoflurane preconditioning demonstrates a strong and ameliorative effect on cerebral I/R damage in rats. The neuroprotective mechanisms of sevoflurane preconditioning are associated with its properties of anti-apoptosis and anti-oxidation as well as regulation of PI3K and p-Akt signal activation.

Gender-specific brain regional variation of neurons, endogenous estrogen, neuroinflammation and glial cells during rotenone-induced mouse model of Parkinson's disease

Rotenone (RT) produces reactive oxygen species (ROS) by inhibiting the mitochondrial electron transport chain; causing dopaminergic (DA) cell death in the substantia nigra (SN) and simulates other models of induced Parkinson's disease (PD). There is a sincere dearth of knowledge regarding the status of glial cells, neuroprotective estrogen and the status of neuroinflammatory TNF-α in the different brain regions in either sex during healthy, as well as during PD conditions. In the present study of RT-induced mouse model of PD, we have selected the frontal cortex (FC), hippocampus (HC) and SN from either sex of Swiss albino mice as these are the major regions involved during PD pathogenesis. During non pathogenic conditions, the ROS-scavenging enzyme activity varied among the brain regions and also in between genders. The number of DOPA decarboxylase-positive cells, astrocytes and microglia was similar in the respective regions of the brain in both the sexes. The level of proinflammatory cytokine TNF-α was same in the respective FC and HC in either sex except that of SN. The expression level of estrogen and its receptors varied among the three brain regions. During RT treatment, ROS-scavenging enzyme activities increased, DOPA decarboxylase-positive neurons and fibers in DA as well as in norepinephrinergic (NE) systems become degenerated, number of astrocytes decreased and microglial cells increased in those specific brain regions in either of the sexes except in the SN region of males where astrocyte number remained unaltered and microglial cell percentage decreased. TNF-α increased in the FC and SN but remained unaltered in the HC of both sexes. Estradiol level decreased in the HC and SN but the level unevenly varied in the FC. Similarly, the estrogen bound and nuclear-cytosolic receptor α and β also varied differentially among the brain regions of the two sexes. Therefore our present study depicts that there exists a clear variation of neuronal and astroglial cell population, estrogen and its receptor levels in different brain regions of both the sexes during control and RT-treated pathogenic condition and these variations have major implication in PD pathogenesis and progression.

Understanding the role of heat shock protein isoforms in male fertility, aging and apoptosis

Heat shock proteins (HSPs) play a role in the homeostasis, apoptosis regulation and the maintenance of the various other physiological processes. Aging is accompanied by a decrease in the resistance to environmental stress, while mitochondria are primary targets in the process of aging, their expression decreasing with age. Mitochondrion also plays a significant role in the process of spermatogenesis. HSPs have been shown to be involved in apoptosis with some of acting as apoptotic inhibitors and are involved in cytoprotection. In this review we discuss the roles of Hsp 27, 60, 70, and 90 in aging and male infertility and have concluded that these particular HSPs can be used as a molecular markers for mitochondrially- mediated apoptosis, aging and male infertility.

Anti-inflammatory potential of newly synthesized 4-[(butylsulfinyl)methyl]-1,2-benzenediol in lipopolysaccharide-stimulated BV2 microglia

In this study, we investigated the anti-inflammatory effects of newly synthesized 4-[(butylsulfinyl)methyl]-1,2-benzenediol (SMBD) in lipopolysaccharide (LPS)-stimulated BV2 microglia and the subsequent signaling events. Following stimulation with LPS, elevated production of nitric oxide (NO) and prostaglandin E₂ (PGE₂) was detected in BV2 cells; however, SMBD pretreatment inhibited the production of NO and PGE₂ through suppressing gene expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2), respectively, at non-toxic concentrations. LPS-stimulated gene expression and production of interleukin (IL)-1β and tumor necrosis factor (TNF)-α were also significantly reduced by SMBD. The anti-inflammatory effects of SMBD were associated with suppression of LPS-induced nuclear translocation of nuclear factor-kappa B (NF-κB), and phosphorylation of mitogen-activated protein kinases (MAPKs) and Akt, a phosphatidylinositol 3-kinase (PI3K) downstream effector. Therefore, the present results demonstrate that SMBD down-regulates inflammatory gene expression by inhibiting the activation of NF-κB through interference with the activation of MAPKs and PI3K/Akt signaling. Taken together, our data suggest that SMBD may have potential to be developed into an effective anti-inflammatory agent.

Free radical scavenging activity and neuroprotective potentials of D138, one Cu(II)/Zn(II) Schiff-base complex derived from N,N'-bis(2-hydroxynaphthylmethylidene)-1,3-propanediamine

There is increasing evidence that free radicals play an important role in neuronal damages induced by diabetes mellitus or cerebral ischemia insults. Antioxidants with free radical scavenging activities have been shown to be beneficial and neuroprotective for these pathological conditions. Here, we report free radical scavenging activity and neuroprotective potential of D138, one copper(II)/zinc(II) Schiff-base complex derived from N,N'-2(2-hydroxynaphthylmethylidene)-1,3-propanediamine. The data from three in vitro assays, 2,2-diphenyl-1-picrylhydrazyl assay, nitro blue tetrazolium assay and hydroxyl radical scavenging assay, indicated that D138 presented a potent free radical scavenging activity. The neuroprotective and antioxidative effects of D138 were further evaluated in vivo using bilateral common carotid artery occlusion (BCCAO) mouse model and streptozotocin (STZ) diabetic mouse model. Our results indicated that treatment of D138 significantly ameliorated the hippocampal neuronal damage and the oxidative stress levels in these animal models. Moreover, D138 also reversed the behavioral deficiencies induced by BCCAO or STZ, as assessed by Y-maze test and fear conditioning test. In conclusion, all these findings support that D138 exerts free radical scavenging and neuroprotective activities and has the potentials to be a potent therapeutic candidate for brain oxidative damage induced by cerebral ischemia or diabetes mellitus.

Oxidative Stress and the Use of Antioxidants in Stroke

Transient or permanent interruption of cerebral blood flow by occlusion of a cerebral artery gives rise to an ischaemic stroke leading to irreversible damage or dysfunction to the cells within the affected tissue along with permanent or reversible neurological deficit. Extensive research has identified excitotoxicity, oxidative stress, inflammation and cell death as key contributory pathways underlying lesion progression. The cornerstone of treatment for acute ischaemic stroke remains reperfusion therapy with recombinant tissue plasminogen activator (rt-PA). The downstream sequelae of events resulting from spontaneous or pharmacological reperfusion lead to an imbalance in the production of harmful reactive oxygen species (ROS) over endogenous anti-oxidant protection strategies. As such, anti-oxidant therapy has long been investigated as a means to reduce the extent of injury resulting from ischaemic stroke with varying degrees of success. Here we discuss the production and source of these ROS and the various strategies employed to modulate levels. These strategies broadly attempt to inhibit ROS production or increase scavenging or degradation of ROS. While early clinical studies have failed to translate success from bench to bedside, the combination of anti-oxidants with existing thrombolytics or novel neuroprotectants may represent an avenue worthy of clinical investigation. Clearly, there is a pressing need to identify new therapeutic alternatives for the vast majority of patients who are not eligible to receive rt-PA for this debilitating and devastating disease.

Radiation-modifying abilities of Nigella sativa and thymoquinone on radiation-induced nitrosative stress in the brain tissue

To investigate Nigella sativa oil (NSO) and Thymoquinone (TQ) for their antioxidant effects on the brain tissue of rats exposed to ionizing radiation. Fifty-four male albino Wistar rats, divided into six groups, were designed as group I (normal control group) did not receive NSO, TQ or irradiation; group II (control group of TQ) received dimethyl sulfoxide and sham irradiation; group III (control group of NSO) received saline and sham irradiation; group IV (irradiation plus NSO group) received both 5 Gray of gamma irradiation to total cranium and NSO; group V (irradiation plus TQ group) received both irradiation and TQ; group VI (irradiation alone group) received irradiation plus saline. Alterations in nitric oxide (NO·) and peroxynitrite (ONOO(-)) levels, and nitric oxide synthase (NOS) enzyme activity were measured by biochemical methods in homogenized brain tissue of rats. Levels of NO· and ONOO(-), and enzyme activity of NOS in brain tissue of the rats treated with NSO or TQ were found to be lower than in received IR alone (p<0.002) Nigella sativa oil (NSO) and its active component, TQ, clearly protect brain tissue from radiation-induced nitrosative stress.

Infratentorial strokes for posterior circulation folks: clinical correlations for current translational therapeutics

Approximately 20 percent of all strokes will occur in the Infratentorial brain. This is within the vascular territory of the posterior vascular circulation. Very few clinical specifics are known about the therapeutic needs of this patient sub-population. Most evidence-based practices are founded from research about the treatment of anterior circulatory stroke. As a consequence, little is known about how stroke in the Infratentorial brain region would require a different approach. We characterized the neurovascular features of Infratentorial stroke, pathophysiological responses, and experimental models for further translational study.

The effect of a polyurethane-based reverse thermal gel on bone marrow stromal cell transplant survival and spinal cord repair

Cell therapy for nervous tissue repair is limited by low transplant survival. We investigated the effects of a polyurethane-based reverse thermal gel, poly(ethylene glycol)-poly(serinol hexamethylene urethane) (ESHU) on bone marrow stromal cell (BMSC) transplant survival and repair using a rat model of spinal cord contusion. Transplantation of BMSCs in ESHU at three days post-contusion resulted in a 3.5-fold increase in BMSC survival at one week post-injury and a 66% increase in spared nervous tissue volume at four weeks post-injury. These improvements were accompanied by enhanced hindlimb motor and sensorimotor recovery. In vitro, we found that ESHU protected BMSCs from hydrogen peroxide-mediated death, resulting in a four-fold increase in BMSC survival with two-fold fewer BMSCs expressing the apoptosis marker, caspase 3 and the DNA oxidation marker, 8-oxo-deoxyguanosine. We argue that ESHU protected BMSCs transplanted is a spinal cord contusion from death thereby augmenting their effects on neuroprotection leading to improved behavioral restoration. The data show that the repair effects of intraneural BMSC transplants depend on the degree of their survival and may have a widespread impact on cell-based regenerative medicine.

Neuropilin-1 modulates vascular endothelial growth factor-induced poly(ADP-ribose)-polymerase leading to reduced cerebrovascular apoptosis

Cerebral ischemia is encompassed by cerebrovascular apoptosis, yet the mechanisms behind apoptosis regulation are not fully understood. We previously demonstrated inhibition of endothelial apoptosis by vascular endothelial growth factor (VEGF) through upregulation of poly(ADP-ribose)-polymerase (PARP) expression. However, PARP overactivation through oxidative stress can lead to necrosis. This study tested the hypothesis that neuropilin-1 (NP-1), an alternative VEGF receptor, regulates the response to cerebral ischemia by modulating PARP expression and, in turn, apoptosis inhibition by VEGF. In endothelial cell culture, NP-1 colocalized with VEGF receptor-2 (VEGFR-2) and acted as its coreceptor. This significantly enhanced VEGF-induced PARP mRNA and protein expression demonstrated by receptor-specific inhibitors and VEGF-A isoforms. NP-1 augmented the inhibitory effect of VEGF/VEGFR-2 interaction on apoptosis induced by adhesion inhibition through the αV-integrin inhibitor cRGDfV. NP-1/VEGFR-2 signal transduction involved JNK and Akt. In rat models of permanent and temporary middle cerebral artery occlusion, the ischemic cerebral hemispheres displayed endothelial and neuronal apoptosis next to increased endothelial NP-1 and VEGFR-2 expression compared to non-ischemic cerebral hemispheres, sham-operated or untreated controls. Increased vascular superoxide dismutase-1 and catalase expression as well as decreased glycogen reserves indicated oxidative stress in the ischemic brain. Of note, protein levels of intact PARP remained stable despite pro-apoptotic conditions through increased PARP mRNA production during cerebral ischemia. In conclusion, NP-1 is upregulated in conditions of imminent cerebrovascular apoptosis to reinforce apoptosis inhibition and modulate VEGF-dependent PARP expression and activation. We propose that NP-1 is a key modulator of VEGF maintaining cerebrovascular integrity during ischemia. Modulating the function of NP-1 to target PARP could help to prevent cellular damage in cerebrovascular disease.

Drug-like property profiling of novel neuroprotective compounds to treat acute ischemic stroke: guidelines to develop pleiotropic molecules

The development of novel neuroprotective compounds to treat acute ischemic stroke (AIS) has been problematic and quite complicated, since many candidates that have been tested clinically lacked significant pleiotropic activity, were unable to effectively cross the blood brain barrier (BBB), had poor bioavailability or were toxic. Moreover, the compounds did not confer significant neuroprotection or clinical efficacy measured using standard behavioral endpoints, when studied in clinical trials in a heterogeneous population of stroke patients. To circumvent some of the drug development problems describe above, we have used a rational funnel approach to identify and develop promising candidates. Using a step-wise approach, we have identified a series of compounds based upon two different neuroprotection assays. We have then taken the candidates and determined their "drug-like" properties. This guidelines article details in vitro screening assays used to show pleiotropic activity of a series of novel compounds; including enhanced neuroprotective activity compared to the parent compound fisetin. Moreover, for preliminary drug de-risking or risk reduction during development, we used compound assessment in the CeeTox assay, ADME toxicity using the AMES test for genotoxicity and interaction with Cytochrome P450 using CYP450 inhibition analysis against a spectrum of CYP450 enzymes (CYP1A2, CYP2C9, CYP2C19, CYP2D6 and CYP3A4) as a measure of drug interaction. Moreover, the compounds have been studied using a transfected Madin Darby canine kidney (MDCK) cell assay to assess blood brain barrier penetration (BBB). Using this series of assays, we have identified 4 novel molecules to be developed as an AIS treatment.

Up-regulation of heme oxygenase-1 attenuates brain damage after cerebral ischemia via simultaneous inhibition of superoxide production and preservation of NO bioavailability

Cerebral ischemia exacerbates neuronal death and neurological dysfunction. Evidence supports the involvement of oxidative/nitrative stress in the pathophysiology of cerebral ischemia. Heme oxygenase-1 (HO-1) is a rate-limiting enzyme in heme catabolism, possessing potent anti-oxidant and anti-apoptosis effects. In transgenic mice, HO-1 overproduction is neuroprotective against cerebral ischemia injury, but by unclear mechanisms. The present study determined whether treatment with adenoviral vector overexpressing HO-1 (Ad-HO-1) attenuates post-ischemic brain damage via reduction of oxidative/nitrative stress. After focal cerebral ischemia, Ad-HO-1 reduced lipid peroxidation and protein nitration, decreased infarct volume, and attenuated neurologic deficits. Zinc protoporphyrin IX (ZnPP IX, a specific HO-1 inhibitor) blocked Ad-HO-1 mediated effects against ischemic brain damage. Although Ad-HO-1 slightly reduced ischemic brain NO concentrations, Ad-HO-1 treatment significantly inhibited cerebral expression of iNOS protein expression, without significant effect upon nNOS or eNOS expression compared to vehicle after focal cerebral ischemia. Ad-HO-1 preserved NO bioavailability by increasing eNOS phosphorylation during ischemia compared to vehicle. Together, our results suggest that Ad-HO-1 attenuates post-ischemic brain damage via simultaneous reduction of oxidative/nitrative stress and preservation of NO bioavailability.

Posterior circulation stroke: animal models and mechanism of disease

Posterior circulation stroke refers to the vascular occlusion or bleeding, arising from the vertebrobasilar vasculature of the brain. Clinical studies show that individuals who experience posterior circulation stroke will develop significant brain injury, neurologic dysfunction, or death. Yet the therapeutic needs of this patient subpopulation remain largely unknown. Thus understanding the causative factors and the pathogenesis of brain damage is important, if posterior circulation stroke is to be prevented or treated. Appropriate animal models are necessary to achieve this understanding. This paper critically integrates the neurovascular and pathophysiological features gleaned from posterior circulation stroke animal models into clinical correlations.

Hydrogen gas ameliorates oxidative stress in early brain injury after subarachnoid hemorrhage in rats

OBJECTIVE

Hydrogen gas has been demonstrated to neutralize free radicals and reduce oxidative stress recently. Our objective was to determine the therapeutic effect of H2 inhalation and its antioxidative activity on early brain injury after subarachnoid hemorrhage.

DESIGN

Controlled in vivo laboratory study.

SETTING

Animal research laboratory.

SUBJECTS

One hundred thirty-seven adult male Sprague-Dawley rats weighing 280-350 g.

INTERVENTIONS

Subarachnoid hemorrhage was induced by endovascular perforation method in rats. Subarachnoid hemorrhage rats were treated with 2.9% hydrogen gas inhaled for 2 hrs after perforation. At 24 and 72 hrs, mortality, body weight, neurologic deficits, and brain water content were assessed. Blood-brain barrier permeability and apoptosis were also measured at 24 hrs. To investigate the antioxidative activity of hydrogen gas, the expression of malondialdehyde, nitrotyrosine, and 8-hydroxyguanosine, which are oxidative markers of lipid, protein, and DNA damage, respectively, were measured at 24 hrs.

MEASUREMENTS AND MAIN RESULTS

Hydrogen gas significantly alleviated brain edema and blood-brain barrier disruption, reduced apoptosis, and improved neurologic function at 24 hrs but not 72 hrs after subarachnoid hemorrhage. These effects were associated with the amelioration of oxidative injury of lipid, protein, and DNA.

CONCLUSIONS

Hydrogen gas could exert its neuroprotective effect against early brain injury after subarachnoid hemorrhage by its antioxidative activity.

Chemokines and their receptors in intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a devastating clinical event which results in a high rate of disability and death. At present, no effective treatment is available for ICH. Accumulating evidence suggests that inflammatory responses contribute significantly to the ICH-induced secondary brain outcomes. During ICH, inflammatory cells accumulate at the ICH site attracted by gradients of chemokines. This review summarizes recent progress in ICH studies and the chemoattractants that act during the injury and focuses on and introduces the basic biology of the chemokine monocyte chemoattractant protein-1 (MCP1) and its role in the progression of ICH. Better understanding of MCP1 signaling cascade and the compensation after its inhibition could shed light on the development of effective treatments for ICH.

Role of oxidative stress in retinal photoreceptor cell death in N-methyl-N-nitrosourea-treated mice

This study aimed to investigate whether oxidative stress contributes to retinal cell death in a mouse model of photoreceptor degeneration induced by N-methyl-N-nitrosourea (MNU). We measured in vitro MNU-induced radical production in retinal cell cultures of murine 661W photoreceptor-derived cells; RGC-5, a mouse ganglion cell line; and primary retinal cells. The addition of MNU induced oxidative radical generation in 661W and primary retinal cells, but not in RGC-5 cells. Edaravone, a free radical scavenger, at 1 µM reduced MNU-induced radical production in 661W and primary retinal cells. To induce in vivo retinal photoreceptor degeneration in mice, we administered 60 mg/kg MNU by intraperitoneal injection. We intravenously administered 1 mg/kg edaravone immediately and at 6 h after the MNU injection. Retinal photoreceptor degeneration was evaluated by measuring the thickness of the outer nuclear layer (ONL) by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining and by oxidative stress markers. MNU caused photoreceptor cell loss at 7 days after administration. Edaravone inhibited ONL thinning and reduced TUNEL-positive cells and the oxidative stress markers. These findings indicate that MNU leads to selective photoreceptor degradation via oxidative stress in vitro and in vivo and may help to understand the pathogenic mechanism of retinitis pigmentosa.

Regulation of nitric oxide generation by up-regulated arginase I in rat spinal cord injury

Recently, arginase is suggested to regulate nitric oxide production by competing with nitric oxide synthase for the same substrate, L-arginine, in experimental asthma. We investigated the role of arginase and its relationship to nitric oxide production after spinal cord injury. Rats were subjected to laminectomy and complete transection of their spinal cords (injury group) or laminectomy only (sham group). In the injury group, arginase I was increased in the macrophages at the transection edge, and the peak was observed 48 h after spinal cord injury. However, nitric oxide production decreased significantly in the injury group despite increased nitric oxide synthase2 mRNA expression compared with the sham group. We also demonstrated the reduction in L-arginine concentrations, which was inversely associated with changes in arginase activity. Therefore, arginase appeared to regulate nitric oxide production by consuming L-arginine. The regulation of arginase activity and L-arginine levels may improve nitroxidative stress and reduce tissue damage in spinal cord injury.

Caffeinated coffee, decaffeinated coffee, and the phenolic phytochemical chlorogenic acid up-regulate NQO1 expression and prevent H₂O₂-induced apoptosis in primary cortical neurons

Neurodegenerative disorders are strongly associated with oxidative stress, which is induced by reactive oxygen species including hydrogen peroxide (H₂O₂). Epidemiological studies have suggested that coffee may be neuroprotective, but the molecular mechanisms underlying this effect have not been clarified. In this study, we investigated the protective effects of caffeinated coffee, decaffeinated coffee, and the phenolic phytochemical chlorogenic acid (5-O-caffeoylquinic acid), which is present in both caffeinated and decaffeinated coffee, against oxidative neuronal death. H₂O₂-induced apoptotic nuclear condensation in neuronal cells was strongly inhibited by pretreatment with caffeinated coffee, decaffeinated coffee, or chlorogenic acid. Pretreatment with caffeinated coffee, decaffeinated coffee, or chlorogenic acid inhibited the H₂O₂-induced down-regulation of anti-apoptotic proteins Bcl-2 and Bcl-X(L) while blocking H₂O₂-induced pro-apoptotic cleavage of caspase-3 and pro-poly(ADP-ribose) polymerase. We also found that caffeinated coffee, decaffeinated coffee, and chlorogenic acid induced the expression of NADPH:quinine oxidoreductase 1 (NQO1) in neuronal cells, suggesting that these substances protect neurons from H₂O₂-induced apoptosis by up-regulation of this antioxidant enzyme. The neuroprotective efficacy of caffeinated coffee was similar to that of decaffeinated coffee, indicating that active compounds present in both caffeinated and decaffeinated coffee, such as chlorogenic acid, may drive the effects.