Cyclo-oxygenase-2 inhibitors: rationale and therapeutic potential for Alzheimer's disease

Interaction between escitalopram and ibuprofen or paracetamol: DFT and molecular docking on the drug-drug interactions

A large number of drugs are introduced each year to treat different diseases. Most of the time, patients suffer from more than one health problem which makes it necessary to take multiple drugs. When drugs are combined, the problem of drug-drug interaction becomes relevant. In this work, we studied the drug-drug interaction between escitalopram and ibuprofen or paracetamol using density functional theory and quantum theory of atoms in molecules. The results suggest that following the interactions, the activity of drugs changes according to site of interaction. Most reactive and most stable interactions would be preferable for the purpose of use. The in silico drug-likeness studies show that escitalopram and paracetamol couple is more bioavailable than escitalopram and ibuprofen couple. Moreover, in order to gain additional insights into the mentioned drugs' interactions, the drugs were docked separately and jointly against the potential targets for antidepressants and NSAIDs, namely 6HIS and 2PXX. The molecular docking results showed a potential improvement of the effectiveness of the drugs after combining by forming hydrogen bonds, hydrophobic contacts and π…π stacking.Communicated by Ramaswamy H. Sarma.

New hybrids of tacrine and indomethacin as multifunctional acetylcholinesterase inhibitors

A new series of hybrid compounds were designed, consisting of anti-AChE and BuChE activity components with an anti-inflammatory component. A series of 9-amino-1,2,3,4-tetrahydroacridine and indomethacin derivatives were synthesized. All compounds were created using alkyldiamine with different chain lengths as a linker. Various biological activities were evaluated, including inhibitory activity against AChE and BuChE. The tested compounds showed high inhibitory activities against cholinesterases. The IC50 values for all compounds ranging from 10 nM to 7 µM. The potency of inhibition was much higher than well-known AChE and BuChE inhibitors (tacrine and donepezil). Compound 3h had the strongest inhibitory activity; kinetic studies showed it to have a mixed-type of acetylcholinesterase inhibition properties. The cytotoxicity of the newly-synthesized compounds against HepG2 (hepatocarcinoma cells) and EA.hy96 (human vein endothelial cells) cell lines was determined using the MTT and MTS tests. All investigated compounds presented similar cytotoxic activity against HepG2 and EA.hy926 cell line, ranged in micromolar values. Compounds with longer linkers showed higher antioxidant activity. The most active compound was 3h. Docking studies confirmed interactions with important regions of AChE and BuChE. Its multifunctional properties, i.e. high activity against AChE and BuChE, antioxidant activity and low cytotoxicity, highlight 3h as a promising agent for the treatment of AD.

Aspirin and other non-steroidal anti-inflammatory drugs for the prevention of dementia

BACKGROUND

Dementia is a worldwide concern. Its global prevalence is increasing. At present, there is no medication licensed to prevent or delay the onset of dementia. Inflammation has been suggested as a key factor in dementia pathogenesis. Therefore, medications with anti-inflammatory properties could be beneficial for dementia prevention.

OBJECTIVES

To evaluate the effectiveness and adverse effects of aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) for the primary or secondary prevention of dementia.

SEARCH METHODS

We searched ALOIS, the specialised register of the Cochrane Dementia and Cognitive Improvement Group up to 9 January 2020. ALOIS contains records of clinical trials identified from monthly searches of several major healthcare databases, trial registries and grey literature sources. We ran additional searches across MEDLINE (OvidSP), Embase (OvidSP) and six other databases to ensure that the searches were as comprehensive and up-to-date as possible. We also reviewed citations of reference lists of included studies.

SELECTION CRITERIA

We searched for randomised controlled trials (RCTs) and controlled clinical trials (CCTs) comparing aspirin or other NSAIDs with placebo for the primary or secondary prevention of dementia. We included trials with cognitively healthy participants (primary prevention) or participants with mild cognitive impairment (MCI) or cognitive complaints (secondary prevention).

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures according to the Cochrane Handbook for Systematic Reviews of Interventions. We rated the strength of evidence for each outcome using the GRADE approach.

MAIN RESULTS

We included four RCTs with 23,187 participants. Because of the diversity of these trials, we did not combine data to give summary estimates, but presented a narrative description of the evidence. We identified one trial (19,114 participants) comparing low-dose aspirin (100 mg once daily) to placebo. Participants were aged 70 years or older with no history of dementia, cardiovascular disease or physical disability. Interim analysis indicated no significant treatment effect and the trial was terminated slightly early after a median of 4.7 years' follow-up. There was no evidence of a difference in incidence of dementia between aspirin and placebo groups (risk ratio (RR) 0.98, 95% CI 0.83 to 1.15; high-certainty evidence). Participants allocated aspirin had higher rates of major bleeding (RR 1.37, 95% CI 1.17 to 1.60, high-certainty evidence) and slightly higher mortality (RR 1.14, 95% CI 1.01 to 1.28; high-certainty evidence). There was no evidence of a difference in activities of daily living between groups (RR 0.84, 95% CI 0.70 to 1.02; high-certainty evidence). We identified three trials comparing non-aspirin NSAIDs to placebo. All three trials were terminated early due to adverse events associated with NSAIDs reported in other trials. One trial (2528 participants) investigated the cyclo-oxygenase-2 (COX-2) inhibitor celecoxib (200 mg twice daily) and the non-selective NSAID naproxen (220 mg twice daily) for preventing dementia in cognitively healthy older adults with a family history of Alzheimer's disease (AD). Median follow-up was 734 days. Combining both NSAID treatment arms, there was no evidence of a difference in the incidence of AD between participants allocated NSAIDs and those allocated placebo (RR 1.91, 95% CI 0.89 to 4.10; moderate-certainty evidence). There was also no evidence of a difference in rates of myocardial infarction (RR 1.21, 95% CI 0.61 to 2.40), stroke (RR 1.82, 95% CI 0.76 to 4.37) or mortality (RR 1.37, 95% CI 0.78 to 2.43) between treatment groups (all moderate-certainty evidence). One trial (88 participants) assessed the effectiveness of celecoxib (200 mg or 400 mg daily) in delaying cognitive decline in participants aged 40 to 81 years with mild age-related memory loss but normal memory performance scores. Mean duration of follow-up was 17.6 months in the celecoxib group and 18.1 months in the placebo group. There was no evidence of a difference between groups in test scores in any of six cognitive domains. Participants allocated celecoxib experienced more gastrointestinal adverse events than those allocated placebo (RR 2.66, 95% CI 1.05 to 6.75; low-certainty evidence). One trial (1457 participants) assessed the effectiveness of the COX-2 inhibitor rofecoxib (25 mg once daily) in delaying or preventing a diagnosis of AD in participants with MCI. Median duration of study participation was 115 weeks in the rofecoxib group and 130 weeks in the placebo group. There was a higher incidence of AD in the rofecoxib than the placebo group (RR 1.32, 95% CI 1.01 to 1.72; moderate-certainty evidence). There was no evidence of a difference between groups in cardiovascular adverse events (RR 1.07, 95% CI 0.68 to 1.66; moderate-certainty evidence) or mortality (RR 1.62, 95% CI 0.85 to 3.05; moderate-certainty evidence). Participants allocated rofecoxib had more upper gastrointestinal adverse events (RR 3.53, 95% CI 1.17 to 10.68; moderate-certainty evidence). Reported annual mean difference scores showed no evidence of a difference between groups in activities of daily living (year 1: no data available; year 2: 0.0, 95% CI -0.1 to 0.2; year 3: 0.1, 95% CI -0.1 to 0.3; year 4: 0.1, 95% CI -0.1 to 0.4; moderate-certainty evidence).

AUTHORS' CONCLUSIONS

There is no evidence to support the use of low-dose aspirin or other NSAIDs of any class (celecoxib, rofecoxib or naproxen) for the prevention of dementia, but there was evidence of harm. Although there were limitations in the available evidence, it seems unlikely that there is any need for further trials of low-dose aspirin for dementia prevention. If future studies of NSAIDs for dementia prevention are planned, they will need to be cognisant of the safety concerns arising from the existing studies.

Elamipretide (SS-31) improves mitochondrial dysfunction, synaptic and memory impairment induced by lipopolysaccharide in mice

Background

It is widely accepted that mitochondria have a direct impact on neuronal function and survival. Oxidative stress caused by mitochondrial abnormalities play an important role in the pathophysiology of lipopolysaccharide (LPS)-induced memory impairment. Elamipretide (SS-31) is a novel mitochondrion-targeted antioxidant. However, the impact of elamipretide on the cognitive sequelae of inflammatory and oxidative stress is unknown.

Methods

We utilized MWM and contextual fear conditioning test to assess hippocampus-related learning and memory performance. Molecular biology techniques and ELISA were used to examine mitochondrial function, oxidative stress, and the inflammatory response. TUNEL and Golgi-staining was used to detect neural cell apoptosis and the density of dendritic spines in the mouse hippocampus.

Results

Mice treated with LPS exhibited mitochondrial dysfunction, oxidative stress, an inflammatory response, neural cell apoptosis, and loss of dendritic spines in the hippocampus, leading to impaired hippocampus-related learning and memory performance in the MWM and contextual fear conditioning test. Treatment with elamipretide significantly ameliorated LPS-induced learning and memory impairment during behavioral tests. Notably, elamipretide not only provided protective effects against mitochondrial dysfunction and oxidative stress but also facilitated the regulation of brain-derived neurotrophic factor (BDNF) signaling, including the reversal of important synaptic-signaling proteins and increased synaptic structural complexity.

Conclusion

These findings indicate that LPS-induced memory impairment can be attenuated by the mitochondrion-targeted antioxidant elamipretide. Consequently, elamipretide may have a therapeutic potential in preventing damage from the oxidative stress and neuroinflammation that contribute to perioperative neurocognitive disorders (PND), which makes mitochondria a potential target for treatment strategies for PND.

Acetaminophen attenuates lipopolysaccharide-induced cognitive impairment through antioxidant activity

Background

Considerable evidence has shown that neuroinflammation and oxidative stress play an important role in the pathophysiology of postoperative cognitive dysfunction (POCD) and other progressive neurodegenerative disorders. Increasing evidence suggests that acetaminophen (APAP) has unappreciated antioxidant and anti-inflammatory properties. However, the impact of APAP on the cognitive sequelae of inflammatory and oxidative stress is unknown. The objective of this study is to explore whether APAP could have neuroprotective effects on lipopolysaccharide (LPS)-induced cognitive impairment in mice.

Methods

A mouse model of LPS-induced cognitive impairment was established to evaluate the neuroprotective effects of APAP against LPS-induced cognitive impairment. Adult C57BL/6 mice were treated with APAP half an hour prior to intracerebroventricular microinjection of LPS and every day thereafter, until the end of the study period. The Morris water maze was used to assess cognitive function from postinjection days 1 to 3. Animal behavioural tests as well as pathological and biochemical assays were performed to evaluate LPS-induced hippocampal damage and the neuroprotective effect of APAP.

Results

Mice treated with LPS exhibited impaired performance in the Morris water maze without changing spontaneous locomotor activity, which was ameliorated by treatment with APAP. APAP suppressed the accumulation of pro-inflammatory cytokines and microglial activation induced by LPS in the hippocampus. In addition, APAP increased SOD activity, reduced MDA levels, modulated glycogen synthase kinase 3β (GSK3β) activity and elevated brain-derived neurotrophic factor (BDNF) expression in the hippocampus. Moreover, APAP significantly decreased the Bax/Bcl-2 ratio and neuron apoptosis in the hippocampus of LPS-treated mice.

Conclusions

Our results suggest that APAP may possess a neuroprotective effect against LPS-induced cognitive impairment and inflammatory and oxidative stress via mechanisms involving its antioxidant and anti-inflammatory properties, as well as its ability to inhibit the mitochondrial permeability transition (MPT) pore and the subsequent apoptotic pathway.

Prostaglandin I2 upregulates the expression of anterior pharynx-defective-1α and anterior pharynx-defective-1β in amyloid precursor protein/presenilin 1 transgenic mice

Cyclooxygenase‐2 (COX‐2) has been recently identified to be involved in the pathogenesis of Alzheimer's disease (AD). Yet, the role of an important COX‐2 metabolic product, prostaglandin (PG) I₂, in the pathogenesis of AD remains unknown. Using human‐ and mouse‐derived neuronal cells as well as amyloid precursor protein/presenilin 1 (APP/PS1) transgenic mice as model systems, we elucidated the mechanism of anterior pharynx‐defective (APH)‐1α and pharynx‐defective‐1β induction. In particular, we found that PGI₂ production increased during the course of AD development. Then, PGI₂ accumulation in neuronal cells activates PKA/CREB and JNK/c‐Jun signaling pathways by phosphorylation, which results in APH‐1α/1β expression. As PGI₂ is an important metabolic by‐product of COX‐2, its suppression by NS398 treatment decreases the expression of APH‐1α/1β in neuronal cells and APP/PS1 mice. More importantly, β‐amyloid protein (Aβ) oligomers in the cerebrospinal fluid (CSF) of APP/PS1 mice are critical for stimulating the expression of APH‐1α/1β, which was blocked by NS398 incubation. Finally, the induction of APH‐1α/1β was confirmed in the brains of patients with AD. Thus, these findings not only provide novel insights into the mechanism of PGI₂‐induced AD progression but also are instrumental for improving clinical therapies to combat AD.

Systemic inflammation, blood-brain barrier vulnerability and cognitive/non-cognitive symptoms in Alzheimer disease: relevance to pathogenesis and therapy

The incidence of dementia is increasing at an alarming rate, and has become a major public health concern. Alzheimer disease (AD) is the most common form of dementia and is characterized by progressive cognitive impairment. In addition to classical neuropathological features such as amyloid plaques and neurofibrillary tangles (NFT), accumulation of activated immune cells has been documented in the AD brain, suggesting a contribution of neuroinflammation in the pathogenesis of AD. Besides cognitive deterioration, non-cognitive symptoms, such as agitation, aggression, depression and psychosis, are often observed in demented patients, including those with AD, and these neuropsychological symptoms place a heavy burden on caregivers. These symptoms often exhibit sudden onset and tend to fluctuate over time, and in many cases, they are triggered by an infection in peripheral organs, suggesting that inflammation plays an important role in the pathogenesis of these non-cognitive symptoms. However, there is no mechanistic explanation for the relationship between inflammation and neuropsychiatric symptoms. Observations from experimental mouse models indicate that alteration of brain blood vessels, especially blood-brain barrier (BBB) dysfunction, may contribute to the relationship. The current review summarizes the results from recent studies on the relationship between inflammation and AD, while focusing on cerebrovascular alterations, which might provide an insight into the pathogenesis of cognitive/non-cognitive symptoms in AD patients and suggest a basis for the development of new therapeutic treatments for these conditions.

Ibuprofen rescues abnormalities in periodontal tissues in conditional presenilin 1 and presenilin 2 double knockout mice

We used forebrain-specific conditional presenilin 1 (PS1) and presenilin 2 (PS2) double knockout mice (dKO mice) that exhibit symptoms of neurodegenerative diseases, especially Alzheimer’s disease, to investigate whether ibuprofen can rescue brain and periodontal tissue abnormalities by attenuating the inflammatory response. Mandibles were dissected for alveolar bone-height analysis. Maxillae were fixed and decalcified for histological observation and osteoclast detection. ELISA measurements from the hippocampus, cortex, and gingiva of the mandibular incisor teeth were used to assay inflammatory mediators. We confirmed periodontal tissue abnormalities and inflammatory responses in brain and periodontal tissues in naive nine- and 12-month-old dKO mice. The other two groups of age-matched dKO mice that received 375-ppm ibuprofen treatment for six consecutive months exhibited significantly attenuated damage in periodontal tissues and reduction in several inflammation-related factors in brain and periodontal tissues. Our findings showed that the anti-inflammatory drug ibuprofen significantly decreased inflammation through the cyclooxygenase (COX) pathway in brain and periodontal tissues in dKO mice, and then attenuated abnormalities in periodontal tissues. This suggests that ibuprofen could be an ideal drug for preventing both nervous system and periodontal tissue damage caused by inflammatory responses.

Inflammation in Alzheimer disease-a brief review of the basic science and clinical literature

Biochemical and neuropathological studies of brains from individuals with Alzheimer disease (AD) provide clear evidence for an activation of inflammatory pathways, and long-term use of anti-inflammatory drugs is linked with reduced risk to develop the disease. As cause and effect relationships between inflammation and AD are being worked out, there is a realization that some components of this complex molecular and cellular machinery are most likely promoting pathological processes leading to AD, whereas other components serve to do the opposite. The challenge will be to find ways of fine tuning inflammation to delay, prevent, or treat AD.

Effects of lithium on lipopolysaccharide-induced inflammation in rat primary glia cells

Lithium is the gold-standard treatment for bipolar disorder, a severe mental illness. A large body of evidence suggests that inflammation plays a role in the pathogenesis of bipolar disorder and that mood stabilizers exhibit anti-inflammatory properties. However, contradicting findings have also been reported. In this study, we examined the effects of lithium on LPS-induced inflammation in rat primary glia cells. Cells were pre-treated with lithium (1 or 10 mM) for 6 or 24 h, after which, inflammation was induced by the addition of LPS (for another 18 h) to the culture medium. Thereafter, medium was collected and cells were harvested for further analyses. Levels of TNF-α, IL1-β and PGE2 were determined by ELISA and NO levels by the Griess reaction assay. Expression levels of cyclooxygenase-2 (COX-2) and inducible NO synthase (iNOS) were examined by Western blot analysis. We found that pre-treatment with lithium 10 mM (but not 1 mM) significantly reduced LPS-induced secretion of TNF-α, IL1-β, PGE2 and NO. In addition, lithium significantly reduced the expression of COX-2 and iNOS. These findings indicate that lithium exhibits a potent anti-inflammatory effect. However, it’s important to emphasize that this effect was obtained mainly under treatment with an extra-therapeutic concentration of the drug.

Cerebral arachidonate cascade in dementia: Alzheimer's disease and vascular dementia

Phospholipase A(2) (PLA(2)), cyclooxygenase (COX) and prostaglandin (PG) synthase are enzymes involved in arachidonate cascade. PLA(2) liberates arachidonic acid (AA) from cell membrane lipids. COX oxidizes AA to PGG(2) followed by an endoperoxidase reaction that converts PGG(2) into PGH(2). PGs are generated from astrocytes, microglial cells and neurons in the central nervous system, and are altered in the brain of demented patients. Dementia is principally diagnosed into Alzheimer's disease (AD) and vascular dementia (VaD). In older patients, the brain lesions associated with each pathological process often occur together. Regional brain microvascular abnormalities appear before cognitive decline and neurodegeneration. The coexistence of AD and VaD pathology is often termed mixed dementia. AD and VaD brain lesions interact in important ways to decline cognition, suggesting common pathways of the two neurological diseases. Arachidonate cascade is one of the converged intracellular signal transductions between AD and VaD. PLA(2) from mammalian sources are classified as secreted (sPLA(2)), Ca(2+)-dependent, cytosolic (cPLA(2)) and Ca(2+)-independent cytosolic PLA(2) (iPLA(2)). PLA(2) activity can be regulated by calcium, by phosphorylation, and by agonists binding to G-protein-coupled receptors. cPLA(2) is upregulalted in AD, but iPLA(2) is downregulated. On the other hand, sPLA(2) is increased in animal models for VaD. COX-2 is induced and PGD(2) are elevated in both AD and VaD. This review presents evidences for central roles of PLA(2)s, COXs and PGs in the dementia.

Non-Steroidal Anti-Inflammatory Drugs in Alzheimer's Disease and Parkinson's Disease: Reconsidering the Role of Neuroinflammation

Alzheimer's disease (AD) and Parkinson's disease (PD) are the most common neurodegenerative diseases with age as the greatest risk factor. As the general population experiences extended life span, preparation for the prevention and treatment of these and other age-associated neurological diseases are warranted. Since epidemiological studies suggested that non-steroidal anti-inflammatory drug (NSAID) use decreased risk for AD and PD, increasing attention has been devoted to understanding the costs and benefits of the innate neuroinflammatory response to functional recovery following pathology onset. This review will provide a general overview on the role of neuroinflammation in these neurodegenerative diseases and an update on NSAID treatment in recent experimental animal models, epidemiological analyses, and clinical trials.

MMPBSA decomposition of the binding energy throughout a molecular dynamics simulation of amyloid-beta (Abeta(10-35)) aggregation

Recent experiments with amyloid-beta (Aβ) peptides indicate that the formation of toxic oligomers may be an important contribution to the onset of Alzheimer’s disease. The toxicity of Aβ oligomers depend on their structure, which is governed by assembly dynamics. However, a detailed knowledge of the structure of at the atomic level has not been achieved yet due to limitations of current experimental techniques. In this study, replica exchange molecular dynamics simulations are used to identify the expected diversity of dimer conformations of Aβ₁₀₋₃₅ monomers. The most representative dimer conformation has been used to track the dimer formation process between both monomers. The process has been characterized by means of the evolution of the decomposition of the binding free energy, which provides an energetic profile of the interaction. Dimers undergo a process of reorganization driven basically by inter-chain hydrophobic and hydrophilic interactions and also solvation/desolvation processes.

Effects of non-steroidal anti-inflammatory drugs on Abeta deposition in Abeta(1-42) transgenic C. elegans

Although epidemiological studies have shown that long-term treatment with non-steroidal anti-inflammatory drugs (NSAIDs) may protect against Alzheimer's disease (AD), the mechanism(s) by which NSAIDs reduce the risk of AD remain to be determined. As C. elegans possess neither inflammatory cells nor the arachidonate cascade, we could evaluate the effects of NSAIDs on amyloid beta (Abeta) deposition in the absence of immune cells using Abeta-transgenic C. elegans. For this purpose, we established a strain of Abeta-transgenic C. elegans in which thioflavin S-reactive deposits are reproducibly detectable by confocal microscopy. Among the NSAIDs examined, ibuprofen and naproxen reduced the number of thioflavin S-reactive deposits. Furthermore, ibuprofen and naproxen neither affect the thioflavin S binding to Abeta nor Abeta expression in transgenic C. elegans. These data suggest that ibuprofen and naproxen, the most frequently used NSAIDs for the treatment of AD, have an inhibitory effect on Abeta deposition that is independent of the arachidonate cascade and cellular immune systems.

Blueberry opposes beta-amyloid peptide-induced microglial activation via inhibition of p44/42 mitogen-activation protein kinase

Alzheimer's Disease (AD) is the most common age-related dementia, with a current prevalence in excess of five million individuals in the United States. The aggregation of amyloid-beta (A beta) into fibrillar amyloid plaques is a key pathological event in the development of the disease. Microglial proinflammatory activation is widely known to cause neuronal and synaptic damage that correlates with cognitive impairment in AD. However, current pharmacological attempts at reducing neuroinflammation mediated via microglial activation have been largely negative in terms of slowing AD progression. Previously, we have shown that microglia express proinflammatory cytokines and a reduced capacity to phagocytose A beta in the context of CD40, A beta peptides and/or lipopolysaccharide (LPS) stimulation, a phenomenon that can be opposed by attenuation of p44/42 mitogen-activated protein kinase (MAPK) signaling. Other groups have found that blueberry (BB) extract both inhibits phosphorylation of this MAPK module and also improves cognitive deficits in AD model mice. Given these considerations and the lack of reduced A beta quantities in behaviorally improved BB-fed mice, we wished to determine whether BB supplementation would alter the microglial proinflammatory activation state in response to A beta. We found that BB significantly enhances microglial clearance of A beta, inhibits aggregation of A beta(1-42), and suppresses microglial activation, all via suppression of the p44/42 MAPK module. Thus, these data may explain the previously observed behavioral recovery in PSAPP mice and suggest a means by which dietary supplementation could mitigate an undesirable microglial response toward fibrillar A beta.

Reassessing the amyloid cascade hypothesis of Alzheimer's disease

Since its inception, the amyloid cascade hypothesis has dominated the field of Alzheimer's disease (AD) research and has provided the intellectual framework for therapeutic intervention. Although the details of the hypothesis continue to evolve, its core principle has remained essentially unaltered. It posits that the amyloid-beta peptides, derived from amyloid precursor protein (APP), are the root cause of AD. Substantial genetic and biochemical data support this view, and yet a number of findings also run contrary to its tenets. The presence of familial AD mutations in APP and presenilins, demonstration of Abeta toxicity, and studies in mouse models of AD all support the hypothesis, whereas the presence of Abeta plaques in normal individuals, the uncertain nature of the pathogenic Abeta species, and repeated disappointments with Abeta-centered therapeutic trials are inconsistent with the hypothesis. The current state of knowledge does not prove nor disprove the amyloid hypothesis, but rather points to the need for its reassessment. A view that Abeta is one of the factors, as opposed to the factor, that causes AD is more consistent with the present knowledge, and is more likely to promote comprehensive and effective therapeutic strategies.

Cyclooxygenase-2 inhibition improves amyloid-beta-mediated suppression of memory and synaptic plasticity

Non-steroidal anti-inflammatory agents (NSAIDs) are associated with a marked reduction in the risk of developing Alzheimer's disease, a form of dementia characterized by the accumulation of amyloid plaques containing the amyloid-beta protein (Abeta). Studies of the effects of NSAIDs upon the inflammatory response surrounding amyloid plaques and upon the generation of Abeta from the amyloid precursor protein (APP) have led to two proposed mechanisms by which NSAIDs may protect against Alzheimer's disease: one, the selective lowering of Abeta42 by a subset of NSAIDs; and two, the reduction of inflammation. Although Alzheimer's disease is a disorder of brain and synaptic function, the effects of NSAIDs on Abeta-mediated suppression of synaptic plasticity and memory function have never been reported. We therefore investigated how three different NSAIDs, chosen for their distinct effects on Abeta42 production and the inhibition of the cyclooxygenase (COX) isoenzymes, COX-1 and COX-2, affect memory function and synaptic plasticity. By focusing upon brain and synapse function, we made novel observations about the effects of NSAIDs on Abeta-mediated neural processes. Here we report that the selective inhibition of COX-2, but not COX-1, acutely prevented the suppression of hippocampal long-term plasticity (LTP) by Abeta. The non-selective NSAIDs, ibuprofen and naproxen, and a selective COX-2 inhibitor, MF-tricyclic, each restored memory function in Tg2576 mice over-expressing APP, and also blocked Abeta-mediated inhibition of LTP. There was no advantage of ibuprofen, a selective Abeta42-lowering agent (SALA), over the non-SALAs, naproxen and MF-tricyclic. The beneficial effects on memory did not depend upon lowered levels of Abeta42 or the inflammatory cytokines, tumour necrosis factor alpha (TNF-alpha) and interleukin 1beta (IL-1beta). Intriguingly, improved memory function was inversely related to prostaglandin E2 (PGE2) levels. Conversely, exogenous PGE2 prevented the restorative effects of COX-2 inhibitors on LTP. The data indicate that the inhibition of COX-2 blocks Abeta-mediated suppression of LTP and memory function, and that this block occurs independently of reductions in Abeta42 or decreases in inflammation. The results lead us to propose a third possible mechanism by which NSAIDs may protect against Alzheimer's disease, involving the blockade of a COX-2-mediated PGE2 response at synapses.

New Dosage Formulations for Targeted Delivery of Cyclo-Oxygenase-2 Inhibitors

NSAIDs are a widely used class of analgesic and anti-inflammatory drugs that act by inhibiting the cyclo-oxygenase (COX) enzyme. However, because of their nonspecificity of action, use of these agents as long-term therapy for chronic pain in diseases such as rheumatoid arthritis (RA) and osteoarthritis (OA) is often discouraged. Among NSAIDs, COX-2 inhibitors are promising candidates for long-term therapy of chronic diseases, particularly in the elderly, because of their reduced incidence of gastrointestinal adverse effects. However, in recent times these agents have also been shown to cause adverse effects such as cardiovascular effects (myocardial infarction, stroke and hypertension) and renal effects (decreased renal blood flow/glomerular filtration rate), which in 2004 led to the withdrawal of rofecoxib and in 2005 the withdrawal of valdecoxib from the US market. Importantly, these adverse effects can be effectively reduced by achieving site specific/targeted delivery through new formulation approaches. These formulations not only restrict the drug supply to specific organs but also reduce the dose required. As a result, use of new delivery systems such as nanoparticles, microparticles, microemulsions and nanogels has gained widespread applicability in the management of chronic disease, especially in the elderly, and particularly when there is a need to decrease dose-dependent adverse effects (as is the case with COX-2 inhibitors). This article reviews various new approaches to the delivery of COX-2 inhibitors and highlights issues related to the development of delivery systems for these agents for RA, OA, cancer (familial adenomatous polyposis, prostate, breast and non-small cell lung cancer), ocular diseases (such as diabetic retinopathy) and inflammatory diseases of the skin, with emphasis on their potential for use in the elderly. Emphasis is also placed on the preparation of these particulate systems, their release profile and behaviour in biological systems.

Organic anion-transporting polypeptides at the blood-brain and blood-cerebrospinal fluid barriers

Organic anion-transporting polypeptides (Oatps) are solute carrier family members that exhibit marked evolutionary conservation. Mammalian Oatps exhibit wide tissue expression with an emphasis on expression in barrier cells. In the brain, Oatps are expressed in the blood-brain barrier endothelial cells and blood-cerebrospinal fluid barrier epithelial cells. This expression profile serves to illustrate a central role for Oatps in transporting endo- and xenobiotics across brain barrier cells. This chapter will detail the expression patterns and substrate specificities of Oatps expressed in the brain, and will place special emphases on the role of Oatps in prostaglandin synthesis and in the transport of conjugated endobiotics.

Prostaglandin D2 mediates neuronal damage by amyloid-β or prions which activates microglial cells

Microglial cells killed neurons damaged following incubation with sub-lethal concentrations of peptides derived from either the human prion protein (HuPrP82-146) or amyloid-beta1-42 (a peptide found in Alzheimer's disease). HuPrP82-146 or amyloid-beta1-42 induced phenotypic changes in neurons that caused them to bind a CD14-IgG chimera. In co-cultures microglial cells produced interleukin (IL)-6 in response to HuPrP82-146 or amyloid-beta1-42 damaged neurons. The binding of the CD14-IgG chimera to HuPrP82-146 or amyloid-beta1-42 damaged neurons was reduced by pre-treatment with cyclo-oxygenase (COX)-1 inhibitors and in co-cultures, COX-1 inhibitors significantly increased neuronal survival. Studies with individual prostaglandins demonstrated that the addition of prostaglandin D2, or prostaglandin E2, but not other prostaglandins (F2alpha, H2, I2 or 15-dJ2), mimicked the effects of amyloid-beta1-42 on neurons. Thus, prostaglandin D2 or E2 damaged neurons bound the CD14-IgG chimera, and in co-cultures prostaglandin D2 damaged neurons activated microglial cells. These effects were mediated via the DP prostanoid receptor; DP receptor agonists BW245C or SQ27986 induced neuronal damage, while the DP receptor antagonist BWA868C was neuroprotective in co-cultures. These results indicate that prostaglandin D2, produced following activation of COX-1 by sub-lethal concentrations of HuPrP82-146 or amyloid-beta1-42, causes phenotypic changes in neurons that activates microglial cells and leads to neuronal loss.

Mapping cellular transcriptosomes in autopsied Alzheimer's disease subjects and relevant animal models

Alzheimer's disease (AD) is a late-onset and progressive neurodegenerative disorder characterized clinically by memory loss, impairment of other cognitive functions, and changes in behavior and personality. The overall aim of this review is to summarize recent advances in studies of AD progression and the use of animal models in gene expression studies of AD progression. Genetic causes of AD are known only for early-onset AD patients. For a majority of late-onset AD patients, causal factors are still unknown. Currently, there are no early detectable biomarkers for late-onset AD, and there is a lack of understanding of AD pathophysiology, particularly at the early stages of disease progression, before pathology develops. Human histopathological and biochemical studies provide valuable information regarding the last stages of AD pathogenesis. However, to understand early cellular changes in AD progression before symptoms develop, animal models are still our only alternative. Several research groups have created genetically engineered animal models, particularly models of the mouse, rat, fly, and worm, which have allowed us to better, understand the initiating events of AD progression. Recently, state-of-the-art methods have helped elucidate gene expression changes in affected and unaffected tissues from postmortem AD brains and from animal models developed for AD studies. These methods allow the investigation of mRNA-based transcriptosomal profiles of brain specimens from AD humans and transgenic animals. The major finding from these studies is that AD progression and pathogenesis involve multiple cellular pathways, which suggests that AD is a complex and heterogeneous disease.

Clinical effects of COX-2 inhibitors on cognition in schizophrenia

An activation of pro-inflammatory cytokines in the central nervous system is associated with cognitive disturbances. This process is mediated by prostaglandins and cyclo-oxygenase-2 (COX-2). COX-2 inhibitors have been suggested to show beneficial effects in disorders associated with cognitive disturbance, although clinical effects on cognition have not been shown until today. Data from a schizophrenia study were reevaluated under the aspect whether an effect on the positive and negative syndrome scale (PANSS) factor cognition can be observed during therapy with the COX-2 inhibitor celecoxib add on to risperidone in comparison to riperidone alone. Beside the effect on the PANSS total score, the effect on the cognition factor was the most pronounced using the analysis of covariance compared to all other factors of the PANSS (p < 0.06). Although suggestions of basic research led to an expected therapeutic effect of COX-2 inhibitors on cognition, this effect could not yet be shown clinically. In schizophrenia, the effect on cognition contributes to the therapeutic effect of COX-2 inhibitors.

The potential role of non-steroidal anti-inflammatory drugs in treating Alzheimer’s disease

Epidemiological studies suggest that long-term use of non-steroidal anti-inflammatory drugs (NSAIDs) may protect against Alzheimer's disease (AD). Despite encouraging evidence, all large, long-term, placebo-controlled clinical trials aimed at reducing inflammation in the brain of AD patients produced negative results. More recently it has been shown that some NSAIDs decrease the production of amyloid-beta(1-42) (Abeta42), the major component of senile plaques of the AD brain, and counteract the progression of Abeta42 pathology in transgenic mouse models of AD. The proposed mechanism for this activity is an allosteric modulation of gamma-secretase activity, the enzyme responsible for the formation of amyloid-beta. The inhibition of Abeta42 production is independent from the anti-cyclooxygenase (COX) activity and is related to the chemical structure of the compounds, with some NSAIDs being active (ibuprofen, sulindac, flurbiprofen, indomethacin, diclofenac) and others not (naproxen, aspirin, celecoxib). This could explain the negative results of the large AD trials carried out so far, as they were conducted with compounds (naproxen, hydroxychloroquine, dapsone, prednisone, rofecoxib and celecoxib) that are not able to decrease Abeta42 production. Unfortunately, the use of these NSAIDs in AD is hampered by a significant gastrointestinal toxicity associated with COX inhibition. Thus, new NSAID analogues are being developed with potent and selective inhibitory activity on Abeta42 but with either lack of COX inhibitory activity or reduced gastrointestinal toxicity potential.

Age-related loss of neuronal nicotinic receptor expression in the aging mouse hippocampus corresponds with cyclooxygenase-2 and PPAR? expression and is altered by long-term NS398 administration

Age-related changes in the mammalian dorsal hippocampus are associated with diminished expression of neuronal nicotinic acetylcholine receptors (nAChR), which is particularly severe in pathologies such as those associated with dementias, including Alzheimer's disease. Because the mouse is a useful model for age-related decline in nAChR expression in the basal forebrain and limbic system, we used immunohistochemistry to examine the influence of long-term (12-month) oral administration of nicotine and/or the cyclooxygenase-2 (COX-2) preferring non-steroidal anti-inflammatory drug (NSAID) NS398 on nAChR alpha4, alpha5, alpha7, and beta4 expression in the C57BL/6 mouse. Inhibitory neurons of the dorsal hippocampus that express nAChRs also constitutively express COX-2 and the peroxisome proliferator-antagonist receptor subtype gamma-2 (PPAR gamma2) which is also a target of NS398. Administration of NS398 correlated with retention of nAChR alpha4 and to a lesser extent nAChR beta4, but not nAChR alpha5 or alpha7, but nicotine exhibited no similar effect. Nicotine and NS398 co-administration abolished the NS398-related effect on nAChR alpha4 retention. These results provide evidence that the interaction during aging between oral administration of nicotine and NSAIDs are not straightforward and could even be antagonistic when combined.

Non-steroidal anti-inflammatory drugs protect amyloid beta protein-induced increase in the intracellular Cl- concentration in cultured rat hippocampal neurons

Long-term use of non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen reportedly decrease a risk for the progression of Alzheimer's disease (AD), whose mechanisms are still controversial. We previously reported that pathophysiological concentrations (1-10 nM) of amyloid beta proteins (Abetas) increased intracellular Cl- concentration ([Cl-]i) and aggravated glutamate neurotoxicity in the rat brain neuronal culture. In this study, we examined the effects of therapeutic concentrations of ibuprofen and other drugs with cyclo-oxygenase (COX)-1 and/or COX-2 inhibiting activities on 10 nM Abeta25-35-induced changes in cultured rat hippocampal neurons. Ibuprofen (10-100 microM) dose-dependently inhibited the Abeta25-35-induced increase in [Cl-]i in pyramidal cell-like neurons. Not only ibuprofen, aspirin (100 microM), indomethacin (50 microM), and selective COX-1 or COX-2 inhibitor (10 nM ketrolac or 2 microM NS398) also blocked the Abeta-induced increase in neuronal [Cl-]i, though such effects of COX-2 preferring drugs were limited in aggregated Abeta-induced changes. Further, ibuprofen as well as selective COX-1 or COX-2 inhibitor reduced Abeta-induced aggravation of glutamate toxicity as assessed by cell viability. These findings suggest that NSAIDs protect neurons from Abeta-induced degeneration via inhibition of neuronal COX-1 as well as COX-2.

Cyclooxygenase Isozymes: The Biology of Prostaglandin Synthesis and Inhibition

Nonsteroidal anti-inflammatory drugs (NSAIDs) represent one of the most highly utilized classes of pharmaceutical agents in medicine. All NSAIDs act through inhibiting prostaglandin synthesis, a catalytic activity possessed by two distinct cyclooxygenase (COX) isozymes encoded by separate genes. The discovery of COX-2 launched a new era in NSAID pharmacology, resulting in the synthesis, marketing, and widespread use of COX-2 selective drugs. These pharmaceutical agents have quickly become established as important therapeutic medications with potentially fewer side effects than traditional NSAIDs. Additionally, characterization of the two COX isozymes is allowing the discrimination of the roles each play in physiological processes such as homeostatic maintenance of the gastrointestinal tract, renal function, blood clotting, embryonic implantation, parturition, pain, and fever. Of particular importance has been the investigation of COX-1 and -2 isozymic functions in cancer, dysregulation of inflammation, and Alzheimer's disease. More recently, additional heterogeneity in COX-related proteins has been described, with the finding of variants of COX-1 and COX-2 enzymes. These variants may function in tissue-specific physiological and pathophysiological processes and may represent important new targets for drug therapy.

Aberrant expressions of pathogenic phenotype in Alzheimer's diseased transgenic mice carrying NSE-controlled APPsw

Mutations in the APP gene lead to enhanced cleavage by the beta- and gamma-secretase, and increased Abeta formation, which are tightly associated with Alzheimer's disease (AD)-like neuropathological changes. To examine whether depositions of Abeta by APP mutations are increased, and if this is associated with potential pathogenic phenotypes, the APPsw was expressed in a transgenic line under the control of the neuron-specific enolase (NSE) promoter. A behavioral dysfunction was shown at 12 months, and intensive staining bands, with APP and Abeta-42 antibodies, were visible in the brains of transgenic mice. Of the MAPK family, both JNK and p38 were activated in the brains of transgenic mice, whereas there was no significant activation of the ERK. In parallel, tau phosphorylation was also enhanced in the transgenic relative to the control mice. Moreover, the Cox-2 levels, from Western blot and immunostaining, were increased in the brains of the transgenic line. Furthermore, there were significant caspase-3- and TUNEL-stained nuclei in the transgenic line compared to the age-matched control mice. Thus, these results suggest that NSE-controlled APPsw transgenic mice appear to be a more relevant model in neuropathological phenotypes of AD, and thus could be useful in developing new therapeutic treatments for targeting the aberrant phenotypes that appear in these mice.

Neurones treated with cyclo-oxygenase-1 inhibitors are resistant to amyloid-β1-42

Epidemiological studies have shown that the risk of developing Alzheimer's disease is reduced by the chronic use of classical non-steroidal anti-inflammatory drugs (NSAIDs), drugs that inhibit the cyclo-oxygenase (COX) enzymes that convert arachidonic acid to prostaglandins. In the present study, human SH-SY5Y neuroblastoma cells or murine primary cortical neurones treated with NSAIDs were protected against the otherwise toxic effects of amyloid-beta1-42. COX-1 selective inhibitors provided greater protection than did COX-2 selective inhibitors or lipoxygenase inhibitors, suggesting that activation of COX-1 is required for amyloid-beta1-42-induced neurotoxicity. Although the production of neuronal prostaglandin E2 in response to amyloid-beta1-42 was reduced by the presence of COX-1 inhibitors, no neurotoxic effects of prostaglandin E2, or any other prostaglandin, were observed.

Neuroinflammation and anti-inflammatory therapy for Alzheimer's disease

Neuroinflammation is now recognized as a prominent feature in Alzheimer's pathology and a potential target for therapy aimed at treatment and prevention of disease. This review provides a synopsis of current information about cellular and molecular mediators involved in Alzheimer's neuroinflammation as well as interactions between these mediators that influence pathology. Anti-inflammatory therapies, particularly nonsteroidal anti-inflammatory drugs, are considered from experimental and clinical perspectives and potential mechanisms underlying their apparent benefits are discussed. Finally, possible protective effects of the inflammatory response in Alzheimer's are described. Taken all together, evidence presented in this review suggests a scheme for Alzheimer's pathogenesis, with neuroinflammation playing a crucial role influencing and linking beta-amyloid deposition to neuronal damage and clinical disease.

Local neuroinflammation and the progression of Alzheimer's disease

Postmortem immunohistochemical studies have revealed a state of chronic inflammation limited to lesioned areas of brain in Alzheimer's disease. Some key actors in this inflammation are activated microglia (brain macrophages), proteins of the classical complement cascade, the pentraxins, cytokines, and chemokines. The inflammation does not involve the adaptive immune system or peripheral organs, but is rather due to the phylogenetically much older innate immune system, which appears to operate in most tissues of the body. Chronic inflammation can damage host tissue and the brain may be particularly vulnerable because of the postmitotic nature of neurons. Many of the inflammatory mediators have been shown to be locally produced and selectively elevated in affected regions of Alzheimer's brain. Moreover, studies of tissue in such degenerative processes as atherosclerosis and infarcted heart suggest a similar local innate immune reaction may be important in such conditions. Much epidemiological and limited clinical evidence suggests that nonsteroidal anti-inflammatory drugs may impede the onset and slow the progression of Alzheimer's disease. But these drugs strike at the periphery of the inflammatory reaction. Much better results might be obtained if drugs were found that could inhibit the activation of microglia or the complement system in brain, and combinations of drugs aimed at different inflammatory targets might be much more effective than single agents.

Risk factors for Alzheimer's disease: role of multiple antioxidants, non-steroidal anti-inflammatory and cholinergic agents alone or in combination in prevention and treatment

The etiology of Alzheimer's disease (AD) is not well understood. Etiologic factors, chronic inflammatory reactions, oxidative and nitrosylative stresses and high cholesterol levels are thought to be important for initiating and promoting neurodegenerative changes commonly found in AD brains. Even in familial AD, oxidative stress plays an important role in the early onset of the disease. Mitochondrial damage and proteasome inhibition represent early events in the pathogenesis of AD, whereas increased processing of amyloid precursor protein (APP) to beta-amyloid (Abeta) fragments (Abeta(40) and Abeta(42)) and formation of senile plaques and neurofibrillary tangles (NFTs) represent late events. We propose a hypothesis that in idiopathic AD, epigenetic components of neurons such as mitochondria, proteasomes and post-translation protein modifications (processing of amyloid precursor protein to beta-amyloid and hyperphosphorylation of tau), rather than nuclear genes, are the primary targets for the action of diverse groups of neurotoxins. Based on epidemiologic, laboratory and limited clinical studies, we propose that a combination of non steroidal anti-inflammatory drugs (NSAIDs) and appropriate levels and types of multiple micronutrients, including antioxidants, may be more effective than the individual agents in the prevention, and they, in combination with a cholinergic agent, may be more effective in the treatment of AD than the individual agents alone. In addition, agents, which can prevent formation of plaques or dissolve these plaques may further enhance the efficacy of our proposed treatment strategy.

Cyclo-oxygenase inhibitors protect against prion-induced neurotoxicity in vitro

The mechanisms of neuronal loss during the course of the prion diseases are not fully understood. In this study, neurones treated with certain non-steroidal anti-inflammatory drugs (NSAIDs) were protected against the otherwise toxic effects of a peptide derived from the prion protein, or extracts containing infectious prions (PrP ). These NSAIDs inhibit the cyclo-oxygenase (cox) enzymes that metabolise arachidonic acid to prostaglandins (PG). Conversely, drugs that inhibited the metabolism of arachidonic acid to leucotrienes enhanced neurotoxicity. Studies with selective inhibitors highlighted the importance of the cox-1 isoform in prion-induced neurotoxicity. The cox-1 inhibitors also inhibited neuronal PGE production and protected both neuroblastoma cells and primary cortical neurones against prions. They also reduced microglia-mediated killing of prion-treated neurones.

Inflammatory processes in amyotrophic lateral sclerosis

Neuroinflammation is a characteristic of pathologically affected tissue in several neurodegenerative disorders. These changes can be observed in the brainstem and spinal cord of amyotrophic lateral sclerosis (ALS) cases and in mouse models of the disease. They include an accumulation of large numbers of activated microglia and astrocytes, as well as small numbers of T cells, mostly adhering to postcapillary venules. Accompanying biochemical alterations include the appearance of numerous molecules characteristic of free-radical attack, the occurrence of proteins associated with activation of the complement cascade, and a sharp upregulation of the enzyme cyclooxygenase 2 (COX-2). Anti-inflammatory agents may have a role to play in treating ALS. COX-2 is a particularly attractive target because of its marked increase in ALS spinal cord.

Prevention of brain aging and dementia

The brain is subjected to multiple factors that result in damage to its cellular constituents, the neuron and supporting cells, and the neural networks that form the bases of cognitive ability. Like other systems, the brain has remarkable capacity to repair that damage and to adapt or compensate for the loss of neurons and the disruption of the neural architecture. Brain aging and dementia can be conceptualized as a balance between neuronal injury and repair. This balance can be affected not only by genetic and age-related factors but also by multiple environmental factors. The latter includes many factors, including education, nutrition, exercise, socialization, and stress. As individuals, we have the potential to modify these factors through lifestyle choices. Advances in neuroscience have led to the development of pharmacologic agents that can ameliorate the effects of even genetic (e.g., statins and antihypertensive agents) and age-related (e.g., antioxidants and estrogen replacement) factors. By altering the balance between neuronal injury and repair, we can delay the expression and progression of the neurodegenerative processes of brain aging, AD, and related dementias.

Cyclin D1 and cyclin E are co-localized with cyclo-oxygenase 2 (COX-2) in pyramidal neurons in Alzheimer disease temporal cortex

Regular use of non-steroidal anti-inflammatory drugs (NSAIDs) seems to reduce the progression of several diseases, including colon cancer, lung cancer, breast cancer and Alzheimer disease (AD). Several studies have shown that NSAIDs can modulate cell cycle progression, especially in the G0/G1 phase. The main target of most NSAIDs is the enzyme cyclo-oxygenase (COX), which occurs in 2 isoforms, COX-1 and COX-2. In AD and non-demented control brain, COX-2 is expressed in neuronal cells. In this study the expression of COX-2, cyclin D1, and cyclin E was investigated at the immunohistochemical level in AD and non-demented control temporal cortex. COX-2, cyclin D1, and cyclin E expression was detected in pyramidal neurons in both AD and control patients. The number of COX-2-immunoreactive neurons positively correlated with the number of cyclin E- and cyclin D1-immunoreactive neurons. Moreover, immunostaining of sequential tissue sections and double immunofluorescence labeling revealed co-expression of COX-2 and cyclin D1 and E in neuronal cells. In addition, an inverse correlation was observed between the neuronal expression of COX-2 and cyclin E and the Braak score for amyloid beta deposits. Our findings suggest a relationship between the neuronal expression of COX-2 and cell cycle markers, which may be involved early in AD pathology.

Innate immunity, local inflammation, and degenerative disease

The brain lesions associated with Alzheimer's disease (AD), which are referred to as neurofibrillary tangles and senile plaques, are characterized by the presence of a broad spectrum of inflammatory mediators. Surprisingly, these mediators, which include complement proteins, inflammatory cytokines, prostaglandins, and acute phase reactants such as C-reactive protein and amyloid P, are produced by resident brain cells, including neurons. Although secondary to the fundamental pathology caused by the presence of tangles and plaques, there is strong evidence that inflammation exacerbates the neuronal loss. In particular, AD lesions show evidence of self-attack by the complement system--a part of the immune system that normally functions to rid the body of invading pathogens. However, the lesions are devoid of significant T cell infiltration, a hallmark of an inflammatory immune response, and antibodies. We define this phenomenon as autotoxicity to distinguish it from classical autoimmunity, in which the body raises antibodies to normal endogenous macromolecules. Locally produced inflammatory mediators have also been identified in atherosclerotic plaques, along with evidence of complement self-attack. As was previously shown for heart attacks, epidemiological evidence indicates that extended use of nonsteroidal anti-inflammatory drugs (NSAIDs) results in a reduced risk of AD. NSAIDs inhibit the production of prostaglandin inflammatory mediators, but powerful new therapeutic agents might be developed by targeting more critical inflammatory mechanisms, especially the complement system.

Acetaminophen protects hippocampal neurons and PC12 cultures from amyloid beta-peptides induced oxidative stress and reduces NF-kappaB activation

The present findings show that an atypical non-steroidal anti-inflammatory drug, such as acetaminophen, retains the ability to recover amyloid beta-peptides driven neuronal apoptosis through the impairment of oxidative stress. Moreover, this compound reduces the increased NF-kappaB binding activity, which occurs in these degenerative conditions. Therapeutic interventions aimed at reducing the inflammatory response in Alzheimer's disease (AD) recently suggested the application of non-steroidal anti-inflammatory drugs. Although the anti-inflammatory properties of acetaminophen are controversial, it emerged that in an amyloid-driven astrocytoma cell degeneration model acetaminophen proved to be effective. On these bases, we analyzed the role of acetaminophen against the toxicity exerted by different Abeta-peptides on rat primary hippocampal neurons and on a rat pheochromocytoma cell line. We found a consistent protection from amyloid beta-fragments 1-40 and 1-42-induced impairment of mitochondrial redox activity on both cell cultures, associated with a marked reduction of apoptotic nuclear fragmentation. An antioxidant component of the protective activity emerged from the analysis of the reduction of phospholipid peroxidation, and also from a significant reduction of cytoplasmic accumulation of peroxides in the pheochromocytoma cell line. Moreover, activation of NF-kappaB by amyloid-derived peptides was greatly impaired by acetaminophen pre-treatment in hippocampal cells. This evidence points out antioxidant and anti-transcriptional properties of acetaminophen besides the known capability to interfere with inflammation within the central nervous system, and suggests that it can be exploited as a possible therapeutic approach against AD.

Novel therapeutic strategies provide the real test for the amyloid hypothesis of Alzheimer's disease

The amyloid and tangle cascade hypothesis is the dominant explanation for the pathogenesis of Alzheimer's disease (AD). A complete knowledge of the metabolic pathways leading to beta-amyloid (A beta) production and clearance in vivo and of the pathological events that lead to fibril formation and deposition into plaques is crucial for the development of an 'anti-amyloid' therapeutic strategy. Important advances in this respect have been achieved recently, revealing new candidate drug targets. Among the most promising potential treatments are beta- and gamma-secretase inhibitors, A beta vaccination, Cu-Zn chelators, cholesterol-lowering drugs and non-steroidal anti-inflammatory drugs. Now, the major question is whether these drugs will work in the clinic.

Pain management and beyond: evolving concepts and treatments involving cyclooxygenase inhibition

Chronic uncontrolled pain may be the greatest health care crisis facing the United States. It is the major symptom for which patients seek medical care and is associated with substantial economic and psychosocial costs. For many patients, particularly the elderly and those suffering from cancer, chronic pain is often undertreated. Because pain has an emotional component and is frequently accompanied by depression and/or anxiety, patients benefit from a comprehensive assessment and multidisciplinary approach to treatment. It is likely that coxibs (cyclooxygenase or COX-2-selective inhibitors) will assume an increasingly prominent role in the treatment of chronic pain associated with arthritis, cancer, and other diseases either as monotherapy or in combination with other drugs. In addition, the role of COX-2 inhibition in the prevention and treatment of colon cancer, Alzheimer's disease (AD), and other chronic health problems is an area currently undergoing intense investigation.

The diet-induced proinflammatory state: a cause of chronic pain and other degenerative diseases?

BACKGROUND

It is the rare physician who includes diet therapy and nutritional supplements in patient care. Perhaps this is because chiropractic and medical schools devote very few classroom hours to nutrition. It is also possible that physicians are under the misconception that a detailed biochemical understanding of each individual disease is required before nutritional interventions can be used.

OBJECTIVE

The purpose of this article is two-fold: (1) to demonstrate that chronic pain and other degenerative conditions encountered in clinical practice have similar biochemical etiologies, such as a diet-induced proinflammatory state, and (2) to outline a basic nutritional program that can be used by all practitioners.

DATA SOURCES

The data were accumulated over a period of years by reviewing contemporary articles and books and subsequently by retrieving relevant articles. Articles were also selected through MEDLINE and manual library searches.

RESULTS

The typical American diet is deficient in fruits and vegetables and contains excessive amounts of meat, refined grain products, and dessert foods. Such a diet can have numerous adverse biochemical effects, all of which create a proinflammatory state and predispose the body to degenerative diseases. It appears that an inadequate intake of fruits and vegetables can result in a suboptimal intake of antioxidants and phytochemicals and an imbalanced intake of essential fatty acids. Through different mechanisms, each nutritional alteration can promote inflammation and disease.

CONCLUSION

We can no longer view different diseases as distinct biochemical entities. Nearly all degenerative diseases have the same underlying biochemical etiology, that is, a diet-induced proinflammatory state. Although specific diseases may require specific treatments, such as adjustments for hypomobile joints, beta-blockers for hypertension, and chemotherapy for cancer, the treatment program must also include nutritional protocols to reduce the proinflammatory state.

A subset of NSAIDs lower amyloidogenic Abeta42 independently of cyclooxygenase activity

Epidemiological studies have documented a reduced prevalence of Alzheimer's disease among users of nonsteroidal anti-inflammatory drugs (NSAIDs). It has been proposed that NSAIDs exert their beneficial effects in part by reducing neurotoxic inflammatory responses in the brain, although this mechanism has not been proved. Here we report that the NSAIDs ibuprofen, indomethacin and sulindac sulphide preferentially decrease the highly amyloidogenic Abeta42 peptide (the 42-residue isoform of the amyloid-beta peptide) produced from a variety of cultured cells by as much as 80%. This effect was not seen in all NSAIDs and seems not to be mediated by inhibition of cyclooxygenase (COX) activity, the principal pharmacological target of NSAIDs. Furthermore, short-term administration of ibuprofen to mice that produce mutant beta-amyloid precursor protein (APP) lowered their brain levels of Abeta42. In cultured cells, the decrease in Abeta42 secretion was accompanied by an increase in the Abeta(1-38) isoform, indicating that NSAIDs subtly alter gamma-secretase activity without significantly perturbing other APP processing pathways or Notch cleavage. Our findings suggest that NSAIDs directly affect amyloid pathology in the brain by reducing Abeta42 peptide levels independently of COX activity and that this Abeta42-lowering activity could be optimized to selectively target the pathogenic Abeta42 species.

Effects of S-2474, a novel nonsteroidal anti-inflammatory drug, on amyloid beta protein-induced neuronal cell death

1. The accumulation of amyloid beta protein (Abeta) in the brain is a characteristic feature of Alzheimer's disease (AD). Clinical trials of AD patients with nonsteroidal anti-inflammatory drugs (NSAIDs) indicate a clinical benefit. NSAIDs are presumed to act by suppressing inhibiting chronic inflammation in the brain of AD patients. 2. In the present study, we investigated effects of S-2474 on Abeta-induced cell death in primary cultures of rat cortical neurons. 3. S-2474 is a novel NSAID, which inhibits cyclo-oxygenase-2 (COX-2) and contains the di-tert-butylphenol antioxidant moiety. S-2474 significantly prevented neurons from Abeta(25 - 35)- and Abeta(1 - 40)-induced cell death. S-2474 ameliorated Abeta-induced apoptotic features such as the condensation of chromatin and the fragmentation of DNA completely. 4. Prior to cell death, Abeta(25 - 35) generated prostaglandin D(2) (PGD(2)) and free radicals from neurons. PGD(2) is a product of cyclo-oxygenase (COX), and caused neuronal cell death. 5. S-2474 significantly inhibited the Abeta(25 - 35)-induced generation of PGD(2) and free radicals. 6. The present cortical cultures contained little non-neuronal cells, indicating that S-2474 affected neuronal survival directly, but not indirectly via non-neuronal cells. Both an inhibitory effect of COX-2 and an antioxidant effect might contribute to the neuroprotective effects of S-2474. 7. In conclusion, S-2474 exhibits protective effects against neurotoxicity of Abeta. Furthermore, the present study suggests that S-2474 may possess therapeutic potential for AD via ameliorating degeneration in neurons as well as suppressing chronic inflammation in non-neuronal cells.

Expression and function of inducible nitric oxide synthase in neurons

Enzymatically derived nitric oxide (NO) has been implicated in numerous physiological and pathological processes in the brain. Whereas during development NO participates in developmental and maturation processes, excess NO production in the adult in response to inflammation, injury, or trauma participates in both cell death and repair. The expression and activity of the inducible isoform of NO synthase (iNOS) play a pivotal role in sustained and elevated NO release. Recent evidence suggests that neurons can respond to proinflammatory stimuli and take part in brain inflammation. Neuronal iNOS expression has been described in different experimental settings, including cytokine stimulation of neuronal cell lines and primary neurons in vitro as well as in animal models of stroke and neurodegeneration. This article outlines different conditions leading to iNOS gene transcription and expression in neurons and neuronal cells and highlights the potential impact on human brain inflammation and neurodegeneration.