Evaluation of coenzyme Q as an antioxidant strategy for Alzheimer's disease

Role of mitochondria-associated membranes in the hippocampus in the pathogenesis of depression

BACKGROUND

Pathological changes, such as microglia activation in the hippocampus frequently occur in individuals with animal models of depression; however, they may share a common cellular mechanism, such as endoplasmic reticulum (ER) stress and mitochondrial dysfunction. Mitochondria associated membranes (MAMs) are communication platforms between ER and mitochondria. This study aimed to investigate the role of intracellular stress responses, especially structural and functional changes of MAMs in depression.

METHODS

We used chronic social defeat stress (CSDS) to mimic depression in C57 mice to investigate the pathophysiological changes in the hippocampus associated with depression and assess the antidepressant effect of electroacupuncture (EA). Molecular, histological, and electron microscopic techniques were utilized to study intracellular stress responses, including the ER stress pathway reaction, mitochondrial damage, and structural and functional changes in MAMs in the hippocampus after CSDS. Proteomics technology was employed to explore protein-level changes in MAMs caused by CSDS.

RESULTS

CSDS caused mitochondrial dysfunction, ER stress, closer contact between ER and mitochondria, and enrichment of functional protein clusters at MAMs in hippocampus along with depressive-like behaviors. Also, EA showed beneficial effects on intracellular stress responses and depressive-like behaviors in CSDS mice.

LIMITATION

The cellular specificity of MAMs related protein changes in CSDS mice was not explored.

CONCLUSIONS

In the hippocampus, ER stress and mitochondrial damage occur, along with enriched mitochondria-ER interactions and MAM-related protein enrichment, which may contribute to depression's pathophysiology. EA may improve depression by regulating intracellular stress responses.

Involvement of Coenzyme Q10 in Various Neurodegenerative and Psychiatric Diseases

Coenzyme Q10 (CoQ10), commonly known as ubiquinone, is a vitamin-like component generated in mitochondrial inner membranes. This molecule is detected broadly in different parts of the human body in various quantities. This molecule can be absorbed by the digestive system from various nutritional sources as supplements. CoQ10 exists in three states: in a of reduced form (ubiquinol), in a semiquinone radical form, and in oxidized ubiquinone form in different organs of the body, playing a crucial role in electron transportation and contributing to energy metabolism and oxygen utilization, especially in the musculoskeletal and nervous systems. Since the early 1980s, research about CoQ10 has become the interest for two reasons. First, CoQ10 deficiency has been found to have a link with cardiovascular, neurologic, and cancer disorders. Second, this molecule has an antioxidant and free-radical scavenger nature. Since then, several investigations have indicated that the drug may benefit patients with cardiovascular, neuromuscular, and neurodegenerative illnesses. CoQ10 may protect the neurological system from degeneration and degradation due to its antioxidant and energy-regulating activity in mitochondria. This agent has shown its efficacy in preventing and treating neurological diseases such as migraine, Parkinson's disease, Alzheimer's disease, Huntington's disease, amyotrophic lateral sclerosis, and Friedreich's ataxia. This study reviews the literature to highlight this agent's potential therapeutic effects in the mentioned neurological disorders.

Antioxidants: an approach for restricting oxidative stress induced neurodegeneration in Alzheimer's disease

Alzheimer's disease (AD) is the leading cause of dementia, affecting millions of people worldwide. Oxidative stress contributes towards induction of neurodegeneration. It is one of the reasons behind initiation and progression of Alzheimer's disease. Understanding of oxidative balance and restoration of oxidative stress has demonstrated its effectiveness in the management of AD. Various natural and synthetic molecules have been found to be effective in different models of AD. Some clinical studies also support the use of antioxidants for prevention of neurodegeneration in AD. In this review we are summarizing the development of antioxidants to restrict oxidative stress induced neurodegeneration in AD.

Coenzyme Q10 and Dementia: A Systematic Review

It is well known that coenzyme Q₁₀ (CoQ₁₀) has important antioxidant properties. Because one of the main mechanisms involved in the pathogenesis of Alzheimer's disease (AD) and other neurodegenerative diseases is oxidative stress, analysis of the concentrations of CoQ₁₀ in different tissues of AD patients and with other dementia syndromes and the possible therapeutic role of CoQ₁₀ in AD have been addressed in several studies. We performed a systematic review and a meta-analysis of these studies measuring tissue CoQ₁₀ levels in patients with dementia and controls which showed that, compared with controls, AD patients had similar serum/plasma CoQ₁₀ levels. We also revised the possible therapeutic effects of CoQ₁₀ in experimental models of AD and other dementias (which showed important neuroprotective effects of coenzyme Q₁₀) and in humans with AD, other dementias, and mild cognitive impairment (with inconclusive results). The potential role of CoQ₁₀ treatment in AD and in improving memory in aged rodents shown in experimental models deserves future studies in patients with AD, other causes of dementia, and mild cognitive impairment.

Non-Enzymatic Antioxidants against Alzheimer's Disease: Prevention, Diagnosis and Therapy

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by progressive memory loss and cognitive decline. Although substantial research has been conducted to elucidate the complex pathophysiology of AD, the therapeutic approach still has limited efficacy in clinical practice. Oxidative stress (OS) has been established as an early driver of several age-related diseases, including neurodegeneration. In AD, increased levels of reactive oxygen species mediate neuronal lipid, protein, and nucleic acid peroxidation, mitochondrial dysfunction, synaptic damage, and inflammation. Thus, the identification of novel antioxidant molecules capable of detecting, preventing, and counteracting AD onset and progression is of the utmost importance. However, although several studies have been published, comprehensive and up-to-date overviews of the principal anti-AD agents harboring antioxidant properties remain scarce. In this narrative review, we summarize the role of vitamins, minerals, flavonoids, non-flavonoids, mitochondria-targeting molecules, organosulfur compounds, and carotenoids as non-enzymatic antioxidants with AD diagnostic, preventative, and therapeutic potential, thereby offering insights into the relationship between OS and neurodegeneration.

Assessing Cellular Uptake of Exogenous Coenzyme Q10 into Human Skin Cells by X-ray Fluorescence Imaging

X-ray fluorescence (XRF) imaging is a highly sensitive non-invasive imaging method for detection of small element quantities in objects, from human-sized scales down to single-cell organelles, using various X-ray beam sizes. Our aim was to investigate the cellular uptake and distribution of Q₁₀, a highly conserved coenzyme with antioxidant and bioenergetic properties. Q₁₀ was labeled with iodine (I₂-Q₁₀) and individual primary human skin cells were scanned with nano-focused beams. Distribution of I₂-Q₁₀ molecules taken up inside the screened individual skin cells was measured, with a clear correlation between individual Q₁₀ uptake and cell size. Experiments revealed that labeling Q₁₀ with iodine causes no artificial side effects as a result of the labeling procedure itself, and thus is a perfect means of investigating bioavailability and distribution of Q₁₀ in cells. In summary, individual cellular Q₁₀ uptake was demonstrated by XRF, opening the path towards Q₁₀ multi-scale tracking for biodistribution studies.

Cytokine profile and cholesterol levels in patients with Niemann-Pick type C disease presenting neurological symptoms: The in vivo effect of miglustat and the in vitro effect of N-acetylcysteine and Coenzyme Q10

Niemann Pick type C is an inborn error of metabolism (IEM), classified as a lysosomal storage disease (LSD) caused by a dysfunction in NPC transport protein, that leads to intracellular accumulation of non-esterified cholesterol and other lipids. Clinical manifestations are ample, with visceral and neurological symptoms. Miglustat, a molecule that reversibly inhibits glucosylceramide synthase is used as treatment for this disorder. Studies demonstrated the influence of oxidative stress and inflammation in IEM, as well in animal model of NP-C disease. Nonetheless, literature lacks data on patients, so our work aimed to investigate if there is influence of chronic inflammation in the pathophysiology of NP-C disease, and the effect of miglustat, N-acetylcysteine (NAC) and Coenzyme Q10 (CoQ10). We evaluated the plasmatic cytokines in NPC patients at diagnosis and during the treatment with miglustat. Additionally, we performed an in vitro study with antioxidants NAC (1 mM and 2.5 mM) and CoQ10 (5 μM and 10 μM), where we could verify its effect on inflammatory parameters, as well as in cholesterol accumulation. Our results showed that NP-C patients have higher plasmatic levels of pro and anti-inflammatory cytokines (IL-6, IL-8, and IL-10) at diagnosis and the treatment with miglustat was able to restore it. In vitro study showed that treatment with antioxidants in higher concentrations significantly decrease cholesterol accumulation, and NAC at 2.5 mM normalized the level of pro-inflammatory cytokines. Although the mechanism is not completely clear, it can be related to restoration in lipid traffic and decrease in oxidative stress caused by antioxidants.

Reactive Oxygen Species: Angels and Demons in the Life of a Neuron

Reactive oxygen species (ROS) have emerged as regulators of key processes supporting neuronal growth, function, and plasticity across lifespan. At normal physiological levels, ROS perform important roles as secondary messengers in diverse molecular processes such as regulating neuronal differentiation, polarization, synapse maturation, and neurotransmission. In contrast, high levels of ROS are toxic and can ultimately lead to cell death. Excitable cells, such as neurons, often require high levels of metabolic activity to perform their functions. As a consequence, these cells are more likely to produce high levels of ROS, potentially enhancing their susceptibility to oxidative damage. In addition, because neurons are generally post-mitotic, they may be subject to accumulating oxidative damage. Thus, maintaining tight control over ROS concentration in the nervous system is essential for proper neuronal development and function. We are developing a more complete understanding of the cellular and molecular mechanisms for control of ROS in these processes. This review focuses on ROS regulation of the developmental and functional properties of neurons, highlighting recent in vivo studies. We also discuss the current evidence linking oxidative damage to pathological conditions associated with neurodevelopmental and neurodegenerative disorders.

Mechanistic Link between Vitamin B12 and Alzheimer's Disease

Alzheimer's disease (AD) is the most common form of dementia in the elderly population, affecting over 55 million people worldwide. Histopathological hallmarks of this multifactorial disease are an increased plaque burden and tangles in the brains of affected individuals. Several lines of evidence indicate that B12 hypovitaminosis is linked to AD. In this review, the biochemical pathways involved in AD that are affected by vitamin B12, focusing on APP processing, Aβ fibrillization, Aβ-induced oxidative damage as well as tau hyperphosphorylation and tau aggregation, are summarized. Besides the mechanistic link, an overview of clinical studies utilizing vitamin B supplementation are given, and a potential link between diseases and medication resulting in a reduced vitamin B12 level and AD are discussed. Besides the disease-mediated B12 hypovitaminosis, the reduction in vitamin B12 levels caused by an increasing change in dietary preferences has been gaining in relevance. In particular, vegetarian and vegan diets are associated with vitamin B12 deficiency, and therefore might have potential implications for AD. In conclusion, our review emphasizes the important role of vitamin B12 in AD, which is particularly important, as even in industrialized countries a large proportion of the population might not be sufficiently supplied with vitamin B12.

Coenzyme Q10 effects in neurological diseases

Coenzyme Q10 (CoQ10), a lipophilic substituted benzoquinone, is present in animal and plant cells. It is endogenously synthetized in every cell and involved in a variety of cellular processes. CoQ10 is an obligatory component of the respiratory chain in inner mitochondrial membrane. In addition, the presence of CoQ10 in all cellular membranes and in blood. It is the only endogenous lipid antioxidant. Moreover, it is an essential factor for uncoupling protein and controls the permeability transition pore in mitochondria. It also participates in extramitochondrial electron transport and controls membrane physicochemical properties. CoQ10 effects on gene expression might affect the overall metabolism. Primary changes in the energetic and antioxidant functions can explain its remedial effects. CoQ10 supplementation is safe and well-tolerated, even at high doses. CoQ10 does not cause any serious adverse effects in humans or experimental animals. New preparations of CoQ10 that are less hydrophobic and structural derivatives, like idebenone and MitoQ, are being developed to increase absorption and tissue distribution. The review aims to summarize clinical and experimental effects of CoQ10 supplementations in some neurological diseases such as migraine, Parkinson´s disease, Huntington´s disease, Alzheimer´s disease, amyotrophic lateral sclerosis, Friedreich´s ataxia or multiple sclerosis. Cardiovascular hypertension was included because of its central mechanisms controlling blood pressure in the brainstem rostral ventrolateral medulla and hypothalamic paraventricular nucleus. In conclusion, it seems reasonable to recommend CoQ10 as adjunct to conventional therapy in some cases. However, sometimes CoQ10 supplementations are more efficient in animal models of diseases than in human patients (e.g. Parkinson´s disease) or rather vague (e.g. Friedreich´s ataxia or amyotrophic lateral sclerosis).

The influence of vinpocetine alone or in combination with Epigallocatechin-3-gallate, Coenzyme COQ10, Vitamin E and Selenium as a potential neuroprotective combination against aluminium-induced Alzheimer's disease in Wistar Albino Rats

Alzheimer's disease (AD) is one of such diseases that represent the most prominent cause of dementia in elderly people. To explore the possible neuroprotective effect as well as mechanism of action of Vinpocetine either alone or in combination with EGCG, CoQ10, or VE & Se in ameliorating aluminum chloride-induced AD in rats. Rats were received AlCl₃ (70 mg/kg) intraperitoneal daily dose for 30 days along with EGCG (10 mg/kg, I.P), CoQ10 (200 mg/kg, P.O), VE (100 mg/kg, P.O) & Se (1 mg/kg, P.O) as well as Vinpocetine (20 mg/kg, P.O) either alone or in combination. Results revealed that the combination of Vinpocetine with EGCG showed the best neuroprotection. This protection in the brain was indicated by the significant decrease in Aβ and ACHE. The same pattern of results were shown in the levels of monoamines and BDNF. In addition, the combination of Vinpocetine with EGCG showed more pronounced anti-inflammatory (TNF-α, IL-1β) and antioxidant (MDA, SOD, TAC) effects in comparison to other combinations. These results were confirmed using histopathological examinations as well as DNA fragmentation assays. Vinpocetine with EGCG showed pronounced protection on neurons against AD induced by AlCl₃ in rats.

Coenzyme Q10 a mitochondrial restorer for various brain disorders

Coenzyme Q10 (ubiquinone or CoQ10) is a lipid molecule that acts as an electron mobile carrier of the electron transport chain and also contains antioxidant properties. Supplementation of CoQ10 has been very useful to treat mitochondrial diseases. CoQ10 along with its synthetic analogue, idebenone, is used largely to treat various neurodegenerative diseases including Alzheimer's disease, Parkinson's disease, Huntington's disease, Amyotrophic lateral sclerosis, and Friedreich's ataxia and additional brain disease condition like autism, multiple sclerosis, epilepsy, depression, and bipolar disorder, which are related to mitochondrial impairment. In this article, we have reviewed numerous physiological functions of CoQ10 and the rationale for its use in clinical practice in different brain disorders.

Ubisol-Q10, a Nanomicellar and Water-Dispersible Formulation of Coenzyme-Q10 as a Potential Treatment for Alzheimer's and Parkinson's Disease

The world continues a desperate search for therapies that could bring hope and relief to millions suffering from progressive neurodegenerative diseases such as Alzheimer’s (AD) and Parkinson’s (PD). With oxidative stress thought to be a core stressor, interests have long been focused on applying redox therapies including coenzyme-Q₁₀. Therapeutic use has failed to show efficacy in human clinical trials due to poor bioavailability of this lipophilic compound. A nanomicellar, water-dispersible formulation of coenzyme-Q₁₀, Ubisol-Q₁₀, has been developed by combining coenzyme-Q₁₀ with an amphiphilic, self-emulsifying molecule of polyoxyethanyl α-tocopheryl sebacate (derivatized vitamin E). This discovery made possible, for the first time, a proper assessment of the true therapeutic value of coenzyme-Q₁₀. Micromolar concentrations of Ubisol-Q₁₀ show unprecedented neuroprotection against neurotoxin exposure in in vitro and in vivo models of neurodegeneration and was extremely effective when delivered either prior to, at the time of, and most significantly, post-neurotoxin exposure. These findings indicate a possible way forward for clinical development due to effective doses well within Federal Drug Administration guidelines. Ubisol-Q₁₀ is a potent mobilizer of astroglia, antioxidant, senescence preventer, autophagy activator, anti-inflammatory, and mitochondrial stabilizer. Here we summarize the work with oil-soluble coenzyme-Q₁₀, its limitations, and focus mainly on efficacy of water-soluble coenzyme-Q₁₀ in neurodegeneration.

Secondary coenzyme Q deficiency in neurological disorders

Coenzyme Q (CoQ) is a ubiquitous lipid serving essential cellular functions. It is the only component of the mitochondrial respiratory chain that can be exogenously absorbed. Here, we provide an overview of current knowledge, controversies, and open questions about CoQ intracellular and tissue distribution, in particular in brain and skeletal muscle. We discuss human neurological diseases and mouse models associated with secondary CoQ deficiency in these tissues and highlight pharmacokinetic and anatomical challenges in exogenous CoQ biodistribution, recent improvements in CoQ formulations and imaging, as well as alternative therapeutical strategies to CoQ supplementation. The last section proposes possible mechanisms underlying secondary CoQ deficiency in human diseases with emphasis on neurological and neuromuscular disorders.

Leveraging functional annotation to identify genes associated with complex diseases

To increase statistical power to identify genes associated with complex traits, a number of transcriptome-wide association study (TWAS) methods have been proposed using gene expression as a mediating trait linking genetic variations and diseases. These methods first predict expression levels based on inferred expression quantitative trait loci (eQTLs) and then identify expression-mediated genetic effects on diseases by associating phenotypes with predicted expression levels. The success of these methods critically depends on the identification of eQTLs, which may not be functional in the corresponding tissue, due to linkage disequilibrium (LD) and the correlation of gene expression between tissues. Here, we introduce a new method called T-GEN (Transcriptome-mediated identification of disease-associated Genes with Epigenetic aNnotation) to identify disease-associated genes leveraging epigenetic information. Through prioritizing SNPs with tissue-specific epigenetic annotation, T-GEN can better identify SNPs that are both statistically predictive and biologically functional. We found that a significantly higher percentage (an increase of 18.7% to 47.2%) of eQTLs identified by T-GEN are inferred to be functional by ChromHMM and more are deleterious based on their Combined Annotation Dependent Depletion (CADD) scores. Applying T-GEN to 207 complex traits, we were able to identify more trait-associated genes (ranging from 7.7% to 102%) than those from existing methods. Among the identified genes associated with these traits, T-GEN can better identify genes with high (>0.99) pLI scores compared to other methods. When T-GEN was applied to late-onset Alzheimer's disease, we identified 96 genes located at 15 loci, including two novel loci not implicated in previous GWAS. We further replicated 50 genes in an independent GWAS, including one of the two novel loci.

Combination of Omega 3 and Coenzyme Q10 Exerts Neuroprotective Potential Against Hypercholesterolemia-Induced Alzheimer's-Like Disease in Rats

Alzheimer's disease (AD) is the most common form of dementia that progressively disrupts neurocognitive function, which has neither cure nor effective treatment. Hypercholesterolemia might be involved in brain alterations that could evolve into AD. The present study aims to evaluate the potential of omega-3, Co-enzyme Q10 (Co-Q10), as well as their combination in ameliorating hypercholesterolemia-initiated AD-like disease. We adapted a hypercholesterolemic (HC) rat model, a model of oxidative stress-mediated neurodegeneration, to study AD-like pathology. Hypercholesterolemia resulted in increased lipid peroxidation coupled with declined nitric oxide production, reduced glutathione levels, and decreased antioxidant activities of glutathione-s-transferase (GST) and glutathione peroxidase (GSH-Px) in the brain. Moreover, hypercholesterolemia resulted in decreased acetylcholine (ACh) levels and increased acetylcholine-esterase (AChE) activity, along with an increment of tumor necrosis factor and amyloid-β 42. Behaviorally, HC-rats demonstrated depressive-like behavior and declined memory. Treatment of HC-rats with omega-3 and Co-Q10 (alone or in combination) alleviated the brain oxidative stress and inflammation, regulated cholinergic functioning, and enhanced the functional outcome. These findings were verified by the histopathological investigation of brain tissues. This neuroprotective potential of omega-3 and Co-Q10 was achieved through anti-oxidative, anti-inflammatory, anti-amyloidogenic, pro-cholinergic, and memory-enhancing activities against HC-induced AD-like disease; suggesting that they may be useful as prophylactic and therapeutic agents against the neurotoxic effects of hypercholesterolemia.

Alpha lipoic acid and vitamin E improve atorvastatin-induced mitochondrial dysfunctions in rats

To determine the effects of alpha lipoic acid (ALA) and vitamin E (Vit E) on mitochondrial dysfunction caused by statins. A total of 38 Wistar Albino rats were used in this study. The control group received dimethyl sulfoxide. The atorvastatin (A) group received atorvastatin (10 mg/kg). The A + ALA group received atorvastatin (10 mg/kg) and ALA (100 mg/kg). The A + Vit E group was administered atorvastatin (10 mg/kg) and Vit E (100 mg/kg). The A + ALA + Vit E group was administered atorvastatin (10 mg/kg), ALA (100 mg/kg) and Vit E (100 mg/kg). All applications were administered simultaneously by gavage for 20 days. ATP level and complex I activity were measured from liver, muscle, heart, kidney and brain. Atorvastatin significantly decreased the ATP levels in heart and kidney, while a slight decrease was seen in liver, muscle and brain. Atorvastatin caused an insignificant decrease in the complex I activity in all tissues examined. ALA administration significantly improved the ATP levels in the liver, heart and kidney, while Vit E improved the ATP levels in all tissues except the muscle compared to Atorvastatin group. Single administration of both ALA and vit E ameliorated complex I activity in the muscle, heart, kidney and brain. The combination of ALA and Vit E significantly improved the ATP levels in the liver, heart, kidney and brain and also provided significant improvements the complex I activity in all tissues. The undesirable effects of Atorvastatin on mitochondrial functions in this study ameliorated by using ALA and/or Vit E alone and in combination.

Photobiomodulation for Alzheimer's Disease: Has the Light Dawned?

Next to cancer, Alzheimer's disease (AD) and dementia is probably the most worrying health problem facing the Western world today. A large number of clinical trials have failed to show any benefit of the tested drugs in stabilizing or reversing the steady decline in cognitive function that is suffered by dementia patients. Although the pathological features of AD consisting of beta-amyloid plaques and tau tangles are well established, considerable debate exists concerning the genetic or lifestyle factors that predispose individuals to developing dementia. Photobiomodulation (PBM) describes the therapeutic use of red or near-infrared light to stimulate healing, relieve pain and inflammation, and prevent tissue from dying. In recent years PBM has been applied for a diverse range of brain disorders, frequently applied in a non-invasive manner by shining light on the head (transcranial PBM). The present review discusses the mechanisms of action of tPBM in the brain, and summarizes studies that have used tPBM to treat animal models of AD. The results of a limited number of clinical trials that have used tPBM to treat patients with AD and dementia are discussed.

Inferring the Molecular Mechanisms of Noncoding Alzheimer's Disease-Associated Genetic Variants

Most of the loci identified by genome-wide association studies (GWAS) for late-onset Alzheimer's disease (LOAD) are in strong linkage disequilibrium (LD) with nearby variants all of which could be the actual functional variants, often in non-protein-coding regions and implicating underlying gene regulatory mechanisms. We set out to characterize the causal variants, regulatory mechanisms, tissue contexts, and target genes underlying these associations. We applied our INFERNO algorithm to the top 19 non-APOE loci from the IGAP GWAS study. INFERNO annotated all LD-expanded variants at each locus with tissue-specific regulatory activity. Bayesian co-localization analysis of summary statistics and eQTL data was performed to identify tissue-specific target genes. INFERNO identified enhancer dysregulation in all 19 tag regions analyzed, significant enrichments of enhancer overlaps in the immune-related blood category, and co-localized eQTL signals overlapping enhancers from the matching tissue class in ten regions (ABCA7, BIN1, CASS4, CD2AP, CD33, CELF1, CLU, EPHA1, FERMT2, ZCWPW1). In several cases, we identified dysregulation of long noncoding RNA (lncRNA) transcripts and applied the lncRNA target identification algorithm from INFERNO to characterize their downstream biological effects. We also validated the allele-specific effects of several variants on enhancer function using luciferase expression assays. By integrating functional genomics with GWAS signals, our analysis yielded insights into the regulatory mechanisms, tissue contexts, genes, and biological processes affected by noncoding genetic variation associated with LOAD risk.

Imaging mass spectrometry analysis of ubiquinol localization in the mouse brain following short-term administration

We analyzed the localization of ubiquinol, the reduced form of coenzyme Q10 (Re-CoQ10), in mouse brain sections using matrix-assisted laser desorption/ionization Fourier transform ion cyclotron resonance imaging mass spectrometry (IMS) to evaluate the effect of dietary Re-CoQ10 in mouse brain. Mice were orally administered Re-CoQ10 for 14 days and brain Re-CoQ10 content was subsequently quantified using liquid chromatography-mass spectrometry. IMS was employed to visualize Re-CoQ10 at a resolution of 150 μm in the mouse brain. Increased Re-CoQ10 was observed in the corpus callosum, hippocampus, midbrain, cerebellum, brain stem, substantia nigra and striatum. These regions are related to movement, memory and vital life functions. Thus, we demonstrated the effect of Re-CoQ10 administration on the specific localization of Re-CoQ10 in the brain.

Improved photostability and cytotoxic effect of coenzyme Q10 by its association with vitamin E acetate in polymeric nanocapsules

The present study showed the development of nanocapsules containing the association of the coenzyme Q10 and vitamin E acetate and the evaluation of their effect on in vitro cells culture of malignant glioma and melanoma. In order to investigate if nanocapsules are able to protect coenzyme Q10 from degradation under UVC radiation, a photostability study was carried out. For this, three concentrations of vitamin E acetate were evaluated (1%, 2%, or 3%). Nanocapsules presented suitable physicochemical characteristics and were able to protect coenzyme Q10 from photodegradation. In addition, this protection was influenced by higher vitamin E acetate concentrations, attributing to this oil an important role on coenzyme Q10 photostabilization. Regarding to in vitro citotoxicity assay, nanocapsules containing coenzyme Q10 and 2% vitamin E significantly reduced glioma and melanoma cell viability in 61% and 66%, respectively. In this sense, these formulations represent interesting platforms for the delivery of coenzyme Q10 and vitamin E acetate, presenting effect on the reduction of malignant cells viability.

Melatonin prevents mitochondrial dysfunction and promotes neuroprotection by inducing autophagy during oxaliplatin-evoked peripheral neuropathy

Oxaliplatin, an organoplatinum compound, is used in the treatment of colorectal cancer, but its clinical use can be limited due to the development of peripheral neuropathy. Whilst mitochondrial dysfunction has been implicated as a major pathomechanism for oxaliplatin-induced neurotoxicity, the prevention of autophagy may also aggravate neuronal cell death. Melatonin, a well-known mitoprotectant and autophagy inducer, was used to examine its neuroprotective role in oxaliplatin-induced peripheral neuropathy (OIPN). Melatonin prevented the loss of mitochondrial membrane potential (Ψm) and promoted neuritogenesis in oxaliplatin-challenged neuro-2a cells. It did not interfere with the cytotoxic activity of oxaliplatin in human colon cancer cell line, HT-29. Melatonin treatment significantly alleviated oxaliplatin-induced pain behavior and neuropathic deficits in rats. It also ameliorated nitro-oxidative stress mediated by oxaliplatin, thus prevented nitrosylation of proteins and loss of antioxidant enzymes, and therefore, it improved mitochondrial electron transport chain function and maintained cellular bioenergetics by improving the ATP levels. The protective effects of melatonin were attributed to preventing oxaliplatin-induced neuronal apoptosis by increasing the autophagy pathway (via LC3A/3B) in peripheral nerves and dorsal root ganglion (DRG). Hence, it preserved the epidermal nerve fiber density in oxaliplatin-induced neuropathic rats. Taken together, we provide detailed molecular mechanisms for the neuroprotective effect of melatonin and suggest it has translational potential for oxaliplatin-induced neuropathy.

Role of Gasotransmitters in Oxidative Stresses, Neuroinflammation, and Neuronal Repair

To date, three main gasotransmitters, that is, hydrogen sulfide (H₂S), carbon monoxide (CO), and nitric oxide (NO), have been discovered to play major bodily physiological roles. These gasotransmitters have multiple functional roles in the body including physiologic and pathologic functions with respect to the cellular or tissue quantities of these gases. Gasotransmitters were originally known to have only detrimental and noxious effects in the body but that notion has much changed with years; vast studies demonstrated that these gasotransmitters are precisely involved in the normal physiological functioning of the body. From neuromodulation, oxidative stress subjugation, and cardiovascular tone regulation to immunomodulation, these gases perform critical roles, which, should they deviate from the norm, can trigger the genesis of a number of neurodegenerative diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD). The purpose of this review is to discuss at great length physical and chemical properties and physiological actions of H₂S, NO, and CO as well as shedding light on recently researched molecular targets. We particularly put emphasis on the roles in neuronal inflammation and neurodegeneration and neuronal repair.

The effects of coenzyme Q10 supplementation on cardiometabolic markers in overweight type 2 diabetic patients with stable myocardial infarction: A randomized, double-blind, placebo-controlled trial

BACKGROUND

Limited data are present that have assessed the effects of coenzyme Q10 (CoQ10) intake on cardiometabolic markers in type 2 diabetic patients with coronary heart disease (CHD). This study was done to determine the effects of CoQ10 administration on cardiometabolic markers in overweight diabetic patients with stable myocardial infarction.

METHODS

This randomized double-blind placebo-controlled clinical trial was done among 60 diabetic patients with CHD aged 45-75 years old. Subjects were randomly allocated into two groups to receive either 100 mg/day CoQ10 supplements (n = 30) or placebo (n = 30) for 8 weeks.

RESULTS

Compared with the placebo, CoQ10 intake led to a significant reduction in serum interleukin 6 (IL-6) (-1.7 ± 1.6 vs. 0.8 ± 1.7 ng/l, P < 0.001) and protein carbonyl (PCO) levels (-0.2 ± 0.3 vs. 0.1 ± 0.2 nmol/mg protein, P < 0.001). Supplementation with CoQ10 did not affect serum lipoprotein(a), advanced glycation end-products and thiol concentrations compared with the placebo.

CONCLUSION

Overall, this study indicated that CoQ10 intake after 8 weeks among diabetic patients with the stable CHD had beneficial effects on serum IL-6 and PCO levels, but did not alter other cardiometabolic markers.

The influence of common free radicals and antioxidants on development of Alzheimer's Disease

Alzheimer's Disease (AD) is one of the most important neurodegenerative disorders in the 21st century for the continually aging population. Despite an increasing number of patients, there are only few drugs to treat the disease. Numerous studies have shown several causes of the disorder, one of the most important being oxidative stress. Oxidative stress is connected with a disturbance between the levels of free radicals and antioxidants in organisms. Solutions to this problem are antioxidants, which counteract the negative impact of the reactive molecules. Unfortunately, the currently available drugs against AD do not exhibit activity toward these structures. Due to the fact that natural substances are extremely significant in new drug development, numerous studies are focused on substances which exhibit a few activities including antioxidants and other anti-AD behaviors. This review article presents the most important studies connected with the influence of free radicals on development of AD and antioxidants as potential drugs toward AD.

Strategies for oral delivery and mitochondrial targeting of CoQ10

Coenzyme Q10 (CoQ10), also known as ubiquinone or ubidecarenone, is a powerful, endogenously produced, intracellularly existing lipophilic antioxidant. It combats reactive oxygen species (ROS) known to be responsible for a variety of human pathological conditions. Its target site is the inner mitochondrial membrane (IMM) of each cell. In case of deficiency and/or aging, CoQ10 oral supplementation is warranted. However, CoQ10 has low oral bioavailability due to its lipophilic nature, large molecular weight, regional differences in its gastrointestinal permeability and involvement of multitransporters. Intracellular delivery and mitochondrial target ability issues pose additional hurdles. To maximize CoQ10 delivery to its biopharmaceutical target, numerous approaches have been undertaken. The review summaries the current research on CoQ10 bioavailability and highlights the headways to obtain a satisfactory intracellular and targeted mitochondrial delivery. Unresolved questions and research gaps were identified to bring this promising natural product to the forefront of therapeutic agents for treatment of different pathologies.

Coenzyme q10 therapy

For a number of years, coenzyme Q10 (CoQ10) was known for its key role in mitochondrial bioenergetics; later studies demonstrated its presence in other subcellular fractions and in blood plasma, and extensively investigated its antioxidant role. These 2 functions constitute the basis for supporting the clinical use of CoQ10. Also, at the inner mitochondrial membrane level, CoQ10 is recognized as an obligatory cofactor for the function of uncoupling proteins and a modulator of the mitochondrial transition pore. Furthermore, recent data indicate that CoQ10 affects the expression of genes involved in human cell signaling, metabolism and transport, and some of the effects of CoQ10 supplementation may be due to this property. CoQ10 deficiencies are due to autosomal recessive mutations, mitochondrial diseases, aging-related oxidative stress and carcinogenesis processes, and also statin treatment. Many neurodegenerative disorders, diabetes, cancer, and muscular and cardiovascular diseases have been associated with low CoQ10 levels as well as different ataxias and encephalomyopathies. CoQ10 treatment does not cause serious adverse effects in humans and new formulations have been developed that increase CoQ10 absorption and tissue distribution. Oral administration of CoQ10 is a frequent antioxidant strategy in many diseases that may provide a significant symptomatic benefit.

Coenzyme Q10 treatment ameliorates cognitive deficits by modulating mitochondrial functions in surgically induced menopause

The mechanisms associated with cognitive decline in post-menopausal state driven by loss of ovarian function and reduced estrogen levels are not well understood. The aim of the present study is to investigate the role of mitochondrial dysfunctions in cognitive impairment in post-menopausal state and to evaluate the protective effect of Coenzyme Q10 (CoQ10). A significant decline in cognitive functions was observed in mice after four weeks of ovariectomy as assessed by morris water maze and elevated plus maze. Administration of CoQ10 (10 mg/kg body weight, orally) daily for 4 weeks was found to reverse cognitive deficits observed in ovariectomized (Ovx) mice. The activity of mitochondrial electron transport chain components; NADH: cytochrome c reductase, succinate dehydrogenase and cytochrome c oxidase was significantly reduced in the brain of Ovx mice. This was accompanied by higher levels of ROS, protein carbonyls, lipid peroxidation, mitochondrial swelling and reduced activity of aconitase. The levels of GSH were observed to be significantly lowered resulting in reduced redox ratio (GSH/GSSG) in brain of Ovx mice. Activities of antioxidant enzymes; superoxide dismutase and catalase were also found to be reduced in brain of Ovx animals. CoQ10 supplementation to Ovx mice mitigated the mitochondrial dysfunctions and oxidative stress. Thus, the data indicates that CoQ10 improves cognitive decline in post-menopausal state by modulating mitochondrial functions and oxidative stress.

Oxidative stress in Alzheimer's disease

Oxidative stress plays a significant role in the pathogenesis of Alzheimer's disease (AD), a devastating disease of the elderly. The brain is more vulnerable than other organs to oxidative stress, and most of the components of neurons (lipids, proteins, and nucleic acids) can be oxidized in AD due to mitochondrial dysfunction, increased metal levels, inflammation, and β-amyloid (Aβ) peptides. Oxidative stress participates in the development of AD by promoting Aβ deposition, tau hyperphosphorylation, and the subsequent loss of synapses and neurons. The relationship between oxidative stress and AD suggests that oxidative stress is an essential part of the pathological process, and antioxidants may be useful for AD treatment.

Pharmacologic Approaches to the Aging Athlete

As America’s baby boomer population matures, there is an increasing interest in supplements that can delay or oppose the aging process. This antiaging movement has exploded over the past decade. While most supplements are not supported by scientific literature or government controls, a number of products have been the subject of significant scientific inquiry. Hormone replacement therapy, including testosterone and growth hormone, has mixed results, and antioxidative strategies are supported by basic science but lack clinical evidence-based outcomes. While the process of aging has become better understood leading to more rational approaches to combat its effects on health, the clinician is reminded to carefully discern between the science and marketing that is available in this area.

Mitochondrial dysfunction in psychiatric and neurological diseases: cause(s), consequence(s), and implications of antioxidant therapy

Mitochondrial dysfunction is at the base of development and progression of several psychiatric and neurologic diseases with different etiologies. MtDNA/nDNA mutational damage, failure of endogenous antioxidant defenses, hormonal malfunction, altered membrane permeability, metabolic dysregulation, disruption of calcium buffering capacity and ageing have been found to be the root causes of mitochondrial dysfunction in psychatric and neurodegenerative diseases. However, the overall consequences of mitochondrial dysfunction are only limited to increase in oxidative/nitrosative stress and cellular energy crises. Thus far, extensive efforts have been made to improve mitochondrial function through specific cause-dependent antioxidant therapy. However, owing to complex genetic and interlinked causes of mitochondrial dysfunction, it has not been possible to achieve any common, unique supportive antioxidant therapeutic strategy for the treatment of psychiatric and neurologic diseases. Hence, we propose an antioxidant therapeutic strategy for management of consequences of mitochondrial dysfunction in psychiatric and neurologic diseases. It is expected that this will not only reduces oxidative stress, but also promote anaerobic energy production.

Drug development for rare mitochondrial disorders

Currently, all treatment of mitochondrial disorders is performed with dietary supplements or by off-label use of drugs approved for other indications. The present challenge is translation of our collective knowledge of the molecular details underlying the pathophysiology of mitochondrial disorders into safe and effective therapies that are approved by the regulatory authorities. Molecular details permit precise diagnoses, but homogeneity is gained at the expense of limiting numbers of subjects for clinical trials and of small markets from which to recoup the considerable expense of drug discovery and development. The Food and Drug Administration recognizes that trial designs suitable for common diseases are often not feasible for rare disorders. They have developed a number of programs to facilitate development of novel therapies for such rare diseases, without compromise of regulatory standards. With advances in technology, including the use of biomarkers, replacement therapies and sophisticated trial designs, both biotechnology firms and, increasingly, large integrated pharmaceutical companies, are taking advantage of the opportunities in rare disorders. Precise molecular delineation of pathophysiology and of responsive patients has led to success rates with rare diseases that are significantly greater than those for common disorders. It appears likely, but not yet proven, that this may now be the case for rare mitochondrial disorders as well.

Effects of edaravone on amyloid-β precursor protein processing in SY5Y-APP695 cells

Previous reports have revealed that reactive oxygen species (ROS) is involved in the development of Alzheimer's disease (AD), and recent studies indicate that free radical-generating systems can regulate amyloid-β precursor protein (APP) processing. Edaravone is a novel free radical scavenger currently used to reduce cerebral damages after acute cerebral infarction. In the present study, we used SH-SY5Y cells stably transfected with the human "Swedish" APP mutation APP695 (SY5Y-APP695swe) as an in vitro model to investigate the effect of edaravone on APP processing. The result showed that edaravone treatment for 24 h down-regulated β-amyloid (Aβ) production in a dose-dependent manner. Moreover, edaravone modulated APP processing by increasing α-secretase-derived APP fragments and decreasing β-secretase-derived APP fragments. In addition, the mRNA and protein levels of insulin degrading enzyme (IDE) and neprilysin (NEP), two key Aβ degrading enzymes, were not changed after edaravone administration. Taken together, our data suggested that edaravone played an important role in regulating Aβ production by enhancing the non-amyloidogenic pathway and inhibiting the amyloidogenic pathway. Thus, edaravone may be potentially useful for treating Alzheimer's disease (AD).

Drug pipeline in neurodegeneration based on transgenic mice models of Alzheimer's disease

Alzheimer's disease (AD) is one of the most important neurodegenerative disorders, bringing about huge medical and social burden in the elderly worldwide. Many aspects of its pathogenesis have remained unclear and no effective treatment exists for it. Within the past 20 years, various mice models harboring AD-related human mutations have been produced. These models imitate diverse AD-related pathologies and have been used for basic and therapeutic investigations in AD. In this regard, there are a wide variety of preclinical trials of potential therapeutic modalities using AD mice models which are of paramount importance for future clinical trials and applications. This review summarizes more than 140 substances and treatment modalities being used in transgenic AD mice models from 2001 to 2011. We also discuss advantages and disadvantages of each model to be used in therapeutic development for AD.

Antioxidants for Alzheimer disease: a randomized clinical trial with cerebrospinal fluid biomarker measures

OBJECTIVE

To evaluate whether antioxidant supplements presumed to target specific cellular compartments affected cerebrospinal fluid (CSF) biomarkers.

DESIGN

Double-blind, placebo-controlled clinical trial.

SETTING

Academic medical centers.

PARTICIPANTS

Subjects with mild to moderate Alzheimer disease.

INTERVENTION

Random assignment to treatment for 16 weeks with 800 IU/d of vitamin E (α-tocopherol) plus 500 mg/d of vitamin C plus 900 mg/d of α-lipoic acid (E/C/ALA); 400 mg of coenzyme Q 3 times/d; or placebo.

MAIN OUTCOME MEASURES

Changes from baseline to 16 weeks in CSF biomarkers related to Alzheimer disease and oxidative stress, cognition (Mini-Mental State Examination), and function (Alzheimer's Disease Cooperative Study Activities of Daily Living Scale).

RESULTS

Seventy-eight subjects were randomized; 66 provided serial CSF specimens adequate for biochemical analyses. Study drugs were well tolerated, but accelerated decline in Mini-Mental State Examination scores occurred in the E/C/ALA group, a potential safety concern. Changes in CSF Aβ42, tau, and P-tau(181) levels did not differ between the 3 groups. Cerebrospinal fluid F2-isoprostane levels, an oxidative stress biomarker, decreased on average by 19% from baseline to week 16 in the E/C/ALA group but were unchanged in the other groups.

CONCLUSIONS

Antioxidants did not influence CSF biomarkers related to amyloid or tau pathology. Lowering of CSF F2-isoprostane levels in the E/C/ALA group suggests reduction of oxidative stress in the brain. However, this treatment raised the caution of faster cognitive decline, which would need careful assessment if longer-term clinical trials are conducted.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00117403.

Discovery of Multi-Target Agents for Neurological Diseases via Ligand Design

The incidence of neurological disorders in the developed world is rising in concert with an increase in human life expectancy, due in large part to better nutrition and health care. Even as drug discovery efforts are refocused on these disorders, there has been a dearth in the introduction of new disease-modifying therapies to prevent or delay their onset, or reverse their progression. Mounting evidence points to complex and heterogeneous etiopathologies that underlie these diseases. Therefore, it is unlikely that disorders in this class will be mitigated by any single drug that acts exclusively on a single pathway or target. The rational design of novel drug entities with the ability to simultaneously address multiple drug targets of a complex pathophysiology has recently emerged as a new paradigm in drug discovery. Similarly to the concept of multi-target agents within the psychopharmacology field, ligand design has gained an increasing prominence within the medicinal chemistry community. In this chapter we discuss several examples of select chemical scaffolds (polyamines, alkylxanthines, and propargyl carbamates) wherein these concepts were applied to develop novel drug candidates for Alzheimer's disease and Parkinson's disease.

Ubiquinone-10 in gold-immobilized lipid membrane structures acts as a sensor for acetylcholine and other tetraalkylammonium cations

It is reported that the reduction of ubiquinone incorporated into supported lipid bilayers and into immobilized liposome layers on gold electrodes is kinetically and thermodynamically enhanced by the presence of acetylcholine and tetrabutylammonium (TBA(+)) in solution. The reduction peak and the mid-peak potentials of the redox reactions, determined by cyclic voltammetry, are displaced towards more positive potentials by approximately 500 and 250mV, respectively, in the case of TBA(+); and by approximately 750 and 530mV, respectively, in the case of acetylcholine. The intensity of the signal varies with the cation concentration, allowing for quantitative determinations in the millimolar range. It is proposed that the enhanced reduction of ubiquinone arises from the formation of tetraalkylammonium cation-ubiquinone radical anion ion-pairs. Electrochemical quartz crystal microbalance with dissipation monitoring (EQCM-D) measurements confirmed that the potential shift and the intensity of the redox signal are coupled with the adsorption of the tetraalkylammonium cations on the lipid membrane. The Langmuir adsorption equilibrium constant (K) of TBA(+) on lipid membranes at physiological pH is determined. In supported lipid bilayers K=440.7±160M(-1), while in an immobilized liposome layer K=35.53±3.53M(-1).

Oxidative stress underlying axonal degeneration in adrenoleukodystrophy: a paradigm for multifactorial neurodegenerative diseases?

X-linked adrenoleukodystrophy (X-ALD) is an inherited neurodegenerative disorder expressed as four disease variants characterized by adrenal insufficiency and graded damage in the nervous system. X-ALD is caused by a loss of function of the peroxisomal ABCD1 fatty-acid transporter, resulting in the accumulation of very long chain fatty acids (VLCFA) in the organs and plasma, which have potentially toxic effects in CNS and adrenal glands. We have recently shown that treatment with a combination of antioxidants containing α-tocopherol, N-acetyl-cysteine and α-lipoic acid reversed oxidative damage and energetic failure, together with the axonal degeneration and locomotor impairment displayed by Abcd1 null mice, the animal model of X-ALD. This is the first direct demonstration that oxidative stress, which is a hallmark not only of X-ALD, but also of other neurodegenerative processes, such as Alzheimer's disease (AD), Parkinson's disease (PD) and Huntington's disease (HD), contributes to axonal damage. The purpose of this review is, first, to discuss the molecular and cellular underpinnings of VLCFA-induced oxidative stress, and how it interacts with energy metabolism and/or inflammation to generate a complex syndrome wherein multiple factors are contributing. Particular attention will be paid to the dysregulation of redox homeostasis by the interplay between peroxisomes and mitochondria. Second, we will extend this analysis to the aforementioned neurodegenerative diseases with the aim of defining differences as well as the existence of a core pathogenic mechanism that would justify the exchange of therapeutic opportunities among these pathologies.

Psoriasin (S100A7) increases the expression of ROS and VEGF and acts through RAGE to promote endothelial cell proliferation

Psoriasin (S100A7), originally identified in psoriasis, is a calcium-binding protein belonging to the multigenic S100 family. In high-grade ductal carcinoma in situ, psoriasin was identified as one of the most abundant transcripts. We have previously shown that psoriasin was induced by reactive oxygen species (ROS). Moreover, the downregulation of psoriasin by short hairpin RNA (shRNA) led to the reduced expression of vascular endothelial growth factor (VEGF) and inhibited tumor growth in vivo. The aim of the present study was to investigate whether psoriasin could have direct effects on endothelial cells. In this study we demonstrated that psoriasin increased VEGF expression in mammary epithelial cells. The treatment of endothelial cells with recombinant psoriasin increased proliferation comparable to that of recombinant VEGF protein. No change in proliferation was seen when endothelial cells were infected with psoriasin-expressing adenoviruses, suggesting that the proliferative effect of psoriasin was mediated by a specific receptor. Treatment with sRAGE, targeting the receptor for advanced glycation end products (RAGE), thus inhibited endothelial cell proliferation and tube formation enhanced by recombinant psoriasin. We showed that VEGF expression was not induced by hydrogen peroxide, when psoriasin was silenced by shRNA, which led to the hypothesis that psoriasin induces ROS. Indeed, psoriasin was shown to induce ROS in both endothelial and epithelial cells. Moreover, sRAGE inhibited the psoriasin-dependent generation of ROS in endothelial cells. Finally, treatment with antioxidant Bcl-2 protein abolished the effect of psoriasin on endothelial cell proliferation. Our data suggest that psoriasin expression in mammary epithelial cells leads to increased endothelial cell proliferation in a paracrine manner through RAGE. Psoriasin may therefore play a role in breast cancer progression by promoting oxidative stress response and angiogenesis.

Postprandial antioxidant effect of the Mediterranean diet supplemented with coenzyme Q10 in elderly men and women

Postprandial oxidative stress is characterized by an increased susceptibility of the organism towards oxidative damage after consumption of a meal rich in lipids and/or carbohydrates. We have investigated whether the quality of dietary fat alters postprandial cellular oxidative stress and whether the supplementation with coenzyme Q(10) (CoQ) lowers postprandial oxidative stress in an elderly population. In this randomized crossover study, 20 participants were assigned to receive three isocaloric diets for periods of 4 week each: (1) Mediterranean diet supplemented with CoQ (Med+CoQ diet), (2) Mediterranean diet (Med diet), and (3) saturated fatty acid-rich diet (SFA diet). After a 12-h fast, the volunteers consumed a breakfast with a fat composition similar to that consumed in each of the diets. CoQ, lipid peroxides (LPO), oxidized low-density lipoprotein (oxLDL), protein carbonyl (PC), total nitrite, nitrotyrosine plasma levels, catalase, superoxide dismutase (SOD), and glutathione peroxidase (GPx) activities and ischemic reactive hyperaemia (IRH) were determined. Med diet produced a lower postprandial GPx activity and a lower decrease in total nitrite level compared to the SFA diet. Med and Med+CoQ diets induced a higher postprandial increase in IRH and a lower postprandial LPO, oxLDL, and nitrotyrosine plasma levels than the SFA diet. Moreover, the Med+CoQ diet produced a lower postprandial decrease in total nitrite and a greater decrease in PC levels compared to the other two diets and lower SOD, CAT, and GPx activities than the SFA diet.In conclusion, Med diet reduces postprandial oxidative stress by reducing processes of cellular oxidation and increases the action of the antioxidant system in elderly persons and the administration of CoQ further improves this redox balance.

Antioxidant properties of natural polyphenols and their therapeutic potentials for Alzheimer's disease

Alzheimer's disease (AD) is the most prevalent neurodegenerative disease and most common cause of dementia. However, there is no known way to halt or cure the neurodegenerative disease. Oxidative stress is a cardinal hallmark of the disease and has been considered as therapeutic target for AD treatment. Several factors may contribute to oxidative stress in AD brains. First, mitochondrion is a key player that produces reactive oxygen species (ROS). Mitochondrial dysfunction found in AD patients may exaggerate generation of ROS and oxidative stress. Second, amyloid-beta peptide generates ROS in the presence of metal ions such as Fe(2+) and Cu(2+). Third, activated glial cells in AD brains may produce excessive amount of superoxide and nitric oxide through NADPH oxidase and inducible nitric oxide synthase, respectively. Increased ROS can cause damage to protein, lipid and nucleic acids. Numerous studies demonstrated that natural polyphenolic compounds protect against various neurotoxic insults in vitro and in vivo AD models. In these studies, dietary polyphenolic compounds exhibit neuroprotective effects through scavenging free radicals and increasing antioxidant capacity. Furthermore, they could facilitate the endogenous antioxidant system by stimulating transcription. Some epidemiological and clinical studies highlighted their therapeutic potential for AD treatment. In this review, we will briefly discuss causes of oxidative stress in AD brains, and describe antioxidant neuroprotective effects and therapeutic potential for AD of selected natural polyphenolic compounds.

Frontiers in Alzheimer's disease therapeutics

Alzheimer disease (AD) is a progressive neurodegenerative disease which begins with insidious deterioration of higher cognition and progresses to severe dementia. Clinical symptoms typically involve impairment of memory and at least one other cognitive domain. Because of the exponential increase in the incidence of AD with age, the aging population across the world has seen a congruous increase AD, emphasizing the importance of disease altering therapy. Current therapeutics on the market, including cholinesterase inhibitors and N-methyl-D-aspartate receptor antagonists, provide symptomatic relief but do not alter progression of the disease. Therefore, progress in the areas of prevention and disease modification may be of critical interest. In this review, we summarize novel AD therapeutics that are currently being explored, and also mechanisms of action of specific drugs within the context of current knowledge of AD pathologic pathways.

Neuroprotective strategies involving ROS in Alzheimer disease

Alzheimer disease (AD) is a neurodegenerative disorder in which oxidative stress is a key hallmark. It occurs early in disease pathogenesis and can exacerbate its progression. Several causes of oxidative stress have been determined over the years. First, mitochondria play an important role in the generation and accumulation of free radicals. In addition to mitochondria, inflammation can also induce oxidative damage, especially via microglia, and microglia are also important for Aβ clearance. In AD, both mitochondrial function and inflammatory response are affected, leading to increased ROS formation and oxidative damage to lipid, proteins, and nucleic acids. Some other sources have also been identified. From these findings, various neuroprotective strategies against ROS-mediated damages have been elaborated in AD research. This review recapitulates some of the major strategies used to prevent oxidative stress and disease progression. Outcomes from in vitro and in vivo studies using models of AD are encouraging. However, only a few clinical trials have provided positive results in terms of slowing down cognitive decline. Nonetheless, there is still hope for improved compounds that would better target pathways implicated in ROS production. In fact, facilitating the endogenous antioxidant system by modulating transcription has great promise for AD therapy.

Aging and amyloid beta-induced oxidative DNA damage and mitochondrial dysfunction in Alzheimer's disease: implications for early intervention and therapeutics

Alzheimer's disease (AD) is an age-related progressive neurodegenerative disease affecting thousands of people in the world and effective treatment is still not available. Over two decades of intense research using AD postmortem brains, transgenic mouse and cell models of amyloid precursor protein and tau revealed that amyloid beta (Aβ) and hyperphosphorylated tau are synergistically involved in triggering disease progression. Accumulating evidence also revealed that aging and amyloid beta-induced oxidative DNA damage and mitochondrial dysfunction initiate and contributes to the development and progression of the disease. The purpose of this article is to summarize the latest progress in aging and AD, with a special emphasis on the mitochondria, oxidative DNA damage including methods of its measurement. It also discusses the therapeutic approaches against oxidative DNA damage and treatment strategies in AD.

Phytic acid as a potential treatment for alzheimer's pathology: evidence from animal and in vitro models

Alzheimer's disease (AD) causes progressive, age-dependent cortical and hippocampal dysfunction leading to abnormal intellectual capacity and memory. We propose a novel protective treatment for AD pathology with phytic acid (inositol hexakisphosphate), a phytochemical found in food grains and a key signaling molecule in mammalian cells. We evaluated the protective and beneficial effects of phytic acid against amyloid-β (Aβ) pathology in MC65 cells and the Tg2576 mouse model. In MC65 cells, 48-72-hour treatment with phytic acid provided complete protection against amyloid precursor protein-C-terminal fragment-induced cytotoxicity by attenuating levels of increased intracellular calcium, hydrogen peroxide, superoxide, Aβ oligomers, and moderately upregulated the expression of autophagy (beclin-1) protein. In a tolerance paradigm, wild type mice were treated with 2% phytic acid in drinking water for 70 days. Phytic acid was well tolerated. Ceruloplasmin activity, brain copper and iron levels, and brain superoxide dismutase and ATP levels were unaffected by the treatment. There was a significant increase in brain levels of cytochrome oxidase and a decrease in lipid peroxidation with phytic acid administration. In a treatment paradigm, 12-month old Tg2576 and wild type mice were treated with 2% phytic acid or vehicle for 6 months. Brain levels of copper, iron, and zinc were unaffected. The effects of phytic acid were modest on the expression of AβPP trafficking-associated protein AP180, autophagy-associated proteins (beclin-1, LC3B), sirtuin 1, the ratio of phosphorylated AMP-activated protein kinase (PAMPK) to AMPK, soluble Aβ1-40, and insoluble Aβ1-42. These results suggest that phytic acid may provide a viable treatment option for AD.