Role of free radicals in the neurodegenerative diseases: therapeutic implications for antioxidant treatment

Molecular Mechanisms behind Free Radical Scavengers Function against Oxidative Stress

Accumulating evidence shows that oxidative stress is involved in a wide variety of human diseases: rheumatoid arthritis, Alzheimer's disease, Parkinson's disease, cancers, etc. Here, we discuss the significance of oxidative conditions in different disease, with the focus on neurodegenerative disease including Parkinson's disease, which is mainly caused by oxidative stress. Reactive oxygen and nitrogen species (ROS and RNS, respectively), collectively known as RONS, are produced by cellular enzymes such as myeloperoxidase, NADPH-oxidase (nicotinamide adenine dinucleotide phosphate-oxidase) and nitric oxide synthase (NOS). Natural antioxidant systems are categorized into enzymatic and non-enzymatic antioxidant groups. The former includes a number of enzymes such as catalase and glutathione peroxidase, while the latter contains a number of antioxidants acquired from dietary sources including vitamin C, carotenoids, flavonoids and polyphenols. There are also scavengers used for therapeutic purposes, such as 3,4-dihydroxyphenylalanine (L-DOPA) used routinely in the treatment of Parkinson's disease (not as a free radical scavenger), and 3-methyl-1-phenyl-2-pyrazolin-5-one (Edaravone) that acts as a free radical detoxifier frequently used in acute ischemic stroke. The cell surviving properties of L-DOPA and Edaravone against oxidative stress conditions rely on the alteration of a number of stress proteins such as Annexin A1, Peroxiredoxin-6 and PARK7/DJ-1 (Parkinson disease protein 7, also known as Protein deglycase DJ-1). Although they share the targets in reversing the cytotoxic effects of H₂O₂, they seem to have distinct mechanism of function. Exposure to L-DOPA may result in hypoxia condition and further induction of ORP150 (150-kDa oxygen-regulated protein) with its concomitant cytoprotective effects but Edaravone seems to protect cells via direct induction of Peroxiredoxin-2 and inhibition of apoptosis.

Effect of walnut protein hydrolysate on scopolamine-induced learning and memory deficits in mice

A walnut protein hydrolysate (WPH) was prepared by using a mixture of pancreatin and viscozyme L from industrially available defatted walnut meal. The antioxidant effects of WPH were confirmed and quantified by reducing power, oxygen radical absorbance capacity, hydroxyl radical radical-scavenging activity and ABTS⁺· radical-scavenging activity assays. The protective effects of WPH on scopolamine-induced learning and memory deficits in mice were also evaluated based on in vivo behavioral tests. Results showed that WPH administration would lead to significantly decreased latencies while increased crossing times and target times in the spatial probe test, and increased escape latency and decreased error times in the step-down avoidance test for the scopolamine-induced dementia mice. Biochemical results indicated that the ameliorative effects of WPH on scopolamine-induced dementia mice could be attributed to the significantly increased amount of acetylcholine receptors. Therefore, WPH may be a potential therapeutic agent against Alzheimer's disease.

Identification and Characterization of a Novel Antioxidant Peptide from Bovine Skim Milk Fermented by Lactococcus lactis SL6

A novel peptide having free radical scavenging activity was separated, using an on-line high-performance liquid chromatography (HPLC) - ABTS screening method, from bovine skim milk fermented by Lactococcus lactis SL6 (KCTC 11865BP). It was further purified using reverse phase-HPLC (RP-HPLC) and sequenced by RP-HPLC-tandem mass spectrometry. The amino acid sequence of the identified peptide was determined to be Phe-Ser-Asp-Ile-Pro-Asn-Pro-Ile-Gly-Ser-Glu-Asn-Ser-Glu-Lys-Thr-Thr-Met-Pro-Leu-Trp (2,362 Da), which is corresponding to the C-terminal fragment of bovine α_s1-casein (f179-199). The hydroxyl radicals scavenging activity (IC₅₀ 28.25±0.96 μM) of the peptide chemically synthesized based on the MS/MS data showed a slightly lower than that of the natural antioxidant Trolox (IC₅₀ 15.37±0.52 μM). Furthermore, derivatives of the antioxidant peptide were synthesized. The antioxidative activity of the derivatives whose all three proline residues replaced by alanine significantly decreased, whereas replacement of two proline residues in N-terminal region did not affect its antioxidative activity, indicating that 3^rd proline in C-terminal region is critical for the antioxidative activity of the peptide identified in this study. In addition, N-terminal region of the antioxidant peptide did not show its activity, whereas C-terminal region maintained antioxidative activity, suggesting that C-terminal region of the peptide is important for antioxidative activity.

Increased Oxidative Parameters and Decreased Cytokine Levels in an Animal Model of Attention-Deficit/Hyperactivity Disorder

Attention-deficit/hyperactivity disorder (ADHD) is a highly heterogeneous disorder characterized by impairing levels of hyperactivity, impulsivity and inattention. Oxidative and inflammatory parameters have been recognized among its multiple predisposing pathways, and clinical studies indicate that ADHD patients have increased oxidative stress. In this study, we aimed to evaluate oxidative (DCFH oxidation, glutathione levels, glutathione peroxidase, catalase and superoxide dismutase activities) and inflammatory (TNF-α, IL-1β and IL-10) parameters in the most widely accepted animal model of ADHD, the spontaneously hypertensive rats (SHR). Prefrontal cortex, cortex (remaining regions), striatum and hippocampus of adult male SHR and Wistar Kyoto rats were studied. SHR presented increased reactive oxygen species (ROS) production in the cortex, striatum and hippocampus. In SHR, glutathione peroxidase activity was decreased in the prefrontal cortex and hippocampus. TNF-α levels were reduced in the prefrontal cortex, cortex (remaining regions), hippocampus and striatum of SHR. Besides, IL-1β and IL-10 levels were decreased in the cortex of the ADHD model. Results indicate that SHR presented an oxidative profile that is characterized by an increase in ROS production without an effective antioxidant counterbalance. In addition, this strain showed a decrease in cytokine levels, mainly TNF-α, indicating a basal deficit. These results may present a new approach to the cognitive disturbances seen in the SHR.

Melatonin as a Novel Interventional Candidate for Fragile X Syndrome with Autism Spectrum Disorder in Humans

Fragile X syndrome (FXS) is the most common monogenic form of autism spectrum disorder (ASD). FXS with ASD results from the loss of fragile X mental retardation (fmr) gene products, including fragile X mental retardation protein (FMRP), which triggers a variety of physiological and behavioral abnormalities. This disorder is also correlated with clock components underlying behavioral circadian rhythms and, thus, a mutation of the fmr gene can result in disturbed sleep patterns and altered circadian rhythms. As a result, FXS with ASD individuals may experience dysregulation of melatonin synthesis and alterations in melatonin-dependent signaling pathways that can impair vigilance, learning, and memory abilities, and may be linked to autistic behaviors such as abnormal anxiety responses. Although a wide variety of possible causes, symptoms, and clinical features of ASD have been studied, the correlation between altered circadian rhythms and FXS with ASD has yet to be extensively investigated. Recent studies have highlighted the impact of melatonin on the nervous, immune, and metabolic systems and, even though the utilization of melatonin for sleep dysfunctions in ASD has been considered in clinical research, future studies should investigate its neuroprotective role during the developmental period in individuals with ASD. Thus, the present review focuses on the regulatory circuits involved in the dysregulation of melatonin and disruptions in the circadian system in individuals with FXS with ASD. Additionally, the neuroprotective effects of melatonin intervention therapies, including improvements in neuroplasticity and physical capabilities, are discussed and the molecular mechanisms underlying this disorder are reviewed. The authors suggest that melatonin may be a useful treatment for FXS with ASD in terms of alleviating the adverse effects of variations in the circadian rhythm.

Oxidative stress affects processing of amyloid precursor protein in vascular endothelial cells

BACKGROUND

Oxidative stress is thought to be a key player in the pathogenesis of neurodegenerative dementia, including Alzheimer's disease (AD). It has been assumed that oxidative stress contributes to the ß-amyloid deposition in cerebral blood vessels.

METHODS

In order to prove this hypothesis, we examined the effect of oxidative stress on the processing of amyloid precursor protein (APP) in primary endothelial cells (EC) derived from cerebral cortical tissue of transgenic Tg2576 mice. Following exposure of EC by 1 μM hydrogen peroxide for up to 48 hours, formation and secretion of APP cleavage products sAPPα and sAPPß into the culture medium as well as the expression of endothelial APP were assessed.

RESULTS

Oxidative stress resulted in enhanced secretion of sAPPß into the culture medium as compared to controls (absence of hydrogen peroxide), which was accompanied by an increased APP expression, induction of VEGF synthesis, nitric oxide and oxygen free radicals productions, and differential changes of endothelial phospo-p42/44 MAPK expression.

CONCLUSION

The data suggest that oxidative stress may represent a major risk factor in causing Aß deposition in the brain vascular system by initiating the amyloidogenic route of endothelial APP processing. The enhanced β-secretase activity following oxidative stress exposure, possibly promoted by phosphorylation of p42/44 MAPK.

Protective effect of gallic acid in experimental model of ketamine-induced psychosis: possible behaviour, biochemical, neurochemical and cellular alterations

Gallic acid has been reported to possess a number of psychopharmacological activities. These activities are attributed to the antioxidant potential due to the presence of phenolic moeity. The present study was carried out to investigate the protective effects of gallic acid in an experimental model of ketamine-induced psychosis in mice. Ketamine (50 mg/kg, i.p.) was used to induce stereotyped psychotic behavioural symptoms in mice. Behavioural studies (locomotor activity, stereotype behaviour, immobility duration and memory retention) were carried out to investigate the protective of gallic acid on ketamine-induced psychotic symptoms, followed by biochemical and neurochemical changes and cellular alterations in the brain. Chronic treatment with gallic acid for 15 consecutive days significantly attenuated stereotyped behavioural symptoms in mice. Biochemical estimations revealed that gallic acid reduced the lipid peroxidation and restored the total brain proteins. Furthermore, gallic acid remarkably reduced the dopamine levels, AChE activity and inflammatory surge (serum TNF-α), and increased the levels of GABA and increased glutathione in mice. The study revealed that gallic acid could ameliorate psychotic symptoms and biochemical changes in mice, indicating protective effects in psychosis.

Can Co-Activation of Nrf2 and Neurotrophic Signaling Pathway Slow Alzheimer's Disease?

Alzheimer’s disease (AD) is a multifaceted disease that is hard to treat by single-modal treatment. AD starts with amyloid peptides, mitochondrial dysfunction, and oxidative stress and later is accompanied with chronic endoplasmic reticulum (ER) stress and autophagy dysfunction, resulting in more complicated pathogenesis. Currently, few treatments can modify the complicated pathogenic progress of AD. Compared to the treatment with exogenous antioxidants, the activation of global antioxidant defense system via Nrf2 looks more promising in attenuating oxidative stress in AD brains. Accompanying the activation of the Nrf2-mediated antioxidant defense system that reduce the AD-causative factor, oxidative stress, it is also necessary to activate the neurotrophic signaling pathway that replaces damaged organelles and molecules with new ones. Thus, the dual actions to activate both the Nrf2 antioxidant system and neurotrophic signaling pathway are expected to provide a better strategy to modify AD pathogenesis. Here, we review the current understanding of AD pathogenesis and neuronal defense systems and discuss a possible way to co-activate the Nrf2 antioxidant system and neurotrophic signaling pathway with the hope of helping to find a better strategy to slow AD.

The novel multitarget iron chelating and propargylamine drug M30 affects APP regulation and processing activities in Alzheimer's disease models

In many of the neurodegenerative diseases, such as Alzheimer's disease (AD) and AD-related disorders, as well as in the regular ageing process, excessive generation of oxidative stress (OS) and accumulation of iron levels and deposition have been observed in specific affected-brain regions and thus, regarded as contributing factors to the pathogenesis of the diseases. In AD, iron promotes amyloid β (Aβ) neurotoxicity by producing free radical damage and OS in brain areas affected by neurodegeneration, presumably by facilitating the aggregation of Aβ. In addition, it was shown that iron modulates intracellular levels of the holo amyloid precursor protein (APP) by iron-responsive elements (IRE) RNA stem loops in the 5' untranslated region (5'UTR) of the APP transcript. As a consequence of these observations, iron chelation is one of the major new therapeutic strategies for the treatment of AD. This review describes the benefits and importance of the multimodal brain permeable chimeric iron-chelating/propargylamine drug M30, concerning its neuroprotective/neurorestorative inter-related activities relevant of the pathological features ascribed to AD, with a special focus on the effect of the drug on APP regulation and processing.

Brain iron concentrations in regions of interest and relation with serum iron levels in Parkinson disease

Brain iron has been previously found elevated in the substantia nigra pars compacta (SNpc), but not in other brain regions, of Parkinson's disease (PD) patients. However, iron in circulation has been recently observed to be lower than normal in PD patients. The regional selectivity of iron deposition in brain as well as the relationship between SNpc brain iron and serum iron within PD patients has not been completely elucidated. In this pilot study we measured brain iron in six regions of interest (ROIs) as well as serum iron and serum ferritin, in 24 PD patients and 27 age- gender-matched controls. Brain iron was measured on magnetic resonance imaging (MRI) with a T2 prime (T2') method. Difference in brain iron deposition between PD cases and controls for the six ROIs were calculated. SNpc/white matter brain iron ratios and SNpc/serum iron ratios were calculated for each study participant, and differences between PD patients and controls were tested. PD patients overall had higher brain iron than controls in the SNpc. PD patients had significantly higher SNpc/white matter brain iron ratios than controls, and significantly higher brain SNpc iron/serum iron ratios than controls. These results indicate that PD patients' iron metabolism is disrupted toward a higher partitioning of iron to the brain SNpc at the expenses of iron in the circulation.

Efficacy and safety of S-acyl glutathione 2% cream vs. placebo against UVB-induced erythema: a randomized, double-blinded clinical trial

BACKGROUND

Reactive oxygen species have a major role in the UV-induced short- and long-term damage, thus the exogenous supplementation of antioxidant molecules may allow better skin protection. Despite glutathione has pivotal properties in the complex cytoplasmic antioxidant system, its supplementation is hampered by limited transmembrane absorption. Modification of glutathione pharmacokinetic properties via acetylation with long-chain polyunsaturated fatty acid may improve its passage through phospholipidic membranes.

METHODS

This was a single center randomized double-blinded clinical trial, versus placebo, cross-sectional pairwise at time 0. The participants were 10 healthy volunteers with skin phototypes II or III and age ≥18 years interested in performing minimal erythema dose (MED) evaluation performed by photoallergology unit of Division of Dermatology at P. Palagi Hospital, in Florence. Each volunteer underwent UVB phototesting, treating four different areas with increasing UVB doses in four different conditions. One arm was treated as standard procedure (naïve arm), one applying linolenic-glutathione conjugate (Lin-GSH) cream 2% before irradiation (pre-Lin-GSH arm), one with placebo (placebo arm) and one applying Lin-GSH cream 2% (SoloSale Srl, Florence, Italy) after irradiation (post-Lin-GSH arm). The main endpoint was to evaluate efficacy of Lin-GSH cream 2% before UVB irradiation compared with placebo. A secondary endpoint was the evaluation of the same cream applied after irradiation compared to no treatment. Another secondary objective is the evaluation of safety in both conditions. Mean MED was evaluated at distinct conditions. Safety was evaluated reporting all grade 3-4 adverse events up to 30 days after treatment. All volunteers were treated in all four experimental conditions. The pre-Lin-GSH and placebo arms were applied in a double-blind condition for each volunteer. Neither the volunteer nor the investigator executing MED evaluation knew which arm was given Lin-GSH and which one placebo.

RESULTS

Ten volunteers among 12 recruited for the study were correctly randomized and completed all study evaluations. Recruitment went from April 1st, 2016 to May 1st, 2016, up to adequate population number. Mean MED in pre-Lin-GSH arm was superior to mean MED in placebo arm (135±5.53 mJ/cm2 vs. 105±7.64 mJ/cm2, P=0.0003). No difference was observed among mean MED in post-Lin-GSH and naïve arms. No grade 3-4 adverse events were reported.

CONCLUSIONS

Lin-GSH 2% cream seems a safe and effective in producing a significant increase in MED compared with placebo thanks to its antioxidant properties.

Neuroprotective effect of three caffeic acid derivatives via ameliorate oxidative stress and enhance PKA/CREB signaling pathway

This study was conducted to elucidate the neuroprotective effect of caffeic acid phenethyl ester (CAPE), (R)-2-Hydroxy-3-(3,4-dihydroxyphenyl) propionic acid (Danshensu) and Curcumin, three caffeic acid derivatives which are contained in fruits, grains and certain dietary supplements. Our results showed that these compounds significantly attenuated H₂O₂-induced toxicity in PC12 cells in a dose-dependent manner. Furthermore, these compounds significantly improved the behavioral performance of d-gal-treated mice in both step-down avoidance test and Morris water maze test. Biochemical examination and western blot analysis showed that these compounds could ameliorate oxidative stress and facilitate activation of the protein kinase A (PKA)-cyclic AMP response element-binding protein (CREB) pathway. Its beneficial effects may partly relate to enhancing the activity of endogenous antioxidant enzymes and modulating the PKA/CREB signaling pathway. Furthermore, our results also indicated that the presence of 3, 4-dihydroxyphenyl groups in A ring may enhance their neuroprotective activity.

Metallothionein, Copper and Alpha-Synuclein in Alpha-Synucleinopathies

Metallothioneins (MTs) are proteins that function by metal exchange to regulate the bioavailability of metals, such as zinc and copper. Copper functions in the brain to regulate mitochondria, neurotransmitter production, and cell signaling. Inappropriate copper binding can result in loss of protein function and Cu(I)/(II) redox cycling can generate reactive oxygen species. Copper accumulates in the brain with aging and has been shown to bind alpha-synuclein and initiate its aggregation, the primary aetiological factor in Parkinson's disease (PD), and other alpha-synucleinopathies. In PD, total tissue copper is decreased, including neuromelanin-bound copper and there is a reduction in copper transporter CTR-1. Conversely cerebrospinal fluid (CSF) copper is increased. MT-1/2 expression is increased in activated astrocytes in alpha-synucleinopathies, yet expression of the neuronal MT-3 isoform may be reduced. MTs have been implicated in inflammatory states to perform one-way exchange of copper, releasing free zinc and recent studies have found copper bound to alpha-synuclein is transferred to the MT-3 isoform in vitro and MT-3 is found bound to pathological alpha-synuclein aggregates in the alpha-synucleinopathy, multiple systems atrophy. Moreover, both MT and alpha-synuclein can be released and taken up by neural cells via specific receptors and so may interact both intra- and extra-cellularly. Here, we critically review the role of MTs in copper dyshomeostasis and alpha-synuclein aggregation, and their potential as biomarkers and therapeutic targets.

Neuropsychological state of the population living in the Aral Sea region (zone of ecological crisis)

Background The Aral Sea crisis has led to harmful effects on human habitat. In recent years, mild cognitive impairment is a growing problem. Objectives This article provides the results of studying the neuropsychological state of residents living in the crisis zone of the Aral Sea region in the case of Shalkar city. We have provided an assessment of the neuropsychological state of examined population and determined the leading pathology in this region. Methods The survey sample included 344 persons of reproductive age from 21 to 45 years. We have obtained results in biochemical studies, indicating perturbations of proteometabolism and lipid metabolism. Results A correlation analysis showed dependence between a decrease of albumin and high-density lipoproteins, an increase of low-density lipoproteins and parameters of cognitive function. Conclusions The research suggests a high prevalence of cerebrovascular pathology among the population, changes in cognitive function parameters, long-term and short-term memory problems and high levels of depression.

Thioredoxin 1 modulates apoptosis induced by bioactive compounds in prostate cancer cells

Accumulating evidence suggests that natural bioactive compounds, alone or in combination with traditional chemotherapeutic agents, could be used as potential therapies to fight cancer. In this study, we employed four natural bioactive compounds (curcumin, resveratrol, melatonin, and silibinin) and studied their role in redox control and ability to promote apoptosis in androgen sensitive and insensitive prostate cancer cells. Here is shown that curcumin and resveratrol promote ROS production and induce apoptosis in LNCaP and PC-3. An increase in reactive species is a trigger event in curcumin-induced apoptosis and a consequence of resveratrol effects on other pathways within these cells. Moreover, here we demonstrated that these four compounds affect differently one of the main intracellular redox regulator, the thioredoxin system. Exposure to curcumin and resveratrol promoted TRX1 oxidation and altered its subcellular location. Furthermore, resveratrol diminished TRX1 levels in PC-3 cells and increased the expression of its inhibitor TXNIP. Conversly, melatonin and silibinin only worked as cytostatic agents, reducing ROS levels and showing preventive effects against TRX oxidation. All together, this work explores the effect of compounds currently tested as chemo-preventive agents in prostate cancer therapy, on the TRX1 redox state and function. Our work shows the importance that the TRX system might have within the differences found in their mechanisms of action. These bioactive compounds trigger different responses and affect ROS production and redox systems in prostate cancer cells, suggesting the key role that redox-related pathways might play in processes like differentiation or survival in prostate cancer.

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Resveratrol decreases TRX1 by increasing TXNIP while curcumin induces TRX1 oxidation.

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Antioxidants decrease TRX1 oxidation and nuclear translocation to prevent cell death.

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TRX1 oxidation and nuclear translocation play a key role in apoptosis.

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Differences in the apoptosis induction of bioactive compounds relay on TRX1 oxidation.

Gold nanoparticles prevent cognitive deficits, oxidative stress and inflammation in a rat model of sporadic dementia of Alzheimer's type

Alzheimer's disease (AD) is the most common form of neurodegenerative dementia in the aged brain. Even though its etiology is unknown, factors such as neuroinflammation, mitochondrial dysfunction, formation of reactive oxygen species (ROS), and impaired insulin signaling may play a role. We used a sporadic AD model in rats generated by intracerebroventricular-streptozotocin (i.c.v.-STZ) injection to test the therapeutic effect of gold nanoparticles (GNPs). We tested the null hypothesis that there would be no difference between the STZ+GNPs group and the STZ group in the analyzed markers. We observed that STZ-induced impairment in mitochondrial ATP production, neuroinflammation, and oxidative stress were all prevented by GNP treatment. Moreover, while STZ induced deficits in both spatial and recognition memory, GNPs prevented this effect. These results suggest that GNPs may be considered as a potential treatment for dementias.

Assessment of the Anti-Hyperglycaemic, Anti-Inflammatory and Antioxidant Activities of the Methanol Extract of Moringa Oleifera in Diabetes-Induced Nephrotoxic Male Wistar Rats

Diabetes mellitus is an endocrine disease of multiple aetiologies in insulin secretion. A deficiency in insulin results in hyperglycemia with metabolic disturbances of biomolecules. Moringa oleifera (MO) is endemic in the tropics with a variety of ethnomedicinal importance. The leaf of this plant has been reported to possess antioxidant and medicinal properties that may be helpful in the treatment and management of diabetes and its associated complications. Diabetes was induced intraperitoneally in rats by a single dose of streptozotocin (55 mg/kg) and treated with methanolic extract of Moringa oleifera (250 mg/kg b.wt) for six weeks. Forty-eight (48) adult male Wistar strain rats were randomly divided into four groups: normal control (NC), Moringa oleifera treated control rats (NC + MO), diabetic rats (DM) and Moringa oleifera treated diabetic rats (DM + MO). Estimation of antioxidant capacity, total polyphenols, flavonoids and flavonols content of Moringa oleifera extract was performed and serum biochemical markers were evaluated. Antioxidants such as catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD) activities, glutathione (GSH) and inflammatory biomarkers were determined in the kidney. Results showed high antioxidant capacities of MO extract and improved serum biochemical markers, whilst lipid peroxidation (MDA) levels were reduced in non-diabetic and diabetic rats after MO treatment when compared to normal control. Subsequent administration of MO led to an increased concentration of serum albumin, globulin and total protein with a decrease in the level of MDA, and improvements in CAT, SOD, GSH, GPx, (tumour necrosis factor-alpha)TNF-α and (interleukin-6)IL-6. MO contains potent phytochemical constituents that offer protective action against diabetic-induced renal damage, reactive oxygen species (ROS) and inflammation and could therefore play a role in reducing diabetic complications, particularly in developing countries such as in Africa where the majority cannot afford orthodox medicine.

Dietary habits; concentration of copper, zinc, and Cu-to-Zn ratio in serum and ability status of patients with relapsing-remitting multiple sclerosis

OBJECTIVE

Dietary habits and adequate intake of antioxidants in the diet-for example, copper (Cu) and zinc (Zn)-may be an environmental factor in the occurrence of multiple sclerosis (MS). The aim of this study was to estimate the influence of dietary habits on the concentration of Cu, Zn in the serum, and the effect of Cu-to-Zn ratio on the ability status of patients with relapsing-remitting MS.

METHODS

This was an observational case-control study that included 101 individuals with MS and 68 healthy individuals (controls). Food frequency questionnaires were used to collect dietary data. Serum concentrations of Cu and Zn were determined by the electrothermal and flame atomic absorption spectrometry method, respectively. The ratio of Cu to Zn was calculated and compared with the Expanded Disability Status Scale of patients.

RESULTS

The concentration of Zn was significantly lower in the serum of individuals with MS (0.776 ± 0.195 mg/L) than in the control group (0.992 ± 0.315 mg/L). The ratio of Cu to Zn was higher in the examined patients (1.347 ± 0.806) than in the healthy volunteers (1.012 ± 0.458). Lower ability status (P < 0.05) was revealed in patients with an abnormal ratio of Cu to Zn, particularly, in cerebellar function, pyramidal tracts, and emotional conditions. Selected dietary habits have a significant influence on Cu and Zn concentration in the serum of patients with MS.

CONCLUSIONS

Lower serum concentrations of Zn and higher ratio of Cu to Zn in patients with MS can suggest a relationship between MS and oxidative stress. Products that are a source of Zn should be included in the diet, which can improve the clinical condition of people with MS.

Pulmonary delivery systems for polyphenols

This review reports on the beneficial pharmacological properties of naturally occurring polyphenols for the treatment of inflammatory pulmonary diseases. In addition, it presents an overview of the different types of inhalable formulations which have been developed in order to achieve efficient delivery of polyphenols to the respiratory tract. The main biological activities of polyphenols (anti-oxidant and anti-inflammatory) are covered, with particular emphasis on the studies describing their therapeutic effects on different factors and conditions characteristic of lung pathologies. Special focus is on the technological aspects which influence the pulmonary delivery of drugs. The various polyphenol-based inhalable formulations reported in the literature are examined with specific attention to the preparation methodologies, aerosol performance, lung deposition and in vitro and in vivo polyphenol uptake by the pulmonary epithelial cells.

Protective roles of nanomelatonin in cerebral ischemia-reperfusion of aged brain: Matrixmetalloproteinases as regulators

Cerebral ischemia-reperfusion (CIR) injury occurs as a result of oxygen occlusion in the carotid artery through embolus or thrombus formation or cerebrovascular hemorrhage. The oxygen thrust during reperfusion causes the generation of reactive oxidative species (ROS) which exert a potential threat to neuronal survival. ROS may possibly be arrested by antioxidants. After CIR, extracellular matrix remodeling takes place, which is governed by matrix metalloproteinases (MMPs). Augmentation of lipid per oxidation, perturbation of antioxidant enzyme activities and the loss of pyramidal neuronal cells in rat brain were attributed to CIR injury. Melatonin can readily cross the blood-brain barrier (BBB) to exert protective effects as an antioxidant but it is quickly cleared by the circulating blood. Also melatonin is easily degraded by light and hence is found to be ineffective during daytime. Results of the present study showed that unlike free melatonin (FM), the application of nanocapsulated melatonin (NM) exhibited significantly higher potential even at much lower concentrations to rescue neuronal cells and mitochondria during CIR insult and also restored the activities of antioxidative enzymes and MMPs to their normal levels. Hence, nanoencapsulated melatonin may be considered as a suitable drug delivery system for brain to exert protection against CIR injury.

Modulatory effect of vanillic acid on antioxidant status in high fat diet-induced changes in diabetic hypertensive rats

The worldwide incidence of diabetes has increased dramatically along with widespread lifestyle and dietary changes. Diets high in fat are strongly associated with the development of obesity and can induce insulin resistance in humans and animals. It is clear that obesity constitutes a risk factor for contributing to the development of type 2 diabetes. In the present study, we investigated the therapeutic potential action of vanillic acid on diabetes associated complications using a rat model. Rats were made diabetic hypertensive by high fat diet (HFD) for 20 weeks and were treated with vanillic acid (50mg/kg bw) for last 8 weeks. The effects of vanillic acid on glucose, plasma insulin, systolic and diastolic blood pressure, thiobarbituric acid reactive substances (TBARS), hydroperoxides as a lipid peroxidation marker, and the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), reduced glutathione (GSH), vitamin C and vitamin E as an antioxidant marker, AST and ALT as a liver function marker, urea, uric acid and creatinine as a kidney function marker were investigated. Histopathology of liver and kidney was also investigated as part of the pathology of diabetes. Treatment of diabetic rats with oral administration of vanillic acid at a dose of 50mgkg/body weight for 8 weeks resulted in a significant decrease in fasting plasma glucose, insulin and blood pressure levels in comparison with diabetic control group. The antioxidant activities were significantly increased and the levels of lipid peroxidation markers were significantly decreased in diabetic hypertensive rats treated with vanillic acid. These results suggest that vanillic acid offer a modulatory effect on control of diabetic hypertension by reduction of blood glucose, insulin and blood pressure, combating oxidative stress by activation of tissue antioxidants.

Possible antioxidant effect of Lycium barbarum polysaccharides on hepatic cadmium-induced oxidative stress in rats

The aim of this study was to investigate the potential protective effect of Lycium barbarum polysaccharides (LBP) pretreatment against cadmium (Cd)-induced hepatotoxicity in rats. Wistar rats were divided into control group, LBP group (300 mg/kg orally, once a day, for 30 days), Cd group (CdCl₂ 4 mg/kg i.p. once), and LBP + Cd group (LBP 300 mg/kg orally, once a day, for 30 days + CdCl₂ 4 mg/kg i.p. 24 h after the last treatment). Cd liver injury was examined by morphological/histological changes, transaminases, total protein concentration, and oxidative stress evaluated by MDA, 3NT, GSH, SOD, and TEAC activities. Cd intoxication caused gross morphological changes with hyperemia of the parenchyma, increased volume, and disappearance of the anatomical limits of the lobes associated with an increase of ALT, GSH, and TEAC in plasma and a decrease of MDA, GSH, and TEAC in liver, SOD, and total proteins in plasma. LBP pretreatment caused a slight improvement in the histological architecture and in the 3NT amount together with a significant improvement of hematic parameters. On the basis of the obtained results, we can affirm that LBP pretreatment can ameliorate liver conditions, but further studies are needed to better evaluate the protective antioxidant effects of LBP against Cd-induced toxicity.

Analogues of desferrioxamine B designed to attenuate iron-mediated neurodegeneration: synthesis, characterisation and activity in the MPTP-mouse model of Parkinson's disease

One dual-function (2) and one first-generation (9) conjugate of the Fe(iii) chelator desferrioxamine B (DFOB,1) showed significant rescue of neurons in the MPTP mouse model of Parkinson's disease.

Subchronic treatment with acai frozen pulp prevents the brain oxidative damage in rats with acute liver failure

Acai has been used by the population due to its high nutritional value and its benefits to health, such as its antioxidant properties. The aim of this study was to evaluate the protective effect of acai frozen pulp on oxidative stress parameters in cerebral cortex, hippocampus and cerebellum of Wistar rats treated with carbon tetrachloride (CCl₄). Thirty male Wistar rats (90-day-old) were orally treated with water or acai frozen pulp for 14 days (7 μL/g). On the 15th day, half of the animals received treatment with mineral oil and the other half with CCl₄ (3.0 mL/kg). The cerebral cortex, hippocampus and cerebellum were dissected and used for analysis of creatine kinase activity (CK), thiobarbituric acid reactive substances (TBARS), carbonyl, sulfhydryl, and the activity of antioxidant enzymes catalase (CAT) and superoxide dismutase (SOD). Statistical analysis was performed by ANOVA followed by Tukey's post-test. CCl₄ was able to inhibit CK activity in all tissues tested and to provoke lipid damage in cerebral cortex and cerebellum, and protein damage in the three tissues tested. CCl₄ enhanced CAT activity in the cerebral cortex, and inhibited CAT activity in the hippocampus and cerebellum and reduced SOD activity in all tissues studied. Acai frozen pulp prevented the inhibition of CK, TBARS, carbonyl and CAT activity in all brain structures and only in hippocampus for SOD activity. Therefore, acai frozen pulp has antioxidant properties and maybe could be useful in the treatment of some diseases that affect the central nervous system that are associated with oxidative damage.

Molecular mechanisms of the antiglycative and cardioprotective activities of Psidium guajava leaves in the rat diabetic myocardium

CONTEXT

Antiglycative potential of Psidium guajava L. (Myrtaceae) leaves has been established. However, the molecular basis of its antiglycative potential remains unknown.

OBJECTIVE

The ethyl acetate fraction of P. guajava leaves (PGEt) was evaluated to determine the cardioprotective effect and its mechanism of action compared to quercetin.

MATERIALS AND METHODS

After the induction of diabetes by streptozotocin (55 mg/kg body weight), PGEt and quercetin (50 mg/kg body weight) was administered for 60 days. Rats were grouped as follows: Group C: Control, Group D: Diabetic, Group D + E: Diabetic rats treated with PGEt, Group D + Q: Diabetic rats treated with quercetin. The antiglycative potential was evaluated by assaying glycosylated haemoglobin, serum fructosamine and advanced glycation end product levels. The differential receptor for advanced glycation end products and nuclear factor kappa B (NFκB) protein levels was determined by western blot and the transcript level changes of connective tissue growth factor (CTGF), brain natriuretic peptide (BNP) and TGF-β1 in heart tissue were assessed by RT-PCR analysis.

RESULTS

Glycated haemoglobin and serum fructosamine levels were found to be enhanced in diabetic rats when compared with control. Administration of PGEt significantly reduced the glycated haemoglobin and fructosamine levels to a larger extent than quercetin treated diabetic rats. PGEt reduced the translocation of NFκB from cytosol to nucleus when compared with diabetic rats. Expression of TGF-β1, CTGF and BNP was downregulated in PGEt treated groups compared with diabetic controls.

DISCUSSION AND CONCLUSION

Administration of PGEt ameliorated diabetes associated changes in the myocardium to a greater extent than quercetin.

Possible antioxidant effect of Lycium barbarum polysaccharides on hepatic cadmium-induced oxidative stress in rats

The aim of this study was to investigate the potential protective effect of Lycium barbarum polysaccharides (LBP) pretreatment against cadmium (Cd)-induced hepatotoxicity in rats. Wistar rats were divided into control group, LBP group (300 mg/kg orally, once a day, for 30 days), Cd group (CdCl₂ 4 mg/kg i.p. once), and LBP + Cd group (LBP 300 mg/kg orally, once a day, for 30 days + CdCl₂ 4 mg/kg i.p. 24 h after the last treatment). Cd liver injury was examined by morphological/histological changes, transaminases, total protein concentration, and oxidative stress evaluated by MDA, 3NT, GSH, SOD, and TEAC activities. Cd intoxication caused gross morphological changes with hyperemia of the parenchyma, increased volume, and disappearance of the anatomical limits of the lobes associated with an increase of ALT, GSH, and TEAC in plasma and a decrease of MDA, GSH, and TEAC in liver, SOD, and total proteins in plasma. LBP pretreatment caused a slight improvement in the histological architecture and in the 3NT amount together with a significant improvement of hematic parameters. On the basis of the obtained results, we can affirm that LBP pretreatment can ameliorate liver conditions, but further studies are needed to better evaluate the protective antioxidant effects of LBP against Cd-induced toxicity.

Peripheral Inflammatory Markers and Antioxidant Response during the Post-Acute and Chronic Phase after Severe Traumatic Brain Injury

Traumatic brain injury (TBI) is a mechanical insult to the brain caused by external forces and associated with inflammation and oxidative stress. The patients may show different profiles of neurological recovery and a combination of oxidative damage and inflammatory processes can affect their courses. It is known that an overexpression of cytokines can be seen in peripheral blood in the early hours/days after the injury, but little is known about the weeks and months encompassing the post-acute and chronic phases. In addition, no information is available about the antioxidant responses mediated by the major enzymes that regulate reactive oxygen species levels: superoxide dismutase, catalase, peroxidases, and GSH-related enzymes. This study investigates the 6-month trends of inflammatory markers and antioxidant responses in 22 severe TBI patients with prolonged disorders of consciousness, consecutively recruited in a dedicated neurorehabilitation facility. Patients with a high degree of neurological impairment often show an uncertain outcome. In addition, the profiles of plasma activities were related to the neurological recovery after 12 months. Venous peripheral blood samples were taken blindly as soon as clinical signs and laboratory markers confirmed the absence of infections, 3 and 6 months later. The clinical and neuropsychological assessment continued up to 12 months. Nineteen patients completed the follow-up. In the chronic phase, persistent high plasma levels of cytokines can interfere with cognitive functioning and higher post-acute levels of cytokines [interferon (IFN)-γ, tumor necrosis factor (TNF)-α, IL1b, IL6] are associated with poorer cognitive recoveries 12 months later. Moreover, higher IFN-γ, higher TNF-α, and lower glutathione peroxidase activity are associated with greater disability. The results add evidence of persistent inflammatory response, provide information about long-term imbalance of antioxidant activity, and suggest that the over-production of cytokines and the alteration of the redox homeostasis in the post-acute phase might adversely affect the neurological and functional recovery. Inflammatory and antioxidant activity markers might offer a feasible way to highlight some of the processes opposing recovery after a severe TBI.

Estimation of Early Postmortem Interval Through Biochemical and Pathological Changes in Rat Heart and Kidney

Accurate estimation of time passed since death is a complicated task in forensic medicine especially in homicide or unwitnessed death investigations. Changes in oxidant/antioxidant parameters were investigated if it can be relied upon in estimating the early postmortem interval (EPI) in rat heart and kidney, and whether these changes were correlated with histopathological findings in these tissues. Heart and kidney tissues of 84 male albino rats were divided into 2 parts. One part used for estimation of levels of malondialdehyde (MDA), nitric oxide (NO), and total thiol as well as the activity of glutathione reductase (GR), glutathione S transferase, and catalase. The second part was examined histopathologically. It was found that MDA and NO were significantly increased earlier in the heart than kidney tissues. Meanwhile, total thiol, catalase, glutathione S transferase, and GR were commenced to be significantly decreased in the heart before kidney tissues. Linear regression analysis of independent variables of heart was found to be of a high predictive value of 97.2% (EPI = 8.607 - 0.240 GR + 0.002 MDA + 0.014 NO). Structural deterioration of heart started 3 to 4 hours compared with renal sections that began 5 to 6 hours after death. The relationship between oxidant and antioxidant parameters is crucial in determining the EPI. The kidney was found to be more resistible to oxidative damage. Further research on humans is needed.

Neuroprotective Effects of Açaí (Euterpe oleracea Mart.) against Rotenone In Vitro Exposure

Neuropsychiatric diseases, such as bipolar disorder (BD) and schizophrenia (SCZ), have a very complex pathophysiology. Several current studies describe an association between psychiatric illness and mitochondrial dysfunction and consequent cellular modifications, including lipid, protein, and DNA damage, caused by cellular oxidative stress. Euterpe oleracea (açaí) is a powerful antioxidant fruit. Açaí is an Amazonian palm fruit primarily found in the lowlands of the Amazonian rainforest, particularly in the floodplains of the Amazon River. Given this proposed association, this study analyzed the potential in vitro neuropharmacological effect of Euterpe oleracea (açaí) extract in the modulation of mitochondrial function and oxidative metabolism. SH-SY5Y cells were treated with rotenone to induce mitochondrial complex I dysfunction and before and after we exposed the cells to açaí extract at 5 μg/mL. Treated and untreated cells were then analyzed by spectrophotometric, fluorescent, immunological, and molecular assays. The results showed that açaí extract can potentially increase protein amount and enzyme activity of mitochondrial complex I, mainly through NDUFS7 and NDUFS8 overexpression. Açaí extract was also able to decrease cell reactive oxygen species levels and lipid peroxidation. We thus suggest açaí as a potential candidate for drug development and a possible alternative BD therapy.