The wanderings of a free radical

Protective effect of magnesium acetyltaurate against NMDA-induced retinal damage involves restoration of minerals and trace elements homeostasis

Glutamate-mediated excitotoxicity involving N-methyl-d-aspartate (NMDA) receptors has been recognized as a final common outcome in pathological conditions involving death of retinal ganglion cells (RGCs). Overstimulation of NMDA receptors results in influx of calcium (Ca) and sodium (Na) ions and efflux of potassium (K). NMDA receptors are blocked by magnesium (Mg). Such changes due to NMDA overstimulation are also associated with not only the altered levels of minerals but also that of trace elements and redox status. Both the decreased and elevated levels of trace elements such as iron (Fe), zinc (Zn), copper (Cu) affect NMDA receptor excitability and redox status. Manganese (Mn), and selenium (Se) are also part of antioxidant defense mechanisms in retina. Additionally endogenous substances such as taurine also affect NMDA receptor activity and retinal redox status. Therefore, the aim of this study was to evaluate the effect of Mg acetyltaurate (MgAT) on the retinal mineral and trace element concentration, oxidative stress, retinal morphology and retinal cell apoptosis in rats after-NMDA exposure. One group of Sprague Dawley rats received intravitreal injection of vehicle while 4 other groups similarly received NMDA (160nmolL^-1). Among the NMDA injected groups, 3 groups also received MgAT (320nmolL^-1) as pre-treatment, co-treatment or post-treatment. Seven days after intravitreal injection, rats were sacrificed, eyes were enucleated and retinae were isolated for estimation of mineral (Ca, Na, K, Mg) and trace element (Mn, Cu, Fe, Se, Zn) concentration using Inductively Coupled Plasma (DRC ICP-MS) techniques (NexION 300D), retinal oxidative stress using Elisa, retinal morphology using H&E staining and retinal cell apoptosis using terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL). Intravitreal NMDA injection resulted in increased concentration of Ca (4.6 times, p<0.0001), Mg (1.5 times, p<0.01), Na (3 times, p<0.0001) and K (2.3 times, p<0.0001) compared to vehicle injected group. This was accompanied with significant increase of Ca/Mg and Na/K ratios, 3 and 1.27 times respectively, compared to control group. The trace elements such as Cu, Fe and Zn also showed a significant increase amounting to 3.3 (p<0.001), 2.3 (p<0.0001) and 3 (p<0.0001) times respectively compared to control group. Se was increased by 60% (p<0.005). Pre-treatment with MgAT abolished effect of NMDA on minerals and trace elements more effectively than co- and post-treatment. Similar observations were made for retinal oxidative stress, retinal morphology and retinal cell apoptosis. In conclusion, current study demonstrated the protective effect of MgAT against NMDA-induced oxidative stress and retinal cell apoptosis. This effect of MgAT was associated with restoration of retinal concentrations of minerals and trace elements. Further studies are warranted to explore the precise molecular targets of MgAT. Nevertheless, MgAT seems a potential candidate in the management of diseases involving NMDA-induced excitotoxicity.

Natural Compounds as a Therapeutic Intervention following Traumatic Brain Injury: The Role of Phytochemicals

There has been a tremendous focus on the discovery and development of neuroprotective agents that might have clinical relevance following traumatic brain injury (TBI). This type of brain injury is very complex and is divided into two major components. The first component, a primary injury, occurs at the time of impact and is the result of the mechanical insult itself. This primary injury is thought to be irreversible and resistant to most treatments. A second component or secondary brain injury, is defined as cellular damage that is not immediately obvious after trauma, but that develops after a delay of minutes, hours, or even days. This injury appears to be amenable to treatment. Because of the complexity of the secondary injury, any type of therapeutic intervention needs to be multi-faceted and have the ability to simultaneously modulate different cellular changes. Because of diverse pharmaceutical interactions, combinations of different drugs do not work well in concert and result in adverse physiological conditions. Research has begun to investigate the possibility of using natural compounds as a therapeutic intervention following TBI. These compounds normally have very low toxicity and have reduced interactions with other pharmaceuticals. In addition, many natural compounds have the potential to target numerous different components of the secondary injury. Here, we review 33 different plant-derived natural compounds, phytochemicals, which have been investigated in experimental animal models of TBI. Some of these phytochemicals appear to have potential as possible therapeutic interventions to offset key components of the secondary injury cascade. However, not all studies have used the same scientific rigor, and one should be cautious in the interpretation of studies using naturally occurring phytochemical in TBI research.

Intake of bilberries (Vaccinium myrtillus L.) reduced risk factors for cardiovascular disease by inducing favorable changes in lipoprotein profiles

Cardiovascular diseases (CVDs) are the leading causes of death, and lifestyle modification, including dietary changes, is recommended to improve this condition. In this study, regular consumption of bilberries was hypothesized to have beneficial effects on CVD risk reduction, by changes in human health indicators such as decreasing low-density lipoprotein cholesterol (LDL-C) and triglycerides (TGs) and increasing high-density lipoprotein cholesterol (HDL-C). The research involved women (n=25) and men (n=11) who consumed 150 g of frozen stored bilberries 3 times a week for 6 weeks. Anthropometric parameters, blood pressure, lipid profile, glucose, liver enzymes, creatinine, albumin, magnesium, and antiradical activity were measured. Except for the body mass index of women (P=.019), no significant changes were found for anthropometric indicators. The consumption of bilberries led to a decrease in the following parameters: total cholesterol (P=.017), LDL-C (P=.0347), TG (P=.001), glucose (P=.005), albumin (P=.001), γ-glutamyltransferase (P=.046), and a positive increase in HDL-C (P=.044). In men, additionally, favorable changes were observed in total cholesterol (P=.004), glucose (P=.015), albumin (P=.028), aspartate aminotransferase (P=.012), γ-glutamyltransferase (P=.013), and HDL-C (P=.009; in this group, LDL-C increased [P=.007]). Changes in other parameters were not significant, for both women and men. Thus, the regular intake of bilberries can be important to reduce CVDs risk, by decreasing LDL-C/TG and increasing HDL-C.

An iron-deficient diet during development induces oxidative stress in relation to age and gender in Wistar rats

Iron is a trace element and a structural part of antioxidant enzymes, and its requirements vary according to age and gender. We hypothesized that iron deficiency (ID) leads to an increase in free radicals which mainly affect the brain, and the severity of damage would therefore be dependent on age and gender. Two groups of Wistar rats were evaluated evolutionarily: 100 rats (50 males; 50 females) with ID diet and 100 rats (50 males; 50 females) with standard diet. Both groups were offspring from mothers who were previously under the same dietary intervention. The ages studied roughly correspond to stages of human development: birth (0 postnatal day "PND" in rats), childhood (21 PND), early adolescence (42 PND), late adolescence (56 PND), and adulthood (70 PND). The following biomarkers in the brain, blood, and liver were analyzed: lipid peroxidation products (LPO), protein carbonyl content and activity of the antioxidant enzymes, superoxide dismutase, catalase, and glutathione peroxidase. It was demonstrated that ID subjects are born with high levels of LPO in the brain and low antioxidant activity, the damage being more severe in males. After birth, antioxidant defense focuses on the central level (brain) in ID females and on the peripheral level (blood and liver) in ID males. In two critical stages of development, birth and late adolescence, antioxidant protection is insufficient to counteract oxidative damage in ID subjects. Moreover, we observed that the variability of results in the literature on oxidative stress and ID comes from gender and age of the subjects under study. With this, we can establish patterns and exact moments to carry out studies or treatments.

An evaluation of in vitro intestinal absorption of iron, calcium and potassium in chickens receiving gold nanoparticles

This study evaluated the effect of oral administration of colloidal gold nanoparticles on accumulation of gold in the small intestine and intestinal absorption of iron, calcium and potassium under in vitro conditions. The gold nanoparticles are non-ionic, nanocrystalline, chemically pure particles 5 nm in size, produced in a physical process. In total, 126 one day-old Ross 308 chicks were assigned to 7 experimental groups of 18 birds each (3 replications of 6 individuals each). The control group (G-C) did not receive gold nanoparticles. Groups: Au-5(7), Au-10(7) and Au-15(7) received gold nanoparticles in their drinking water in the amounts of 5 mg l(-1) for group Au-5(7), 10 mg l(-1) for group Au-10(7) and 15 mg l(-1) for group Au-15(7) in 8-14, 22-28 and 36-42 d of life. The birds in groups Au-5(3), Au-10(3) and Au-15(3) received gold nanoparticles in the same amounts, but only in 8-10, 22-24 and 36-38 d of life. The study revealed that nanogold supplied via ingestion leads to dose- and time-dependent accumulation of gold in the intestinal walls. Nanogold present in the jejunum has a negative impact on the absorption of calcium, iron and potassium under in vitro conditions.

Physico-Chemical Alternatives in Lignocellulosic Materials in Relation to the Kind of Component for Fermenting Purposes

The complete bioconversion of the carbohydrate fraction is of great importance for a lignocellulosic-based biorefinery. However, due to the structure of the lignocellulosic materials, and depending basically on the main parameters within the pretreatment steps, numerous byproducts are generated and they act as inhibitors in the fermentation operations. In this sense, the impact of inhibitory compounds derived from lignocellulosic materials is one of the major challenges for a sustainable biomass-to-biofuel and -bioproduct industry. In order to minimise the negative effects of these compounds, numerous methodologies have been tested including physical, chemical, and biological processes. The main physical and chemical treatments have been studied in this work in relation to the lignocellulosic material and the inhibitor in order to point out the best mechanisms for fermenting purposes. In addition, special attention has been made in the case of lignocellulosic hydrolysates obtained by chemical processes with SO₂, due to the complex matrix of these materials and the increase in these methodologies in future biorefinery markets. Recommendations of different detoxification methods have been given.

Structural Aspects of Antioxidant and Genotoxic Activities of Two Flavonoids Obtained from Ethanolic Extract of Combretum leprosum

Combretum leprosum Mart., a member of the Combretaceae family, is a traditionally used Brazilian medicinal plant, although no evidence in the literature substantiates its antioxidant action and the safety of its use. We evaluated the antioxidant properties of the ethanolic extract (EE) from flowers of C. leprosum and its isolated products 5,3′-dihydroxy-3,7,4′-trimethoxyflavone (FCL2) and 5,3′,4′-trihydroxy-3,7-dimethoxyflavone (FCL5) in Saccharomyces cerevisiae strains proficient and deficient in antioxidant defenses. Their mutagenic activity was also assayed in S. cerevisiae, whereas cytotoxic and genotoxic properties were evaluated by MTT and Comet Assays, respectively, in V79 cells. We show that the EE, FCL2, and FCL5 have a significant protective effect against H₂O₂. FCL2 showed a better antioxidant action, which can be related to the activation of the 3′-OH in the presence of a methoxyl group at 4′ position in the B-ring of the molecule, while flavonoids did not induce mutagenesis in yeast, and the EE was mutagenic at high concentrations. The toxicity of these compounds in V79 cells increases from FCL2 = FCL5 < EE; although not cytotoxic, FCL5 induced an increase in DNA damage. The antioxidant effect, along with the lower toxicity and the absence of genotoxicity, suggests that FCL2 could be suitable for pharmacological use.

Pathways of cardiac toxicity: comparison between chemotherapeutic drugs doxorubicin and mitoxantrone

Anthracyclines, e.g., doxorubicin (DOX), and anthracenediones, e.g., mitoxantrone (MTX), are drugs used in the chemotherapy of several cancer types, including solid and non-solid malignancies such as breast cancer, leukemia, lymphomas, and sarcomas. Although they are effective in tumor therapy, treatment with these two drugs may lead to side effects such as arrhythmia and heart failure. At the same clinically equivalent dose, MTX causes slightly reduced cardiotoxicity compared with DOX. These drugs interact with iron to generate reactive oxygen species (ROS), target topoisomerase 2 (Top2), and impair mitochondria. These are some of the mechanisms through which these drugs induce late cardiomyopathy. In this review, we compare the cardiotoxicities of these two chemotherapeutic drugs, DOX and MTX. As described here, even though they share similarities in their modes of toxicant action, DOX and MTX seem to differ in a key aspect. DOX is a more redox-interfering drug, while MTX induces energy imbalance. In addition, DOX toxicity can be explained by underlying mechanisms that include targeting of Top2 beta, mitochondrial impairment, and increases in ROS generation. These modes of action have not yet been demonstrated for MTX, and this knowledge gap needs to be filled.

Oxidative stress biomarkers in endometrial secretions: A comparison between successful and unsuccessful in vitro fertilization cycles

A potential role of oxidative stress has been implicated in the outcome of various steps of assisted reproductive technology (ART). In a prospective cohort study, a total of 100 patients undergoing IVF/ICSI procedure due to male factor infertility were recruited based on the inclusion criteria. In all patients, 1-2ml of endometrial secretions was aspirated prior to embryo transfer. The oxidative stress markers in endometrial secretions, including superoxide dismutase (SOD), catalase (CAT) activities, lipid peroxidation (LPO), total thiol groups (TTG), and total antioxidant power (TAP) were investigated and compared among study groups including term pregnancy, failed IVF cycle, and miscarriage. P<0.05 was considered statistically different. Of the 100 patients, 28 cases (28%) resulted in ongoing pregnancy (biochemical pregnancy followed by clinical pregnancy), 11 cases (11%) resulted in miscarriage, and 61 cases (61%), resulted in failed IVF cycle. SOD, LPO, CAT, and TAP levels in the endometrial secretions of the three groups were statistically different (P-value <0.01, <0.001, <0.001, and <0.001, respectively). TTG levels in endometrial secretion of three groups were not statistically different (P-value=0.837). Our results indicated that higher levels of antioxidants such as SOD, CAT, or TAP, and lower levels of oxidative stress markers such as LPO in the endometrial secretions were associated with successful IVF outcome.

Correlation between vitamin D levels and apoptosis in geriatric patients infected with hepatitis C virus genotype 4

Background

Vitamin D levels play a pivotal role in most biological processes and differ according to age. A deficiency of vitamin D in chronic hepatitis C (CHC) patients has been shown to be linked with the severity of liver fibrosis, but little is known about the mechanism of this association.

Objective

In this study, we evaluate the potential interrelation between vitamin D levels, oxidative stress, and apoptosis, based on liver fibrosis in geriatric patients infected with hepatitis C virus (HCV) genotype 4.

Subjects and methods

A total of 120 adult individuals aged 30–68 years were recruited in this study. Of these, 20 healthy subjects (15 men and five women) with a mean age of 48.3±6.1 years were selected as controls, and 100 patients with a mean age of 47.8±4.9 years with chronic HCV (CHC) who had undergone liver biopsy (80 men and 20 women) were included in this study. Based on liver radiographic (computed tomography, magnetic resonance imaging) and histological Metavir system analyses, the CHC patients were classified into three groups: asymptomatic CHC carriers (n=30), fibrosis (n=25), and cirrhosis (n=45). HCV RNA, HCV genotypes, inflammatory cytokines AFP and TNFα, 25-hydroxyvitamin D (25[OH]D) levels, apoptotic markers single-stranded DNA (ssDNA) and soluble Fas (sFas), and oxidative stress markers nitric oxide (NO) and total antioxidant capacity (TAC) were estimated by using molecular, immunoassay, and colorimetric techniques.

Results

Approximately 30% of the study population (n=30) were diagnosed as asymptomatic CHC carriers, and 70% of the study population (n=70) had severe fibrosis; these were classified into fibrosis and cirrhosis. There was a significant reduction in 25(OH)D levels and TAC activity, along with an increase in levels of NO, AFP, TNFα, ssDNA, and sFas in fibrosis and cirrhosis subjects compared with those of asymptomatic CHC carriers and health controls. The deficiency in 25(OH)D levels correlated positively with sFas, ssDNA, AFP, TNFα, NO, and TAC, and negatively with age, sex, liver function, body mass index, homeostatic model assessment – insulin resistance, HCV RNA, and viral load. Significant intercorrelation was reported between serum 25(OH)D concentrations and apoptotic and oxidative markers, which suggested progression of liver pathogenesis and fibrogenesis via oxidative and apoptotic mechanisms.

Conclusion

The data showed that vitamin D status was significantly correlated with pathogenesis and fibrogenesis of the liver in geriatric patients infected with HCV genotype 4. The deficiency in 25(OH)D levels was shown to have a pivotal role in the pathogenesis of liver via apoptotic, oxidative stress, and inflammatory mechanistic pathways. The data point to adequate vitamin D levels being recommended for a good response to treatment strategies, especially in older CHC patients.

URB597 inhibits oxidative stress induced by alcohol binging in the prefrontal cortex of adolescent rats

Heavy episodic drinking (binging), which is highly prevalent among teenagers, results in oxidative damage. Because the prefrontal cortex (PFC) is not completely mature in adolescents, this brain region may be more vulnerable to the effects of alcohol during adolescence. As endocannabinoids may protect the immature PFC from the harmful effects of high doses of alcohol, this study investigated the effect of the fatty acid amide hydrolase (FAAH) inhibitor URB597 on oxidative stress induced by acute or chronic binge alcohol intake in adolescent rats. At 40min after intraperitoneal pre-treatment with URB597 (0.3mg/kg) or vehicle (Veh), ethanol (EtOH; 3 or 6g/kg, intragastrically) or distilled water (DW) was administered in 3 consecutive sessions (acute binging) or 3 consecutive sessions over 4 weeks (chronic binging). Oxidative stress in PFC slices in situ was measured by dihydroethidium fluorescence staining. At the higher EtOH dose (6g/kg), pre-treatment with URB597 significantly reduced (p<0.01) the production of superoxide anions in the PFC after acute (42.8% decrease) and chronic binge EtOH consumption (44.9% decrease) compared with pre-treatment with Veh. As URB597 decreases anandamide metabolism, this evidence shows an antioxidant effect of endocannabinoids to suppress acute and chronic binge alcohol intake-induced oxidative stress in the PFC of adolescent rats.

The Role of Mitochondrial Reactive Oxygen Species in Cardiovascular Injury and Protective Strategies

Ischaemia/reperfusion (I/R) injury of the heart represents a major health burden mainly associated with acute coronary syndromes. While timely coronary reperfusion has become the established routine therapy in patients with ST-elevation myocardial infarction, the restoration of blood flow into the previously ischaemic area is always accompanied by myocardial injury. The central mechanism involved in this phenomenon is represented by the excessive generation of reactive oxygen species (ROS). Besides their harmful role when highly generated during early reperfusion, minimal ROS formation during ischaemia and/or at reperfusion is critical for the redox signaling of cardioprotection. In the past decades, mitochondria have emerged as the major source of ROS as well as a critical target for cardioprotective strategies at reperfusion. Mitochondria dysfunction associated with I/R myocardial injury is further described and ultimately analyzed with respect to its role as source of both deleterious and beneficial ROS. Furthermore, the contribution of ROS in the highly investigated field of conditioning strategies is analyzed. In the end, the vascular sources of mitochondria-derived ROS are briefly reviewed.

Computational studies of free radical-scavenging properties of phenolic compounds

For more than half a century free radical-induced alterations at cellular and organ levels have been investigated as a probable underlying mechanism of a number of adverse health conditions. Consequently, significant research efforts have been spent for discovering more effective and potent antioxidants / free radical scavengers for treatment of these adverse conditions. Being by far the most used antioxidants among natural and synthetic compounds, mono- and polyphenols have been the focus of both experimental and computational research on mechanisms of free radical scavenging. Quantum chemical studies have provided a significant amount of data on mechanisms of reactions between phenolic compounds and free radicals outlining a number of properties with a key role for the radical scavenging activity and capacity of phenolics. The obtained quantum chemical parameters together with other molecular descriptors have been used in quantitative structure-activity relationship (QSAR) analyses for the design of new more effective phenolic antioxidants and for identification of the most useful natural antioxidant phenolics. This review aims at presenting the state of the art in quantum chemical and QSAR studies of phenolic antioxidants and at analysing the trends observed in the field in the last decade.

New strategy for drug discovery by large-scale association analysis of molecular networks of different species

The development of modern omics technology has not significantly improved the efficiency of drug development. Rather precise and targeted drug discovery remains unsolved. Here a large-scale cross-species molecular network association (CSMNA) approach for targeted drug screening from natural sources is presented. The algorithm integrates molecular network omics data from humans and 267 plants and microbes, establishing the biological relationships between them and extracting evolutionarily convergent chemicals. This technique allows the researcher to assess targeted drugs for specific human diseases based on specific plant or microbe pathways. In a perspective validation, connections between the plant Halliwell-Asada (HA) cycle and the human Nrf2-ARE pathway were verified and the manner by which the HA cycle molecules act on the human Nrf2-ARE pathway as antioxidants was determined. This shows the potential applicability of this approach in drug discovery. The current method integrates disparate evolutionary species into chemico-biologically coherent circuits, suggesting a new cross-species omics analysis strategy for rational drug development.

Assessment of the redox status in patients with metabolic syndrome and type 2 diabetes reveals great variations

The aim of the present study was to examine the effectiveness of a new redox status marker, the static oxidation reduction potential (sORP), for assessing oxidative stress in 75 patients with metabolic syndrome (MetS) and type 2 diabetes (T2D). A total of 35 normal subjects were used as the controls. Moreover, conventional markers of oxidative stress were assessed, such as thiobarbituric acid reactive substances (TBARS), protein carbonyls, the total antioxidant capacity in plasma, glutathione (GSH) levels and catalase (CAT) activity in erythrocytes. The results revealed that sORP was significantly higher (by 13.4%) in the patients with MetS and T2D compared to the controls, indicating an increase in oxidative stress. This finding was also supported by the significantly lower levels (by 27.7%) of GSH and the higher levels (by 23.3%) of CAT activity in the patients with MetS and T2D compared to the controls. Moreover, our results indicated a great variation in oxidative stress markers between the different patients with MetS and T2D, particarly as regards the GSH levels. Thus, the patients with MetS and T2D were divided into 2 subgroups, one with low GSH levels (n=31; GSH <3 µmol/g Hb) and another with high GSH levels (n=35; GSH >4 µmol/g Hb). The comparison of the markers between the 2 subgroups indicated that in the low GSH group, the GSH levels were significantly lower (by 51.7 and 52.9%) than those in the high GSH group and the controls, respectively. Furthermore, sORP in the low GSH group was significantly higher (by 8.1%) compared to the high GSH group, suggesting its sensitivity for assessing oxidative stress in patients wtih MetS and T2D. Moreover, this variation in oxidative stress levels between the different patients with T2D suggests that the assessment of the redox status may be important in prediabetic conditions, since there is evidence indicating that differences in the redox status in pre-diabetes may result in different outcomes.

Phytochemical characterization and bioactive properties of Osyris quadripartita Salzm. ex Decne. leaves from Algeria

Medicinal plants are sources of bioactive compounds with recognized beneficial effects on human health.

Oxidative Stress-Mediated Skeletal Muscle Degeneration: Molecules, Mechanisms, and Therapies

Oxidative stress is a loss of balance between the production of reactive oxygen species during cellular metabolism and the mechanisms that clear these species to maintain cellular redox homeostasis. Increased oxidative stress has been associated with muscular dystrophy, and many studies have proposed mechanisms that bridge these two pathological conditions at the molecular level. In this review, the evidence indicating a causal role of oxidative stress in the pathogenesis of various muscular dystrophies is revisited. In particular, the mediation of cellular redox status in dystrophic muscle by NF-κB pathway, autophagy, telomere shortening, and epigenetic regulation are discussed. Lastly, the current stance of targeting these pathways using antioxidant therapies in preclinical and clinical trials is examined.

Human eukaryotic elongation factor 1A forms oligomers through specific cysteine residues

Eukaryotic elongation factor 1A (eEF1A) is a multifunctional protein involved in bundling actin, severing microtubule, activating the phosphoinositol-4 kinase, and recruiting aminoacyl-tRNAs to ribosomes during protein biosynthesis. Although evidence has shown the presence of the isoform eEF1A1 oligomers, the substantial mechanism of the self-association remains unclear. Herein, we found that human eEF1A1 could spontaneously form oligomers. Specifically, mutagenesis screen on cysteine residues demonstrated that Cys(234) was essential for eEF1A1 oligomerization. In addition, we also found that hydrogen peroxide treatment could induce the formation of eEF1A oligomers in cells. By cysteine replacement, eEF1A2 isoform displayed the ability to oligomerize in cells under the oxidative environment. In summary, in this study we characterized eEF1A1 oligomerization and demonstrated that specific cysteine residues are required for this oligomerization activity.

Oxidative Stress and DNA Damage: Implications in Inflammatory Bowel Disease

This review will focus on published human studies on oxidative stress and DNA damage in inflammatory bowel disease (IBD), both ulcerative colitis and Crohn's disease, assessing their role in the pathophysiology of these diseases. Search was performed over PubMed and ScienceDirect databases to identify relevant bibliography, using keywords including "oxidative stress," "DNA damage," "IBD," and "oxidative DNA damage." Whether as cause or effect, mechanisms underlying oxidative stress have the potential to condition the course of various pathologies, particularly those driven by inflammatory scenarios. IBDs are chronic inflammatory relapsing conditions. Oxidative stress has been associated with some of the characteristic clinical features exhibited in IBD, namely tissue injury and fibrosis, and also to the ulcerative colitis-associated colorectal cancer. The possible influence of oxidative stress over therapeutic behavior and response, as well as their contribution to the oxidative burden and consequences, is also addressed. Due to the high prevalence and incidence of IBD worldwide, and also to its associated morbidity, complications, and disease and treatment costs, it is of paramount importance to better understand the pathophysiology of these diseases.

Protective Effect of Plantago major Extract against t-BOOH-Induced Mitochondrial Oxidative Damage and Cytotoxicity

Plantago major L. produces several chemical substances with anti-inflammatory and analgesic activities and its use in the treatment of oral and throat inflammation in popular medicine is well described. In this study, the antioxidant potential of the Plantago major hydroethanolic extract was screened and its protective action was evaluated against t-BOOH-induced oxidative stress. The extract was obtained by fractionated percolation using 50% ethanolic solution and, after drying, suspended in dimethyl sulfoxide. The chromatographic profile of crude extract was obtained with the identification of some phytochemical markers and the total phenols and flavonoids were quantified. The scavenger activity against DPPH (1,1-diphenyl-2-picrylhydrazyl) radicals was determined and the antioxidant activity in biological systems was evaluated in isolated rat liver mitochondria and HepG2 cells. The extract exhibited a significant free radical scavenger activity at 0.1 mg/mL, and decreased the ROS (reactive oxygen species) generation in succinate-energized mitochondria. Such an effect was associated with the preservation of the intrinsic antioxidant defenses (reduced glutathione and NAD(P)H) against the oxidation by t-BOOH, and also to the protection of membranes from lipid oxidation. The cytoprotective effect of PmHE against t-BOOH induced cell death was also shown. These findings contribute to the understanding of the health benefits attributed to P. major.

Evaluation of antioxidant and neuroprotective effect of Hippophae rhamnoides (L.) on oxidative stress induced cytotoxicity in human neural cell line IMR32

AIM AND OBJECTIVE

Hippophae rhamnoides is an edible, nutrient rich plant found in the northern regions of India. It belongs to the family Elaeagnaceae and is well known for its traditional pharmacological activities. The present study was aimed to investigate the antioxidant and neuroprotective activities of H. rhamnoides.

METHODOLOGY

The hydroalcoholic extract of H. rhamnoides was evaluated for free radical scavenging activity using DPPH, hydroxyl radical scavenging and ferric thiocyanate assays. In vitro neuroprotective activity was assessed on human neuroblastoma cell line-IMR32 against hydrogen peroxide (H2O2) induced cytotoxicity. The neuroprotective effect was determined by measuring the cell viability through tetrazolium dye MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) reducing assay and propidium iodide (PI) staining. Also the intracellular reactive oxygen species (ROS) activity was assessed using dichloro-dihydro-fluorescein diacetate (DCFDA) assay by flowcytometer.

RESULTS

The results of the study demonstrated that H. rhamnoides extract possesses potential free radical scavenging activity. The IC50 value for DPPH and OH radical scavenging assay was 70.92 μg/ml and 0.463 mg/ml, also the extract was also found to have considerable level of lipid peroxidation activity. The neuroprotective effect of H. rhamnoides was confirmed by its cell viability enhancing capacity against hydrogen peroxide induced cell cytotoxicity. The extract acted on IMR32 cells in a dose dependent manner as observed through PI and MTT assays. The percentage intracellular ROS activity was reduced by 60-70% in treated cells compared to H2O2 control.

CONCLUSION

Thus the outcome of the study suggests that H. rhamnoides acts as a neuroprotectant against oxidative stress induced neurodegeneration.

Evidence Suggesting a Role of Iron in a Mouse Model of Nephrogenic Systemic Fibrosis

Nephrogenic systemic fibrosis is associated with gadolinium contrast exposure in patients with reduced kidney function and carries high morbidity and mortality. We have previously demonstrated that gadolinium contrast agents induce in vivo systemic iron mobilization and in vitro differentiation of peripheral blood mononuclear cells into ferroportin (iron exporter)-expressing fibrocytic cells. In the present study we examined the role of iron in a mouse model of nephrogenic systemic fibrosis. Chronic kidney disease was induced in 8-week-old male Balb/C mice with a two-step 5/6 nephrectomy surgery. Five groups of mice were studied: control (n = 5), sham surgery control (n = 5), chronic kidney disease control (n = 4), chronic kidney disease injected with 0.5 mmol/kg body weight of Omniscan 3 days per week, for a total of 10 injections (n = 8), and chronic kidney disease with Omniscan plus deferiprone, 125 mg/kg, in drinking water (n = 9). Deferiprone was continued for 16 weeks until the end of the experiment. Mice with chronic kidney disease injected with Omniscan developed skin changes characteristic of nephrogenic systemic fibrosis including hair loss, reddening, ulceration, and skin tightening by 10 to 16 weeks. Histopathological sections demonstrated dermal fibrosis with increased skin thickness (0.25±0.06 mm, sham; 0.34±+0.3 mm, Omniscan-injected). Additionally, we observed an increase in tissue infiltration of ferroportin-expressing, fibrocyte-like cells accompanied by tissue iron accumulation in the skin of the Omniscan-treated mice. The deferiprone-treated group had significantly decreased skin thickness (p<0.05) and significantly decreased dermal fibrosis compared to the Omniscan-only group. In addition, iron chelation prevented tissue infiltration of ferroportin-expressing, fibrocyte-like cells. Our in vitro experiments demonstrated that exposure to Omniscan resulted in the release of catalytic iron and this was prevented by the iron chelator deferiprone. Deferiprone inhibited the differentiation of human peripheral blood mononuclear cells into ferroportin-expressing cells by immunohistochemical staining and western blot analysis. Our studies support an important role of iron in the pathophysiology of gadolinium chelate toxicity and nephrogenic systemic fibrosis.

Do airborne biogenic chemicals interact with the PI3K/Akt/mTOR cell signalling pathway to benefit human health and wellbeing in rural and coastal environments?

Living and taking recreation in rural and coastal environments promote health and wellbeing, although the causal factors involved are unclear. It has been proposed that such environments provide a counter to the stresses of everyday living, leading to enhanced mental and physical health. Living in natural environments will result in airborne exposure to a wide range of biogenic chemicals through inhalation and ingestion of airborne microbiota and particles. The "biogenics" hypothesis formulated here is that regular exposure to low concentrations of mixtures of natural compounds and toxins in natural environments confers pleiotropic health benefits by inhibiting the activities of interconnected cell signalling systems, particularly PI3K/Akt/mTORC1. When overactive, Akt and mTOR (mTORC1) can lead to many pathological processes including cancers, diabetes, inflammation, immunosuppression, and neurodegenerative diseases. There is a substantial body of evidence that many natural products (i.e., from bacteria, algae, fungi and higher plants) inhibit the activities of these protein kinases. Other mTOR-related interconnected metabolic control "switches" (e.g., PTEN & NF-κB), autophagy and other cytoprotective processes are also affected by natural products. The "biogenics" hypothesis formulated here is that regular intermittent exposure to a mixture of airborne biogenic compounds in natural environments confers pleiotropic health benefits by inhibiting activities of the highly interconnected PI3K/Akt/mTORC1 system. It is proposed that future experimental exposures to biogenic aerosols in animal models coupled with epidemiology, should target the activities of the various kinases in the PI3K/Akt/mTORC1 systems and related physiological processes for selected urban, rural and coastal populations in order to test this hypothesis.

Standardization and quality control in quantifying non-enzymatic oxidative protein modifications in relation to ageing and disease: Why is it important and why is it hard?

Post-translational modifications (PTM) of proteins determine the activity, stability, specificity, transportability and lifespan of a protein. Some PTM are highly specific and regulated involving various enzymatic pathways, but there are other non-enzymatic PTM (nePTM), which occur stochastically, depend on the ternary structure of proteins and can be damaging. It is often observed that inactive and abnormal proteins accumulate in old cells and tissues. The nature, site and extent of nePTM give rise to a population of that specific protein with alterations in structure and function ranging from being fully active to totally inactive molecules. Determination of the type and the amount (abundance) of nePTM is essential for establishing connection between specific protein structure and specific biological role. This article summarizes analytical demands for reliable quantification of nePTM, including requirements for the assay performance, standardization and quality control, and points to the difficulties, uncertainties and un-resolved issues.

ROS produced by NOX2 control in vitro development of cerebellar granule neurons development

Reactive oxygen species (ROS) act as signaling molecules that regulate nervous system physiology. ROS have been related to neural differentiation, neuritogenesis, and programmed cell death. Nevertheless, little is known about the mechanisms involved in the regulation of ROS during neuronal development. In this study, we evaluated the mechanisms by which ROS are regulated during neuronal development and the implications of these molecules in this process. Primary cultures of cerebellar granule neurons (CGN) were used to address these issues. Our results show that during the first 3 days of CGN development in vitro (days in vitro; DIV), the levels of ROS increased, reaching a peak at 2 and 3 DIV under depolarizing (25 mM KCl) and nondepolarizing (5 mM KCl) conditions. Subsequently, under depolarizing conditions, the ROS levels markedly decreased, but in nondepolarizing conditions, the ROS levels increased gradually. This correlated with the extent of CGN maturation. Also, antioxidants and NADPH-oxidases (NOX) inhibitors reduced the expression of Tau and MAP2. On the other hand, the levels of glutathione markedly increased at 1 DIV. We inferred that the ROS increase at this time is critical for cell survival because glutathione depletion leads to axonal degeneration and CGN death only at 2 DIV. During the first 3 DIV, NOX2 was upregulated and expressed in filopodia and growth cones, which correlated with the hydrogen peroxide (H2O2) distribution in the cell. Finally, NOX2 KO CGN showed shorter neurites than wild-type CGN. Taken together, these results suggest that the regulation of ROS is critical during the early stages of CGN development.

Hydrogen peroxide generation and biocompatibility of hydrogel-bound mussel adhesive moiety

To decouple the extracellular oxidative toxicity of catechol adhesive moiety from its intracellular non-oxidative toxicity, dopamine was chemically bound to a non-degradable polyacrylamide hydrogel through photo-initiated polymerization of dopamine methacrylamide (DMA) with acrylamide monomers. Network-bound dopamine released cytotoxic levels of H2O2 when its catechol side chain oxidized to quinone. Introduction of catalase at a concentration as low as 7.5 U/mL counteracted the cytotoxic effect of H2O2 and enhanced the viability and proliferation rate of fibroblasts. These results indicated that H2O2 generation is one of the main contributors to the cytotoxicity of dopamine in culture. Additionally, catalase is a potentially useful supplement to suppress the elevated oxidative stress found in typical culture conditions and can more accurately evaluate the biocompatibility of mussel-mimetic biomaterials. The release of H2O2 also induced a higher foreign body reaction to catechol-modified hydrogel when it was implanted subcutaneously in rat. Given that H2O2 has a multitude of biological effects, both beneficiary and deleterious, regulation of H2O2 production from catechol-containing biomaterials is necessary to optimize the performance of these materials for a desired application.

Assesment of oxidative status and its association with thyroid autoantibodies in patients with euthyroid autoimmune thyroiditis

Oxidative stress results from either overproduction of free radicals or insufficiency of several anti-oxidant defense systems. It leads to oxidation of main cellular macromolecules and a resultant molecular dysfunction. Thyroid hormones regulate oxidative metabolism and, thus, play a role in free radical production. Studies evaluating oxidative stress in patients with hypothyroidism and hyperthyroidism have been encountered in recent years; however, oxidative status in patients with euthyroid autoimmune thyroiditis (AIT) was not investigated previously. Thirty-five subjects with euthyroid AIT and 35 healthy controls were enrolled in the study. Serum oxidative status was determined by the measurement of total anti-oxidant status (TAS), total oxidant status (TOS), ischemia-modified albumin (IMA), and oxidized-low density lipoprotein (ox-LDL) levels. Serum TAS levels were significantly lower (p<0.001), while serum TOS levels and IMA levels were significantly higher (p<0.001 and p=0.020, respectively) in patients compared to controls. In both groups, ox-LDL levels were similar (p=0.608). Serum TAS levels were negatively correlated with anti-thyroid peroxidase and anti-thyroglobulin (anti-TG) levels (rho=-0.415, p=0.001 and rho=-0.484, p<0.001, respectively). Serum TOS was positively correlated with anti-TG levels (rho=0.547, p<0.001). Further, TAS was positively correlated with free T4 levels (r=0.279, p=0.043). No correlation was observed between thyrotropin, free T3 levels, and TOS and TAS levels. These results suggest that oxidants are increased, and anti-oxidants are decreased in patients with euthyroid AIT, and oxidative/anti-oxidative balance is shifted to the oxidative side. Increased oxidative stress might have a role in thyroid autoimmunity.

Oxidative stress in neurodegenerative diseases

Reactive oxygen species are constantly produced in aerobic organisms as by-products of normal oxygen metabolism and include free radicals such as superoxide anion (O₂⁻) and hydroxyl radical (OH⁻), and non-radical hydrogen peroxide (H₂O₂). The mitochondrial respiratory chain and enzymatic reactions by various enzymes are endogenous sources of reactive oxygen species. Exogenous reactive oxygen species -inducing stressors include ionizing radiation, ultraviolet light, and divergent oxidizing chemicals. At low concentrations, reactive oxygen species serve as an important second messenger in cell signaling; however, at higher concentrations and long-term exposure, reactive oxygen species can damage cellular macromolecules such as DNA, proteins, and lipids, which leads to necrotic and apoptotic cell death. Oxidative stress is a condition of imbalance between reactive oxygen species formation and cellular antioxidant capacity due to enhanced ROS generation and/or dysfunction of the antioxidant system. Biochemical alterations in these macromolecular components can lead to various pathological conditions and human diseases, especially neurodegenerative diseases. Neurodegenerative diseases are morphologically featured by progressive cell loss in specific vulnerable neuronal cells, often associated with cytoskeletal protein aggregates forming inclusions in neurons and/or glial cells. Deposition of abnormal aggregated proteins and disruption of metal ions homeostasis are highly associated with oxidative stress. The main aim of this review is to present as much detailed information as possible that is available on various neurodegenerative disorders and their connection with oxidative stress. A variety of therapeutic strategies designed to address these pathological processes are also described. For the future therapeutic direction, one specific pathway that involves the transcription factor nuclear factor erythroid 2-related factor 2 is receiving considerable attention.

Evaluation of antioxidant and anticancer activity of extract and fractions of Nardostachys jatamansi DC in breast carcinoma

Background

Nardostachys jatamansi DC is a Himalayan medicinal herb that has been described in various traditional systems of medicine for its use in cancer. In view of its traditional claims, and chemical constituents, antioxidant and anticancer activities were evaluated in breast carcinoma.

Methods

Petroleum ether (NJPE), methanol extract (NJM) and subsequent diethyl ether (NJDE), ethyl acetate (NJEA) and aqueous (NJAQ) fractions of roots and rhizomes of N. jatamansi were prepared. Total phenolic, flavonoid content, and antioxidant activities were determined using suitable methods. Antiproliferative activity was assessed in estrogen receptor (ER)-positive (MCF-7) and ER-negative breast carcinoma (MDA-MB-231) cells by MTT and SRB assay. Cell cycle analysis, Hoechst staining, and clonogenic assay were employed to determine the mode of antiproliferative and pro-apoptotic activity in MDA-MB-231 cells.

Results

NJM/fractions exhibited prominent antioxidant activity with significant correlation between phenolic content and ABTS (IC₅₀) scavenging (R = −0.9680, P < 0.05), and total antioxidant capacity (R = 0.8396, P > 0.05). In MTT assay, NJM exhibited the highest antiproliferative activity (IC₅₀: 58.01 ± 6.13 and 23.83 ± 0.69 μg/mL in MCF-7 and MDA-MB-231 respectively). Among the fractions, NJPE and NJDE were found to be most potent in MCF-7 (IC₅₀: 60.59 ± 4.78 μg/mL) and MDA-MB-231 (IC₅₀: 25.04 ± 0.90 μg/mL) cells respectively. Statistical analyses revealed NJM and NJDE exhibited significantly higher (P < 0.05) cytotoxicity in MDA-MB-231 cells. Cell cycle analysis demonstrated that NJM, NJPE and NJEA caused G₂/M arrest while NJDE caused G₀/G₁ phase arrest in MDA-MB-231 cells. Further, NJM/fractions induced significant (P < 0.001) cell death by apoptosis characterized by apoptotic morphological changes in Hoechst staining and inhibited long-term proliferation (P < 0.001) of MDA-MB-231 cells in clonogenic assay. Lupeol and β-sitosterol were identified as anticancer principles in NJM/fractions by HPTLC.

Conclusion

Our results suggest that NJM/fractions possess significant antiproliferative potential which is mediated through cell cycle perturbation and pro-apoptotic effects in MDA-MB-231 cells. Moreover, this study highlights the antioxidant potential of NJM/fractions which can be attributed to the presence of phenols. NJDE emerged as the most potent fraction and further mechanistic and phytochemical investigations are under way to identify the active principles.

Antioxidative and antiatherogenic effects of flaxseed, α-tocopherol and their combination in diabetic hamsters fed with a high-fat diet

Oxidative stress has previously been shown to play a role in the pathogenesis of diabetes mellitus (DM) and its complications. In the present study, the effects of supplementation with dietary antioxidants, flaxseed and α-tocopherol were investigated in diabetic golden Syrian hamsters fed with a high-fat diet. Thirty-five golden Syrian hamsters were randomly divided into a control group (C) and four diabetic groups (DM, DM + flax, DM + E and DM + Flax + E). The hamsters received four different diets for a 20-week period, as follows: i) Groups C and DM received a high-fat diet (40% energy as fat), deficient in α-linolenic acid (ALA); ii) the DM + Flax group received a high-fat diet enriched with ground flaxseed 15 g/100 g of food, rich in ALA; iii) the DM + E group received a high-fat diet enriched with vitamin E, 40 mg α-tocopherol/100 g of food; and iv) the DM + Flax + E group received a high-fat diet enriched with flaxseed and vitamin E. The results of serum lipid and oxidative stress analysis suggested that the antiatherogenic effect of flaxseed, α-tocopherol and their combination added to a high-fat diet in diabetic hamsters was based primarily on their antioxidative role, demonstrated by decreased serum lipid peroxidation and increased liver glutathione content. Improvements of serum glucose and non-high-density lipoprotein cholesterol (HDL-C) levels were observed and may have contributed to the prevention of diabetic macroangiopathy evidenced in the histopathological examination. The antioxidant effect of flaxseed was similar to that of α-tocopherol in diabetic hamsters fed a high-fat diet and combined supplementation did not appear to bring more benefits than flaxseed alone. Moreover, the high dose of ground flaxseed alone may have a better cardioprotective effect than α-tocopherol in diabetic hamsters by reducing total cholesterol and non-HDL-C levels and increasing HDL-C levels.

Oxidative stress and its significant roles in neurodegenerative diseases and cancer

Reactive oxygen and nitrogen species have been implicated in diverse pathophysiological conditions, including inflammation, neurodegenerative diseases and cancer. Accumulating evidence indicates that oxidative damage to biomolecules including lipids, proteins and DNA, contributes to these diseases. Previous studies suggest roles of lipid peroxidation and oxysterols in the development of neurodegenerative diseases and inflammation-related cancer. Our recent studies identifying and characterizing carbonylated proteins reveal oxidative damage to heat shock proteins in neurodegenerative disease models and inflammation-related cancer, suggesting dysfunction in their antioxidative properties. In neurodegenerative diseases, DNA damage may not only play a role in the induction of apoptosis, but also may inhibit cellular division via telomere shortening. Immunohistochemical analyses showed co-localization of oxidative/nitrative DNA lesions and stemness markers in the cells of inflammation-related cancers. Here, we review oxidative stress and its significant roles in neurodegenerative diseases and cancer.

Validation of a high throughput flow cytometric in vitro micronucleus assay including assessment of metabolic activation in TK6 cells

Genotoxicity is an unacceptable property for new drug candidates and we employ three screening assays during the drug discovery process to identify genotoxicity early and optimize chemical series. One of these methods is the flow cytometric in vitro micronucleus assay for which protocol optimizations have been described recently. Here, we report further validation of the assay in TK6 cells including assessment of metabolic activation. We first optimized assay conditions to allow for testing with and without metabolic activation in parallel in a 96-well plate format. Then, we tested a set of 48 compounds carefully selected to contain known in vivo genotoxins, nongenotoxins and drugs. Avoidance of irrelevant positives, a known issue with mammalian cell-based genotoxicity assays, is important to prevent early deselection of potentially promising compounds. Therefore, we enriched the validation set with compounds that were previously reported to produce irrelevant positive results in mammalian cell-based genotoxicity assays. The resulting dataset was used to set the relevant cut-off values for scoring a compound positive or negative, such that we obtained an optimal balance of high sensitivity (88%) and high specificity (87%). Finally, we tested an additional set of 16 drugs to further probe assay performance and 14 of them were classified correctly. To our knowledge, the present study is the most comprehensive validation of the in vitro flow cytometric micronucleus assay and the first to report parallel assessment with metabolic activation in reasonable throughput. The assay allows for rapidly screening novel compounds for genotoxicity and is therefore well-suited for use in early drug discovery projects. Environ.

Hydrogen peroxide administered into the rat spinal cord at the level elevated by contusion spinal cord injury oxidizes proteins, DNA and membrane phospholipids, and induces cell death: attenuation by a metalloporphyrin

We previously demonstrated that hydrogen peroxide concentration ([H2O2]) significantly increases after spinal cord injury (SCI). The present study explored (1) whether SCI-elevated [H2O2] is sufficient to induce oxidation and cell death, (2) if apoptosis is a pathway of H2O2-induced cell death, and (3) whether H2O2-induced oxidation and cell death could be reversed by treatment with the catalytic antioxidant Mn (III) tetrakis (4-benzoic acid) porphyrin (MnTBAP). H2O2 was perfused through a microcannula into the uninjured rat spinal cord to mimic the conditions induced by SCI. Protein and DNA oxidation, membrane phospholipids peroxidation (MLP), cell death and apoptosis were characterized by histochemical and immunohistochemical staining with antibodies against markers of oxidation and apoptosis. Stained cells were quantified in sections of H2O2-, or artificial cerebrospinal fluid (ACSF)-exposed with vehicle-, or MnTBAP-treated groups. Compared with ACSF-exposed animals, SCI-elevated [H2O2] significantly increased intracellular protein and DNA oxidation by threefold and MLP by eightfold in neurons, respectively. H2O2-elevated extracellular malondialdehyde was measured by microdialysis sampling. We demonstrated that SCI-elevated [H2O2] significantly increased extracellular malondialdehyde above pre-injury levels. H2O2 also significantly increased cell loss and the numbers of terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate-(dUTP)-biotin nick end labeling (TUNEL)-positive and active caspase-3-positive neurons by 2.3-, 2.8-, and 5.6-fold compared to ACSF controls, respectively. Our results directly and unequivocally demonstrate that SCI-elevated [H2O2] contributes to post-SCI MLP, protein, and DNA oxidation to induce cell death. Therefore, we conclude that (1) the role of H2O2 in secondary SCI is pro-oxidation and pro-cell death, (2) apoptosis is a pathway for SCI-elevated [H2O2] to induce cell death, (3) caspase activation is a mechanism of H2O2-induced apoptosis after SCI, and (4) MnTBAP treatment significantly decreased H2O2-induced oxidation, cell loss, and apoptosis to the levels of ACSF controls, further supporting MnTBAP's ability to scavenge H2O2 by in vivo evidence.

Viral load is associated with abnormal serum levels of micronutrients and glutathione and glutathione-dependent enzymes in genotype 3 HCV patients

Background

Oxidative stress in hepatitis C patients has been linked to hepatitis C virus. We verified this assumption in HCV genotype 3 patients by detecting the relationship between viral load and certain specific oxidative stress markers like Cu, Mn, Fe, Se, Zn and glutathione and glutathione-dependent enzymes.

Method

Subjects (n = 200, average age 24 years) with quantitative HCV RNA polymerase chain reaction-proven genotype 3 hepatitis C were simultaneously evaluated. Cu, Mn, Fe, Se and Zn serum levels were by using atomic absorption spectrophotometer. Internationally accepted methods were used for viral load quantification of glutathione, GR and Gpx serum levels.

Result

There was a significant correlation between HCV viral load and studied parameters. With the increase of viral load from mild group (200,000–1,000,000 copies/ml) to severe group (5,000,000–25,000,000 copies/ml) the serum levels of Cu, Mn, Zn, and Fe and glutathione reductase were found to be abnormally high. However, in severe viral load group serum concentration of Se and glutathione was less than the healthy controls.

Conclusion

As a significant correlation was detected between the study parameters in genotype 3 HCV patients, it is concluded that the studied micronutrients and glutathione and glutathione-dependent enzymes are the biomolecular targets of HCV to induce oxidative stress.

General significance

Constant monitoring and regulation of the recommended biomolecular targets of HCV can improve the plight of more than 170 million patients suffering from hepatitis C virus around the globe.

•

Viral load, micronutrients, antioxidants are key factors involved in oxidative stress.

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We investigated viral load GSH, GPx, GR, Cu, Mn, Zn, Se, and Fe in genotype 3 HCV patients.

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Abnormal levels of GSH, GPx, Gr and micronutrients are linked with the progression of hepatitis C.

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These parameters are associated to immune response, mitochondrial damage and inflammation.

Potential role of catalase in mice with lipopolysaccharide/D-galactosamine-induced fulminant liver injury

AIM

Lipopolysaccharide (LPS)-induced liver injury in D-galactosamine (D-Gal)-sensitized mice is a well-established animal model widely used in exploring the pathogenesis of fulminant hepatitis. Increasing evidence has indicated that reactive oxygen species (ROS)-induced oxidative injury may be involved in LPS/D-Gal-induced hepatitis. Catalase (CAT) is a major antioxidant enzyme while aminotriazole (ATZ) is commonly used as a CAT inhibitor. In the present study, the effects of ATZ on LPS/D-Gal-induced liver injury were investigated.

METHODS

Fuliminant liver injury was induced by intraperitoneal injection of LPS combined with D-Gal, ATZ was administrated 0.5 h prior to LPS/D-Gal challenge. The degree of liver injury, the level of hepatic oxidative stress, the grade of hepatic apoptosis and the survival of experimental animals were determined.

RESULTS

Our experimental data showed that treatment with ATZ significantly enhanced LPS/D-Gal-induced elevation of serum aspartate transaminase (AST) and alanine transaminase (ALT), exacerbated the hepatic histopathological abnormality and decreased the survival rate of experimental animals. ATZ inhibited the activity of CAT, increased the content of H2 O2 and the levels of malondialdehyde (MDA) in liver tissues. In addition, treatment with ATZ also enhanced LPS/D-Gal-induced hepatic apoptosis as evidenced by increased caspases activities in liver tissues and increased number of terminal deoxynucleotidyl transferase dUTP nick end labeling positive cells in liver sections.

CONCLUSION

These findings suggested that CAT might be involved in the progression of LPS/D-Gal-induced fulminant liver injury.

Composition of protein supplements used for human embryo culture

PURPOSE

To determine the composition of commercially available protein supplements for embryo culture media and test if differences in protein supplement composition are biologically relevant in a murine model.

METHODS

Amino acid, organic acid, ion and metal content were determined for 6 protein supplements: recombinant human albumin (AlbIX), human serum albumin (HSA and Buminate), and three complex protein supplements (SSS, SPS, LGPS). To determine if differences in the composition of these supplements are biologically relevant, mouse one-cell embryos were collected and cultured for 120 hours in each protein supplement in Global media at 5 and 20 % oxygen in an EmbryoScope time-lapse incubator. The compositions of six protein supplements were analyzed for concentrations of 39 individual amino acids, organic acids, ions and elements. Blastocyst development and cell cycle timings were calculated at 96-hours of culture and the experiments were repeated in triplicate. Blastocyst gene expression was analyzed.

RESULTS

Recombinant albumin had the fewest undefined components , the lowest concentration of elements detected, and resulted in high blastocyst development in both 5 and 20 % oxygen. Buminate, LGPS and SPS had high levels of transition metals whereas SSS had high concentrations of amino acids. Pre-compaction mouse embryo development was delayed relative to embryos in AlbIX for all supplements and blastocyst formation was reduced in Buminate, SPS and SSS.

CONCLUSIONS

The composition of protein supplements are variable, consisting of previously undescribed components. High concentrations of pro-oxidant transition metals were most notable. Blastocyst development was protein dependent and showed an interaction with oxygen concentration and pro-oxidant supplements.

Immunosenescence in monocytes, macrophages, and dendritic cells: lessons learned from the lung and heart

In the absence of an immune challenge, healthy, aged individuals have a significantly higher basal inflammatory state where circulating levels of cytokines, including IL-6, TNF-α and IL-1β, are elevated [1]. This progressive pro-inflammatory state, termed "inflamm-aging", affects the phenotype/function of cells present in the aged as well as renders the older individuals more susceptible to a poor prognosis after systemic insults. Although it is important to understand the mechanisms that underlie the progression of disease, most preclinical analyses of disease therapies are performed in young adult mice that have an intact, functional immune system. Oftentimes, this is not necessarily representative of the immune disposition in the aged, let alone diseased, aged. Herein, two distinct responses that are not only commonly associated with aging but that also have dendritic cells and/or monocytes and macrophages as key players are discussed: pulmonary infection and myocardial infarction. Although studies of pulmonary infection in the aged have progressed significantly, studies of monocytes and macrophages in inflammation and cardiac injury following ischemia in the aged have not been as forthcoming. Nonetheless, several elegant studies have established the dynamic role of monocytes and macrophages post infarction. These will be discussed in light of what is known with aging.

A synthetic bioisoster of trimethadione and phenytoin elicits anticonvulsant effect, protects the brain oxidative damage produced by seizures and exerts antidepressant action in mice

Epilepsy is recognized as one of the most common and serious neurological disorder affecting 1-2% of the world׳s population. The present study demonstrates that systemic administration of 3-butyl-5,5-dimethyl-1,2,3-oxathiazolidine-4-one-2,2-dioxide (DIOXIDE), a synthetic compound bioisoster of trimethadione and phenytoin (classical anticonvulsants), elicits a dose dependent anticonvulsant response in mice submitted to the subcutaneous pentylenetetrazole seizure test (scPTZ). Among various factors supposed to play role in epilepsy, oxidative stress and reactive species have strongly emerged. The protection exerted by DIOXIDE over the extent of brain oxidative damage produced by PTZ was determined, by measuring the levels of lipid peroxidation and reduced glutathione and the activity of Na(+)/K(+)-ATPase. Psychiatric disorders represent frequent comorbidities in persons with epilepsy. In this report, the potential anxiolytic and antidepressant activities of DIOXIDE were evaluated in several widely used models for assessing anxiolytic and antidepressant activities in rodents. Although DIOXIDE did not evidence anxiolytic activity at the doses tested, it revealed a significant antidepressant-like effect. Preliminary studies of its mechanism of action, by means of its capacity to act via the GABAA receptor (using the [(3)H]flunitrazepam binding assay in vitro and the picrotoxin test in vivo) and the Na(+) channel (using the alkaloid veratrine, a voltage-Na(+) channel agonist) demonstrated that the anticonvulsant effect is not likely related to the GABAergic pathway and the antidepressant-like effect could be due to its Na(+) channel blocking properties. The results for DIOXIDE suggested it as a new anticonvulsant-antioxidant and antidepressant compound that deserves further development.

Reactive oxygen species-scavenging nanomedicines for the treatment of oxidative stress injuries

This Progress Report describes a development of two types of reactive oxygen species (ROS)-scavenging nanomedicines for the treatment of oxidative stress injuries, referred to as pH-sensitive redox nanoparticle (RNP(N) ) and pH-insensitive redox nanoparticle (RNP(O) ), which are prepared by self-assembling amphiphilic block copolymers possessing nitroxide radicals as a side chain of hydrophobic segment via amine and ether linkages, respectively. Due to a protonation of amino groups in hydrophobic core, RNP(N) disintegrates in low pH environments such as ischemic, inflamed, and tumor tissues, resulting in increased ROS-scavenging activity because of the exposed nitroxide radicals from the core. Utilizing pH-responsiveness of RNP(N) , it shows remarkable therapeutic effects on oxidative stress injuries such as renal and cerebral ischemia-reperfusion injuries after intravenous administration. Moreover, RNP(N) shows an enhancement of the activity of anticancer drugs by suppression of activation of transcription factors in tumor due to the ROS scavenging. On the other hand, orally administered RNP(O) has notable characteristics such as preferential accumulation in mucosa and inflamed area of gastrointestinal tract and no uptake into blood stream. Based on these characters, RNP(O) shows a remarkable therapeutic effect for the gastrointestinal inflammation without any adverse effects. Thus, ROS-scavenging nanomedicines have therapeutic efficacy in numerous oxidative stress diseases.

Uptake and protective effects of ergothioneine in human endothelial cells

Ergothioneine is a thiourea derivative of histidine found in food, especially mushrooms. Experiments in cell-free systems and chemical assays identified this compound as a powerful antioxidant. Experiments were designed to test the ability of endothelial cells to take up ergothioneine and hence benefit from protection against oxidative stress. Reverse-transcription polymerase chain reaction and Western blotting demonstrated transcription and translation of an ergothioneine transporter in human brain microvascular endothelial cells (HBMECs). Uptake of [(3)H]ergothioneine occurred by the organic cation transporter novel type-1 (OCTN-1), was sodium-dependent, and was reduced when expression of OCTN-1 was silenced by small interfering RNA (siRNA). The effect of ergothioneine on the production of reactive oxygen species (ROS) in HBMECs was measured using dichlorodihydrofluorescein and lucigenin, and the effect on cell viability was studied using the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. ROS production and cell death induced by pyrogallol, xanthine oxidase plus xanthine, and high glucose were suppressed by ergothioneine. The antioxidant and cytoprotective effects of ergothioneine were abolished when OCTN-1 was silenced using siRNA. The expression of NADPH oxidase 1 was decreased, and those of glutathione reductase, catalase, and superoxide dismutase enhanced by the compound. In isolated rat basilar arteries, ergothioneine attenuated the reduction in acetylcholine-induced relaxation caused by pyrogallol, xanthine oxidase plus xanthine, or incubation in high glucose. Chronic treatment with the compound improved the response to acetylcholine in arteries of rats with streptozotocin-induced diabetes. In summary, ergothioneine is taken up by endothelial cells via OCTN-1, where the compound then protects against oxidative stress, curtailing endothelial dysfunction.

Ovothiol isolated from sea urchin oocytes induces autophagy in the Hep-G2 cell line

Ovothiols are histidine-derived thiols isolated from sea urchin eggs, where they play a key role in the protection of cells toward the oxidative burst associated with fertilization by controlling the cellular redox balance and recycling oxidized glutathione. In this study, we show that treatment of a human liver carcinoma cell line, Hep-G2, with ovothiol A, isolated from Paracentrotus lividus oocytes, results in a decrease of cell proliferation in a dose-dependent manner. The activation of an autophagic process is revealed by phase contrast and fluorescence microscopy, together with the expression of the specific autophagic molecular markers, LC3 II and Beclin-1. The effect of ovothiol is not due to its antioxidant capacity or to hydrogen peroxide generation. The concentration of ovothiol A in the culture media, as monitored by HPLC analysis, decreased by about 24% within 30 min from treatment. The proliferation of normal human embryonic lung cells is not affected by ovothiol A. These results hint at ovothiol as a promising bioactive molecule from marine organisms able to inhibit cell proliferation in cancer cells.