Activation Of Defense System Research Articles

Oxidative Stress in Spinocerebellar Ataxia Type 7 Is Associated with Disease Severity.

Spinocerebellar ataxia type 7 is a neurodegenerative inherited disease caused by a CAG expansion in the coding region of the ATXN7 gene, which results in the synthesis of polyglutamine-containing ataxin-7. Expression of mutant ataxin-7 disturbs different cell processes, including transcriptional regulation, protein conformation and clearance, autophagy, and glutamate transport; however, mechanisms underlying neurodegeneration in SCA7 are still unknown. Implication of oxidative stress in the pathogenesis of various neurodegenerative diseases, including polyglutamine disorders, has recently emerged. We perform a cross-sectional study to determine for the first time pheripheral levels of different oxidative stress markers in 29 SCA7 patients and 28 age- and sex-matched healthy subjects. Patients with SCA7 exhibit oxidative damage to lipids (high levels of lipid hydroperoxides and malondialdehyde) and proteins (elevated levels of advanced oxidation protein products and protein carbonyls). Furthermore, SCA7 patients showed enhanced activity of various anti-oxidant enzymes (glutathione reductase, glutathione peroxidase, and paraoxonase) as well as increased total anti-oxidant capacity, which suggest that activation of the antioxidant defense system might occur to counteract oxidant damage. Strikingly, we found positive correlation between some altered oxidative stress markers and disease severity, as determined by different clinical scales, with early-onset patients showing a more severe disturbance of the redox system than adult-onset patients. In summay, our results suggest that oxidative stress might contribute to SCA7 pathogenesis. Furthermore, oxidative stress biomarkers that were found relevant to SCA7 in this study could be useful to follow disease progression and monitor therapeutic intervention.

Silicon and its application method effects on modulation of cadmium stress responses in Triticum aestivum (L.) through improving the antioxidative defense system and polyamine gene expression

Identification of the optimum application method of exogenous supports for crop plants to improve their growth under environmental stresses such as heavy metals represents key priorities for researchers worldwide. Influences of different application methods of silicon (Si; 3 mM); soil treatment, foliar spray and seed soaking on growth, chlorophyll fluorescence, photosynthetic gas exchange, cell membrane injury, osmoprotectants contents, antioxidative defense system activity, and polyamines contents and their gene expression in wheat plants grown under normal and 2 mM cadmium (Cd) stress conditions were investigated in 3-repeated pot experiment. Cd stress severely depressed growth, chlorophyll fluorescence, photosynthetic gas exchange, tissue health, water use efficiency (WUE) and Si content, and elevated osmoprotectants and Cd2+ contents, antioxidative defense system activity, and polyamines contents and their gene expression. However, Si in different application methods alleviated the Cd stress effects and significantly reduced Cd2+ and MDA contents and electrolyte leakage, significantly increased growth, chlorophyll fluorescence, photosynthetic gas exchange, WUE, membrane stability index, relative water content and Si content, and further increased proline and soluble sugars contents, antioxidative (enzymatic and non-enzymatic) defense system activity, and polyamines contents and their gene expression. Among the three methods, Si applied as soil addition was the best and most effective in alleviating the Cd stress effects.

Natural Biostimulants Improve Saline Soil Characteristics and Salt Stressed-Sorghum Performance

ABSTRACTHumus substances (HM) and Moringa oleifera leaf extract (MLE) are considered as biostimulants used for plant growing under normal and salt stress conditions. Therefore, effects of soil HM and foliar MLE applications on soil characteristics and on sorghum growth, physio-biochemical properties, and antioxidant defense system activity were investigated under salt stress using pot experiments. The experimental design was a split-split plot with three soil salinities (S1, S2, and S3) as main-plots, two HM levels (0 and 0.1 g kg‒1 soil) as subplots, and two MLE levels (0% and 3%) as sub-subplots, and each one of the 12 treatments was replicated 20 times. Saline soil properties were improved by HM. Under saline conditions, either HM or MLE increased growth characteristics, photochemical activity, contents of RNA, DNA, phytohormones, osmoprotectants and non-enzymatic antioxidants, and activities of antioxidant enzymes in sorghum plants compared to those in the untreated control plants. The interactive HM×MLE application was most effective at overcoming the harmful effects of soil salinity stress and further increased the abovementioned criteria. This study, therefore, recommends using the integrative HM+MLE treatment for growing sorghum plants in saline soils up to more than 6.12 dS m‒1 without loss in growth characteristics.

Comparative Proteomic Analysis of Potato (Solanum tuberosum L.) Tuberization In Vitro Regulated by IAA

Auxin (IAA) is one of the important factors regulating potato tuberization among the multiple environmental signals and hormonal factors. To understand the molecular mechanism of potato tuberization regulated by IAA, a comparative proteomic approach was applied to analyze proteome change of tubers in vitro subjected to exogenous IAA treatments (0, 2 and 4 mg L−1) using two-dimensional gel electrophoresis (2-DE). Quantitative image analysis showed a total of 76 protein spots with abundance significantly altered (P < 0.05) more than 1.2-fold. Mass spectrometry analysis allowed the identification of 49 differential abundance proteins, mainly involved in metabolism and bioenergy, storage, redox homeostasis, transcription and translation, defense and rescue, chaperone and unknown. The promotion effects of low IAA concentration treatment (2 mg L−1) on tuberization were found in various cellular processes, which mainly included changes in the metabolism of carbohydrates and amino acids, the accumulation of storage proteins, the activation of more antioxidation and defense systems as well as the higher efficiency of transcription and translation for protein synthesis. The corresponding inhibition effects were shown at higher concentration (4 mg L−1). This study provides some new insights into the underlying molecular mechanism of potato tuberization regulated by IAA.

Sequenced ascorbate-proline-glutathione seed treatment elevates cadmium tolerance in cucumber transplants

During its life cycle, plant has to cope with a number of abiotic stresses including cadmium stress. Cadmium (Cd) is highly toxic to plant and greatly influences its growth and entire metabolism. Antioxidants have to enable plant to beat such stresses. Therefore, effects of ascorbate (AsA), proline (Pro) and glutathione (GSH) applied, as seed soaking solutions, singly or in a sequence on cucumber transplant growth, physio-biochemical attributes and antioxidant defense system activity were investigated under 2 mM Cd stress. Adding Cd to transplants in irrigation water reduced photosynthetic efficiency, and nutrient (K+ and Ca2+) contents, while increased the activity of defense systems (non-enzymatic and enzymatic antioxidants) and Cd2+ contents in roots and leaves. Exogenous AsA, Pro and GSH applied singly or in a sequence improved transplant growth (e.g., shoot length, leaf area, shoot fresh weight and shoot dry weight), photosynthetic efficiency (i.e., SPAD chlorophyll, Fv/Fm and PI), transplant health (i.e., increased leaf MSI and RWC, and decreased root and leaf Cd2+ contents), antioxidant defense systems activity (enzymatic; superoxide dismutase, catalase, glutathione reductase and ascorbate peroxidase, and non-enzymatic; Pro, AsA and GSH antioxidants) and nutrient (K+ and Ca2+) contents. These positive results were obtained under irrigation with or without Cd, AsA. Sequenced AsA-Pro-GSH was the best treatment of which this study recommends to use, followed by GSH treatment, for growing cucumber transplants under Cd stress.

The Phenolic Components of Gastrodia elata improve Prognosis in Rats after Cerebral Ischemia/Reperfusion by Enhancing the Endogenous Antioxidant Mechanisms.

Pharmacological or spontaneous thrombolysis in ischemic stroke triggers an outbreak of reactive oxygen species and results in neuron death. Nrf2-mediated antioxidation in cells has been proved as a pivotal target for neuroprotection. This research reports that phenolic components of Gastrodia elata Blume (PCGE), a traditional Chinese medicine, can alleviate the pathological lesions in the penumbra and hippocampus by increasing the survival of neurons and astrocytes and improve neurofunction and cognition after reperfusion in a rat model of middle cerebral artery occlusion. LDH assay indicated that pretreatment of cells with PCGE (25 μg/ml) for 24 h significantly reduced H2O2-induced cell death in astrocytes and SH-SY5Y cells. Western blot showed that the nucleus accumulation of Nrf2 and the expression of cellular HO-1 and NQO-1, two of Nrf2 downstream proteins, were increased in both cells. BDNF, an Nrf2-dependent neurotrophic factor, was also upregulated by PCGE in astrocytes. These results illustrated that PCGE can reduce the cerebral ischemia/reperfusion injury and improve prognosis by remedying the cell damage within affected tissues. The protective effects of PCGE seem to be via activation of a Nrf2-mediated cellular defense system. Therefore, PCGE could be a therapeutic candidate for ischemic stroke and other oxidative stress associated neurological disorders.

Neutrophils in Tissue Trauma of the Skin, Bone, and Lung: Two Sides of the Same Coin.

Following severe tissue injury, patients are exposed to various danger- and microbe-associated molecular patterns, which provoke a strong activation of the neutrophil defense system. Neutrophils trigger and modulate the initial posttraumatic inflammatory response and contribute critically to subsequent repair processes. However, severe trauma can affect central neutrophil functions, including circulation half-life, chemokinesis, phagocytosis, cytokine release, and respiratory burst. Alterations in neutrophil biology may contribute to trauma-associated complications, including immune suppression, sepsis, multiorgan dysfunction, and disturbed tissue regeneration. Furthermore, there is evidence that neutrophil actions depend on the quality of the initial stimulus, including trauma localization and severity, the micromilieu in the affected tissue, and the patient's overall inflammatory status. In the present review, we describe the effects of severe trauma on the neutrophil phenotype and dysfunction and the consequences for tissue repair. We particularly concentrate on the role of neutrophils in wound healing, lung injury, and bone fractures, because these are the most frequently affected tissues in severely injured patients.

Therapeutic Potential of Salviae Miltiorrhizae Radix et Rhizoma against Human Diseases Based on Activation of Nrf2-Mediated Antioxidant Defense System: Bioactive Constituents and Mechanism of Action.

Oxidative stress plays a central role in the pathogenesis of many human diseases. The nuclear factor erythroid 2-related factor 2 (Nrf2) is a key transcription factor regulating the intracellular antioxidant response and is an emerging target for the prevention and therapy of oxidative stress-related diseases. Salviae Miltiorrhizae Radix et Rhizoma (SMRR) is a traditional Chinese medicine (TCM) and is commonly used for the therapy of cardiac cerebral diseases. Cumulative evidences indicated that the extract of SMRR and its constituents, represented by lipophilic diterpenoid quinones and hydrophilic phenolic acids, were capable of activating Nrf2 and inhibiting oxidative stress. These bioactive constituents demonstrated a therapeutic potential against human diseases, exemplified by cardiovascular diseases, neurodegenerative diseases, diabetes, nephropathy, and inflammation, based on the induction of Nrf2-mediated antioxidant response and the inhibition of oxidative stress. In the present review, we introduced the SMRR and Nrf2 signaling pathway, summarized the constituents with an Nrf2-inducing effect isolated from SMRR, and discussed the molecular mechanism and pharmacological functions of the SMRR extract and its constituents.

L-ARGININE IS AN EFFECTIVE MEDICATION FOR PREVENTION OF ENDOTHELIAL DYSFUNCTION, A PREDICTOR OF ANTHRACYCLINE CARDIOTOXICITY IN PATIENTS WITH ACUTE LEUKEMIA

To evaluate the effectiveness of L-arginine in the prevention of endothelial dysfunction, which may be a predictor of anthracycline-induced myocardial injury, in patients with acute leukemia (AL) on the background of anthracycline antibiotics low cumulative doses from 100to 200mg/m2. A total of 81adult AL patients (38males and 43females with the age of 16-59years) were studied. The patients were divided into two groups: group I (n = 34), AL patients treated with chemotherapy (CT) and L-arginine hydrochloride; group II (n = 47)- AL patients treated with CT only. Cardiac evaluation and endothelial function assessment were performed at baseline and after second CT. Electrocardiography (ECG) parameters, lipid peroxidation activity, antioxidant protection and NO system state were evaluated. The bioelectric activity abnormalities of the myocardium were observed in studied patients with low cardiac risk after induction CT. In case of L-arginine administration, only minimal daily ECG changes were recorded. A significant difference in the lipid peroxidation and antioxidant defense system activity in patients of groupsI andII was determined. We noticed deepening of endothelial dysfunction on the background of cytostatic therapy with anthracycline antibiotics compared with baseline values in patients of group II. It was found that prophylactic L-arginine increases superoxide dismutase level and reduces the total NOS activity due to its inducible isoform. The leading factor of anthracycline-induced cardiotoxicity is the imbalance between free radical generation and their inactivation that leads to endothelial dysfunction development. L-arginine eliminates the prooxidant-antioxidant imbalance and improves the endothelial function.

Ultrasonication of in vitro potato single node explants: Activation and recovery of antioxidant defence system and growth responses

The ability to use sound or ultrasound (US) to modify plant growth in vitro, and if possible, to improve yield or productivity, would benefit horticultural scientists. In this study, potato (Solanum tuberosum L. cv. Desirée) in vitro node segments with a single leaf were exposed to US (35 kHz, 70 W, for 20 min). Morphological, physiological and biochemical parameters were measured. Treatment with US 24 h after ultrasonication temporarily accelerated shoot growth but inhibited the development and growth of roots due to a decrease in the level of AA directly after ultrasonication. At the end of the subculture period, i.e., 4 weeks after US treatment, shoot length increased 20% more than control shoots after 4 weeks, while shoot fresh weight was 24% higher than that of control shoots, representing the long-term after-effect of the US treatment. The antioxidant defence system was induced, partly by intensive plantlet growth and development from node segments, and partly by abiotic stress caused by the US treatment. Immediately (0 h) or 24 h after ultrasonication, superoxide dismutase, ascorbate peroxidase, and glutathione reductase activity increased significantly, as did the concentration of low molecular weight antioxidants (GSSG, GSH, AA, TCPa). However, there was no glutathione peroxidase activity, most likely due to the lack of selenium in the basal in vitro growth medium. Therefore, the glutathione-S-transferase path of the ascorbate-glutathione pathway was induced both by metabolic processes and by abiotic stresses and took part in the reduction of organic peroxides using glutathione. US treatment ameliorated the ratios of ascorbic acid/glutathione and reduced/oxidized glutathione, ensuring the development of plantlets with significantly improved shoot parameters, such as higher shoot length and fresh weight, by the end of the subculture period.

Ameliorative effect of black ginseng extract against oxidative stress-induced cellular damages in mouse hepatocytes

BackgroundOxidative stress induces the production of reactive oxygen species (ROS), which play important causative roles in various pathological conditions. Black ginseng (BG), a type of steam-processed ginseng, has drawn significant attention due to its biological activity, and is more potent than white ginseng (WG) or red ginseng (RG). MethodsWe evaluated the protective effects of BG extract (BGE) against oxidative stress-induced cellular damage, in comparison with WG extract (WGE) and RG extract (RGE) in a cell culture model. Ethanolic extracts of WG, RG, and BG were used to evaluate ginsenoside profiles, total polyphenols, flavonoid contents, and antioxidant activity. Using AML-12 cells treated with H2O2, the protective effects of WGE, RGE, and BGE on cellular redox status, DNA, protein, lipid damage, and apoptosis levels were investigated. ResultsBGE exhibited significantly enhanced antioxidant potential, as well as total flavonoid and polyphenol contents. ATP levels were significantly higher in BGE-treated cells than in control; ROS generation and glutathione disulfide levels were lower but glutathione (GSH) and NADPH levels were higher in BGE-treated cells than in other groups. Pretreatment with BGE inhibited apoptosis and therefore protected cells from oxidative stress-induced cellular damage, probably through ROS scavenging. ConclusionCollectively, our results demonstrate that BGE protects AML-12 cells from oxidative stress-induced cellular damages more effectively than WGE or RGE, through ROS scavenging, maintenance of redox status, and activation of the antioxidant defense system.

Ecotoxicological impact assessment of the brine discharges from a desalination plant in the marine waters of the Algerian west coast, using a multibiomarker approach in a limpet, Patella rustica.

The aim of our study is to evaluate the impact of Bousfer desalination plant brine discharges on the Algerian west coast, on a natural population of the marine gastropod mollusc Patella rustica. The effects of a chronic exposure to such discharges are complex to understand due to the combined effects of environmental physico-chemical parameters (e.g., high salinity) and different pollutants that can modulate the physiological responses of this species to stress. In this context, we assessed the biological effects in a marine species P. rustica, by a multibiomarker approach that provided information on the health status of organisms in response to such an environmental stress. We measured biomarkers in the whole soft tissues of limpets as indicators of neurotoxicity (AChE activity), oxidative stress (CAT, SOD, GR, and GPx activities), biotransformation (GST), oxidative damage (LPO through TBARS levels), and genotoxicity (CSP 3-like activity). In parallel, hydrological parameters were measured in the Bay of Oran, at four selected sites: site H considered as a "hotspot," located at Bousfer desalination plant; two other sites E and W, at the east and the west of H respectively; finally, site R "reference" located in Madragh, which is considered as a remote clean site. Our analyses revealed that the activities of antioxidant defense enzymes reached the highest levels in P. rustica collected from site H. The activation of antioxidant defense system in these organisms translated the alteration of their status health, reflecting a level of environmental disruption generated by the desalination plant brine discharges and the high salinity in this area. We also observed that the tissues of limpets collected from site H as well as the two other sites, E and W, had undergone molecular damage, confirmed by the high levels of CSP 3-like activity. This damage resulted from chronic exposure to environmental conditions, potentially genotoxic, due to the desalination plant discharges. The present results indicate the adverse impact of brine effluents from desalination plants on marine fauna and suggest the need for a more consistent approach to environmental management of brine discharges.

Ascophyllum nodosum Seaweed Extract Alleviates Drought Stress in Arabidopsis by Affecting Photosynthetic Performance and Related Gene Expression.

Drought represents one of the most relevant abiotic stress affecting growth and yield of crop plants. In order to improve the agricultural productivity within the limited water and land resources, it is mandatory to increase crop yields in presence of unfavorable environmental stresses. The use of biostimulants, often containing seaweed extracts, represents one of the options for farmers willing to alleviate abiotic stress consequences on crops. In this work, we investigated the responses of Arabidopsis plants treated with an extract from the brown alga Ascophyllum nodosum (ANE), under drought stress conditions, demonstrating that ANE positively influences Arabidopsis survival. Pre-treatment with ANE induced a partial stomatal closure, associated with changes in the expression levels of genes involved in ABA-responsive and antioxidant system pathways. The pre-activation of these pathways results in a stronger ability of ANE-treated plants to maintain a better photosynthetic performance compared to untreated plants throughout the dehydration period, combined with a higher capacity to dissipate the excess of energy as heat in the reaction centers of photosystem II. Our results suggest that drought stressed plants treated with ANE are able to maintain a strong stomatal control and relatively higher values of both water use efficiency (WUE) and mesophyll conductance during the last phase of dehydration. Simultaneously, the activation of a pre-induced antioxidant defense system, in combination with a more efficient energy dissipation mechanism, prevents irreversible damages to the photosynthetic apparatus. In conclusion, pre-treatment with ANE is effective to acclimate plants to the incoming stress, promoting an increased WUE and dehydration tolerance.

Antioxidant Activity of Yichun Blue Honeysuckle (YBHS) Berry Counteracts CCl₄-Induced Toxicity in Liver Injury Model of Mice.

Yichun Blue Honeysuckle (YBHS) is reported to have a broad range of health benefits including protection against a number of chronic diseases. The objective of our study was to determine whether YBHS exhibits antioxidant activity, and if so, determine how it provides protection against oxidative stress. Eight-week old mice (25 male and 25 female) were randomized into five groups (n = 10 per group). YBHS extract (at 6.25%, 12.5%, or 25%) was administrated via intra-gastric tube to mice at 0.1 mL/10 g body weight once daily for 7 days. On the 8th day, all animals except for the controls received 250 mg/kg of CCl4 through an intra-gastric tube. The animals were sacrificed 6 h after CCl4 administration. Liver samples obtained from these mice were analyzed for the levels of Thiobarbituric Acid Reactive Substances (TBARS) and glutathione and the activities of Superoxide Dismutase (SOD), Catalase (CAT), and Glutathione Peroxidase (GPx), using biochemical assay kits. Our results showed that YBHS indeed reduces lipid peroxidation, suggesting that YBHS decreases the Reactive Oxygen Species (ROS) levels. We also found that YBHS activated the endogenous antioxidant enzymes including superoxide dismutase, catalase, and glutathione peroxidase and its co-enzyme glutathione reductase. In addition, we showed that glutathione levels were increased by YBHS treatment. Furthermore, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay revealed that YBHS has potent free radical scavenging activity. Based on the results from our study, we conclude that YBHS scavenges ROS by enhancing the activity of the endogenous antioxidant defense system activity for conferring liver protective effects.

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.

Strains of Bacillus ssp. regulate wheat resistance to Septoria nodorum Berk.

The ability of Bacillus subtilis Cohn and Bacillus thuringiensis Berliner to induce systemic resistance in wheat plants to the casual agent of Septoria nodorum Berk., blotch has been studied. It has been shown that strains of Bacillus ssp. that possess the capacity for endophytic survival have antagonistic activity against this pathogen in vitro. A reduction of the degree of Septoria nodorum blotch development on wheat leaves under the influence of Bacillus spp. was accompanied by the suppression of catalase activity, an increase in peroxidase activity and H2O2 content, and expression of defence related genes such us PR-1, PR-6, and PR-9. It has been shown that B. subtilis 26 D induces expression levels of wheat pathogenesis-related (PR) genes which marks a SA-dependent pathway of sustainable development and that B. thuringiensis V-5689 and V-6066 induces a JA/ET-dependent pathway. These results suggest that these strain Bacillus spp. promotes the formation of wheat plant resistance to S. nodorum through systemic activation of the plant defense system. The designed bacterial consortium formed a complex biological response in wheat plants infected phytopathogen.

Synthesis and characterization of chitosan nanoparticles and their effect on Fusarium head blight and oxidative activity in wheat

The main aim of present study was to prepare chitosan (CS) and chitosan nanoparticles (CS/NPs) to evaluate their antifungal and oxidative activity. CS/NPs were prepared based on the ionic gelation of CS with tripolyphosphate (TPP) anions by using centrifugation and pH change. The obtained nanoparticles (NPs) were characterized by size and zeta potential analysis. The antifungal activity of the CS and CS/NPs were evaluated on the Fusarium graminearum, which causes Fusarium head blight (FHB) on wheat by the method of spraying on the Potato dextrose agar (PDA) medium. The Dynamic light scattering (DLS) indicated that particle diameter (z-average) was approximately 180.9±35.5–339.4±50.9 and 225.7±42.81–595.7±81.7nm for NPs prepared from CS with different molecular weights by using centrifugation and pH change methods, respectively. Different concentrations of CS and NPs were tested to know the inhibitory effect of F. graminearum. Low molecular weight (LMW) CS and its NPs had high potential of antifungal activity on suppress of fungus growth. The maximum percentage of growth reduction was 68.18%, and 77.5% by CS and its NPs at concentrations of 1000 and 5000ppm, respectively. In greenhouse trials, at 28days after inoculation (dpi), the area under the disease progress curve (AUDPC) from 7 dpi to 28 dpi of control plants treated with acetic acid aqueous solution and distilled water was almost up to 7.36 and 7.7, respectively, while plants treated with CS and NPs only had approximately 3.61 and 3.34, respectively. Results revealed that H2O2 accumulations displayed a different pattern during the activation of plant defense systems, it had brownish sites on the infected palea. Since 24h post inoculation (hpi), the H2O2 accumulations were shown in both CS and NPs, and the elevated H2O2 accumulation appeared in 72 hpi in both treatments. CS and NPs at high concentration increased the degree of tissue and cell injury. The obtained results clearly suggest that CS and its NPs have remarkable potential for further field screening towards crop protection.

Pubertal development and anxiety risk independently relate to startle habituation during fear conditioning in 8-14 year-old females.

Reduced habituation to aversive stimuli has been observed during adolescence and may reflect an underlying mechanism of vulnerability for anxiety disorders. This study examined the startle reflex during a fear-learning task in 54 8-14-year-old girls. We examined the relationship between mean startle, startle habituation, pubertal development, and two measures linked to risk for anxiety: behavioral inhibition system (BIS) and the error-related negativity (ERN). Puberty, BIS, and the ERN were unrelated to mean startle; however, each measure modulated startle habituation. Greater pubertal development was associated with reduced startle habituation across the CS+ and CS-. Higher BIS related to a larger ERN, and both were associated with reduced startle habituation specifically to the CS+. All effects were independent of each other. Findings suggest that puberty alters habituation of defense system activation to both threat and safety cues, and this is independent of risk for anxiety, which uniquely impacts habituation to threat cues.

Biomarker response and hypothalamus-pituitary-interrenal axis functioning in Arctic charr from Bjørnøya (74°30′ N), Norway, with high levels of organohalogenated compounds

The populations of Arctic charr (Salvelinus alpinus) residing in Lake Ellasjøen at Bjørnøya Island in the Norwegian Arctic (74° 30′N, 19° 00′E) possess substantially higher levels of organohalogenated compounds (strongly dominated by polychlorinated biphenyls, PCBs) than conspecifics residing in other, proximate lakes on the island. In the present study we sampled large (<400g), immature charr from Lake Ellasjøen (high PCB levels) and Lake Laksvatn (reference lake, low PCB levels) by hook and line for an immediate blood sampling, and blood and tissue sampling after a 1h confinement stressor. This was done in order to investigate possible effects of pollutants on an acute stress performance in a high-latitude fish species by comparing muscle PCB levels, hepatic cytochrome P4501A (CYP1A) biomarker activation and functioning of the hypothalamus-pituitary-interrenal (HPI) axis between these two populations of Arctic charr. As expected sum PCB muscle levels were 8-fold higher on a wet weigh basis, and 19-fold higher on a lipid weight basis, in charr from Ellasjøen than in charr from Laksvatn. This was accompanied by a 3.5-fold higher liver cyp1a mRNA abundance in the Ellasjøen charr compared to Laksvatn charr. Brain transcript levels encoding glucocorticoid receptor 1 and 2 (GR2) and corticotropin-releasing factor, and pituitary transcript levels encoding GR2 and proopiomelanocortin A1 and A2 were higher in Ellasjøen charr than in Laksvatn charr, while interrenal transcript levels encoding melanocortin 2 receptor and steroidogenic acute regulatory protein were lower. There were no differences in plasma cortisol concentration between the two charr populations immediately after capture and one hour after confinement. The strong biomarker response to OHCs and altered mRNA abundances of key genes related to HPI axis functioning in the Ellasjøen charr suggest endocrine disruptive effects of OHCs in this charr population. Possible ecological implications are not known, but it cannot be excluded that a slower growth rate in Ellasjøen charr compared to Laksvatn charr due to an increased metabolic demand associated with the activation of xenobiotic defense and detoxification systems may have contributed to the lower body mass of Ellasjøen charr compared to Laksvatn charr.

DAMAGING EFFECT OF IMMOBILIZING STRESS ON HYPOXIA HIGH- AND LOW-RESISTANT RATS OF BOTH SEXES

Background. Cardiovascular morbidity is a topical issue; stress is an essential contributing factor. Pathogenic links in damaging stress impact on the animal units of different reactivity is promising in disease prevention and development of individual correction methods.Objective. Stress-induced development of cardiovascular pathology is undeniable, the stress impact depending on individual systemic response, age and sex.Methods. 96 hypoxia high- and low-resistant (HR and LR, respectively) Wistar rats aged 5.5-6 months were used in experiments. Changes of lipid peroxidation processes, as well as protein oxidative modification, nitrite anion content and the indices of antioxidant defence under immobilizing stress were studied in the research. Results. Immobilizing stress causes the development of oxidative and carbonyl stress in HR and LR rats that is more pronounced in LR group; and the activation of antioxidant defence system. In males, stress development is concomitant with increased catalase activity as well as that of blood peroxidase, ceruloplasmin and reduced glutathione content, whereas increased catalase and ceruloplasmin activity has been found in HR females, and that of superoxide dismutase and ceruloplasmin – in LR group. As compared with the females, more intensive oxidative and nitroxidative stress, protein oxidative modification, and stress-related accumulation of circulating immune complexes have been found in the males.Conclusion. The most intensive oxidative and nitroxidative stress, protein oxidative modification, and stress-related accumulation of circulating immune complexes have been found in the hypoxia low-resistant males.