Enhanced Antioxidant Protection Research Articles

Cytokinin oxidase2-deficient mutants improve panicle and grain architecture through cytokinin accumulation and enhance drought tolerance in indica rice.

The Osckx2 mutant accumulates cytokinin thereby enhancing panicle branching, grain yield, and drought tolerance, marked by improved survival rate, membrane integrity, and photosynthetic function. Cytokinins (CKs) are multifaceted hormones that regulate growth, development, and stress responses in plants. Cytokinins have been implicated in improved panicle architecture and grain yield; however, they are inactivated by the enzyme cytokinin oxidase (CKX). In this study, we developed a cytokinin oxidase 2 (Osckx2)-deficient mutant using CRISPR/Cas9 gene editing in indica rice and assessed its function under water-deficit and salinity conditions. Loss of OsCKX2 function increased grain number, secondary panicle branching, and overall grain yield through improved cytokinin content in the panicle tissue. Under drought conditions, the Osckx2 mutant conserved more water and demonstrated improved water-saving traits. Through reduced transpiration, Osckx2 mutants showed an improved survival response than the wild type to unset dehydration stress. Further, Osckx2 maintained chloroplast and membrane integrity and showed significantly improved photosynthetic function under drought conditions through enhanced antioxidant protection systems. The OsCKX2 function negatively affects panicle grain number and drought tolerance, with no discernible impact in response to salinity. The finding suggests the utility of the beneficial Osckx2 allele in breeding to develop climate-resilient, high-yielding cultivars for future food security.

Pd2Spermine as an Alternative Therapeutics for Cisplatin-Resistant Triple-Negative Breast Cancer.

Cisplatin (cDDP) resistance is a matter of concern in triple-negative breast cancer therapeutics. We measured the metabolic response of cDDP-sensitive (S) and -resistant (R) MDA-MB-231 cells to Pd2Spermine(Spm) (a possible alternative to cDDP) compared to cDDP to investigate (i) intrinsic response/resistance mechanisms and (ii) the potential cytotoxic role of Pd2Spm. Cell extracts were analyzed by untargeted nuclear magnetic resonance metabolomics, and cell media were analyzed for particular metabolites. CDDP-exposed S cells experienced enhanced antioxidant protection and small deviations in the tricarboxylic acid cycle (TCA), pyrimidine metabolism, and lipid oxidation (proposed cytotoxicity signature). R cells responded more strongly to cDDP, suggesting a resistance signature of activated TCA cycle, altered AMP/ADP/ATP and adenine/uracil fingerprints, and phospholipid biosynthesis (without significant antioxidant protection). Pd2Spm impacted more markedly on R/S cell metabolisms, inducing similarities to cDDP/S cells (probably reflecting high cytotoxicity) and strong additional effects indicative of amino acid depletion, membrane degradation, energy/nucleotide adaptations, and a possible beneficial intracellular γ-aminobutyrate/glutathione-mediated antioxidant mechanism.

Phytogenics enhance welfare and vaccine efficacy against Vibrio anguillarum in European seabass (Dicentrarchus labrax) juveniles

Disease prevention is pivotal in aquaculture, and while vaccines offer protective immunity, challenges such as cost and low efficacy persist. The present study investigated the potential of plant-derived compounds, known as phytogenics, to bolster the effectiveness of vaccines against vibriosis in European seabass. Two phytogenic blends, namely PHYTO1 (terpenes) and PHYTO2 (terpenes and flavonoids) were supplemented to a commercial diet to obtain three experimental diets: a non-supplemented control diet, PHYTO1 (a 200-ppm blend of garlic and Lamiaceae oils with 87.5 mg kg−1 terpenes), and PHYTO2 (a 1000 ppm blend containing citrus fruits, Asteraceae and Lamiaceae oils with 57 mg kg−1 terpenes and 55 mg kg−1 flavonoids). Following vaccination by bath immersion, juvenile European seabass were divided into groups and fed one of the three diets for 30 days. After this feeding period, fish were anesthetized and boosted with a single dose of vaccine through intraperitoneal injection. They continued to be fed their respective diets for another 30 days. At day 60, after the priming vaccination, fish were challenged with Vibrio anguillarum via intraperitoneal injection. Various parameters were measured at different time points post each vaccination, including total weight, circulating plasma cortisol and glucose levels, serum immunoglobulin M (IgM) titers, antioxidant power of leucocytes, and the expression of several antioxidant and immune-related genes. The results showed that fish fed with phytogenic supplements did not differ in weight compared to the control group. However, they exhibited lower plasma cortisol and glucose levels, increased IgM titers, and enhanced antioxidant protection and antioxidant power of head kidney leucocytes. In addition, phytogenics upregulated several immune-related genes in the gills and head kidney immediately after each vaccination. Notably, PHYTO2, enriched with flavonoids and terpenes, exhibited an even more pronounced positive effect on boosted fish by reducing vaccine-associated stress while improving antioxidant protection and modulating the vaccine-induced immune response. This synergistic effect of vaccination combined with phytogenics introduces new pathways for enhancing fish health in aquaculture.

3-Indolepropionic acid mitigates sub-acute toxicity in the cardiomyocytes of epirubicin-treated female rats.

Epirubicin (EPI) is an effective chemotherapeutic against breast cancer, though EPI-related cardiotoxicity limits its usage. Endogenously derived 3-indolepropionic acid (3-IPA) from tryptophan metabolism is of interest due to its antioxidant capabilities which may have cardioprotective effects. Supplementation with 3-IPA may abate EPI's cardiotoxicity, and herein we studied the possibility of lessening EPI-induced cardiotoxicity in Wistar rats. Experimental rats (n = 30; BW 180-200g) were randomly distributed in five cohorts (A-E; n = 6 each). Group A (control), Group B (EPI 2.5mg/mL), and group C (3-IPA 40mg/kg) while Groups D and E were co-treated with EPI (2.5mg/mL) together with 3-IPA (D: 20 and E: 40mg/kg). Following sacrifice, oxidative status, lipid profile, transaminases relevant to cardiac function, and inflammatory biomarkers were analysed. Also, 8-hydroxyl-2'-deoxyguanosine (8-OHdG) and cardiac troponin T (cTnT) levels were assessed using an enzyme-linked immunosorbent assay (ELISA). EPI-initiated increases in cardiotoxicity biomarkers were significantly (p < 0.05) reduced by 3-IPA supplementation. Decreased antioxidant and increases in reactive oxygen and nitrogen species (RONS), 8-OHdG and lipid peroxidation were lessened (p < 0.05) in rat hearts co-treated with 3-IPA. EPI-induced increases in nitric oxide and myeloperoxidase were reduced (p < 0.05) by 3-IPA co-treatment. In addition, 3-IPA reversed EPI-mediated alterations in alanine aminotransferase (ALT), aspartate amino transaminases (AST), lactate dehydrogenase (LDH), cardiac troponin T (cTnT), and serum lipid profile including total cholesterol and triglycerides. Microscopic examination of the cardiac tissues showed that histopathological lesions severity induced by EPI was lesser in 3-IPA co-treated rats. Our findings demonstrate that supplementing endogenously derived 3-IPA can enhance antioxidant protection in the cardiac tissue susceptible to EPI toxicity in female rats. These findings may benefit breast cancer patients undergoing chemotherapy by further validating these experimental data.

Increasing the efficiency of hypolipidemic therapy with the combined use of quercetin in patients with non-alcoholic fatty liver disease on the background of the metabolic syndrome

The article analyzes the results of a set of biochemical indicators in the course of treatment with the combined use of rosuvastatin with quercetin in patients with metabolic syndrome (MS) combined with non-alcoholic fatty liver disease. Changes in blood biochemical parameters have been identified and presented with MS, essential for revealing generalbiological mechanisms development and interrelationship between the components of MS and non-alcoholic fatty liver. The effect of an increase in free cholesterol and triglycerides and activation of freeradical oxidation of lipids followed by theaccumulation of oxidative stress products was noted. In the course of long-term hypolipidemic therapy (90 days), 86 patients with non-alcoholic fatty liver disease on the background of metabolic syndrome were previously divided into 2 groups: a comparison group (45 patients), who weretreated with basic therapy – only rosuvastatin, the main group (41 patients) received quercetin together with rosuvastatin –40 mg 3 times a day, clinical and laboratory-instrumental examinations were carried out. On the 90th day of treatment, positive results in the functional state of the liver and lipid spectrum of the blood wereregistered in all patients. A more significant advantage of the therapeutic combination of rosuvastatin with quercetin was proved. The inclusion of quercetin contributed to reducing the intensity of oxidative stress and enhancing antioxidant protection activity, resultingin a decrease in apoptosis of hepatocytes (cytokeratin-18 level was 1.27 times decreased). The studies have shown the feasibility of combined use of quercetin with rosuvastatin for the prevention of the development and progression of metabolic disorders associated with non-alcoholic fatty liver disease.

Violations of antioxidant-prooxidant spleen index and ceruloplasmin content in serum during acute blood loss, complicated by ischemia-reperfusion of limb and the effectiveness of its correction with carbacetam

Antioxidant-prooxidant imbalance is one of the key mechanisms of acute blood loss and ischemic-reperfusion syndrome. Under these conditions, the level of ceruloplasmin (CP) plays an important role, enhancing antioxidant protection and promoting hematopoiesis, exhibiting ferrooxidase action. However, in this case, the state of antioxidant-prooxidant balance in the spleen and the content of CP in the serum is studied insufficiently, thus there is no data on the effectiveness of carbacetam, which revealed a pronounced protective effect on antioxidant protection of the spleen.Objective of research: to determine the dynamics of the antioxidant-prooxidant index of the spleen and the content of CP in the serum in acute blood loss complicated by ischemia-reperfusion of the limb, and to evaluate the effectiveness of carbacetam in correction of the identified disorders.Materials of the research and their discussion. 108 nonlinear male rats weighing 200–220 g were used in the experiments. All experiments were performed under thiopental-sodium anesthesia. In animals, limb ischemia-reperfusion and acute blood loss were modeled separately and in one of the groups these injuries were combined. In a separate group, the detected disorders were corrected with carbacetam. After 1 and 2 hours, as well as after 1, 7 and 14 days in the spleen of experimental animals was determined content of reagents to thiobarbituric acid and catalase activity, and according to these results the antioxidant-prooxidant index (API) was calculated and was determined the content of CP in serum.Results of the research and their discussion. Modeling of acute blood loss, complicated by ischemia-reperfusion of the limb, contributed to a decrease in the value of API in the spleen, which indicates a shift in antioxidant-prooxidation balance towards the dominance of prooxidant mechanisms. Under these conditions, the content of CP in the blood serum increases significantly, which on the one hand compensates the lack of antioxidant protection, on the other hand indicates on the activation of the mechanisms of the body's systemic response to inflammation. The use of carbacetam helped to shift the antioxidant-prooxidant balance of the spleen towards the dominance of antioxidant mechanisms and to reduction of the CP content in the serum, which indicates on a pronounced antioxidant and anti-inflammatory effect of the drug, as well as its prospects in cases connected with hemic hypoxia and ischemia-reperfusion syndrome.Conclusions: Complication of acute blood loss by limb ischemia-reperfusion contributes to the shift of antioxidant-prooxidant balance of the spleen towards the dominance of prooxidant mechanisms with a simultaneous increase in the content of CP of serum. The use of carbacetam helps to increase the value of API and reduce the content of CP in the serum.

INVESTIGATING EFFECTS OF 7,8-DISUBSTITUTED DERIVATIVE OF THEOPHYLLINE (BENOPHYLLINE) ON FREE-RADICAL OXIDATION IN RENAL INJURY OF RATS

This article highlights the pharmacological study of new 7,8-disubstituted derivative of theophylline, the substance conditionally named benophylline. Based on the literature data and previous studies of compounds of this class, it has been concluded that studying the effect of benophylline on the pro-antioxidant system under simulated pathologies is of great interest and importance.&#x0D; The study of antihypoxic action of 7,8-disubstituted theophylline in rats was carried out under modelled normobaric hypoxia with hypercapnia (in an enclosed space). It has been found out the application of 7-n-methylbenzyl-8-substituted polyphosphonates increases the longevity of rats in the conditions described above that evidences the improvement of metabolic processes in mitochondrial respiratory chain.&#x0D; Based on the results of screening studies, we selected 7,8-disubstituted derivative of theophylline (benophylline) as a leading substance for further investigation. The purpose of the study was to evaluate the efficacy of benophylline for the pharmacological correction of free radical processes in experimental renal damage in rats based on the evaluation of the expression of lipid peroxidation and antioxidant protection.&#x0D; Materials and methods: blood serum, homogenate and rat kidney tissues were the study materials. The study of the protective effect of benophylline on the functional state of the kidneys was investigated on experimental model of acute renal injury by introducing 50% water solution of glycerol (myoglobin nephropathy). Pathogenesis of this model was described in the methodological recommendations by C. Yu. Shtrygol, V. M. Lysovoi, I. A. Zupanetz et al. in «Methods of experimental modeling of kidney damage for pharmacological research». The content of TBK-R was determined spectrophotometrically by reaction with thiobarbituric acid.&#x0D; Glutathione recovered activity was determined spectrophotometrically in reaction with Elman's reagent using the method of Beutler E. D. et al. The catalase activity was assessed by the method of M.A. Koroluk et al. The influence of benophylline on the morphological state of the renal parenchyma was assessed on the modeled myoglobin nephropathy. The activity of gamma-glutamyltranspeptidase in serum was evaluated photometrically using a reagent test kit (“Filisit”). Statistical processing of the results was performed using the STATISTICA 8.0 software package, with the mean value, standard error of the mean confidence interval (p≤0.05). The microscopic study of microproducts was performed under the Granum microscope. Micrographs were taken with a Granum DMC 310 digital camera. The images were processed on a Pentium 2.4 GHz computer using Toup View software.&#x0D; Research results: Under the influence of benophylline, the processes of LPO and AOP became normalized, the expressiveness of degradation of the nephrocytes decreased, the microscopic picture of renal excretion in all rats got normalized. At the same time, 62.5% of the rats had the morphological condition of kidneys close to the intact control, and 37.5% of the animals were noticed to demonstrate a significant decrease in the dyscirculatory abnormalities, inflammatory manifestations and signs of nephrocyte regeneration.&#x0D; Conclusions: The ability of benophylline to inhibit the processes of free radical oxidation and to enhance antioxidant protection has been found out. The study has shown benophylline enhances regenerative effect kidney tissues.

Decreased malondialdehyde levels in fish (Astyanax altiparanae) exposed to diesel: Evidence of metabolism by aldehyde dehydrogenase in the liver and excretion in water.

Increased malondialdehyde (MDA) levels are commonly considered an indicator of lipid peroxidation derived from oxidative stress insults promoted by exposure of fish to pollutants. However, a decrease in MDA levels after xenobiotic exposure has been also reported, an effect that is mostly attributed to enhanced antioxidant defenses. In this study, we assessed whether pollutant-mediated MDA decrease would be associated with antioxidant enhancement or with its metabolism by aldehyde dehydrogenase (ALDH) in the liver and gills of lambari (Astyanax altiparanae) exposed to diesel oil (0.001, 0.01, and 0.1mL/L). MDA levels were decreased in the liver of lambari exposed to diesel. The activities of the antioxidant enzymes, catalase (CAT) and glutathione peroxidase (GPx), were unchanged in the liver, while that of glucose-6-phosphate dehydrogenase (G6PDH) was decreased. In contrast, levels of total glutathione (tGSH) and the activity of glutathione S-transferase (GST) were increased in the liver, which partly support antioxidant protection against lipid peroxidation. More importantly, ALDH activity increased in a concentration-dependent manner, being negatively correlated with MDA levels, indicating MDA metabolism by ALDH. In the gills, diesel exposure increased MDA and lipid hydroperoxide levels, and promoted increases in antioxidant defenses, indicating oxidative stress. Curiously, ALDH activity was undetectable in the gills, supporting the possibility of direct MDA excretion in the water by the gills. Analyses of MDA in the water revealed increased levels of MDA in the aquaria in which the fish were exposed to diesel, compared to control aquaria. A second experiment was carried out in which the fish were intraperitoneally injected with MDA (10mg/kg) and analyzed after 1, 6, and 12h. MDA injection caused a time-dependent decrease in hepatic MDA levels, did not alter ALDH, CAT, GPx, and GST activities, and decreased G6PDH activity and tGSH levels. In the gills, MDA injection caused a slight increase in MDA levels after 1h, but did not alter GPx, G6PDH, and GST activities. MDA injection also enhanced CAT activity and tGSH levels in the gills. MDA concentration in water increased progressively after 1, 6, and 12h, supporting the hypothesis of direct MDA excretion as an alternative route for MDA elimination in fish. Our results suggest that the decreased MDA levels after exposure of lambari to diesel oil pollutant probably reflects an association between enhanced antioxidant protection, MDA metabolism, and MDA excretion in water.

Melatonin enhances salt stress tolerance in rubber tree (Hevea brasiliensis) seedlings

As a well-known agent, melatonin plays very important roles in animals. However, its possible function is less clear in plants, especially in rubber tree. In this study, we demonstrate that melatonin acts as a potential agent to enhance salt stress tolerance in rubber tree seedlings. Chlorophyll degradation and H2O2 accumulation in leaves of seedlings under salinity stress were significantly relieved by melatonin treatment. Transcriptome analyses suggested that melatonin was a potential antioxidant, and its exogenous application resulted in enhanced antioxidant protection mainly by regulating the genes involved in photosynthesis, ROS metabolism, flavonoids and melatonin biosynthesis. These results demonstrate that melatonin can enhance salt stress tolerance directly or indirectly by counteracting the cellular accumulation of H2O2 in rubber tree. Our findings are helpful for not only understanding melatonin’s roles in salinity stress, but also providing new insights into potential utilization of melatonin against abiotic stresses in rubber tree.

Targeted Mitochondrial COQ10 Delivery Attenuates Antiretroviral-Drug-Induced Senescence of Neural Progenitor Cells.

HIV infection is associated with symptoms of accelerated or accentuated aging that are likely to be driven not only by HIV itself but also by the toxicity of long-term use of antiretroviral drugs. Therefore, it is crucially important to understand the mechanisms by which antiretroviral drugs may contribute to aging. The aim of this study was to investigate the hypothesis that antiretroviral drugs cause increased reactive oxygen species (ROS) generation that results in mitochondrial dysfunction and culminates in promoting cellular senescence. In addition, we applied targeted nanoparticle (NP)-based delivery to specifically enrich mitochondria with coenzyme Q10 (CoQ10) in order to enhance antioxidant protection. The studies employed neural progenitor cells (NPCs), as differentiation of these cells into mature neurons is affected both during HIV infection and in the aging process. Exposure of cultured NPCs to various combinations of HIV antiretroviral therapy (ART) induced a more than 2-fold increase in mitochondrial ROS generation and mitochondrial membrane potential, a more than 50% decrease in oxygen consumption and ATP levels, a 60% decrease in SIRT3 expression, and a 42% decrease in cell proliferation relative to control levels. These alterations were accompanied by a 37% increase in beta-galactosidase staining and a shortening of the telomere length to more than half of the length of controls as assessed by quantitative telomere-FISH labeling, indicating accelerated NPC senescence in response to ART exposure. Importantly, CoQ10 delivered by targeted nanoparticles effectively attenuated these effects. Overall, these results indicate that ART promotes cellular senescence by causing mitochondrial dysfunction, which can be successfully reversed by supplementation with mitochondria-targeted CoQ10.

Age‐ and Muscle‐Specific Oxidative Stress Management Strategies in a Long‐Lived Diver, the Weddell Seal

The free radical theory of aging purports that the accumulation of cellular oxidative damage leads to aging. While this process is not expected to manifest in wild populations, which can suffer from early predation or injury‐induced mortality, physically active long‐lived mammals are a model in which cellular aging may occur. Air breathing divers such as seals experience repeated bouts of ischemia‐reperfusion, potentially exposing their tissues to oxidative stress and thus damage and accelerated aging. We have previously demonstrated that skeletal muscle cellular morphology “ages” in Weddell seals without a corresponding decrease in diving behavior. This suggests stress response may protect against oxidative damage and functional impairment, providing insight into mechanisms for managing oxidative stress. We studied whether muscular senescence might arise from oxidative damage by comparing muscle from old (age 17–27 years) and young (age 9–16 years) cohorts of adult Weddell seals. Muscle biopsies were collected from healthy, active, non‐reproductive seals and frozen in liquid nitrogen. Apoptosis was examined with a cell‐death ELISA, while markers of oxidative damage to lipids (FOX assay) and proteins (4‐HNE western blot) were contrasted with antioxidant profiles (kinetic activity assays or western blots). These variables were statistically compared between age cohorts with an ANOVA model that included animal sex and biopsy site as cofactors. Old seals exhibited a 43% increase (p = 0.002) in apoptosis over young animals. Lipid peroxidation and oxidative protein damage, however, did not differ with age, suggesting that apoptotic differences were not due to oxidative stress. We also assessed antioxidant profiles and found that glutathione peroxidase (GPx) activity was 22% higher in the old cohort (p = 0.026). GPx reduces lipid hydroperoxides; this enhanced antioxidant protection may limit lipid peroxidation and downstream protein modification in old seals. The locomotory (longissimus dorsi, LD) and maneuvering (pectoralis, P) muscles of Weddell seals are perfused differently from one another during a dive, thus we also considered whether oxidative damage and antioxidant patterns are distinct between muscles using the same ANOVA. Lipid peroxidation was highest in LD (24% increase, p = 0.001), though no difference in protein modification was detected. Antioxidant protein levels revealed increased superoxide dismutase (SOD2, p = 0.009), thioredoxin reductase (TRXR2, p = 0.027) and heat shock protein 70 (HSP70, p = 0.00001) in LD. On the other hand, P exhibited a 14% increase in glutathione S‐transferase (GST, p = 0.004), which is consistent with regionally lower levels of oxidized lipid. Together, these findings illustrate that long‐lived air breathing divers display enhanced antioxidant and stress responses, possibly utilizing the pre‐conditioning effect of repeated diving. Thus, the aging Weddell seal is a compelling model for studying the successful management of oxidative stress.Support or Funding InformationNational Science Foundation Office of Polar ProgramsThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Synthesis, crystal structure, and biological properties of the complex [Co(DmgH)2(Seu)1.4(Se-Seu)0.5(Se2)0.1][BF4

A new Co(III) dioxime complex with selenocarbamide was obtained by the reaction of Co(BF4)2 ∙ 6H2O, DmgH2, and Seu (DmgH2 = dimethylglyoxime, Seu = selenocarbamide). According to X-ray diffraction (CIF file CCDC no. 1485732), the product was an ionic coordination compound with unusual composition, [Co(DmgH)2(Seu)1.4(Se-Seu)0.5(Se2)0.1][BF4] (I). Apart from two monodeprotonated DmgH‾ molecules, the central atom coordinates neutral Seu, Se-Seu, and Se2 molecules. Thus, the crystal contains the complex cations [Co(DmgH)2(Seu)2]+, [Co(DmgH)2(Seu)(Se-Seu)]+, and [Co(DmgH)2(Seu)(Se2)]+. Each [BF4]‾ anion is linked to the cations not only by electrostatic forces but also by intermolecular N–H···F hydrogen bonds (H-bonds). The complex cations are combined by intermolecular N–H···O H-bonds. The new coordination compound was found to possess biological activity. Treatment of the garlic (Allium sativum L.) foliage with an aqueous solution of I optimizes the content of selenium in the leaves and cloves and enhances the growth and plant productivity. The organs of treated plants are characterized by enhanced antioxidant protection owing to increasing activity of antioxidant enzymes and contents of proline and assimilation pigments, and decreasing lipid peroxidation.

Experimental Evaluation of the Efficacy of Sodium Selenite as a Remedy for Wounds

Relevance. Emergencies, both of natural and anthropogenic origin, are accompanied by a large number of injuries and wounds, the treatment of which is associated with great difficulties due to frequent infectious complications and lethargic repair of damaged tissues. Promising approach to this problem is the use of antioxidants to reduce the severity of inflammation and stimulate repair. Intention. To evaluate the efficacy of topical application of the antioxidant composition based on selenium for acceleration of reparative processes in woundу. Methods. Experimental studies were carried out on 45 male Wistar rats. Wounds in rats were modeled under ether anesthesia by up to 4 cm excision of a pre-depilated area of the skin of the back to the underlying fascia. Wounds were treated by daily dressings with 0.5 % sodium selenite vs dimethyl sulfoxide solvent as a comparator. The presence and nature of the inflammatory reaction, the condition of edges and bottom of wounds, time to cleaning out necrotic tissues and the appearance of granulation, the nature of granulation tissue, time to the onset of epithelialization of wounds and the general condition of animals, the cytogram of wound prints, and the activity of antioxidant protection enzymes were evaluated in rats. Results and Discussion. It has been established that local use of sodium selenite has a stimulating effect on reparative processes in the wound due to increased activity of antioxidant enzymes. Thus, after 6-day treatment. sodium selenite increased catalase activity by 18.1 %, glutathione peroxidase by 63.2 %, glutathione reductase by 46.1 % compared to ointment with dimethyl sulfoxide. It was revealed that enhanced antioxidant protection of wound tissues accelerates maturation of granulations and wounds heal 1.6 times faster than in the control group. Conclusion. Medicinal compositions with sodium selenite are promising for local treatment of wounds.

Exogenous ATP enhance signal response of suspension cells of transgenic rice (Oryza sativa L.) expressing maize C 4 -pepc encoded phosphoenolpyruvate carboxylase under PEG treatment

The aim of this study was to analyze the biochemical and molecular responses of suspension cells of transgenic rice (Oryza sativa L.) over-expressing the maize C 4 -pepc gene encodes phosphoenolpyruvate carboxylase (PEPC) (PC line) to drought stress by exogenous ATP. Suspension cells of PC and wild-type (WT) rice cultured in N6 basic medium were subjected to the following treatments: a 24-h drought treatment imposed by 20% (m/v) polyethylene glycol 6000 (PEG6000 treatment); an exogenous adenosine 5′-triphosphate treatment (ATP; 1 mmol L−1); and a combined exogenous ATP + PEG6000 treatment. We measured DNA fragmentation, cell viability, lipid peroxidation, antioxidant enzyme activities, PEPC activity, ATP content, and the levels of Ca2+, H2O2, and NO using spectrophotometric methods and fluorescent dyes, and quantified the transcript levels of stress-related genes such as NAC1 (one of the transcription factors from NAC (NAM/ATAF/CUC) family), cytochrome P450 (P450) and programmed cell death (PCD) under these treatments. Compared with WT cells, PC cells showed more stable cellular activity, lower lipid peroxidation, enhanced antioxidant enzyme activity, higher levels of endogenous ATP level, PEPC activity, and transcript levels of C 4 -pepc and the transcription factor NAC1 under drought stress. While the content of H2O2 and the transcript levels of P450 and PCD were decreased and kept at the low levels during the same treatments. Adding ATP, PC reinforced these early signaling effects response to PEG6000 treatment. Based on the results, the exogenous ATP triggers a series of signaling cascade reactions for enhancing antioxidant protection in PC cells during the drought treatment, conferring to the drought-tolerance.

Dietary Intake of Purple Corn Extract Reduces Fat Body Content and Improves Antioxidant Capacity and n‐3 Polyunsaturated Fatty Acid Profile in Plasma of Rainbow Trout, Oncorhynchus mykiss

AbstractA study was conducted to determine the benefits of the intake of purple corn extract (PCE), a natural source of anthocyanins, in rainbow trout, Oncorhynchus mykiss. A control or test diet supplemented with 5% PCE was fed to triplicate tanks with 25 fish each for 8 wk. The concentrations of three anthocyanins, cyanidin‐3‐glucoside, pelargonidin‐3‐glucoside, and peonidin‐3‐glucoside, were measured in PCE. The chemical composition and fatty acid profiles of fish, as well as the fatty acid profiles in plasma, liver, and muscle were determined. The total antioxidant capacity (TAC) and the concentration of oxidative damage biomarkers, for example, protein carbonyls, 8‐hydroxydeoxyguanosine, and thiobarbituric acid reactive substances (TBARS), were determined in plasma. Transcription of two antioxidant enzymes, glutathione peroxidase 1 (gpx1) and superoxide dismutase 1 (sod1), was measured in erythrocytes. Significant lower adiposity and significant higher percentage of total n‐3 and total n‐6 polyunsaturated fatty acids (PUFA) in the body of fish fed the test diet were detected. Significant higher plasma percentage of total n‐3 PUFA, significant higher plasma TAC, and significant higher expression of gpx1 in erythrocytes of fish fed the test diet were measured. Overall, our results suggest potential protection against in vivo lipid peroxidation in fish fed the PCE supplemented diet. This is especially true due to detection of an enhanced antioxidant protection in plasma and erythrocytes in fish, the reduced adiposity and greater proportion of total n‐3 and n‐6 PUFA in the fish body, as well as a tendency toward lower TBARS plasma concentration in fish fed the test diet when compared to the control group.

Melatonin delays leaf senescence and enhances salt stress tolerance in rice.

Melatonin, an antioxidant in both animals and plants, has been reported to have beneficial effects on the aging process. It was also suggested to play a role in extending longevity and enhancing abiotic stress resistance in plant. In this study, we demonstrate that melatonin acts as a potent agent to delay leaf senescence and cell death in rice. Treatments with melatonin significantly reduced chlorophyll degradation, suppressed the transcripts of senescence-associated genes, delayed the leaf senescence, and enhanced salt stress tolerance. Genome-wide expression profiling by RNA sequencing reveals that melatonin is a potent free radical scavenger, and its exogenous application results in enhanced antioxidant protection. Leaf cell death in noe1, a mutant with over-produced H2O2, can be relieved by exogenous application of melatonin. These data demonstrate that melatonin delays the leaf senescence and cell death and also enhances abiotic stress tolerance via directly or indirectly counteracting the cellular accumulation of H2O2.

Knock-down of stress inducible OsSRFP1 encoding an E3 ubiquitin ligase with transcriptional activation activity confers abiotic stress tolerance through enhancing antioxidant protection in rice.

E3 ubiquitin ligases are involved in a variety of physiological processes. This study demonstrated the function of a previously unknown rice RING finger E3 ligase, Oryza sativa Stress-related RING Finger Protein 1 (OsSRFP1) in stress responses in rice. OsSRFP1 was ubiquitously expressed in various rice organs, with the higher expression levels in roots, panicles and culm nodes. The transcript of OsSRFP1 was induced by cold, dehydration, salt, H2O2 and abscisic acid treatments. Interestingly, the OsSRFP1-overexpressing plants were less tolerant to salt, cold and oxidative stresses than wild type plants; while the RNA interference silencing of OsSRFP1 plants were more tolerant than wild type without yield penalty. Compared with the wild type, amounts of free proline and activities of antioxidant enzymes were increased in the RNAi plants but decreased in the overexpression plants under cold stress, which were inversely correlated with the malondialdehyde and hydrogen peroxide (H2O2) levels in the tested lines. Microarray analysis showed that expression of numerous genes involving in ROS homeostasis was altered in the OsSRFP1-overexpressing plants under normal and cold conditions. In vitro ubiquitination assays showed that OsSRFP1 possessed E3 ubiquitin ligase activity and the intact RING domain was essential for the activity. Moreover, OsSRFP1 might function in transcriptional regulation with nuclear localization. Taken together, our results demonstrate that OsSRFP1 may have dual functions in post-translational and transcriptional regulations in modulating abiotic stress responses in rice, at least in part, by negatively regulating antioxidant enzymes-mediated reactive oxygen species removal.

Molecular and cellular mechanisms of macrophage survival in atherosclerosis

Macrophages play a key role in the initiation and progression of atherosclerotic plaques. Although a significant number of macrophages undergoes cell death during plaque development as a result of atherogenic stressors, advanced plaques are characterized by a large macrophage content. Macrophage accumulation is mediated by continuous recruitment of monocytes, reduced emigration of macrophages and poor phagocytosis of dead cells which may trigger secondary necrosis and amplification of plaque inflammation. Moreover, an increasing body of evidence indicates that macrophages have developed several strategies to survive and to proliferate in the adverse environment of an advanced atherosclerotic plaque. Macrophages contain organic molecules or enzymes that provide enhanced antioxidant protection. In addition, synthesis of anti-apoptotic proteins is upregulated and several cellular protection mechanisms such as the unfolded protein response and autophagy are activated in macrophages to promote cellular survival. In this review, we discuss these macrophage survival mechanisms that allow growth and destabilization of advanced atherosclerotic plaques.

Enhanced antioxidant protection at the early stages of leaf expansion in ginkgo under natural environmental conditions

Photosynthetic pigments, gas exchange, chlorophyll (Chl) a fluorescence kinetics, antioxidant enzymes and chloroplast ultrastructure were investigated in ginkgo (Ginkgo biloba L.) leaves from emergence to full size. Under natural conditions, the net photosynthetic rate (PN), contents of Chl a, Chl b and total soluble proteins and fresh and dry leaf mass gradually increased during leaf expansion. The maximum photochemical efficiency of photosystem (PS) 2 (variable to maximum fluorescence ratio, Fv/Fm) was considerably higher at the early stages of leaf development than in fully expanded leaves. During daily course, only reversible decrease in Fv/Fm was distinguished at various stages, implying that no photo-damage occurred. Absorption flux per cross section (CS) and trapped energy flux per CS were significantly lower in newly expanding leaves compared with fully expanded ones, however, dissipated energy flux per CS was only slightly lower in expanding leaves. The ratio of carotenoids (Car)/Chl decreased gradually during leaf expansion due to increasing Chl content. Moreover, activities of the antioxidant enzymes, such as superoxide dismutase, ascorbate peroxidase, catalase and peroxidase, increased at the early stages of leaf expansion. The appearance of osmiophilic granules in fully expanded leaves further proves that photo-protection is significantly strengthened at the early stages of leaf expansion.

Enhanced antioxidant protection at the early stages of leaf expansion in ginkgo under natural environmental conditions

Photosynthetic pigments, gas exchange, chlorophyll (Chl) a fluorescence kinetics, antioxidant enzymes and chloroplast ultrastructure were investigated in ginkgo (Ginkgo biloba L.) leaves from emergence to full size. Under natural conditions, the net photosynthetic rate (PN), contents of Chl a, Chl b and total soluble proteins and fresh and dry leaf mass gradually increased during leaf expansion. The maximum photochemical efficiency of photosystem (PS) 2 (variable to maximum fluorescence ratio, Fv/Fm) was considerably higher at the early stages of leaf development than in fully expanded leaves. During daily course, only reversible decrease in Fv/Fm was distinguished at various stages, implying that no photo-damage occurred. Absorption flux per cross section (CS) and trapped energy flux per CS were significantly lower in newly expanding leaves compared with fully expanded ones, however, dissipated energy flux per CS was only slightly lower in expanding leaves. The ratio of carotenoids (Car)/Chl decreased gradually during leaf expansion due to increasing Chl content. Moreover, activities of the antioxidant enzymes, such as superoxide dismutase, ascorbate peroxidase, catalase and peroxidase, increased at the early stages of leaf expansion. The appearance of osmiophilic granules in fully expanded leaves further proves that photo-protection is significantly strengthened at the early stages of leaf expansion.