Analysis Of Superoxide Dismutase Research Articles

Analyzing the temporal response mechanisms of the vascular bundles formation of grafted cucumber to different light intensity modes: A joint transcriptomic and metabolomic approach

In plant grafting, the reconnection of vascular bundles between the rootstock and scion not only establishes functional xylem and phloem connections, but also signifies the completion of graft healing. In our previous studies focused on early-stage morphology and physiology of grafted seedlings, we have demonstrated that utilizing light intensities of 50-100-150 μmol/(m2·s) during days 1-3, 4-6, and 7-9 optimizes cucumber/pumpkin graft healing. To further explore the underlying mechanisms, we investigate light intensity regimes: 50-100-100 μmol/(m2·s) and 50-100-150 μmol/(m2·s) during the same time frames (days 1-3, 4-6, and 7-9 after grafting), denoted as CK and T treatments. Initially, we observe histological characteristics of vascular bundle formation under these conditions, followed by the analyses of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), glutathione peroxidase (GSH-Px) enzyme activities, ascorbic acid (AsA) content in the antioxidant system, and the sequencing of transcriptome and metabolome. It is found that grafted seedlings under the T treatment achieve faster vascular bundle reconnection and shorter healing process compared to those under the CK treatment. Enzyme activities (POD, SOD, GSH-Px) increase over time under both light regimes, while CAT activity and AsA content decrease. Notably, by the 9th day, the T treatment (T9d) exhibits higher SOD, POD and CAT activities than the CK treatment (CK9d). Our findings indicate that increasing light intensity during the days 7-9 after grafting can mitigate oxidative damage at the grafting site and benefit vascular bundle reconnection. Transcriptome and metabolome analyses show the up-regulations of Cinnamaldehyde in the phenylpropanoid biosynthesis pathway, the PHGDH gene and L-Homocysteine in the cysteine and methionine metabolism pathway under T treatment in the days 7-9 after grafting. These enhance the antioxidant enzyme activities and reduce the oxidative damage to the grafting site. Additionally, GAE-related genes, and metabolites D-Xylose and Undecaprenyl phosphatealpha-L-Ara4FN in the amino sugar and nucleotide sugar metabolism pathways are also up-regulated under T treatment. The ethylene responsive factor (ERF) transcription factor CsaRAP2.3 positively regulates Undecaprenyl phosphatealpha-L-Ara4FN expression, promoting cell wall synthesis and therefore accelerating vascular bundle reconnection. In summary, during the vascular bundle formation period of cucumber graft healing, both light intensity modes coordinate regulation of phenylpropanoid biosynthesis, cysteine and methionine metabolism, amino sugar and nucleoside sugar metabolism, and ERF transcription factors, promoting graft healing from both stress resistance and cell wall synthesis. Furthermore, building upon the light intensity applied during the callus formation phase, increasing the light intensity during the vascular bundle formation period can significantly enhance cell wall synthesis, thus expediting the graft healing process. Nonetheless, the generalizability of these research findings to other grafting techniques and species requires further investigation.

Formulation and characterization of tea tree and jojoba oils nano-emulgel for in-vivo wound healing assessment

Cutaneous wounds are the most common surgical affections among living organisms worldwide, and their healing may be interrupted by several factors. This study aimed to formulate and evaluate the antioxidant, anti-inflammatory, and antimicrobial activity of tea tree and jojoba oils nano-emulsions, additionally, investigating the cytotoxicity of the optimized formula was investigated on normal human lung fibroblast cells (WI-38) by MTT colorimetric assay, additionally its in-vivo wound healing. Nano-emulsions (NEs) were prepared using a high-energy method and characterized by Transmission electron microscopy (TEM), Zeta potential, droplet size, and poly dispersive index (PDI). Nano-emulgel (NEG) was formulated by mixing the standard NE with carbopol® 940. For in-vivo wound healing, thirty adult female albino rats were assigned into control, moist exposed burn ointment (Mebo), and NEG-treated groups. The healing was assessed by analysis of superoxide dismutase (SOD), malondialdehyde (MDA), tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β), and histopathology in healed wound tissues. All formulations demonstrated antioxidant, anti-inflammatory, and antimicrobial activity against Bacillus Subtilis, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Salmonella typhi, Enterococcus faecalis, and Candida albicans. The CC50 of the optimized formula was 453.82± 3.87 µg/mL, with a mean droplet size of 105.4 nm and a zeta potential of −39.2 ± 2.1 mV. NEG enhanced wound closure compared to Mebo-treated and control groups. Also, MDA significantly decreased and SOD significantly increased in NEG and Mebo-treated groups compared to the control (p ˂ 0.05). TNF-α, and IL-1β significantly decreased in NEG and Mebo-treated compared to the control (p < 0.05). Histopathology revealed reduced inflammatory cell infiltration, rapid epithelization, and increased collagen deposition in NEG-treated wound tissues compared to the control and Mebo-treated wounds. In conclusion, the NEG containing tea tree and jojoba oils demonstrated significant antioxidant, anti-inflammatory, antimicrobial, and wound healing activities.

Establishment and identification of the gill cell line from the blunt snout bream (Megalobrama amblycephala) and its application in studying gill remodeling under hypoxia.

To probe the mechanisms of gill remodeling in blunt snout bream under hypoxic conditions, we selected gill tissue for primary cell culture to establish and characterize the first blunt snout bream gill cell line, named MAG. The gill cells were efficiently passaged in M199 medium supplemented with 8% antibiotics and 15% fetal bovine serum at 28°C, exhibiting primarily an epithelial-fibroblast mixed type. Additionally, the MAG cells (17th generation) were subjected to four experimental conditions-normoxia, hypoxia 12h, hypoxia 24h, and reoxygenation 24h (R24h)-to evaluate the effects of hypoxia and reoxygenation on MAG cells during gill remodeling. We found that the MAG cell morphology underwent shrinkage and mitochondrial potential gradually lost, even leading to gradual apoptosis with increasing hypoxia duration and increased reactive oxygen species (ROS) activity. Upon reoxygenation, MAG cells gradually regain cellular homeostasis, accompanied by a decrease in ROS activity. Analysis of superoxide dismutase (SOD), glutathione (GSH), lactate dehydrogenase (LDH), catalase (CAT), anti-superoxide anion, and other enzyme activities revealed enhanced antioxidant enzyme activity in MAG cells during hypoxia, aiding in adapting to hypoxic stress and preserving cell morphology. After reoxygenation, the cells gradually returned to normoxic levels. Our findings underscore the MAG cells can be used to study hypoxic cell apoptosis during gill remodeling. Therefore, the MAG cell line will serve as a vital in vitro model for exploring gill remodeling in blunt snout bream under hypoxia.

Exogenous melatonin enhances the tolerance of tiger nut (Cyperus esculentus L.) via DNA damage repair pathway under heavy metal stress (Cd2+) at the sprout stage

Heavy metal (HM) stress is a non-negligible abiotic stress that seriously restricts crop yield and quality, while the sprout stage is the most sensitive to stress and directly impacts the growth and development of the later stage. Melatonin (N-acetyl-5-methoxytryptamine), as an exogenous additive, enhances stress resistance due to its ability to oxidize and reduce. However, few reports on exogenous melatonin to tiger nuts under HM stress have explored whether exogenous melatonin enhances plants' resistance to heavy metals. Here, “Jisha 2″ was used as material, with a stress concentration of 5 mg/L and 100 μmol/L of CdCl2 to explore whether exogenous melatonin enhances plant resistance and molecular mechanism. The result revealed that stress limits growth, while melatonin alleviated the sprout damage under stress from the phenotypes. Moreover, stress-enhanced reactive oxygen species (ROS) accumulation and membrane lipid peroxidation, while melatonin-increased ROS reduce damage via the analysis of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) and malondialdehyde (MDA) content, hydrogen peroxide (H2O2), superoxide anion (O2-), and Electrolyte leakage (El). Further results indicated that HM leads to DNA damage while exogenous melatonin will repair the damage by analyzing random amplified polymorphic DNA (RAPD), DNA cross-linking, 8-hydroxy-20-deoxyguanine level, and relative density of apurinic sites. Furthermore, gene expression in the DNA-repaired pathway exhibited similar results. These results applied that exogenous melatonin released the hurt caused by HM stress, with DNA repair and ROS balance serving as candidate pathways. This study elucidated the mechanism of melatonin's influence and provided theoretical insights into its application in tiger nuts.

Antioxidant Activity and Flavonoids Identification by LC-MS/MS Analysis in Leaf Extract from Trattinnickia rhoifolia Willd

The objectives of this work were to evaluate the antioxidant and hepatoprotective activities in the oxidative stress model induced by paracetamol in male Swiss mice, to evaluate the hypoglycemic and hypolipidemic action and to identify flavonoids in the leaves ethanolic extract from Trattinnickia rhoifolia. By the LC-MS / MS method, eight flavonoids were identified in the hydromethanolic (HM) and ethyl acetate (EA) fractions, except for Amentoflavone, the flavonoids Apigenin, Canferol, Luteolin, Quercetin, Quercetin-3-β-d-glucoside, Rutin and Taxifoline were identified for the first time in this species. These fractions were evaluated for antioxidant capacity (DPPH— test) and their protective effect in vivo through the analysis of superoxide dismutase, catalase, glutathione-s-transferase, non-protein thiols, ascorbic acid, TBARS and carbonylated proteins. The data showed that EA has antioxidant capacity and superior oxidative stress repair in chemical and biological analyzes, besides hypoglycemic and hypolipidemic action. Thus, the present work contributes significantly to the literature, since it is the first study that identifies the chemical constituents and pharmacological properties of leaves extract from T. rhoifolia.

Effect of artificially accelerated aging on the vigor of Metasequoia glyptostroboides seeds

Metasequoia glyptostroboides is an endangered relict plant native to China that has been widely introduced into many countries and areas around the world. However, its seeds germinate at a very low percentage. Consequently, population regeneration by seed is low under natural conditions, which probably contributes to the endangered status of this plant species. The present study aimed to describe the aging mechanism of M. glyptostroboides seeds. Our objective was to elucidate causes of the low germination rate in an effort to enhance potential for conservation of the species. We used germination tests, relative electrical conductivity and malondialdehyde content determination, ultrastructural observation of embryo cells, and analysis of superoxide dismutase, catalase, ascorbate peroxidase, and dehydroascorbate reductase activities during accelerated aging treatment. We found that M. glyptostroboides seeds have a low level of vigor and poor ability to maintain vigor, which is probably associated with the inefficiency of its enzymatic antioxidative system.

Biochemical and Molecular Analysis of Superoxide Dismutase in Sordaria fimicola and Aspergillus niger Collected from Different Environments

Biochemical and Molecular Analysis of Superoxide Dismutase in Sordaria fimicola and Aspergillus niger Collected from Different Environments

Effect of Ethanolic Extract of Coconut (Cocos nucifera) on Aspirin-induced Gastric Ulcer in Albino Rats

Statement of problem: Aspirin is extensively used as an analgesic, antipyretic, anti-thrombotic and antiinflammatory drug. It is safe in therapeutic doses but it is toxic in over dosage or in chronic injudicious use, when it causes acute or chronic toxicity respectively. Acute toxicity causes gastric ulceration and bleeding. Gastric ulcer developed when the imbalance occurs between aggressive and defensive factors of the stomach and situation favours aggressive factors enough to cause mucosal damage and lead to ulceration. Many antioxidants have been trying to study their protective effects of aspirin and others NSAID’s induced gastric ulcers. Coconut and its products are known for their antioxidant, antibacterial, anti-diabetic, antithrombotic and antiulcer genic effects. Two different studies are documented about the effect of ethanolic extract of coconut on indomethacin induced gastric ulcers. Both are paradoxical, and show controversy at different doses of extract. The present study, therefore, designed in an attempt to observe the effects of high doses of ethanolic extract of coconut on aspirin induced gastric ulcers. This was conducted at University of Health Sciences Lahore. Thirty rats, weighing 175-220 gm, were divided into six groups and were treated with different doses of extract for 14 days and were sacrificed on 15th day of experiment. Methodology involved staining of stomach with H and E and Masson Trichome staining and was observed for desquamation, mucosal congestion, inflammatory Cells and necrosis. Blood samples were drawn for serum analysis of Super Oxide Dismutase (SOD). Findings: The results showed that ethanolic extract of coconut helps to heal the stomach ulcers and gives best results at 400 mg/kg dose and also helps to reduce oxidative stress which also helps to heal ulcers. Conclusion and significance: It was concluded that ethanolic extract of coconut provides a very reliable and cost effective adjunctive therapy to be routinely used in patients who take aspirin and aspirin induced gastric ulcers as well.

Histomorphological Changes in Kidney Associated with the Ethanolic Extracts of the Leaves of &amp;lt;i&amp;gt;Phyllanthus amarus&amp;lt;/i&amp;gt; in Cadmium Induced Kidney Damage in Experimental Animals

Heavy metal poisoning is often as a result of prolonged occupational or domestic exposure to toxic metals and it is difficult to treat it immediately as the effects manifest over time. The use of herbal medicines and phytonutrients continues to expand rapidly across the world with many people now resorting to these products for treatment of various health challenges in different national healthcare settings. Chanca Piedra is a plant that has proven useful in assisting the treatment of various diseases. There have also been controversial claims on the effects of the plant on kidney stones and gall stones. Since cadmium is a very common nephrotoxic agent to which humans and animals are exposed frequently, this study has the potential to provide insight into the possible prophylactic and ameliorative effects of Chanca Piedra on kidney damage and it may also help in providing solutions to the problem of cadmium nephrotoxicity. The present study was carried out to investigate the prophylactic and ameliorative effects of orally administered ethanolic extract of Chanca Piedra (CP) (Phyllantus amarus) against nephrotoxicity produced by cadmium (40mg/kg BW) sulphate in adult male Wistar rats (Rattus novegicus). Forty-two (42) adult male Wistar rats were used in this study and were divided into seven (7) groups of (n=6) as follows: Group A (control), Group B (40mg/kg BW), Group C (100mg/kg BW of CP + 40mg/kg BW), Group D (200mg/kg BW of CP + 40mg/kg BW), Group E (40mg/kg BW + 100mg/kg BW of CP), Group F (40mg/kg BW + 200mg/kg BW of CP), Group G (200mg/kg BW of CP). Both cadmium and Chanca piedra were administered orally through oro-gastric cannula. The animals were sacrificed 24 hours after the last administration through cervical dislocation and blood samples were collected through cardiac puncture for analysis of superoxide dismutase and glutathione peroxidase and the kidney were fixed in 10% formal saline for 24hrs and then processed for histological analysis. Histological analysis using H&E stain for general histoarchitecture and Masson’s Trichrome for collagen fibres, indicated alterations in cell morphology of all the treated groups. The findings indicated that the administration of CP extract has no prophylactic or ameliorative effects on Cd-induced kidney damage and that CP had observable adverse effects on the kidneys of adult Wistar rats.

Both JrWRKY2 and JrWRKY7 of Juglans regia mediate responses to abiotic stresses and abscisic acid through formation of homodimers and interaction.

WRKY transcription factors belong to a large protein family that is involved in diverse developmental processes and abiotic stress responses. Currently, there is little understanding of the role of WRKY transcription factors in regulatory mechanisms in plants, especially in the protein-protein interactions that are essential for biological regulatory functions and networks. In the present study, yeast one-hybrid, yeast two-hybrid, transient expression and quantitative RT-PCR were applied to investigate the potential characteristics of two WRKY proteins from Juglans regia, JrWRKY2 (GenBank Accession No. KU057089) and JrWRKY7 (GenBank Accession No. KP784651). JrWRKY2 and JrWRKY7 can form homodimers and interact with each other. JrWRKY2 and JrWRKY7 can bind to W-box motifs. Similarly high levels of transcription were found for JrWRKY2 and JrWRKY7 under NaCl and polyethylene glycol (PEG) stresses, as well as at different developmental stages, e.g., the pistil or terminal leaf. JrWRKY2 and JrWRKY7 were transiently overexpressed in an independent manner in the terminal leaf. Analyses of superoxide dismutase (SOD) and peroxidase (POD) activities, proline and malondialdehyde (MDA) contents, and electrolyte leakage rate showed that JrWRKY2 and JrWRKY7 overexpression improved plant tolerance to NaCl, PEG, abscisic acid, and cold stress. Additionally, JrWRKY2 and JrWRKY7 overexpression elevated transcription of SOD, POD, glutathione peroxidase (GPX), catalase (CAT), ascorbate peroxidase (APX), and MYB genes, but downregulated the expression of NAC. Overall, the results demonstrate that JrWRKY2 and JrWRKY7 are dimeric proteins that can form functional homodimers and interact with each other and that they are involved in abiotic stress responses.

Lipid profile, inflammation, and oxidative status in peri- and postmenopausal women

Objective: To evaluate the effect of perimenopause and postmenopause on lipid profile, inflammation, and oxidative stress in women.Methods: This cross-sectional study included 117 women (47 ± 6 years) classified as perimenopausal (n = 47), postmenopausal (n = 40), or non-menopausal (n = 30). In serum, we analyzed lipid profile, tumor necrosis factor-alpha (TNF-α), interleukin-1α (IL-1α), and C-reactive protein (CRP). Pro-oxidant status was assessed by thiobarbituric acid reactive substances (TBARS) and protein carbonyls. Antioxidant defense was performed by analysis of superoxide dismutase (SOD) and catalase activities.Results: Compared to non-menopausal women, triacylglycerols (TG) were similar, total cholesterol and LDL-C were higher in perimenopausal and postmenopausal women, while HDL-C concentrations were decreased. TNF-α and IL-1α were higher in postmenopausal women, while CRP concentrations were elevated in both peri-and postmenopausal women (p < 0.05). TBARS and carbonyls were increased in peri- and postmenopausal women (p < 0.05). SOD and CAT activities were decreased in postmenopausal women (p < 0.05) and elevated in perimenopausal women.Conclusion: Menopausal transition and postmenopause were associated with dyslipidemia, inflammation, and unbalanced oxidative status exposing women to cardiovascular risk.

Cadmium Application in Tomato: Nutritional Imbalance and Oxidative Stress

Over the last few decades, the concentration of cadmium (Cd) in the environment has increased considerably in many countries due to anthropogenic activities. Cd is one of the most toxic pollutants in the environment and affects many metabolic processes in plants. The main objective of this study was to evaluate the response of the production, nutritional, and enzymatic antioxidant system of two tomato genotypes (Calabash Rouge and CNPH 0082) grown in tropical soils that were treated with doses of Cd. Soil samples were collected from the layer of earth at a depth of 0–0.2 m in areas subjected to a minimum of human disturbance. The concentrations of Cd applied to the soil samples were 0, 1, 2, and 4 times (0, 3, 6, and 12 mg kg−1 of Cd) the agricultural intervention value adopted by current environmental legislation in the state of Sao Paulo, Brazil. Analysis of superoxide dismutase, catalase, glutathione reductase, guaiacol peroxidase, and ascorbate peroxidase activities, formation of stress indicator compound (malondialdehyde—MDA and hydrogen peroxide), parameters of production—dry mass of the shoot and root system (here in after “shoots” and “roots”), as well as nutrition, and both the bioavailable and total levels of this metal in the soil were performed. When the bioavailable content and total levels of Cd in the soil increased as a result of this metal doses applied, the biomass of both shoots and roots decreased in both genotypes (with the exception of the CNPH 0082 grown in clay soil) and displayed lower SPAD (relative chlorophyll index) values when exposed to contaminated environments with Cd concentrations. Cadmium treatment resulted in nutritional imbalances, mainly in terms of N, P, and Mn metabolism. Plants subjected to an elevated available content of metal in the soil exhibited increases in content of MDA and hydrogen peroxide and increased activity of catalase, ascorbate peroxidase, and guaiacol peroxidase in plant tissues when grown in both clay soil and sandy soil. Cadmium was phytotoxic to the plants causing a nutritional imbalance, especially on the metabolisms of N, P, and Mn. An oxidative stress condition was established in response to the Cd treatments applied, which led to changes in peroxidase activity.

The protective effect of prophylactic ozone administration against retinal ischemia-reperfusion injury

Introduction: Retinal ischemia-reperfusion (IR) injury is associated with many ocular diseases. Retinal IR injury leads to the death of retinal ganglion cells (RGCs), loss of retinal function and ultimately vision loss. The aim of this study was to show the protective effects of prophylactic ozone administration against retinal IR injury.Materials and methods: A sham group (S) (n = 7) was administered physiological saline (PS) intraperitoneally (i.p.) for 7 d. An ischemia reperfusion (IR) group (n = 7) was subjected to retinal ischemia followed by reperfusion for 2 h. An ozone group (O) (n = 7) was administered 1 mg/kg of ozone i.p. for 7 d. In the ozone + IR (O + IR) group (n = 7), 1 mg/kg of ozone was administered i.p. for 7 d before the IR procedure and at 8 d, the IR injury was created (as in IR group). The rats were anesthetized after second hour of reperfusion and their intracardiac blood was drawn completely and they were sacrificed. Blood samples were sent to a laboratory for analysis of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), malondialdehyde (MDA), total oxidant score (TOS) and total antioxidant capacity (TAC). The degree of retinal injury was evaluated according to changes in retinal cells and necrotic and apoptotic cells using the TUNEL method. Data were evaluated statistically with the Kruskal-Wallis test.Results: The number of RGCs and the inner retinal thickness were significantly decreased after ischemia, and treatment with ozone significantly inhibited retinal ischemic injury. In the IR group, the degree of retinal injury was found to be the highest. In the O + IR group, retinal injury was found to be decreased in comparison to the IR group. In the ozone group without retinal IR injury, the retinal injury score was the lowest. The differences in the antioxidant parameters SOD, GSH-Px and TAC were increased in the ozone group and the lowest in the IR group. The oxidant parameters MDA and TOS were found to be the highest in the IR group and decreased in the ozone group.Discussion: IR injury is also positively correlated with the degree of early apoptosis. This study demonstrated that ozone can attenuate subsequent ischemic damage in the rat retina through triggering the increase of the antioxidant capacity.

Neuroprotective Effects of Thymoquinone on the Hippocampus in a Rat Model of Traumatic Brain Injury

Traumatic brain injury is a leading cause of morbidity and mortality worldwide. We evaluated the neuroprotective effects of thymoquinone (TQ) in a rat model of traumatic brain injury by using biochemical and histopathologic methods for the first time. Twenty-four rats were divided into sham (n = 8), trauma (n = 8), and TQ-treated (n = 8) groups. A moderate degree of head trauma was induced with the use of Feeney's falling weight technique, and TQ (5 mg/kg/day) was administered to the TQ-treated group for 7 days. All animals were killed after cardiac perfusion. Brain tissues were extracted immediately after perfusion without damaging the tissues. Biochemical procedures were performed with the serum, and a histopathologic evaluation was performed on the brain tissues. Biochemical experiments included malondialdehyde (MDA), reduced and oxidized coenzyme Q10 analysis, DNA isolation and hydroylazation, and glutathione peroxidase, and superoxide dismutase analyses. Neuron density in contralateral hippocampal regions (CA1, CA2-3, and CA4) 7 days after the trauma decreased significantly in the trauma and TQ-treated groups, compared with that in the control group. Neuron densities in contralateral hippocampal regions (CA1, CA2-3, and CA4) were greater in the TQ-treated group than in the trauma group. TQ did not increase superoxide dismutase or glutathione peroxidase antioxidant levels. However, TQ decreased the MDA levels. These results indicate that TQ has a healing effect on neural cells after head injury and this effect is mediated by decreasing MDA levels in the nuclei and mitochondrial membrane of neurons.

Methods for the assessment of isoenzymes activity in sunflower seeds

Enzyme activity detection in seeds allows the assessment of the deterioration process in the early stages. In this context, the objective was to assess the effectiveness and the degree of similarity between the results of izoenzymes activity using different methods, as follows: spectrophotometry, visual analysis after electrophoresis, evaluation of the bands nodes gels with software GelAnalyzer. 250 hybrid seeds were submitted to artificial aging to form four lots with differences in physiological quality. In addition to the enzymatic determinations, physiological germination tests, emergence and emergence speed index were performed. It was concluded that there are differences in results according to the methods used; the results were consistent between test methods and correlated with physiological results when the catalase enzyme was evaluated; and in the isozyme analysis of superoxide dismutase and alcohol dehydrogenase there was a divergence among the results of the methodologies, and according to such, the relationship to seeds physiological quality.

Effect of Myricetin, Pyrogallol, and Phloroglucinol on Yeast Resistance to Oxidative Stress

The health beneficial effects of dietary polyphenols have been attributed to their intrinsic antioxidant activity, which depends on the structure of the compound and number of hydroxyl groups. In this study, the protective effects of pyrogallol, phloroglucinol, and myricetin on the yeast Saccharomyces cerevisiae were investigated. Pyrogallol and myricetin, which have a pyrogallol structure in the B ring, increased H2O2 resistance associated with a reduction in intracellular oxidation and protein carbonylation, whereas phloroglucinol did not exert protective effects. The acquisition of oxidative stress resistance in cells pretreated with pyrogallol and myricetin was not associated with an induction of endogenous antioxidant defences as assessed by the analysis of superoxide dismutase and catalase activities. However, myricetin, which provided greater stress resistance, prevented H2O2-induced glutathione oxidation. Moreover, myricetin increased the chronological lifespan of yeast lacking the mitochondrial superoxide dismutase (Sod2p), which exhibited a premature aging phenotype and oxidative stress sensitivity. These findings show that the presence of hydroxyl groups in the ortho position of the B ring in pyrogallol and myricetin contributes to the antioxidant protection afforded by these compounds. In addition, myricetin may alleviate aging-induced oxidative stress, particularly when redox homeostasis is compromised due to downregulation of endogenous defences present in mitochondria.

Le degré de l’insuffisance rénale chronique est associé aux taux de cytokines pro-inflammatoires, à l’hyperhomocystéinémie et au stress oxydant

AimTo evaluate pro-inflammatory cytokines, homocysteinemia and markers of oxidative status in the course of chronic renal failure. Patients and methodsOne hundred and two patients (male/female: 38/64; age: 45±07 years) with chronic renal failure were divided into 4 groups according to the National Kidney Foundation classification. They included 28 primary stage renal failure patients, 28 moderate stage renal failure, 28 severe stage renal failure and 18 end stage renal failure. The inflammatory status was evaluated by the determination of pro-inflammatory cytokines (tumor necrosis factor-α, interleukin-1β, interleukin-6) and total homocysteine. Pro-oxidant status was assessed by assaying thiobarbituric acid reactive substances, hydroperoxides, and protein carbonyls. Antioxidant defence was performed by analysis of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase. ResultsInflammatory markers were elevated in the end stage renal failure group compared to the other groups (P<0.001). Indeed, an increase in thiobarbituric acid reactive substances, hydroperoxides and protein carbonyls was noted in the end stage renal failure group in comparison with the other groups (P<0.001), while the levels of antioxidants enzymes activity were decreased in the study population (P<0.001). ConclusionImpaired renal function is closely associated with the elevation of inflammatory markers leading to both increased markers of oxidative stress and decreased antioxidant defense.

Induction of total phenolics and defence-related enzymes during β-aminobutyric acid-induced resistance in Brassica carinata against Alternaria blight

Exogenous foliar application of β-aminobutyric acid (BABA) led to a significant reduction in disease severity in Brassica carinata caused by Alternaria brassicae. To get a better insight about changes in defence-related enzymes like phenylalanine ammonia lyase (PAL) and polyphenol oxidase (PPO), isoform analysis of superoxide dismutase (SOD) and peroxidase (POX) were studied. BABA-treated plants showed a significant increase in PAL, PPO enzyme activities and total phenolic content in response to pathogen inoculation. However, isoform analysis of SOD and POX revealed no change in isoform number but a quantitative change in activity was observed in response to pathogen.

Quantification of in vivo oxidative damage in Caenorhabditis elegans during aging by endogenous F3‐isoprostane measurement

Oxidative damage is thought to be a major cause in development of pathologies and aging. However, quantification of oxidative damage is methodologically difficult. Here, we present a robust liquid chromatography-tandem mass spectrometry (LC-MS/MS) approach for accurate, sensitive, and linear in vivo quantification of endogenous oxidative damage in the nematode Caenorhabditis elegans, based on F3-isoprostanes. F3-isoprostanes are prostaglandin-like markers of oxidative damage derived from lipid peroxidation by Reactive Oxygen Species (ROS). Oxidative damage was quantified in whole animals and in multiple cellular compartments, including mitochondria and peroxisomes. Mutants of the mitochondrial electron transport proteins mev-1 and clk-1 showed increased oxidative damage levels. Furthermore, analysis of Superoxide Dismutase (sod) and Catalase (ctl) mutants uncovered that oxidative damage levels cannot be inferred from the phenotype of resistance to pro-oxidants alone and revealed high oxidative damage in a small group of chemosensory neurons. Longitudinal analysis of aging nematodes revealed that oxidative damage increased specifically with postreproductive age. Remarkably, aging of the stress-resistant and long-lived daf-2 insulin/IGF-1 receptor mutant involved distinct daf-16-dependent phases of oxidative damage including a temporal increase at young adulthood. These observations are consistent with a hormetic response to ROS.

Effect of Different Stages of Chronic Kidney Disease and Renal Replacement Therapies on Oxidant-Antioxidant Balance in Uremic Patients

Oxidative stress seems to be involved in the path physiology of cardiovascular complications of chronic kidney disease (CKD). In this study, we determined the effect of different stages of CKD and substitutive therapies on oxidative stress. One hundred sixty-seven patients (age: 44 ± 06 years; male/female: 76/91) with CKD were divided into 6 groups according to the National Kidney Foundation classification. Prooxidant status was assessed by assaying thiobarbituric acid reactive substances, hydroperoxides, and protein carbonyls. Antioxidant defence was performed by analysis of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, vitamin E, Iron, and bilirubin. TBARS and LPO were higher in HD patients compared to other groups (P < 0.001), while protein carbonyls were more increased in PD patients. The antioxidant enzymes were declined already at severe stage of CKD and they were declined notably in HD patients (P < 0.001). Similar observation was found for vitamin E, Fe, and bilirubin where we observed a significant decrease in the majority of study groups, especially in HD patients (P < 0.001). The evolution of CKD was associated with elevated OS. HD accentuates lipid, while PD aggravates protein oxidation. However, the activity of antioxidant enzymes was altered by impaired renal function and by both dialysis treatments.