Enzymatic Defense System Research Articles

Prospecting toxicity of the avobenzone sunscreen in plants.

Avobenzone (AVO) is a sunscreen with high global production and is constantly released into the environment. Incorporating sewage biosolids for fertilization purposes, the leaching from cultivated soils, and the use of wastewater for irrigation explain its presence in the soil. There is a lack of information about the impact of this sunscreen on plants. In the present study, the ecotoxicity of AVO was tested at concentrations 1, 10, 100, and 1,000ng/L. All concentrations caused a reduction in root growth of Allium cepa, Cucumis sativus, and Lycopersicum esculentum seeds, as well as a mitodepressive effect, changes in the mitotic spindle and a reduction in root growth of A. cepa bulbs. The cell cycle was disturbed because AVO disarmed the enzymatic defense system of root meristems, leading to an accumulation of hydroxyl radicals and superoxides, besides lipid peroxidation in cells. Therefore, AVO shows a high potential to cause damage to plants and can negatively affect agricultural production and the growth of non-cultivated plants.

Elimination of representative antibiotic-resistant bacteria, antibiotic resistance genes and ciprofloxacin from water via photoactivation of periodate using FeS2

The propagation of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) induced by the release of antibiotics poses great threats to ecological safety and human health. In this study, periodate (PI)/FeS2/simulated sunlight (SSL) system was employed to remove representative ARB, ARGs and antibiotics in water. 1 × 107 CFU mL–1 of gentamycin-resistant Escherichia coli was effectively disinfected below limit of detection in PI/FeS2/SSL system under different water matrix and in real water samples. Sulfadiazine-resistant Pseudomonas and Gram-positive Bacillus subtilis could also be efficiently sterilized. Theoretical calculation showed that (110) facet was the most reactive facet on FeS2 to activate PI for the generation of reactive species (·OH, ·O2–, h+ and Fe(IV)=O) to damage cell membrane and intracellular enzyme defense system. Both intracellular and extracellular ARGs could be degraded and the expression levels of multidrug resistance-related genes were downregulated during the disinfection process. Thus, horizontal gene transfer (HGT) of ARB was inhibited. Moreover, PI/FeS2/SSL system could disinfect ARB in a continuous flow reactor and in an enlarged reactor under natural sunlight irradiation. PI/FeS2/SSL system could also effectively degrade the HGT-promoting antibiotic (ciprofloxacin) via hydroxylation and ring cleavage process. Overall, PI/FeS2/SSL exhibited great promise for the elimination of antibiotic resistance from water.

Different regulation strategies of anaerobic digestion by AC/CaO2 and Fe3O4/CaO2: Reactive oxygen species induction, methanogenic performance, and microbial response

This study examined the combination of activated carbon and magnetite with calcium peroxide in enhancing the anaerobic digestion (AD) performance of food waste (FW). The individual mechanisms of these two approaches were also clarified. The results indicated that AC/CaO2 achieved the highest specific methane yield of 434.4 mL/g VS, followed by Fe3O4/CaO2 (416.9 mL/g VS). Both were significantly higher than other groups (control, AC, Fe3O4, and CaO2 were 330.1, 341.4, 342.8, and 373.2 mL/g VS, respectively). Additionally, compared to Fe3O4/CaO2, AC/CaO2 further increased reactive oxygen species (ROS), thereby enhancing the hydrolytic acidification process. Simultaneously, the higher ROS levels of Fe3O4/CaO2 and AC/CaO2 promoted the formation of microbial aggregates and established a more robust enzymatic defense system and unique damage repair strategy. The research comparatively analyzed the synergistic mechanism of iron-based and carbon-based conductive materials with CaO2, providing new perspectives for optimizing the AD of FW.

Enhanced arsenic stress tolerance in landrace and improved rice cultivars through modulation of gibberellic acid (GA3) synthesis and antioxidant metabolism via phosphorus and silicon supplementation

Arsenic (As), an environmental pollutant, imposes toxic impacts on plant health. In recent years, researchers have focused on comprehending the As-induced intrusion in growth and metabolic components. However, the interactions between phosphorus (P) and silicon (Si) remain elusive, specifically in rice (Oryza sativa) cultivars. Therefore, the present study investigated the effects of P and Si on the defense mechanisms, nutrients accumulation, carbohydrate metabolism, gibberellic acid (GA3) synthesis, and growth responses in Indica rice cultivars (landrace and improved) under As stress. With this focus, our study potentially indicated that As stress (150 µM) negatively impacted the underlying physiological and growth traits, with more pronounced effects on the improved cultivar compared to the landrace. However, P (30 mg kg−1 soil) and/ or Si (1 mM) treatments have prominently reduced oxidative stress with improved defense mechanisms and GA synthesis. Modulation of enzymatic defense system increased in both cultivars but more pronounced in landrace, including superoxide dismutase (+36.47%, +24.43%), ascorbate peroxidase (+95.11%, +78.26%), along with non-enzymatic antioxidants such as ascorbate (+29.43%, +21.48%), and reduced glutathione (+75.45%, +62.34%) concentrations, respectively. Notably, GA concentration (+23.78%, +16.48%) was substantially increased by the cumulative application of P and Si under As stress in both cultivars but more conspicuous in the landrace, respectively. Further, employing GA biosynthesis inhibitor, paclobutrazol (PBZ; 10 µM), substantiated the input of GA-mediated As tolerance, wherein, PBZ reversed the impacts of P and Si on the endogenous GA concentration and defense metabolism. In summation, landrace outperformed improved cultivar leading to As tolerance. This implies that the landrace could be used for future breeding programs permitting in-depth considerations of P and Si-mediated GA3 synthesis under As stress conditions.

Responses to lead stress in Scrophularia striata: insights into antioxidative defence mechanisms and changes in flavonoids profile.

Lead (Pb) induces oxidative stress in plants, which results in different responses, including the production of antioxidants and changes in the profile of secondary metabolites. In this study, the responses of Scrophularia striata exposed to 250mgL-1 Pb (NO3 )2 in a hydroponic environment were determined. Growth parameters, oxidative and antioxidative responses, redox status, and the concentration of Pb were analysed in roots and shoots. Malondialdehyde and hydrogen peroxide (H2 O2 ) levels in the roots were significantly increased and reached their highest value at 72h after Pb treatment. Superoxide dismutase, catalase, and peroxidase, as an enzymatic antioxidant system, were responsible for reactive oxygen species scavenging, where their activities were increased in the shoot and root of Pb-treated plants. Enzymatic antioxidant activities were probably not enough to remove a significant H2 O2 content in response to Pb treatment. Therefore, other defence responses were activated. The results stated that the flavonoid components of S. striata progressed towards the increase of isoflavone, flavanol, and stilbenoid contents under Pb treatment. In general, S. striata stimulates the enzymatic defence system and activates the non-enzymatic system by modulating the profile of flavonoids toward the production of flavonoids with high antioxidant activity, such as quercetin and myricetin in response to Pb stress.

Arbuscular mycorrhizal fungi enhanced resistance to low-temperature weak-light stress in snapdragon (Antirrhinum majus L.) through physiological and transcriptomic responses.

Low temperature (LT) and weak light (WL) seriously affects the yield and quality of snapdragon in winter greenhouse. Arbuscular mycorrhizal fungi (AMF) exert positive role in regulating growth and enhancing abiotic stress tolerance in plants. Nevertheless, the molecular mechanisms by AMF improve the LT combined with WL (LTWL) tolerance in snapdragon remain mostly unknown. We compared the differences in root configuration, osmoregulatory substances, enzymatic and non-enzymatic antioxidant enzyme defense systems and transcriptome between AMF-inoculated and control groups under LT, WL, low light, and LTWL conditions. Our analysis showed that inoculation with AMF effectively alleviated the inhibition caused by LTWL stress on snapdragon root development, and significantly enhanced the contents of soluble sugars, soluble proteins, proline, thereby maintaining the osmotic adjustment of snapdragon. In addition, AMF alleviated reactive oxygen species damage by elevating the contents of AsA, and GSH, and the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR), monodehydroascorbate reductase (MDHAR), and glutathione reductase (GR). RNA-seq analysis revealed that AMF regulated the expression of genes related to photosynthesis (photosystem I related proteins, photosystem II related proteins, chlorophyll a/b binding protein), active oxygen metabolism (POD, Fe-SOD, and iron/ascorbate family oxidoreductase), plant hormone synthesis (ARF5 and ARF16) and stress-related transcription factors gene (bHLH112, WRKY72, MYB86, WRKY53, WRKY6, and WRKY26) under LTWL stress. We concluded that mycorrhizal snapdragon promotes root development and LTWL tolerance by accumulation of osmoregulatory substances, activation of enzymatic and non-enzymatic antioxidant defense systems, and induction expression of transcription factor genes and auxin synthesis related genes. This study provides a theoretical basis for AMF in promoting the production of greenhouse plants in winter.

Effects of Glyprolins on Lipid and Protein Peroxidation in the Hypothalamic Region in Experimental Hyperthyroidism

We investigate effects of glyproline-type neuropeptides on lipid and protein peroxidation in the hypothalamic brain region of rats under the conditions of experimental hyperthyroidism. The state of hyperthyroidism in animals was simulated by intragastric administration of sodium pentahydrate of L-thyroxine at a dose of 150 µg/kg for 21 days. The following experimental groups (n=10) were formed: 1) control group — intact animals (control); 2) animals treated with L-thyroxine sodium salt pentahydrate (hyperthyroidism); 3) animals treated with Thr-Lys-Pro-Arg-Pro-Gly-Pro (celank); 4) animals treated with Pro-GlyPro (doses of 87 and 33 µg/kg/day, respectively) intraperitoneally daily during 21 days starting one day after the last administration of sodium pentahydrate of L-thyroxine. The level of lipid peroxidation processes was assessed by the initial level of TBA-reactive products, spontaneous and ascorbate-dependent lipid peroxidation rates in hypothalamic tissue homogenate. Protein peroxidation products were determined by the reaction between oxidized amino acid residues of proteins and 2,4-dinitrophenylhydrazone. The enzymatic part of the antioxidant system of hypothalamic region was estimated by measuring the activity of superoxide dismutase and catalase. In the setting of Thr-Lys-Pro-Arg-Pro-Gly-Pro and Pro-Gly-Pro administration under experimental hyperthyroidism, the intensity of lipid and protein peroxidation processes was decreased, while the activity of antioxidant enzymes-superoxide dismutase and catalase was restored in the hypothalamic tissue. The experimental data obtained indicate that, under the conditions of experimental hyperthyroidism, Thr-Lys-Pro-Arg-Pro-Gly-Pro and Pro-Gly-Pro compounds exhibit an antioxidant and antiradical activity with respect to parameters of lipoperoxidation and oxidative modification of proteins, as well as with respect to enzymatic defense systems in the hypothalamic brain region of laboratory animals.

Antioxidative and Anti-photooxidative Potential of Interruptins from the Edible Fern Cyclosorus terminans in Human Skin Cells.

<p>Background: Human skin is exposed daily to oxidative stress factors such as UV light, chemical pollutants, and invading organisms. Reactive oxygen species (ROS) are intermediate molecules that cause cellular oxidative stress. In order to survive in an oxygen-rich environment, all aerobic organisms, including mammals, have evolved enzymatic and non-enzymatic defence systems. The interruptins from an edible fern Cyclosorus terminans possess antioxidative properties and can scavenge intracellular ROS in adipose-derived stem cells. <p> Objectives: This study aimed to evaluate the antioxidative efficacy of interruptins A, B, and C in cultured human dermal fibroblasts (HDFs) and epidermal keratinocytes (HEKs). Moreover, the anti-photooxidative activity of interruptins in ultraviolet (UV)-exposed skin cells was investigated. <p> Methods: The intracellular ROS scavenging capacity of interruptins in skin cells was measured by flow cytometry. Their induction effects on gene expression of the endogenous antioxidant enzymes was monitored using real-time polymerase chain reaction. <p> Results: Interruptins A and B, but not interruptin C, were highly effective in ROS scavenging, particularly in HDFs. Interruptins A and B upregulated gene expression of superoxide dismutase (SOD)1, SOD2, catalase (CAT), and glutathione peroxidase (GPx) in HEKs, but they only induced SOD1, SOD2, and GPx gene expression in HDFs. Additionally, interruptins A and B efficiently suppressed UVA- and UVB-induced ROS generation in both HEKs and HDFs. <p> Conclusion: The results suggest that these naturally occurring interruptins A and B are potent natural antioxidants and therefore may have the potential in the future of inclusion in antiaging cosmeceutical products.</p>.

Potassium silicate enhances drought tolerance of Bellis perennis by improving antioxidant activity and osmotic regulators

Ornamental plants can usually encounter various types of environmental stress, which reduce plant productivity. A proper application of fertilizers can improve plantsʼ tolerance to drought stress. Nutrients such as potassium and silicon are known to have beneficial effects. This study aimed to evaluate the growth of Bellis perennis under drought stress (80, 70, and 60% FC) and with the application of potassium silicate (0, 2, and 4 mM). The results showed that potassium silicate (2 and 4 mM) increased K and Si accumulation in plants under drought stress. Plants treated with potassium silicate under drought stress exhibited a lower degree of electrolyte leakage and less MDA accumulation in the following order: 2 and 4 mM potassium silicate. An increase in relative water content and chlorophyll was observed with application of potassium silicate under drought stress. Regardless of potassium silicate, the plant enzymatic defense system was significantly improved compared to non-stressed plants. Potassium silicate enhanced the amount of osmotic regulators (carbohydrate and proline) and secondary metabolites (flavonoids and phenols) compared to control plants regardless of drought stress. The anthocyanin content in the flowers significantly decreased by 32.2% when the plants were treated with 4 mM potassium silicate at 60% FC, compared to 80% FC. In conclusion, potassium silicate mitigated the effects of drought stress, enhanced plant tolerance to drought stress, increased the activity of antioxidant enzymes, and improved the amounts of osmotic regulators and secondary metabolites.

The efficacy of Makiang tea drinking on serum lipid profile in the treatment of dyslipidaemia: A randomized controlled trial

The purpose of this study was to investigate the effects of Makiang (MK) tea consumption on the serum lipid profile and oxidative stress biomarkers in participants with dyslipidemia. A randomized, single-blind, parallel-group, placebo-controlled study was conducted at the Outpatient Department of Phayao Hospital, Thailand. This clinical trial enrolled 64 subjects (males and females), aged between 30 and 65 years with hyperlipidemia who were randomized using simple random sampling, receiving a 12-week MK tea (3 g/250 ml hot water) taken daily or a placebo. Body mass index, lipid profile, and serum oxidative stress markers were evaluated at the baseline and the end of the study. Within-group comparisons revealed that drinking only one cup of MK tea daily caused a significant reduction (p &lt; 0.05 all) of total cholesterol (TC), total triglyceride (TG), and low-density lipoprotein cholesterol (LDL-C). Meanwhile, between-group differences showed that serum TC, TG, and LDL-C levels significantly decreased (p &lt; 0.05 all), whereas the levels of high-density lipoprotein cholesterol were unchanged. This phenomenon was accompanied by decreased serum malondialdehyde and increased endogenous enzymatic defence systems (p &lt; 0.05 all). Thus, MK tea may be useful as an adjunct agent to improve the lipid profile in patients with dyslipidemia.

RETRACTED: Nrf2 pathway activation with natural plant-derived exosome-like nanovesicle/hydrogel preparations for oxidative stress modulation in inflammation related diseases

Plant-derived exosome-like nanovesicles (PDENs) currently have significant therapeutic value in the field of disease treatment and sub-health, but the lack of suitable formulation forms further limits their clinical application. Here, we propose a novel concept of a natural plant-derived exosome-like nanovesicle-hydrogel formulation, where exosome-like nanovesicles are isolated from the outer rind of Aloe as a therapeutic component, and the inner pulp of aloe is ultrasonically crushed and concentrated to form a hydrogel matrix. The two components are then mixed to form a formulation. We found that this natural plant-derived hydrogel formulation was biocompatible and exhibited minimal immunogenicity in vivo after topical application. Further release of exosome-like nanovesicles from the hydrogel could enhance the anti-oxidant enzyme defense system in the skin via the Nrf2/HO-1 pathway, and effectively modulate the balance between oxidative and anti-oxidative states towards a more favorable physiological equilibrium in mice with atopic dermatitis (AD) lesions or diabetic wounds. Meanwhile, due to the good moisturizing property of aloe hydrogel itself, it could accelerate the repairment of natural barrier functions in inflammatory skin lesions and wound sites. Overall, this formulation is expected to be a potential and effective strategy for treating AD and diabetic wounds, and provides novel insights into the rational design of exosome-like nanovesicle formulations based on natural plant-derived components.

Impact of Biologically and Chemically Synthesized Zinc Oxide Nanoparticles on Seed Germination and Seedlings’ Growth

Zinc oxide nanoparticles have gained attention in the last decades due to their versatile applications; in agriculture, they have been used for their multiple benefits. In this study, the effects of zinc oxide nanoparticles, obtained via chemical and biological synthesis and of 70–80 nm in size, on the germination and seedling growth of Capsicum annuum and Solanum lycopersicum seed were determined. The physiological parameters, photosynthetic pigments, the content of total phenols, total flavonoids, as well as the antioxidant capacity of 2,2-diphenyl-1-picrylhydrazyl (DPPH), and the enzymatic activity of catalase, peroxidase, and polyphenol oxidase were evaluated. The results indicated that treatment with zinc oxide nanoparticles obtained via green synthesis improved seed germination rate, while chemically synthesized nanoparticles at higher concentrations decreased germination percentage. In general, the parameters of enzymatic and nonenzymatic antioxidants in treated plants showed significant differences with respect to the control. However, the treatments with the bionanoparticles resulted in more beneficial parameters. Zinc oxide nanoparticles obtained via green synthesis are more effective in generating bioactive compounds and activating the enzyme defense system due to being more biocompatible.

Inhibitory Effect of Quercetin on Oxidative Endogen Enzymes: A Focus on Putative Binding Modes.

Oxidative stress is defined as an imbalance between the production of free radicals and reactive oxygen species (ROS) and the ability of the body to neutralize them by anti-oxidant defense systems. Cells can produce ROS during physiological processes, but excessive ROS can lead to non-specific and irreversible damage to biological molecules, such as DNA, lipids, and proteins. Mitochondria mainly produce endogenous ROS during both physiological and pathological conditions. Enzymes like nicotinamide adenine dinucleotide phosphate oxidase (NOX), xanthine oxidase (XO), lipoxygenase (LOX), myeloperoxidase (MPO), and monoamine oxidase (MAO) contribute to this process. The body has enzymatic and non-enzymatic defense systems to neutralize ROS. The intake of bioactive phenols, like quercetin (Que), can protect against pro-oxidative damage by quenching ROS through a non-enzymatic system. In this study, we evaluate the ability of Que to target endogenous oxidant enzymes involved in ROS production and explore the mechanisms of action underlying its anti-oxidant properties. Que can act as a free radical scavenger by donating electrons through the negative charges in its phenolic and ketone groups. Additionally, it can effectively inhibit the activity of several endogenous oxidative enzymes by binding them with high affinity and specificity. Que had the best molecular docking results with XO, followed by MAO-A, 5-LOX, NOX, and MPO. Que's binding to these enzymes was confirmed by subsequent molecular dynamics, revealing different stability phases depending on the enzyme bound. The 500 ns simulation showed a net evolution of binding for NOX and MPO. These findings suggest that Que has potential as a natural therapy for diseases related to oxidative stress.

Study on the antioxidant activity of peptides from soybean meal by fermentation based on the chemical method and AAPH-induced oxidative stress.

Preparation and antioxidant activities of soybean peptides using solid fermentation to decrease the content of trypsin inhibitor (TI) and antigen protein were investigated in this study. The results showed the optimal fermentation conditions were as follows: fermentation time 48 h, the ratio of material to solvent 1:2, inoculum size 12%, and the ratio of Lactic acid bacteria and Aspergillus oryzae 2:1. The hydrolysate was were divided into four components of <1, 1-3, 3-5, and >5 kDa by ultrafiltration based on molecular weight, and the <1 kDa peptides expressed the highest antioxidant activities. Meanwhile, the cell antioxidant activity of the <1 kDa soybean peptides was investigated using AAPH-induced erythrocyte hemolysis, which effectively inhibited erythrocyte hemolysis with the inhibit rate of 85.8% through inhibition of the ROS intracellular generation. In addition, soybean peptides could significantly restore the intracellular antioxidant enzymes (SOD, GSH-Px, and CAT) activities, as well as inhibited intracellular MDA generation and depletion of GSH. The intracellular antioxidant detoxifying mechanism of soybean peptides was associated with both non-enzymatic and enzymatic defense systems. According to this study, fermentation could effectively improve the antioxidant activities of soybean peptides.

Physiological Aspects of Interaction of Nanoparticles with Plant and Microorganism Cells

Nanoparticles (NPs) are materials with unique physical and chemical properties that are less than 100 nm in size. They are widely used in various fields of industry, medicine and agriculture. In agribusiness nanomaterials are used as nanofertilisers and nanopesticides. This fact requires a detailed study of the physiological, biochemical and molecular genetic responses of cells of living organisms – plants, fungi and animals – to interaction with nanomaterials. This review article provides information on the mechanisms of nanoparticle absorption, movement and molecular interaction in plant organisms, as well as mechanisms of their antibacterial and fungicidal activity. Available scientific resources devoted to the physiological features of nanoparticle absorption by plants indicate two possible ways of their penetration into the plant organism – apoplastic and symplastic. In plant cells, nanoparticles act as reactive oxygen species (ROS), causing oxidative stress and triggering enzymatic and non-enzymatic defence systems that result in both inhibition of physiological processes and stimulation of plant growth and development and, consequently, increased yield. The effect on the plant organism is species-specific and depends on the type of nanomaterial and its concentration. Detailed laboratory and field studies are required to determine the specific effect of nanomaterials on a particular plant species, while complying with all toxicological safety standards to avoid environmental contamination with nanomaterials. Nanoparticles act on microorganism cells as physical and chemical disruptors – they change the permeability of cell walls and organelle membranes, protein configuration, damage DNA, leading to physical destruction of cells. Such properties of nanoparticles define antimicrobial and fungicidal activities of nanoparticles. However, nanoparticles should be used cautiously in crop production, as both plant life and productivity depend largely on microbial symbionts, and their effect on microbial cells is not species-specific.

Review Article on Molecular Mechanism of Regulation of Hypertension by Macro-elements (Na, K, Ca and Mg), Micro-elements/Trace Metals (Zn and Cu) and Toxic Elements (Pb and As).

Hypertension (HT) is a medical condition arising due to increase in blood pressure (BP) prevalent worldwide. The balanced dietary intakes of macro-elements and micro-elements including Na, K, Ca, Mg, Zn, and Cu have been described to maintain BP in humans by regulating the osmolarity of blood, cells/tissues, prevention of generation of oxidative and nitrosative stress (OANS), and endothelial damage through their functioning as important components of renin-angiotensin-aldosterone system (RAAS), antioxidant enzyme defense system, and maintenance of blood vascular-endothelial and vascular smooth muscle cell (VSMC) functions. However, inadequate/excess dietary intakes of Na/K, Ca/Mg, and Zn/Cu along with higher Pb and As exposures recognized to induce HT through common mechanisms including the followings: endothelial dysfunctions due to impairment of vasodilatation, increased vasoconstriction and arterial stiffness, blood clotting, inflammation, modification of sympathetic activity and higher catecholamine release, increased peripheral vascular resistance, and cardiac output; increased OANS due to reduced and elevated activities of extracellular superoxide dismutase and NAD(P)H oxidase, less nitric oxide bioavailability, decrease in cGMP and guanylate cyclase activity, increase in intracellular Ca2+ ions in VSMCs, and higher pro-inflammatory cytokines; higher parathyroid and calcitriol hormones; activation/suppression of RAAS resulting imbalance in blood Na+, K+, and water regulated by renin, angiotensin II, and aldosterone through affecting natriuresis/kaliuresis/diuresis; elevation in serum cholesterol and LDL cholesterol, decrease in HDL cholesterol due to defect in lipoprotein metabolism. The present study recommends the need to review simple dietary mineral intervention studies/supplementation trials before keeping their individual dietary excess intakes/exposures in consideration because their interactions lead to elevation and fall of their concentrations in body affecting onset of HT.

Nickel chloride generates cytotoxic ROS that cause oxidative damage in human erythrocytes

BackgroundNickel is a heavy metal that is regarded as a possible hazard to living organisms due to its toxicity and carcinogenicity. Nickel chloride (NiCl2), an inorganic divalent Ni compound, has been shown to cause oxidative stress in cells by altering the redox equilibrium. We have investigated the effect of NiCl2 on isolated human erythrocytes under in vitro condition. MethodsIsolated erythrocytes were treated with different concentrations of NiCl2 (25–500 µM) for 24 h at 37 ºC. Hemolysates were prepared and several biochemical parameters were analyzed in them. ResultsTreatment of erythrocytes with NiCl2 enhanced the intracellular generation of reactive oxygen species (ROS). A significant increase in hydrogen peroxide levels and oxidation of proteins and lipids was also seen. This was accompanied by a reduction in levels of nitric oxide, glutathione, free amino groups and total sulfhydryl groups. NiCl2 treatment impaired both enzymatic and non-enzymatic defense systems, resulting in lowered antioxidant capacity and diminished ability of cells to quench free radicals and reduce metal ions. NiCl2 exposure also had an inhibitory effect on the activity of enzymes involved in pathways of glucose metabolism (glycolytic and pentose phosphate shunt pathways). Increased level of methemoglobin, which is inactive in oxygen transport, was also seen. The rate of heme breakdown increased resulting in the release of free iron. Exposure to NiCl2 led to considerable cell lysis, indicating damage to the erythrocyte membrane. This was supported by the inhibition of membrane bound enzymes and increase in the osmotic fragility of NiCl2 treated cells. NiCl2 treatment caused severe morphological alterations with the conversion of normal discocytes to echinocytes. All changes were seen in a NiCl2 concentration-dependent manner. ConclusionNiCl2 generates cytotoxic ROS in human erythrocytes which cause oxidative damage that can decrease the oxygen carrying capacity of blood and also lead to anemia.

Physiological Modifications and Enzymatic Defense System of Amaranthus blitoides S. Watson and Amaranthus hybridus L. in Response to Water Deficit Stress

Physiological Modifications and Enzymatic Defense System of Amaranthus blitoides S. Watson and Amaranthus hybridus L. in Response to Water Deficit Stress

Iron nanoparticle regulate succinate dehydrogenase activity in canola plants under drought stress

Application of nutrients as nanoparticle (NP) is an operative manner of nutrient supply for plants, especially under stress conditions. The present study was designed to highlight the role of iron NP on drought tolerance and elucidate the underlying mechanisms in drought-stressed canola plants. Drought stress was imposed by polyethylene glycol different concentrations (0, 10 and 15% (W/V)) with or without iron NP (1.5 and 3 mg/l). A comparative study of several physiological and biochemical parameters have been carried out in canola plants treated by drought and iron NP. Stressed-canola plants showed a reduction in growth parameters, whereas iron NP mostly stimulated growth of stressed plants, which was accompanied by reinforcement in defense mechanisms. Regarding impacts on compatible osmolytes, the data revealed that iron NP was able to regulate osmotic potential by increasing protein, proline and soluble sugar contents. The iron NP application was activated the enzymatic defense system (catalase and polyphenol oxidase) and promoted the non-enzymatic antioxidants (phenol, flavonol and flavonoid). Both of these adaptive responses declined free radicals as well as lipid peroxidation and enhanced the membrane stability and drought tolerance of the plants. Enhanced chlorophyll accumulation via induction of protoporphyrin, magnesium protoporphyrin and protochlorophyllide, by iron NP also contributed towards better stress tolerance. Enzymes of Krebs cycle, namely succinate dehydrogenase and aconitase, were induced by iron NP in canola plants grown under drought stress. These results propose a multifaceted involvement of iron NP, through regulation of activity of respiratory enzymes and antioxidant enzymes, production of reactive oxygen species, osmoregulation and secondary metabolites metabolism, in response to drought stress.

55 Impacts of dietary Protandim Nrf2 Synergizer on antioxidant status of mature, sedentary horses

Reactive oxygen species are normal by-products of cellular metabolism but may have detrimental effects on cellular matrices when overproduced. Dietary antioxidants may neutralize excess free radicals and prevent the imbalance of oxidants to antioxidants, referred to as oxidative stress. To test the hypothesis that supplementation of an herbal extract combination (Protandim Nrf2 Synergizer, LifeVantage Corporation) would improve the body's enzymatic defense system, 40 mature, sedentary horses (32 mares, 8 geldings, mean ± SD; 15.7 ± 4.9 y, 519 ± 46 kg) were stratified by age, sex, and body weight (BW) and randomly assigned to one of 4 dietary treatment groups for 56 d: 1) 0 mg (CON); 2) 675 mg (Pro1); 3) 2,025 mg (Pro3); or 4) 4,050 mg (Pro6) Protandim Nrf2 Synergizer per day (n = 10 per group). Horses were group housed and received a basal diet of coastal bermudagrass hay ad libitum and a custom-formulated concentrate grain fed individually at 0.5% BW/d (dry matter basis) split evenly between 2 meals per d. The supplement was top-dressed on the morning grain meal. Blood samples were collected at d 0, 28, and 56 of supplementation before the morning feeding and analyzed for hydrogen peroxide (H2O2) production and concentration, superoxide dismutase(SOD) and glutathione peroxidase (GPx) activities, and malondialdehyde (MDA) concentration. Data were analyzed using linear models in SAS v9.4; sex, treatment, time, time × treatment were fixed effects and time was a repeated effect with horse(treatment) as the subject. Day 0 was included in all models as a covariate. No measure was impacted by dietary treatment. Regardless of treatment, whole blood SOD activity, plasma MDA, and serum H2O2 concentration decreased from d 0 to 28 (P ≤ 0.0001) and remained suppressed at d 56 (P ≤ 0.0007). Conversely, whole blood GPx activity increased from d 0 to 28 (P = 0.01) and decreased from d 28 to 56 (P = 0.02) to be similar to d 0 at d 56. Serum H2O2 production was greater in geldings than mares (P = 0.04) but no other variable was impacted by sex. Dietary supplementation of up to 4,050 mg/d Protandim Nrf2 Synergizer did not impact antioxidant status in mature, sedentary horses. Effects of supplementation on antioxidant status should be investigated in horses subjected to elevated oxidative insult, such as exercise.