Enzymatic Antioxidant Defense System Research Articles

In-vivo anti-inflammatory effects of Roman Chamomile (Chamaemelum nobile) aqueous extracts collected from the National Park of El-Kala (North-East, Algeria).

The aim of our study is to evaluate anti-inflammatory effect of Chamaemelum nobile. Aqueous extracts were administrated to Wistar rats in bronchial-inflammation experimentally induced by an allergen and ovalbumin, administered intraperitoneally / intranasally (20mg/kg/day). Experimentation showed disturbances in bronchoalveolar fluid with increased leukocyte and lymphocyte levels as well as IL-4 concentration in the lungs and erythrocytes associated with high lipid peroxidation. There were disturbances in enzymatic and non-enzymatic antioxidant defense system. Lungs histopathological showed an inflammatory lymphoplasmacytic infiltrate, moderate edema of alveoli, vascular congestion and suffusion hemorrhage. Administration of aqueous extract to OVA-sensitized rats caused a significant and very highly significant improvement of MDA levels in lungs, erythrocytes, GSH, GPx, GST, catalase and SOD. We notice a decrease in IL-4 in LBA and lungs alongside reduced inflammatory cell infiltration, mild bronchiolar dilation, mild alveolar edema and normal cell morphology allowing us to conclude on the effectiveness of anti-inflammatory activity of Roman chamomile.

Liver protective effect of chloroform extract of Bauhinia purpurea leaves is attributed partly to its antioxidant action and the presence of flavonoids

Context Bauhinia purpurea L. (Fabaceae) is used in the Ayurvedic system to treat various oxidative-related ailments (e.g., wounds, ulcers etc.). Therefore, it is believed that the plant also has the potential to alleviate oxidative-related liver damage. Objective This study elucidates the hepatoprotective activity of chloroform extract of B. purpurea leaves (CEBP) in paracetamol (PCM)-induced liver injury (PILI) rats. Materials and methods Male Sprague-Dawley rats (n = 6) were pre-treated once daily (p.o.) with CEBP (50–500 mg/kg) for seven consecutive days before being administered (p.o.) a hepatotoxic agent, 3 g/kg PCM. Liver enzyme levels were determined from the collected blood, while the collected liver was used to determine the activity of endogenous antioxidant enzymes and for histopathological examination. CEBP was also subjected to radical scavenging assays and phytochemical analysis. Results CEBP significantly (p < 0.05) reversed the toxic effect of PCM by increasing the serum levels of AST and ALT, and the activity of endogenous catalase (CAT) and superoxide dismutase (SOD) while reducing the liver weight/body weight (LW/BW) ratio. Other than low TPC value and radical scavenging activity, CEBP had a high antioxidant capacity when evaluated using the oxygen radical absorbance capacity (ORAC) assay. UHPLC-ESI-MS analysis of CEBP showed the presence of flavonoids. Discussion and conclusions CEBP exerts its hepatoprotective activity through a non-free radical scavenging pathway that involves activation of the endogenous enzymatic antioxidant defense system. Further study is needed to identify the responsible bioactive compounds before the plant can be developed as a future alternative hepatoprotective medicament for clinical use.

Comparative studies on the effect of salinity and drought stress on enzymatic antioxidant defense system of two maize (&lt;i&gt;Zea mays&lt;/i&gt; l.). varieties

Soil salinization and drought are serious threat to crop productivity and predicted to increase in face of global climate change. Studies have shown that as much as the 12 billion US dollar will be lost globally each year, due to the reduction in agricultural production from drought and salt-affected areas. Maize is an economically important cereal crop affected by high salinity and drought stress, maize seedling was subjected to 50 mM, 100 mM and 150 mM NaCl and 4, 6 and 8 days to emulate high soil salinity and drought stress. Root and mature leaves were harvested after 21 days of sowing. High salinity induced oxidative stress in the root and mature leaves. The root and matured leaves showed increased malondialdehyde (MDA) and the hydrogen peroxide (H2O2) concentration at 50, 100 and 150 mM NaCl and 4, 6, and 8 days of drought strss. Activities of enzymatic antioxidants, Catylase (CAT, E .C 1.11.1.6) increase in all organs of salt treated maize seedling, while superoxide dismutase (SOD, 1.15.1.1) and peroxidase (POX, E.C. 1.11.1.7) increased specifically in mature leaves. This indicates a possible role of reactive oxygen species (ROS) in the systemic signaling from roots to leaves, allowing leaves to activate their defense mechanism for better protection against salt and drought stress.

Linking the role of melatonin in plant stress acclimatization

Melatonin is a derivative of tryptophan and consists of a conserved domain present ubiquitously from bacteria to higher organisms. Melatonin is an emerging pleiotropic plant growth hormone that is pivotal in coping with various biotic and abiotic stress conditions. It regulates downstream signaling transduction that modulates plants' physiological and biochemical pathways. Melatonin can be externally applied and could strengthen the stress tolerance mechanism of plants by enhancing ROS-scavenging enzymatic and non-enzymatic antioxidant defense systems. Which consequently exhibits lower lipid peroxidation, MDA content, greater enzyme activity, metabolic pool, ion homeostasis, and plasma membrane integrity under stress conditions. In addition, melatonin protects photosynthetic machinery by maintaining cell membrane stability and chlorophyll recovery. It also stimulates the electron transport chain during photosynthesis and D1 protein biosynthesis and maximizes the photochemistry efficiency (Fv/Fm) of photosystem II and photochemical quenching. Besides abiotic stress, melatonin plays a significant role in biotic stress tolerance. This review emphasizes Melatonin as a stress protectant under biotic and abiotic stress. Further, we have highlighted integrating advanced biotechnology tools with recent information for the possible application of melatonin in the current scenario of changing climate.

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.

Promising role of selenium in mitigating the negative effects of iron deficiency in soybean leaves

Little is known about the role of selenium (Se) in modulating the nutritional status and the non-enzymatic and enzymatic antioxidant defense system in iron(Fe)-deficient soybean. Hence, this work aimed to evaluate the possible beneficial effect of Se applied in the nutrient solution on photosynthetic pigments, nutritional status, reactive oxygen species accumulation, ascorbate and glutathione metabolites, activity of enzymes involved in the synthesis pathway of these metabolites, and antioxidant defense enzymes, including expression of superoxide dismutase (SOD) isoforms, after exposure to absence, deficiency, and sufficiency of Fe in combination with absence and presence of Se. The experimental design was completely randomized with 5 replications, containing 4 plants per pot. In this work, through physiological, biochemical, and molecular analyses, we observed a beneficial effect of Se in soybean plants with Fe suppression, mainly in the absence of Fe. Thus, in the absence of Fe with Se, there was higher remobilization of Fe and maintenance of foliar N concentration, which resulted in mitigation of leaf chlorosis and decreased loss of photosynthetic pigments. Additionally, under this cultivation condition, the main positive effect of Se was shown to be associated with the modulation of the glutathione cycle, with increases in the reduced glutathione and total glutathione content, reduced glutathione/oxidized glutathione ratio, and in the activity of the γ-glutamylcysteine synthetase, glutathione peroxidase, and glutathione reductase enzymes. The Se supply also reduced the need to replace SOD-Fe with SOD-Cu due to the positive modulation in the crosstalk between Fe and Cu, as well as attenuated the nutritional imbalance of Zn and Mn, mainly in the absence of Fe. These adjustments prevented lipid peroxidation and showed the beneficial role of Se in Fe-depleted plants.

Nitric Oxide and Proline Modulate Redox Homeostasis and Photosynthetic Metabolism in Wheat Plants under High Temperature Stress Acclimation

The effects of exogenously-sourced NO (nitric oxide, as 100 µM SNP) and proline (50 mM) in the protection of the photosynthetic performance of wheat (Triticum aestivum L.) plants against heat stress were investigated. The study focused on the mechanisms of proline accumulation, activity, gene expression of antioxidant enzymes, and NO generation. Plants were exposed to a temperature of 40 °C for 6 h per day over 15 days, then allowed to recover at 28 °C. Heat-stressed plants showed increased oxidative stress, with higher levels of H2O2 and TBARS (thiobarbituric acid reactive substances) and increased proline accumulation, ACS activity, ethylene evolution, and NO generation, which in turn leads to increased accumulation of antioxidant enzymes and reduced photosynthetic attributes. In the tested wheat cultivar, the exogenous application of SNP and proline under heat stress improved the photosynthesis and reduced oxidative stress by enhancing the enzymatic antioxidant defense system. Potentially, the promoter AOX (alternative oxidase) played a role in maintaining redox homeostasis by lowering H2O2 and TBARS levels. The genes for GR antioxidant and photosystem II core protein encoding psbA and psbB were highly up-regulated in nitric oxide and proline treated heat-stressed plants, indicating that ethylene positively impacted photosynthesis under high temperature stress. Moreover, nitric oxide supplementation under high temperature stress optimized ethylene levels to regulate the assimilation and metabolism of proline and the antioxidant system, lowering the adverse effects. The study showed that nitric oxide and proline increased high temperature stress tolerance in wheat by increasing the osmolytes accumulation and the antioxidant system, resulting in enhanced photosynthesis.

Exploring of the ameliorative effects of Nerium (Nerium oleander L.) ethanolic flower extract in streptozotocin induced diabetic rats via biochemical, histological and molecular aspects.

Nerium oleander L. is ethnopharmacologically used for diabetes. Our aim was to investigate the ameliorative effects of ethanolic Nerium flower extract (NFE) in STZ-induced diabetic rats. Seven random groups including control group, NFE group (50mg/kg), diabetic group, glibenclamide group and NFE treated groups (25mg/kg, 75mg/kg, and 225mg/kg) were composed of forty-nine rats. Blood glucose level, glycated hemoglobin (HbA1c), insulin level, liver damage parameters and lipid profile parameters were investigated. Antioxidant defense system enzyme activities and reduced glutathione (GSH) and malondialdehyde (MDA) contents and immunotoxic and neurotoxic parameters were determined in liver tissue. Additionally, the ameliorative effects of NFE were histopathologically examined in liver. mRNA levels of SLC2A2 gene encoding glucose transporter 2 protein were measured by quantitative real time PCR. NFE caused decrease in glucose level and HbA1c and increase in insulin and C-peptide levels. Additionally, NFE improved liver damage biomarkers and lipid profile parameters in serum. Moreover, lipid peroxidation was prevented and antioxidant enzyme activities in liver were regulated by NFE treatment. Furthermore, anti-immunotoxic and anti-neurotoxic effects of NFE were determined in liver tissue of diabetic rats. Histopathogically, significant liver damages were observed in the diabetic rats. Histopathological changes were decreased partially in the 225mg/kg NFE treated group. SLC2A2 gene expression in liver of diabetic rats significantly reduced compared to healthy rats and NFE treatment (25mg/kg) caused increase in gene expression. Flower extract of Nerium plant may have an antidiabetic potential due to its high phytochemical content.

Alleviation of the adverse effects of NaCl stress on tomato seedlings (Solanum lycopersicum L.) by Trichoderma viride through the antioxidative defense system

BackgroundTrichoderma viride are well known for their biocontrol capabilities, but little is known about how they stimulate plant development and increase their resistance to salt stress. One of the main abiotic factors limiting crop development and yield is salt stress. Therefore, the purpose of this work was to ascertain how NaCl effects on T. viride growth as well as on the seedlings morphological and physio-biochemical parameters of tomato (Solanum lycopersicum L.) under plate culture conditions. Additionally, a pot experiment was conducted to determine how T. viride affected the development characteristics of tomato plants subjected to various salt concentrations (50 and 100 mM NaCl). T. viride's contribution to tomato seedling stress tolerance was also closely examined.ResultsResults showed that 100 mM NaCl decreased the colony diameter of T. viride by 13.4% compared to the control. Under plate and greenhouse conditions, tomato seedlings exposed to salt exposure exhibited an overall decline in growth. Also, a reduction in relative water content (RWC) and protein contents occurred under salt stress. At the same time, increases were found in proline, total phenolics, flavonoids, H2O2 content, malondialdehyde, likewise the activities of peroxidase (POD), catalase (CAT), polyphenol oxidase (PPO), and ascorbate peroxidase (APX) enzymes. Even though, with T. viride application, the salt negative effects on both morphological and physio-biochemical parameters were mitigated to a greater extent. T. viride increased proline and total antioxidant capacity (TAC) in tomato seedlings at 100 mM NaCl by an average of 20.66 and 43.82% compared to their comparable control. T. viride increased the activities of CAT, PPO, and APX enzymes by 74.6, 58.48, and 61.61% at 50 mM NaCl compared to non-saline control seedlings. As well, T. viride decreased MDA and H2O2 contents by an average of 14 and 24.8% in tomato seedlings at 50 mM NaCl compared to their comparable control. Also, under 100 mM NaCl, the T. viride-treated tomato seedlings showed increased total phenolics (17.85%) and flavonoids (33.17%) compared to non- treated one.ConclusionHence, our research sheds new insight on the pathways by which T. viride can boost tomato seedling tolerance to salt stress at morphological and physio-biochemical levels by activating both enzymatic and non-enzymatic antioxidant defense systems.

Determination of the activity of some antioxidant enzymes during the germination periods of cereals and legumes

As a result of the exchange of substances in a living organism, “products” “free radicals” and peroxide compounds of organic and inorganic substances are formed. It is known that free radicals damage cells. Enzymes of the body's antioxidant defense system, superoxide dismutase, catalase, glutathione reductase, glutathione peroxidases, and toxic products of lipid peroxide oxidation turn free radicals into harmless substances. In this work, the activity of one of such enzymes - peroxidase, catalase was studied. The activity of catalase enzyme during the germination periods of cereal and leguminous plants is different, the highest activity of the catalase enzyme during the germination periods of cereal plants was determined on the 5th day of the germination period: in wheat – 5,644 mg H2O2/g, in barley – 4,08 mg H2O2/g, in oats – 5,134 mg H2O2/g. In leguminous plants, the highest activity was determined on the 3rd day of the germination period: it was 11,832 mg H2O2/g in soybean, and 8,126 mg H2O2/g in mash. The highest activity of peroxidase enzyme is on the first day of wheat and is 1,158 µmol/min.g mass. In leguminous plants, the highest activity of the peroxidase enzyme is on the 9th day of the soybean germination period, and its activity is 0,687 µmol/min.g. constituted the mass.

LIPID PEROXIDATION AND THE TOTAL ANTIOXIDANT CAPACITY IN THE PLASMA OF SHETLAND PONY MARES AND STALLIONS INVOLVED IN RECREATIONAL HORSEBACK RIDING: ROLE OF PHOTOPERIOD AND EXERCISE

This study focuses on the photoperiod-induced variability in the levels of biomarkers of lipid peroxidation (2-thiobarbituric acid reactive substances, TBARS) and the total antioxidant capacity (TAC) in the blood of Shetland pony mares and stallions before and after exercise. We have analyzed the effect of photoperiods and exercise on the levels of TBARS and TAC in the blood of Shetland pony mares and stallions involved in recreational horseback riding in the central Pomeranian region (Pomeranian Voivodeship, northern part of Poland). Twenty-one healthy adult Shetland ponies (11 mares and 10 stallions) aged 6.5 ± 1.4 years old were used in this study. All horses participated in recreational horseback riding. Training started at 10:00 AM, lasted 1 hour, and consisted of a ride of cross country by walking (5 min), trotting (15 min), walking (10 min), trotting (10 min), walking (5 min), galloping (5 min), and walking (10 min). Blood was drawn from the jugular veins of the animals in the morning, 90 minutes after feeding, while the horses were in the stables (between 8:30 and 10 AM), and immediately after the exercise test (between 11 AM and 12 AM). Blood samples were taken once per season for one year: summer and winter. The level of lipid peroxidation was determined by quantifying the concentration of 2-thiobarbituric acid reacting substances (TBARS) for determining the malonic dialdehyde (MDA) concentration. The TAC level in samples was estimated by measuring the TBARS level after Tween 80 oxidation. In the stallions and mares before exercise (at rest) in the summer photoperiod, we obtained minimum TBARS values, while maximum levels were determined in the winter photoperiod. In our study, the TAC level illustrated the baseline levels of enzymatic and non-enzymatic antioxidant defense systems, which were different in the mares than in the stallions (statistically significant in the winter photoperiod) both before and after exercise (winter photoperiod). The results of the current study demonstrated that changes in the lipid peroxidation and the total antioxidant capacity in the blood of Shetland ponies are photoperiod-, sex-, and exercise-dependent. The maximum statistically significant values for the effect of the photoperiod-exercise combination defined as the F values were observed. The multivariate analysis of the influence of the three parameters: photoperiods, sex, and exercise on the lipid peroxidation and the total antioxidant capacity in the blood of the ponies indicated the leading role mainly of the photoperiod factor, and next the exercise and sex factors.

PHOTOPERIOD-DEPENDENT ALTERATIONS IN OXIDATIVELY MODIFIED PROTEINS IN THE PLASMA OF SHETLAND PONY MARES AND STALLIONS INVOLVED IN RECREATIONAL HORSEBACK RIDING

This study focuses on the photoperiod-induced variability in the levels of oxidatively modified proteins in the plasma of Shetland pony mares and stallions before and after exercise. We have analyzed the effect of photoperiods and exercise on the levels of aldehydic (AD) and ketonic (KD) derivatives of oxidatively modified proteins (OMP) in the blood of Shetland pony mares and stallions involved in recreational horseback riding in the central Pomeranian region (Pomeranian Voivodeship, northern part of Poland). Twenty-one healthy adult Shetland ponies (11 mares and 10 stallions) aged 6.5 ± 1.4 years old were used in this study. All horses participated in recreational horseback riding. Training started at 10:00 AM, lasted 1 hour, and consisted of a ride of cross country by walking (5 min), trotting (15 min), walking (10 min), trotting (10 min), walking (5 min), galloping (5 min), and walking (10 min). Blood was drawn from the jugular veins of the animals in the morning, 90 minutes after feeding, while the horses were in the stables (between 8:30 and 10 AM), and immediately after the exercise test (between 11 AM and 12 AM). Blood samples were taken once per season for one year: summer and winter. The level of oxidatively modified proteins (OMP) was evaluated by the content of protein carbonyl derivatives in the reaction with 2,4-dinitro-phenylhydrazine (DNFH). There was a statistically significant reduction in the levels of aldehydic derivatives of OMP in the plasma of ponies during the winter photoperiods only after exercise in both sexes. A decrease in the levels of ketonic derivatives of OMP in the summer photoperiod was observed. These changes were observed independently of the sex and only after exercise. Levels of aldehydic and ketonic derivatives of OMP varied depending on the photoperiod and exercise session in our studies. These changes were dependent on the baseline levels of the enzymatic and non-enzymatic antioxidant defense systems in the ponies, which differed between the mares and the stallions (statistically significant differences in the winter period) both before and after exercise (winter). Keywords: oxidatively modified proteins, plasma, exercise, seasonal alterations, photoperiods, Shetland ponies, mares and stallions.

Effect of Powdery Mildew on Physiological and Biochemical Indexes of Different Melon Varieties

In order to study the effect of melon powdery mildew on the physiological indexes of different melon varieties, high resistant to melon powdery mildew variety &lsquo;16-6&rsquo;, medium resistant to melon powdery mildew variety &lsquo;04-38&rsquo;, and highly susceptible melon powdery mildew variety &lsquo;15B-42&rsquo; were used as materials. The activities of antioxidant defense system enzymes, the contents of&nbsp;malondialdehyde&nbsp;(MDA), soluble protein and chlorophyll, and the photosynthetic indicators in leaves of melon seedlings were assayed after inoculated with powdery mildew 1 d, 3 d, 5 d, 7 d and 9 d. The results showed that after inoculation with powdery mildew, except for superoxide dismutase (SOD) activity, the defense enzyme activities, including peroxidase (POD), catalase (CAT), ascorbic acid peroxidase (APX), phenylalanine ammonialyase (PAL) and polyphenol oxidase (PPO) and the MDA content in leaves of the three melon varieties showed a trend of first increase and then decrease, and the increment amplitude of the resistant lines was larger than that of the susceptible lines ; the contents of chlorophyll and soluble protein, and the five photosynthetic indicators, including the net photosynthetic rate (Pn), the stomatal conductance (Gs), the intercellular CO 2 &nbsp;concentration (Ci), the transpiration rate (Tr) and the stomatal limitation (Ls) of leaves of the three melon varieties decreased with different amplitude after inoculation , and the decrement amplitude of the resistant lines was smaller than that of the susceptible lines.

Antioxidant response of Impatiens walleriana L. to drought

Stress caused by drought induces plant morphology, biochemistry, and physiology changes, leading to considerable reductions in plant growth and productivity. This study aimed to evaluate the antioxidant defence system of impatiens seedlings (Impatiens walleriana L.) under drought. The antioxidant response of impatiens to drought was evaluated using following parameters: the activity of catalase, guaiacol peroxidase, pyrogallol peroxidase and ascorbate peroxidase, total phenolic and flavonoids contents and total antioxidant capacity. The experiment was conducted during 2020 in a greenhouse under controlled conditions. Half of the impatiens seedlings (20 plants), after the acclimation period in the greenhouse, were exposed to drought for a period of five days, while the second half was not (20 plants were regularly watered). The results of the study showed that the exposure of impatiens seedlings to drought increased the activity of enzymatic components, total phenolics and flavonoids contents and total antioxidant capacity of leaves. Greater exposure of impatiens to drought (in the observed period) implied a higher plant enzymatic and non-enzymatic antioxidant defence system activity. These results confirm that impatiens has evolved both enzymatic and non-enzymatic antioxidant defence mechanisms to adapt and survive the short-term drought exposure.

Enzymatic and non-enzymatic response of grafted and ungrafted young European pear (Pyrus communis L.) trees to drought stress

The optimization and selection of the scion-rootstock combination are commonly based on its physiological and biochemical alterations capacity, especially in the rootstock, which is significant to elucidate the mechanisms associated with water stress tolerance. To verify the antioxidant defense systems under drought stress, two ungrafted rootstocks, `Dargazi᾿ seedling (D) and `Pyrodwarf᾿ clonal (P), and two pear scion cultivars including `Dargazi᾿ (D) and `Louise Bonne᾿ (L), that were grafted on the studied rootstocks were examined. We considered growth and chlorophyll fluorescence traits, some oxidative stress markers, and non-enzymatic and enzymatic antioxidant parameters in plants subjected to different soil water regimes. Treatments were, well-watered as control (100% FC), moderate (60% FC), and severe drought (30% FC) under greenhouse conditions. Drought stress influenced chlorophyll fluorescence contents and limited the quantum yield of PSII (Fv/Fm), mainly in P rootstock. In contrast, the highest specific leaf area (SLA), and lowest leaf mass area (LMA) was observed in the P rootstock, which indicated that the P rootstock was more sensitive to drought stress. Physiological and biochemical alterations and the main components of multivariate analysis showed that hydrogen peroxide (H2O2) and malondialdehyde (MDA) were accumulated under water deficit conditions, and P and D rootstocks showed a higher level of H2O2. We found a reduction in chlorophyll pigments, carotenoid (CAR), and ascorbic acid (AA), by drought stress, which had the highest amount in P and D rootstocks. Water stress directly influenced anthocyanin (ANT), total phenolic content (TPC), total flavonoid content (TFC), catalase (CAT), guaiacol peroxidase (GPOX), and ascorbate peroxidase (APOX) activity, especially under severe stress levels, and there was a high activity of GPOX in grafted combinations. In general, rootstocks showed more oxidative stress than grafted combinations because of the high increase in H2O2 and MDA, and response to stress by the accumulation of some enzymatic and non-enzymatic factors. However, grafted combinations mostly showed better tolerance with the enzymatic antioxidant defense system, which can be the result of resistance induced by rootstocks and the cultivar's capacity to minimize the negative effects of drought stress.

Antioxidant activity of mycelia methanolic extracts of endophytic fungi BvFV and BvFIX isolated from leaves of Bauhinia variegata.

Endophytes are considered an essential source of natural products. Skin is the body's largest organ; its primary function is the protection of other organs, and aging is one of the most relevant problems associated with this organ. UV radiation generates reactive oxygen species (ROS), which lead to skin degeneration and consequent aging. The main endogenous antioxidants that neutralize ROS are enzymatic antioxidants such as superoxide dismutase (SOD), catalase, glutathione peroxidase, and glutathione reductase, and non-enzymatic antioxidants, such as glutathione and α-tocopherol. Nuclear receptors are involved in molecular mechanisms that control the aging process, especially peroxisome proliferator-activated receptors (PPAR), which regulate the function and expression of genes that modulate the balance between matrix metalloproteinases (MMP) activity and the expression of collagen. Some natural compounds, such as polyphenols, can activate PPAR and reduce the activation of MMP and collagen degradation. In this work, the antioxidant activity of the mycelia methanolic extracts of two endophytic fungi isolated from leaves of Bauhinia variegata, named BvFV and BvFIX, their action as PPAR agonists, and their effect on the activity of antioxidant defense system enzymes were evaluated. The mycelia methanolic extract of BvFV showed a weak agonist effect on PPARβ/δ, a high capability to inhibit lipid peroxidation, increased catalase activity, and increased superoxide dismutase activity by approximately 64%. In contrast, BvFIX increased catalase activity and increased superoxide dismutase activity in a dose-dependent manner, with an increase of 49.62% ± 7.87%, 56.64% ± 12.27%, and 240.46% ± 26.11% at concentrations of 25 µg/mL, 50 µg/mL and 100 µg/mL, respectively, in human dermal fibroblasts submitted to oxidative stress. These results suggest that the metabolites of the mycelia of endophytic fungi studied are promising to act in the chemoprevention of skin aging.

Effect of Prolonged Cold Storage on the Dynamics of the Enzymatic and Non-Enzymatic Antioxidant System in the Mesocarp of Avocado (Persea americana) cv. Hass: Relationship with Oxidative Processes

This work evaluated the enzymatic and non-enzymatic antioxidant defense systems of avocados cv. Hass stored at 7 ± 0.5 °C for 10, 20, and 30 d, and at the stage of edible ripeness. The enzymatic antioxidant enzyme system included superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), and the non-enzymatic antioxidant system was composed of total phenolic compounds (TPC), total carotenoids (TC), α-, β-, and γ-tocopherols, as well as hydrophilic (H-AOX) and lipophilic (L-AOX) antioxidant activities. In addition, polyphenol oxidase (PPO) and lipoxygenase (LOX) activities, TBARS values and pulp browning area were determined. At edible ripeness, low SOD and POD but higher CAT activities were evidenced in response to their joint participation in the oxidative stress developed. In addition, low content of γ-tocopherol and higher contents of TPC and TC were evidenced and suggest their individual or joint participation in defense against oxidation. The other compounds and activities evaluated tended to remain constant. Oxidative damage was evidenced by the increase in PPO activity and TBARS values, while LOX did not play a significant role. Pulp browning area did not surpass 6% in affected fruit. The results indicate that under these conditions oxidative stress was largely restrained by the endogenous fruit antioxidant defense system.

Perinatal exposure to a glyphosate pesticide formulation induces offspring liver damage

The present study investigated the effects of perinatal exposure to glyphosate-based herbicide (GBH) in offspring's liver. Pregnant Wistar rats were exposed to GBH (70 mg glyphosate/Kg body weight/day) in drinking water from gestation day 5 to postnatal day 15. The perinatal exposure to GBH increased 45Ca2+ influx in offspring's liver. Pharmacological tools indicated a role played by oxidative stress, phospholipase C (PLC) and Akt pathways, as well as voltage-dependent Ca2+ channel modulation on GBH-induced Ca2+ influx in offspring's liver. In addition, changes in the enzymatic antioxidant defense system, decreased GSH content, lipid peroxidation and protein carbonylation suggest a connection between GBH-induced hepatotoxic mechanism and redox imbalance. The perinatal exposure to GBH also increased the enzymatic activities of transaminases and gamma-glutamyl transferase in offspring's liver and blood, suggesting a pesticide-induced liver injury. Moreover, we detected increased iron levels in liver, blood and bone marrow of GBH-exposed rats, which were accompanied by increased transferrin saturation and decreased transferrin levels in blood. The levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were increased in the liver of rats perinatally exposed to GBH, which were associated with. Increased phospho-p65NFκB immunocontent. Therefore, we propose that excessive amounts of iron in offspring's liver, blood and bone marrow induced by perinatal exposure to GBH may account for iron-driven hepatotoxicity, which was associated with Ca2+ influx, oxidative damage and inflammation. Further studies will clarify whether these events can ultimately impact on liver function.

Application of 2,4-Epibrassinolide Improves Drought Tolerance in Tobacco through Physiological and Biochemical Mechanisms.

Simple SummaryDrought stress is one of the most serious abiotic stresses and negatively affects crop growth and development. Given global climate change, it is important to identify effective methods of alleviating drought stress effects. Brassinosteroids (2,4-epibrassinolide-EBR) play an important role in mitigating the negative effects of drought stress on plants. Therefore, this study evaluated the role of EBR in improving drought tolerance. The results demonstrated that EBR application improved drought tolerance by strengthening the enzymatic antioxidant defense system and osmoregulation to scavenge reactive oxygen species. EBR application improved BR and IAA phytohormone content and improved drought tolerance by upregulating genes related to their respective signaling pathways. Therefore, EBR application is an effective strategy for improving drought tolerance in crop plants.Drought stress is a major abiotic stress that hinders plant growth and development. Brassinosteroids (BR), including 2,4-epibrassinolide (EBR), play important roles in plant growth, development, and responses to abiotic stresses, including drought stress. This work investigates exogenous EBR application roles in improving drought tolerance in tobacco. Tobacco plants were divided into three groups: WW (well-watered), DS (drought stress), and DSB (drought stress + 0.05 mM EBR). The results revealed that DS decreased the leaf thickness (LT), whereas EBR application upregulated genes related to cell expansion, which were induced by the BR (DWF4, HERK2, and BZR1) and IAA (ARF9, ARF6, PIN1, SAUR19, and ABP1) signaling pathway. This promoted LT by 28%, increasing plant adaptation. Furthermore, EBR application improved SOD (22%), POD (11%), and CAT (5%) enzyme activities and their related genes expression (FeSOD, POD, and CAT) along with a higher accumulation of osmoregulatory substances such as proline (29%) and soluble sugars (14%) under DS and conferred drought tolerance. Finally, EBR application augmented the auxin (IAA) (21%) and brassinolide (131%) contents and upregulated genes related to drought tolerance induced by the BR (BRL3 and BZR2) and IAA (YUCCA6, SAUR32, and IAA26) signaling pathways. These results suggest that it could play an important role in improving mechanisms of drought tolerance in tobacco.

DNA Damage and Antioxidant Defence Responses in The Brain and Liver Tissues of Rainbow Trout Infected With Different Bacteria

Fish farming provides food and livelihood for many people around the world. The fact that trout is produced in many parts of the world and has a very rich content in terms of nutritional value increases the importance of trout. However, there are many problems in trout production due to bacterial factors, making fish production extremely difficult. Bacterial factors cause significant fish deaths and economic losses such as slowdown in growth. In addition to these, these factors also cause some damage to the DNA of fish and the formation of oxidations by disrupting the balance of free radicals in the tissues. Therefore, in this study; In the trout farms in our province, the trout with the main bacterial agents causing infection were determined and bacterial species (Staphylococcus epidermidis, Lactococcus garvieae and Bacillius subtilis) were determined by PCR. The brain and liver tissues of these fish were taken and the changes in antioxidant enzyme levels (SOD, CAT, GSH-Px), lipid peroxidation (MDA) and damage to their DNA (8-OHdG) compared to the control groups were investigated. In the study, it was determined that the antioxidant defense system enzyme levels in all three species of bacteria decreased in tissues, while lipid peroxidation and 8-OHdG levels increased.&#x0D; As a result; Staphylococcus epidermidis, Lactococcus garvieae and Bacillius&#x0D; subtilis bacteria caused changes in antioxidant enzyme levels, lipid peroxidation and 8-OHdG levels in trout brain and liver tissues.