Effects of malic acid and EDTA on oxidative stress and antioxidant enzymes of okra (Abelmoschus esculentus L.) exposed to cadmium stress.

Environmental stresses, including heavy metal pollution, are increasing at a growing rate and influencing arable lands. Chelators play an essential role in several biochemical pathways in the cells of plants treated with heavy metals. This research evaluated the modifying effect of malic acid (MA) and ethylenediaminetetraacetic acid (EDTA) on the physiological and biochemical parameters of okra plants exposed to Cd stress in which the okra plants were cultivated in hydroponic conditions. At the 4-leaf stage, they were applied with the treatments of cadmium nitrate at three levels (0, 50, and 100 mg/L), EDTA and MA at two levels (0.5 and 1 mM), and Cd + EDTA + MA at different rates for one month. The harvested plants were subjected to the measurement of the physico-biochemical factors. The results revealed that the application of Cd alone reduced leaf area (up to 21.57 %), and dissolved sugars (up to 40.51 % in the shoot and 45.19 % in the root) and increased MDA (up to 66.37 % and 76.43 % in the shoot and root, respectively), H2O2 (up to 67.14 % and 53.28 % in the shoot and root, respectively), proline (up to 52.04 % and 40.93 % in the shoot and root, respectively), and dissolved proteins (up to 14.59 % and 21.90 % in the shoot and root, respectively) contents in both shoots and roots whereas the application of MA and EDTA to the Cd-treated plants increased their leaf area and dissolved sugars and reduced MDA, H2O2, proline, and dissolved proteins content. The antioxidant enzymes, e.g., superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX), were significantly higher in the plants treated with MA, EDTA, and Cd, but the application of MA and EDTA to the Cd-treated plants reduced the activity of all these antioxidant enzymes versus the plants only treated with Cd. MA and EDTA are likely to prevent the accumulation of Cd in the cytosol by binding to it and transferring it into vacuoles, thereby mitigating Cd toxicity in the okra plants.

Antioxidant defense response during hibernation and arousal in Chinese soft-shelled turtle Pelodiscus sinensis juveniles.

Antioxidant defense is essential for animals to cope with homeostasis disruption during hibernation. The present study aimed to investigate the antioxidant defense response of juvenile soft-shelled turtle Pelodiscus sinensis during hibernation and following arousal. Turtle brain, liver, and kidney samples were collected at pre-hibernation (17 °C mud temperature; MT), during hibernation (5.8 °C MT) and after arousal (20.1 °C MT) in the field. Transcript levels of NF-E2-related factor 2 (Nrf2) decreased significantly during hibernation and recovered after arousal in all tissues. Cerebral and nephric copper-zinc superoxide dismutase (Cu/Zn SOD), catalase (CAT), glutathione peroxidase 3 (GPx3) and nephric GPx4 mRNA showed similar changing patterns as Nrf2. Cerebral Mn SOD, GPx1 and nephric GPx1 up-regulated after arousal. Hepatic Cu/Zn SOD, GPx1 and GPx3 mRNA kept stable, except hepatic GPx4 increased during hibernation. Hepatic Mn SOD and CAT increased after arousal. In the GSH system, mRNA levels of glutathione synthetases (GSs) kept stable during hibernation and up-regulated after arousal in most tissues except nephric GS2 mRNA remained unchanged. Gene expressions of glutathione reductase (GR) exhibited a tissue specific changing pattern, while those of glutathione-S-Transferase (GST) shared a similar pattern among tissues: remained stable or down-regulated during hibernation then recovered in arousal. In contrast to these diverse responses in gene expressions, most of the antioxidant enzyme activities maintained high and stable. Overall, no preparation for oxidative stress (POS) strategy was found in enzymatic antioxidant system in P. sinensis juveniles during hibernation, the Chinese soft-shelled turtles were able to stay safe from potential oxidative stress during hibernation by maintaining high level activities/concentrations of the antioxidant enzymes/antioxidants.

Moringa oleifera Leaf Extract Upregulates Nrf2/HO-1 Expression and Ameliorates Redox Status in C2C12 Skeletal Muscle Cells.

Moringa oleifera is a multi-purpose herbal plant with numerous health benefits. In skeletal muscle cells, Moringa oleifera leaf extract (MOLE) acts by increasing the oxidative metabolism through the SIRT1-PPARα pathway. SIRT1, besides being a critical energy sensor, is involved in the activation related to redox homeostasis of transcription factors such as the nuclear factor erythroid 2-related factor (Nrf2). The aim of the present study was to evaluate in vitro the capacity of MOLE to influence the redox status in C2C12 myotubes through the modulation of the total antioxidant capacity (TAC), glutathione levels, Nrf2 and its target gene heme oxygenase-1 (HO-1) expression, as well as enzyme activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and transferase (GST). Moreover, the impact of MOLE supplementation on lipid peroxidation and oxidative damage (i.e., TBARS and protein carbonyls) was evaluated. Our results highlight for the first time that MOLE increased not only Nrf2 and HO-1 protein levels in a dose-dependent manner, but also improved glutathione redox homeostasis and the enzyme activities of CAT, SOD, GPx and GST. Therefore, it is intriguing to speculate that MOLE supplementation could represent a valuable nutrition for the health of skeletal muscles.

Investigating the Mechanism of Cadmium-Tolerant Bacterium Cellulosimicrobium and Ryegrass Combined Remediation of Cadmium-Contaminated Soil.

Cadmium (Cd) pollution has been rapidly increasing due to the global rise in industries. Cd not only harms the ecological environment but also endangers human health through the food chain and drinking water. Therefore, the remediation of Cd-polluted soil is an imminent issue. In this work, ryegrass and a strain of Cd-tolerant bacterium were used to investigate the impact of inoculated bacteria on the physiology and biochemistry of ryegrass and the Cd enrichment of ryegrass in soil contaminated with different concentrations of Cd (4 and 20 mg/kg). The results showed that chlorophyll content increased by 24.7% and 41.0%, while peroxidase activity decreased by 56.7% and 3.9%. In addition, ascorbic acid content increased by 16.7% and 6.3%, whereas glutathione content decreased by 54.2% and 6.9%. The total Cd concentration in ryegrass increased by 21.5% and 10.3%, and the soil's residual Cd decreased by 86.0% and 44.1%. Thus, the inoculation of Cd-tolerant bacteria can improve the antioxidant stress ability of ryegrass in Cd-contaminated soil and change the soil's Cd form. As a result, the Cd enrichment in under-ground and above-ground parts of ryegrass, as well as the biomass of ryegrass, is increased, and the ability of ryegrass to remediate Cd-contaminated soil is significantly improved.

The Role of Amino Acids in Non-Enzymatic Antioxidant Mechanisms in Cancer: A Review.

Currently, the antioxidant properties of amino acids and their role in the physicochemical processes accompanying oxidative stress in cancer remain unclear. Cancer cells are known to extensively uptake amino acids, which are used as an energy source, antioxidant precursors that reduce oxidative stress in cancer, and as regulators of inhibiting or inducing tumor cell-associated gene expression. This review examines nine amino acids (Cys, His, Phe, Met, Trp, Tyr, Pro, Arg, Lys), which play a key role in the non-enzymatic oxidative process in various cancers. Conventionally, these amino acids can be divided into two groups, in one of which the activity increases (Cys, Phe, Met, Pro, Arg, Lys) in cancer, and in the other, it decreases (His, Trp, Tyr). The review examines changes in the metabolism of nine amino acids in eleven types of oncology. We have identified the main nonspecific mechanisms of changes in the metabolic activity of amino acids, and described direct and indirect effects on the redox homeostasis of cells. In the future, this will help to understand better the nature of life of a cancer cell and identify therapeutic targets more effectively.

Moringa oleifera Leaf Extract Protects C2C12 Myotubes against H2O2-Induced Oxidative Stress.

The imbalance between reactive oxygen species (ROS) production and antioxidant defense systems leads to macromolecule and tissue damage as a result of cellular oxidative stress. This phenomenon is considered a key factor in fatigue and muscle damage following chronic or high-intensity physical exercise. In the present study, the antioxidant effect of Moringa oleifera leaf extract (MOLE) was evaluated in C2C12 myotubes exposed to an elevated hydrogen peroxide (H2O2) insult. The capacity of the extract to influence the myotube redox status was evaluated through an analysis of the total antioxidant capacity (TAC), glutathione homeostasis (GSH and GSSG), total free thiols (TFT), and thioredoxin (Trx) activity, as well as the enzyme activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) and transferase (GST). Moreover, the ability of MOLE to mitigate the stress-induced peroxidation of lipids and oxidative damage (TBARS and protein carbonyls) was also evaluated. Our data demonstrate that MOLE pre-treatment mitigates the highly stressful effects of H2O2 in myotubes (1 mM) by restoring the redox status (TFT, Trx, and GSH/GSSG ratio) and increasing the antioxidant enzymatic system (CAT, SOD, GPx, GST), thereby significantly reducing the TBARs and PrCAR levels. Our study provides evidence that MOLE supplementation has antioxidant potential, allowing myotubes better able to cope with an oxidative insult and, therefore, could represent a useful nutritional strategy for the preservation of muscle well-being.

Antioxidant enzymatic changes in bell pepper fruit associated with chilling injury tolerance induced by hot water.

Green bell pepper is highly susceptible to low temperature. The activation of the enzymatic antioxidant system plays a determining role in tolerance to chilling injury (CI). Immersion in hot water for short time previous to storage at low temperature induces tolerance to this disorder. However, there is a lack of information about the induction of chilling tolerance in bell pepper by hot water and its relationship with the enzymatic antioxidant system. We evaluated the effect of three immersion times (T, 1-, 2-, 3-min) in hot water (HW, 53°C) on the reduction of CI in bell pepper and its relationship with the enzymatic antioxidant system during storage at 5°C and 21°C. The use of hot water for 1-, 2- or 3-min reduced the decay and CI indexes, maintained quality parameters, ascorbic acid, and total phenolics content. The storage at 5°C by itself activated the enzymatic antioxidant system. The use of HWT 1-, 2-, and 3-min helped to increase this effect, especially by HWT2 . PRACTICAL APPLICATIONS: The application of a treatment with hot water for short times in fruit sensitive to chilling injury is undoubtedly a viable alternative to increase their tolerance and commercialization. In this study, the application of a hot water treatment for 1-, 2- or 3-min in bell pepper reduced the deterioration and susceptibility to chilling injury and stimulated the enzymatic antioxidant system. In this sense, agricultural producers can take advantage of this treatment to prolong the storage period of the fruit maintaining its quality and improving its commercialization.

Polyphenolics and triterpenes presence in chloroform extract of Dicranopteris linearis leaves attenuated paracetamol-induced liver intoxication in rat.

INTRODUCTION: Water-soluble, but not lipid-soluble, extract of Dicranopteris linearis leaves has been proven to possess hepatoprotective activity. The present study aimed to validate the hepatoprotective and antioxidant activities, and phytoconstituents of lipid-soluble (chloroform) extract of D. linearis leaves. METHODS: The extract of D. linearis leaves (CEDL; 50, 250 and 500 mg/kg) was orally administered to rats for 7 consecutive days followed by the oral administration of 3 g/kg PCM to induce liver injury. Blood was collected for liver function analysis while the liver was obtained for histopathological examination and endogenous antioxidant activity determination. The extract was also subjected to antioxidant evaluation and phytochemicals determination via phytochemical screening, HPLC and UPLC-HRMS analyses. RESULTS: CEDL exerted significant (p < 0.05) hepatoprotective activity at 250 and 500 mg/kg and significantly (p < 0.05) reversed the PCM-induced decrease in rat's liver endogenous antioxidant (catalase and superoxide dismutase) level. CEDL possessed a high antioxidant capacity when measured using the ORAC assay, but a low total phenolic content value and radical scavenging activity as confirmed via several radical scavenging assays, which might be attributed particularly to the presence of triterpenes. Phytochemicals screening demonstrated the presence of triterpenes and flavonoids, while UPLC-HRMS analysis showed the presence of polyphenols belonging to the hydroxybenzoic acids, hydroxycinammates and flavonoid groups. DISCUSSION AND CONCLUSION: Lipid-soluble bioactive compounds of CEDL demonstrated hepatoprotective effect against PCM intoxication partly via the modulation of the endogenous antioxidant defense system, and exerted high antioxidant capacity. Further investigation is warranted to identify the potential hepatoprotective leads from CEDL for future drug development.

Coenzyme Q10 supplementation acts as antioxidant on dystrophic muscle cells.

Increased oxidative stress is a frequent feature in Duchenne muscular dystrophy (DMD). High reactive oxygen species (ROS) levels, associated with altered enzyme antioxidant activity, have been reported in dystrophic patients and mdx mice, an experimental model of DMD. In this study, we investigated the effects of coenzyme Q10 (CoQ10) on oxidative stress marker levels and calcium concentration in primary cultures of dystrophic muscle cells from mdx mice. Primary cultures of skeletal muscle cells from C57BL/10 and mdx mice were treated with coenzyme Q10 (5 µM) for 24 h. The untreated mdx and C57BL/10 muscle cells were used as controls. The MTT and live/dead cell assays showed that CoQ10 presented no cytotoxic effect on normal and dystrophic muscle cells. Intracellular calcium concentration, H2O2 production, 4-HNE, and SOD-2 levels were higher in mdx muscle cells. No significant difference in the catalase, GPx, and Gr levels was found between experimental groups. This study demonstrated that CoQ10 treatment was able to reduce levels of oxidative stress markers, such as H2O2, acting as an antioxidant, as well as decreasing abnormal intracellular calcium influx in dystrophic muscles cells. This study demonstrated that CoQ10 treatment was able to reduce levels of oxidative stress markers, such as H2O2, acting as an antioxidant, as well as decreasing abnormal intracellular calcium influx in dystrophic muscles cells. Our findings also suggest that the decrease of oxidative stress reduces the need for upregulation of antioxidant pathways, such as SOD and GSH.

Caffeine prevents high-intensity exercise-induced increase in enzymatic antioxidant and Na+-K+-ATPase activities and reduction of anxiolytic like-behaviour in rats.

OBJECTIVE: Here we investigated the impact of chronic high-intensity interval training (HIIT) and caffeine consumption on the activities of Na+-K+-ATPase and enzymes of the antioxidant system, as well as anxiolytic-like behaviour in the rat brain. METHODS: Animals were divided into groups: control, caffeine (4 mg/kg), caffeine (8 mg/kg), HIIT, HIIT plus caffeine (4 mg/kg) and HIIT plus caffeine (8 mg/kg). Rats were trained three times per week for 6 weeks, and caffeine was administered 30 minutes before training. We assessed the anxiolytic-like behaviour, Na+-K+-ATPase, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities, levels of reduced glutathione (GSH) and thiobarbituric acid reactive substances (TBARS) in the brain. RESULTS AND DISCUSSION: HIIT-induced anxiolytic-like behaviour increased Na+-K+-ATPase and GPx activities and TBARS levels, altered the activities of SOD and CAT in different brain regions, and decreased GSH levels. Caffeine, however, elicited anxiogenic-like behaviour and blocked HIIT effects. The combination of caffeine and HIIT prevented the increase in SOD activity in the cerebral cortex and GPx activity in three brain regions. Our results show that caffeine promoted anxiogenic behaviour and prevented HIIT-induced changes in the antioxidant system and Na+-K+-ATPase activities.

Indicators of oxidative stress in long-lived individuals belonging to the municipality of Santa Clara

Aim: To determine indicators of oxidative stress in long-lived individuals. Methods: 120 subjects were studied and two groups were formed: 50 individuals older than 85 years of nuclear families and 70 adults under 60 years old taken as a control group, all belonging to the municipality of Santa Clara. Indicators of antioxidant defense status included enzymatic activities superoxide dismutase (SOD) and catalase (CAT), as well as reduced glutathione (GSH) concentrations. The determinations were made with the use of spectrophotometric techniques, and the comparisons between the groups were made through the statistical program SPSS with a level of significance of 95 percent. Results: The activity of the antioxidant enzyme SOD and GSH levels showed significant differences when comparing both study groups. In the case of the SOD enzyme, the group of long-lived individuals showed a significant reduction in their activity compared to the controls, while GSH levels also decreased in this group. The CAT enzyme activity showed no significant differences between the two study groups. Conclusions: The decrease in enzymatic activity SOD accompanied by a decrease in GSH levels could be an indicator of a state of oxidative imbalance in individuals older than 85 years, which increases their susceptibility to the action of reactive oxygen species(AU)

Sistema antioxidante enzimático en mujeres con diagnóstico de Atipias celulares y Neoplasia Intraepitelial Cervical grado I / Enzymatic antioxidant system in women diagnosed with cell atypia and grade I cervical intraepithelial neoplasia

Introducción: El virus de papiloma humano per se no es capaz de desarrollar todas las transformaciones neoplásicas en el cérvix uterino, de manera que factores de riesgo como los genéticos, ambientales, estilo de vida sexual y el desbalance oxidativo podrían contribuir a la enfermedad. Objetivo: Determinar el comportamiento del sistema enzimático antioxidante en mujeres con atipia de células escamosas de significado indeterminado y neoplasia intraepitelial cervical grado I. Métodos: Se conformaron tres grupos de estudio: el primero incluyó 30 mujeres con diagnóstico de atipias, el segundo se constituyó con 40 mujeres con neoplasia intraepitelial grado I y el tercero consistió en 30 mujeres con citología negativa tomadas como control, provenientes de la consulta de Patología de Cuello del Agustín Gómez Lubián de Santa Clara. Mediante métodos espectrofotométricos se determinaron los niveles de actividad enzimática superóxido dismutasa y catalasa así, como las concentraciones de glutatión reducido. Las comparaciones se realizaron con el programa SPSS, versión 18. Resultados: En el grupo de atipias aunque los tres parámetros tuvieron una tendencia a la disminución no hubo diferencias significativas con respecto al control. Mientras que el grupo de neoplasia grado I evidenció disminución significativa de los tres indicadores estudiados al ser comparados con el grupo control. Conclusiones: Se constató afectación del sistema antioxidante enzimático en el grupo de neoplasia grado I, lo cual podría considerarse un cofactor importante en la progresión de las lesiones en el cérvix uterino(AU)

Introduction: Human papillomavirus per se can not carry out all the neoplastic transformations occurring in the uterine cervix. Genetic and environmental risk factors as well as sexual behavior and oxidative imbalance may also play a role. Objective: Determine the behavior of the enzymatic antioxidant system in women with squamous cell atypia of indeterminate significance and grade I cervical intraepithelial neoplasia. Methods: Three study groups were formed. The first group included 30 women diagnosed with atypia, the second group was made up of 40 women with grade I intraepithelial neoplasia, and the third or control group consisted of 30 women with negative cytology from Agustín Gómez Lubián Cervical Pathology service in Santa Clara. Spectrophotometric methods were used to determine the levels of superoxide dismutase and catalase enzymatic activity, as well as the concentrations of reduced glutathione. Comparisons were made with the SPSS software, version 18. Results: In the atypia group the three parameters showed a decreasing tendency, but differences with respect to the control group were not significant. In the grade I neoplasia group, however, a significant reduction was found of the three study indicators when compared with the control group. Conclusions: Damage to the enzymatic antioxidant system was observed in the grade I neoplasia group. This could be considered to be an important cofactor in the progress of uterine cervix lesions(AU)

Biochemical and physiological responses of oil palm to bud rot caused by Phytophthora palmivora.

In recent years, global consumption of palm oil has increased significantly, reaching almost 43 million tons in 2010. The sustainability of oil palm (Elaeis guineensis) cultivation has been compromised because of the bud rot disease whose initial symptoms are caused by Phytophthora palmivora. There was a significant incidence of the disease, from an initial stage 1 of the disease to the highest stage 5, that affected photosynthetic parameters, content of pigments, sugars, polyamines, enzymatic antioxidant activities, phenylalanine ammonia-lyase (PAL, EC 4.3.1.5) and ß-(1,3) glucanase (ß-Gluc, EC 3.2.1.39). In healthy palms photosynthesis was 13.29 µmol CO2 m(-2) s(-1) in average, while in stage 5 the average photosynthesis was around 3.66 µmol CO2 m(-2) s(-1). Additionally, total chlorophyll was reduced by half at the last stage of the disease. On the contrary, the contents of putrescine, spermine and spermidine increased three, nine and twelve times with respect to stage 5, respectively. Antioxidant enzyme activities, as well as the phenylalanine ammonia-lyase and ß-(1,3) glucanase showed an increase as the severity of the disease increased, with the latter increasing from 0.71 EAU in healthy palms to 2.60 EAU in plants at stage 5 of the disease. The peroxidase (POD, EC 1.11.1.7) enzymatic activity and the content of spermidine were the most sensitive indicators of disease.