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Introduction: Muscle damage can be triggered by other free radicals formed during intense physical activites and the low response of antioxidants. The antioxidants that plays a role in responding to free radicals during physical activites is glutathione peroxidase. Objective: The main purpose of this study was to analyze the effects of high-intensity and moderate-intensity physical activities on muscle glutathione peroxidase (GPx) and serum troponin I levels as markers of damage. Methodology: The study was used a quantitative true experiment with a post-test only group design. This study was conducted at a total of 18 healthy mice with age of 8 weeks old male Balb/c mice, then divided into 3 groups: high-intensity physical activity (HI), moderate-intensity physical activity (MI), and control (CON) groups. The HI group performed running on a treadmill with a 90% of their maximum speed, while the MI group at 60%. Data was taken of 24 hours post-physical activity by taking blood samples to examine troponin I levels and skeletal muscle gastrocnemius homogenate to determine GPx activity. Results: the study found that the MI group had a higher concentration of GPx in the skeletal muscle gastrocnemius compared to the other control group. However, the concentration of troponin I showed significant differences between the groups, HI group had significantly higher levels of troponin I compared to the other groups. Conclusion: The high-intensity physical activity has the highest result in ncreasing Troponin I and the moderate intensity physical activity has the highest concentration of glutathione peroxidase compare to other groups.

Industrial textile effluents containing azo dyes pose a major environmental challenge due to their persistence and toxicity. This study evaluated the capacity of a native white-rot fungus (Lentinus sp.) to treat a real textile effluent polluted with an azo dye (Red 40) in a packed-bed bioreactor. Fungal biomass was immobilized on low-cost lignocellulosic supports (Luffa cylindrica), and pine sawdust was added as a biological inducer to stimulate ligninolytic enzyme production. Treatment conditions were first optimized in Erlenmeyer flasks (0.15 L), achieving 94.0 ± 0.1 % decolorization. Under scaled-up conditions (6 L, 30 ◦C, 12-day hydraulic retention time, batch mode, no agitation), the system removed 61.5 ± 0.2 % of dye color and reduced chemical oxygen demand (COD) by 99.0 ± 0.3 %. Enzymatic assays revealed manganese peroxidase activity, while laccase was not detected. Nuclear magnetic resonance (NMR) analysis confirmed structural modifications of the dye through azo bond cleavage. These findings demonstrate the potential of native ligninolytic fungi as sustainable and cost-effective biotechnological tools to treat azo dye-polluted industrial effluents, supporting their applicability at larger scales.

The sleepy plant (Mimosa pudica) is renowned for its rapid leaf-folding response to touch, embodying an intriguing blend of dormancy and activity. Inspired by this unique behavior, we have developed a novel electrochemical sensor using screen-printed gold nanoparticle electrodes (SPGNPE) treated with Mimosa pudica peroxidase (MPP) to quantify hydrogen peroxide (H2O2 ). The MPP exhibits a specific activity of 122.9 U/mg and operates optimally at pH 4.0 and a temperature of 55◦C, indicating its robust performance under mildly acidic and moderately high-temperature conditions. The enzyme’s inactivation rate constant (kinact) was -0.018 min−1, suggesting a stable enzymatic activity over time. Cyclic voltammetry (CV) experiments using potassium ferrocyanide as a redox probe revealed a significant increase in current signal in the presence of MPP, indicating effective interaction of electrons with the redox compounds and the electrode interface. The linear relationship between the square root of the scan rate and the anodic and cathodic peaks suggested a surface-controlled, semi-reversible process involving the migration of the electrochemically active species to the electrode interface. A low limit of detection (LOD) of 0.4 𝜇M was achieved, accompanied by a sensitivity of 0.039 𝜇A/𝜇M, demonstrating the electrode’s capability for precise and sensitive H2O2 quantification. This study highlights the unique application of the sleepy plant peroxidase, revealing its potential as a robust and sensitive novel bioelement in electrochemical sensing platforms. The synergy between nanomaterials and biological catalysts opens new avenues for environmentally friendly and efficient detection systems.

The peroxidases are a class of enzymes found in various species of Colombian tropical plants. These enzymes belong to the larger group of peroxidases, which are heme-containing proteins involved in catalysing a wide range of reactions in living organisms. Peroxidases have emerged as promising biocatalysts with versatile biotechnological applications. This paper aims to provide a detailed analysis of peroxidases in Colombian tropical plants and their potential in electrochemical sensing. The review begins by elucidating the structural and functional characteristics of peroxidases in plants, exploring their classification, and highlighting their catalytic mechanisms. It then delves into the various substrate specificity and affinity of plant peroxidases and its comparison with other peroxidases. Furthermore, the diverse electrochemical techniques relevant to biosensing and their applications in biosensor development are thoroughly examined. The challenges and prospects of utilizing Colombian plant peroxidases in biosensing applications are critically evaluated. In summary, this study highlights the significance of peroxidases in plants as valuable bioanalytical tool. Their multifaceted applications in environmental, agricultural, food, and pharmaceutical bioanalysis sectors make them indispensable in addressing contemporary challenges. The insights provided herein serve as a foundation for future research endeavours aimed at harnessing the full potential of Colombian tropical plant peroxidases for the construction of electrochemical biosensors. Las peroxidasas son una clase de enzimas presentes en diversas especies de plantas tropicales colombianas. Estas enzimas pertenecen al grupo más grande de peroxidasas, que son proteínas que contienen el grupo hemo y catalizan una amplia gama de reacciones en organismos vivos. Las peroxidasas han surgido como biocatalizadores prometedores con aplicaciones biotecnológicas versátiles. Este artículo tiene como objetivo proporcionar un análisis detallado de las peroxidasas en plantas tropicales colombianas y su potencial en la detección electroquímica. El estudio comienza elucidando las características estructurales y funcionales de las peroxidasas en plantas, explorando su clasificación y destacando sus mecanismos catalíticos. Luego profundiza en la especificidad y afinidad de los diferentes sustratos de las peroxidasas de plantas y las compara con otras peroxidasas. Además, se examinan exhaustivamente las diversas técnicas electroquímicas relevantes para la detección y sus aplicaciones en el desarrollo de biosensores. Se evalúan críticamente los desafíos y las perspectivas de utilizar peroxidasas de plantas colombianas en aplicaciones de detección. En resumen, este estudio destaca la importancia de las peroxidasas en plantas como herramienta bioanalítica valiosa. Sus aplicaciones multifacéticas en los sectores de análisis ambiental, agrícola, alimentario y farmacéutico las convierten en elementos indispensables para abordar desafíos contemporáneos. La información proporcionada aquí sirve como base para futuros esfuerzos de investigación dirigidos a aprovechar todo el potencial de las peroxidasas de plantas tropicales colombianas para la construcción de biosensores electroquímicos.

Salt damage to plants has been attributed to a combination of several factors including mainly osmotic stress and the accumulation of toxic ions. Recent findings in our laboratory showed that phospholipid hydroperoxide glutathione peroxidase (PHGPX), an enzyme active in the cellular antioxidant system, was induced by salt in citrus cells and mainly in roots of plants. Following this observation we studied the two most important enzymes active in elimination of reactive oxygen species, namely, superoxide dismutase (SOD) and ascorbate peroxidase (APX), to determine whether a general oxidative stress is induced by salt. While Cu/Zn-SOD activity and cytosolic APX protein level were similarly induced by salt and methyl viologen, the response of PHGPX and other APX isozymes was either specific to salt or methyl viologen, respectively. Unlike PHGPX, cytosolic APX and Cu/Zn-SOD were not induced by exogenously added abscisic acid. Salt induced a significant increase in SOD activity which was not matched by the subsequent enzyme APX. We suggest that the excess of H2O2 interacts with lipids to form hydroperoxides which in turn induce and are removed by PHGPX. Ascorbate peroxidase seems to be a key enzyme in determining salt tolerance in citrus as its constitutive activity in salt-sensitive callus is far below the activity observed in salt-tolerant callus, while the activities of other enzymes involved in the defence against oxidative stress, namely SOD, glutathione reductase and PHGPX, are essentially similar.

Objective: In this article a comparison was made between graphene (SPGE) and graphene oxide screen-printed electrodes (SPGOE) to study the bio-electrocatalytic reduction of hydrogen peroxide (H2O2) by guinea grass peroxidase (GGP). Methods and materials: GGP was immobilized onto SPGE and SPGOE by a drop-casting procedure. Electrochemical techniques were carried out to monitor the electrochemical behavior of GGP and the efficiency of electrocatalytic reduction of H2O2. Results and discussion: GGP adsorbed on both electrodes exhibited a couple of well-defined redox peaks at 120 mV/10.5 mV and 184 mV/59 mV for anodic and cathodic peaks, respectively. Linearity between scan rates root and oxidation and reduction peak currents for both electrodes suggest a surface-controlled process. The GGP-modified electrodes exhibited a good electrocatalytic activity to H2O2 reduction at a redox potential of -0.6 V and -0.5 V for SPEG and SPEGO, respectively. Conclusions: SPGE and SPGOE electrodes modified with GGP showed excellent analytical performance towards different concentrations of hydrogen peroxide. This is a preliminary step to developing a bio-analytical portable system based on GGP for the detection of H2O2 in real environmental samples.

The presence of the enzymes of the ascorbate-glutathione cycle was investigated in mitochondria and peroxisomes purified from pea (Pisum sativum L.) leaves. All four enzymes, ascorbate peroxidase (APX; EC 1.11.1.11), monodehydroascorbate reductase (EC 1.6.5.4), dehydroascorbate reductase (EC 1.8.5.1), and glutathione reductase (EC 1.6.4.2), were present in mitochondria and peroxisomes, as well as in the antioxidants ascorbate and glutathione. The activity of the ascorbate-glutathione cycle enzymes was higher in mitochondria than in peroxisomes, except for APX, which was more active in peroxisomes than in mitochondria. Intact mitochondria and peroxisomes had no latent APX activity, and this remained in the membrane fraction after solubilization assays with 0.2 M KCl. Monodehydroascorbate reductase was highly latent in intact mitochondria and peroxisomes and was membrane-bound, suggesting that the electron acceptor and donor sites of this redox protein are not on the external side of the mitochondrial and peroxisomal membranes. Dehydroascorbate reductase was found mainly in the soluble peroxisomal and mitochondrial fractions. Glutathione reductase had a high latency in mitochondria and peroxisomes and was present in the soluble fractions of both organelles. In intact peroxisomes and mitochondria, the presence of reduced ascorbate and glutathione and the oxidized forms of ascorbate and glutathione were demonstrated by high-performance liquid chromatography analysis. The ascorbate-glutathione cycle of mitochondria and peroxisomes could represent an important antioxidant protection system against H2O2 generated in both plant organelles

Reactive oxygen species (ROS) play a prominent role in early and later stages of the plant pathogenesis response, putatively acting as both cellular signaling molecules and direct antipathogen agents. A single-cell assay, based on the fluorescent probe dichlorofluorescein, was used to scrutinize the generation and movement of ROS in tobacco epidermal tissue. ROS, generated within cells, quickly moved apoplastically as H2O2 into neighboring cells. Two classes of rapidly elicited intracellular ROS, originating from distinct sources, were distinguished. Cryptogein, the fungal elicitor from Phytophthora cryptogea, induced ROS from a flavin-containing oxidase source. ROS accumulation could be inhibited by a number of pharmacological agents, suggesting induction through an active signal transduction pathway. The insensitivity of the increase in ROS to the external addition of enzymes that dissipate ROS suggests that this exidative increase is primarily intracellular. In contrast, amines and polyamines, compounds that form during wounding and pathogenesis, induced ROS at an apoplastic site from peroxidase- or amine oxidase-type enzyme(s). Salicylic acid, a putative inhibitor of cellular catalases and peroxidases, did not induce cellular ROS, as messured by dichlorofluorescein fluorescence. The physiological relevance of ROS-generated signals was indicated by the rapid alteration of the epidermal cell glutathione pool and the cellular redox state. In addition, induction of ROS by all elicitors was correlated with subsequent cell death

Recent studies have revealed that dietary flavonoids are potent radical scavengers, acting in a manner similar to ascorbate and alpha-tocopherol. However, it is still not clear whether flavonoids have a similar antioxidative function in plants. We examined the possibility that flavonoids could function as stress protectants in plant cells by scavenging H2O2. Two major flavonoids, quercetin and kaempferol glycosides, were isolated from leaves of the tropical tree Schefflera arboricola Hayata. Both glycosides and aglycones of isolated flavonols were oxidized by H2O2 in the presence of horseradish peroxidase and/or in a soluble fraction of S. arboricola leaf extract. The rates of oxidation were in the order quercetin kaempferol quercetin glycoside kaempferol glycoside. Judging from the effects of inhibitors such as KCN, p-chloromercuribenzoate, and 3-amino-1H-1,2,4-triazole, we conclude that guaiacol peroxidase in the soluble fraction catalyzes H2O2-dependent oxidation of flavonols. In the flavonol-guaiacol peroxidase reaction, ascorbate had the potential to regenerate flavonols by reducing the oxidized product. These results provide further evidence that the flavonoid-peroxidase reaction can function as a mechanism for H2O2 scavenging in plants

Earlier studies with Arabidopsis thaliana exposed to ultraviolet B (UV-B) and ozone (O3) have indicated the differential responses of superoxide dismutase and glutathione reductase. In this study, we have investigated whether A. thaliana genotype Landsberg erecta and its flavonoid-deficient mutant transparent testa (tt5) is capable of metabolizing UV-B- and O3-induced activated oxygen species by invoking similar antioxidant enzymes. UV-B exposure preferentially enhanced guaiacol-peroxidases, ascorbate peroxidase, and peroxidases specific to coniferyl alcohol and modified the substrate affinity of ascorbate peroxidase. O3 exposure enhanced superoxide dismutase, peroxidases, glutathione reductase, and ascorbate peroxidase to a similar degree and modified the substrate affinity of both glutathione reductase and ascorbate peroxidase. Both UV-B and O3 exposure enhanced similar Cu,Zn-superoxide dismutase isoforms. New isoforms of peroxidases and ascorbate peroxidase were synthesized in tt5 plants irradiated with UV-B. UV-B radiation, in contrast to O3, enhanced the activated oxygen species by increasing membrane-localized NADPH-oxidase activity and decreasing catalase activities. These results collectively suggest that (a) UV-B exposure preferentially induces peroxidase-related enzymes, whereas O3 exposure invokes the enzymes of superoxide dismutase/ascorbate-glutathione cycle, and (b) in contrast to O3, UV-B exposure generated activated oxygen species by increasing NADPH-oxidase activity