Melatonin synthesis enzymes interact with ascorbate peroxidase to protect against oxidative stress in cassava

2020 ◽  
Vol 71 (18) ◽  
pp. 5645-5655 ◽  
Author(s):  
Yujing Bai ◽  
Jingru Guo ◽  
Russel J Reiter ◽  
Yunxie Wei ◽  
Haitao Shi
Keyword(s):  
Oxidative Stress ◽  
Antioxidant Capacity ◽  
Stress Tolerance ◽  
Ascorbate Peroxidase ◽  
Stress Responses ◽  
Direct Interaction ◽  
Ros Scavenging ◽  
Melatonin Synthesis

Abstract Melatonin is an important indole amine hormone in animals and plants. The enzymes that catalyse melatonin synthesis positively regulate plant stress responses through modulation of the accumulation of reactive oxygen species (ROS). However, the relationship between melatonin biosynthetic enzymes and ROS-scavenging enzymes has not been characterized. In this study, we demonstrate that two enzymes of the melatonin synthesis pathway in Manihot esculenta (MeTDC2 and MeASMT2) directly interact with ascorbate peroxidase (MeAPX2) in both in vitro and in vivo experiments. Notably, in the presence of MeTDC2 and MeASMT2, MeAPX2 showed significantly higher activity and antioxidant capacity than the purified MeAPX2 protein alone. These findings indicate that MeTDC2–MeAPX2 and MeASMT2–MeAPX2 interactions both activate APX activity and increase antioxidant capacity. In addition, the combination of MeTDC2, MeASMT2, and MeAPX2 conferred improved resistance to hydrogen peroxide in Escherichia coli. Moreover, this combination also positively regulates oxidative stress tolerance in cassava. Taken together, these findings not only reveal a direct interaction between MeTDC2, MeASMT2, and MeAPX2, but also highlight the importance of this interaction in regulating redox homoeostasis and stress tolerance in cassava.

scholarly journals Protective Effect of Coconut Oil Meal Phenolic Antioxidants against Macromolecular Damage: In Vitro and In Vivo Study

2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
A. N. Karunasiri ◽  
C. M. Senanayake ◽  
H. Hapugaswatta ◽  
N. Jayathilaka ◽  
K. N. Seneviratne
Keyword(s):  
Oxidative Stress ◽  
Protective Effect ◽  
Stress Responses ◽  
Coconut Oil ◽  
Oral Feeding ◽  
Phenolic Antioxidants ◽  
Significant Difference ◽  
Macromolecular Damage

Coconut oil meal, a cheap by-product of coconut oil production, is a rich source of phenolic antioxidants. Many age-related diseases are caused by reactive oxygen species- (ROS-) induced damage to macromolecules such as lipids, proteins, and DNA. In the present study, the protective effect of the phenolic extract of coconut oil meal (CMPE) against macromolecular oxidative damage was evaluated using in vitro and in vivo models. Sunflower oil, bovine serum albumin (BSA), and plasmid DNA were used in the in vitro study, and thiobarbituric acid reactive substances (TBARS), protein carbonyl, and nicked DNA were evaluated as oxidation products. The inhibitory effect of CMPE against H2O2-induced macromolecular damage was evaluated using cultured HEp-2 cells. The results indicate that CMPE inhibits macromolecular damage both in vitro and in vivo. In addition, CMPE regulates redox status of HEp-2 cells under oxidative stress conditions by maintaining higher reduced glutathione levels. There was no significant difference in the expression of glutathione peroxidase in stressed and unstressed cells suggesting that CMPE regulates the cellular oxidative stress responses without affecting the expression of oxidative stress response genes. Oral feeding of Wistar rats with CMPE improves the serum and plasma antioxidant status without causing any toxic effects.

scholarly journals Root extracts of Anacardium occidentale reduce hyperglycemia and oxidative stress in vitro

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
TM Archana ◽  
K Soumya ◽  
Jesna James ◽  
Sudheesh Sudhakaran
Keyword(s):  
Oxidative Stress ◽  
Antioxidant Capacity ◽  
Mtt Assay ◽  
Radical Scavenging ◽  
Pcr Analysis ◽  
Total Phenolic ◽  
Β Cells ◽  
Root Extracts

Abstract Background Hyperglycemia is the hallmark of diabetes, and the associated oxidative stress is a major concern that invites an array of diabetic complications. The traditional practices of medicare are of great, current interest due to the high cost and side effects of conventional diabetic medications. The present in vitro study focuses on evaluating the potential of various A. occidentale root extracts for their antihyperglycemic and antioxidant potentials. Materials and methods The four different solvent extracts petroleum ether (PEAO), chloroform (CHAO), ethyl acetate (EAAO), and 80 % methanol (80 % MAO) of A. occidentale roots were evaluated for their total phenolic, flavonoid, and antioxidant capacity. Using MIN6 pancreatic β-cells, the cytotoxicity of the extracts was evaluated by MTT assay and the antidiabetic potential by quantifying the insulin levels by ELISA at a higher concentration of glucose. The effect of 80 % MAO on INS gene expression was determined by qRT PCR analysis. Results Among the four different solvent extracts of A. occidentale roots, 80 % MAO showed the highest concentration of phenolics (437.33 ± 0.03 µg GAE/mg), CHAO to be a rich source of flavonoids (46.04 ± 0.1 µg QE/mg) and with the highest total antioxidant capacity (1865.33 ± 0.09 µg AAE/ mg). Evaluation of the free radical scavenging and reducing properties of the extracts indicated 80 % MAO to exhibit the highest activity. The MTT assay revealed the least cytotoxicity of all four extracts. 80 % MAO enhanced INS up-regulation as well as insulin secretion even under high glucose concentration (27mM). Conclusions The present study demonstrated that the A. occidentale root extracts have effective antihyperglycemic and antioxidative properties, together with the potential of normalizing the insulin secretory system of β-cells. Above mentioned properties have to be studied further by identifying the active principles of A. occidentale root extracts and in vivo effects. The prospect of the present study is identifying drug leads for better management of diabetes from the A. occidentale root extracts. Graphical abstract

scholarly journals Palmitic Acid Curcumin Ester Facilitates Protection of Neuroblastoma against Oligomeric Aβ40 Insult

2017 ◽  
Vol 44 (2) ◽  
pp. 618-633 ◽  
Author(s):  
Zhangyang Qi ◽  
Meihao Wu ◽  
Yun Fu ◽  
Tengfei Huang ◽  
Tingting Wang ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Protective Effect ◽  
Palmitic Acid ◽  
Cell Membranes ◽  
Direct Interaction ◽  
Association Constants ◽  
Ros Production ◽  
Ros Scavenging

Background/Aims: The generation of reactive oxygen species (ROS) caused by amyloid-β (Aβ) is considered to be one of mechanisms underlying the development of Alzheimer’s disease. Curcumin can attenuate Aβ-induced neurotoxicity through ROS scavenging, but the protective effect of intracellular curcumin on neurocyte membranes against extracellular Aβ may be compromised. To address this issue, we synthesized a palmitic acid curcumin ester (P-curcumin) which can be cultivated on the cell membrane and investigated the neuroprotective effect of P-curcumin and its interaction with Aβ. Methods: P-curcumin was prepared through chemical synthesis. Its structure was determined via nuclear magnetic resonance (NMR) and high-resolution mass spectrometry (HRMS). An MTT assay was used to assess Aβ cytotoxicity and the protective effect of P-curcumin on SH-SY5Y cells. The effect of P-curcumin on Aβ-induced ROS production in vitro and in vivo were assessed based on changes in dichlorofluorescein (DCF) fluorescence. A spectrophotometric method was employed to detect lipid peroxidation. To mimic the interaction of P-curcumin on cell membranes with Aβ, liposomes were prepared by thin film method. Finally, the interactions between free P-curcumin and P-curcumin cultivated on liposomes and Aβ were determined via spectrophotometry. Results: A novel derivative, palmitic acid curcumin ester was prepared and characterized. This curcumin, cultivated on the membranes of neurocytes, may prevent Aβ-mediated ROS production and may inhibit the direct interaction between Aβ and the cellular membrane. Furthermore, P-curcumin could scavenge Aβ-mediated ROS as curcumin in vitro and in vivo, and had the potential to prevent lipid peroxidation. Morphological analyses showed that P-curcumin was better than curcumin at protecting cell shape. To examine P-curcumin’s ability to attenuate direct interaction between Aβ and cell membranes, the binding affinity of Aβ to curcumin and P-curcumin was determined. The association constants for free P-curcumin and curcumin were 7.66 × 104 M-1 and 7.61 × 105 M-1, respectively. In the liposome-trapped state, the association constants were 3.71 × 105 M-1 for P-curcumin and 1.44× 106 M-1 for curcumin. With this data, the thermodynamic constants of P-curcumin association with soluble Aβ (ΔH, ΔS, and ΔG) were also determined. Conclusion: Cultivated curcumin weakened the direct interaction between Aβ and cell membranes and showed greater neuroprotective effects against Aβ insult than free curcumin.

scholarly journals Camphene Attenuates Skeletal Muscle Atrophy by Regulating Oxidative Stress and Lipid Metabolism in Rats

Nutrients ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3731
Author(s):  
Suji Baek ◽  
Jisu Kim ◽  
Byung Seok Moon ◽  
Sun Mi Park ◽  
Da Eun Jung ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Skeletal Muscle ◽  
Lipid Metabolism ◽  
Muscle Atrophy ◽  
Gas Analysis ◽  
Skeletal Muscle Atrophy ◽  
Ros Scavenging ◽  
In Vivo Models

Sarcopenia- or cachexia-related muscle atrophy is due to imbalanced energy metabolism and oxidative stress-induced muscle dysfunction. Monoterpenes play biological and pharmacological reactive oxygen species (ROS) scavenging roles. Hence, we explored the effects of camphene, a bicyclic monoterpene, on skeletal muscle atrophy in vitro and in vivo. We treated L6 myoblast cells with camphene and then examined the ROS-related oxidative stress using Mito TrackerTM Red FM and anti-8-oxoguanine antibody staining. To investigate lipid metabolism, we performed real-time polymerase chain reactions, holotomographic microscopy, and respiratory gas analysis. Rat muscle atrophy in in vivo models was observed using 18F-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography and immunocytochemistry. Camphene reversed the aberrant cell size and muscle morphology of L6 myoblasts under starvation and in in vivo models. Camphene also attenuated E3 ubiquitin ligase muscle RING-finger protein-1, mitochondrial fission, and 8-oxoguanine nuclear expression in starved myotubes and hydrogen peroxide (H2O2)-treated cells. Moreover, camphene significantly regulated lipid metabolism in H2O2-treated cells and in vivo models. These findings suggest that camphene may potentially affect skeletal muscle atrophy by regulating oxidative stress and lipid metabolism.

scholarly journals OsnR is an autoregulatory negative transcription factor controlling redox-dependent stress responses in Corynebacterium glutamicum

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Haeri Jeong ◽  
Younhee Kim ◽  
Heung-Shick Lee
Keyword(s):  
Oxidative Stress ◽  
Corynebacterium Glutamicum ◽  
Stress Responses ◽  
Promoter Region ◽  
Underlying Mechanism ◽  
In Vitro Assays ◽  
Expression Of Genes

Abstract Background Corynebacterium glutamicum is used in the industrial production of amino acids and nucleotides. During the course of fermentation, C. glutamicum cells face various stresses and employ multiple regulatory genes to cope with the oxidative stress. The osnR gene plays a negative regulatory role in redox-dependent oxidative-stress responses, but the underlying mechanism is not known yet. Results Overexpression of the osnR gene in C. glutamicum affected the expression of genes involved in the mycothiol metabolism. ChIP-seq analysis revealed that OsnR binds to the promoter region of multiple genes, including osnR and cg0026, which seems to function in the membrane-associated redox metabolism. Studies on the role of the osnR gene involving in vitro assays employing purified OsnR proteins and in vivo physiological analyses have identified that OsnR inhibits the transcription of its own gene. Further, oxidant diamide stimulates OsnR-binding to the promoter region of the osnR gene. The genes affected by the overexpression of osnR have been found to be under the control of σH. In the osnR-overexpressing strain, the transcription of sigH is significantly decreased and the stimulation of sigH transcription by external stress is lost, suggesting that osnR and sigH form an intimate regulatory network. Conclusions Our study suggests that OsnR not only functions as a transcriptional repressor of its own gene and of those involved in redox-dependent stress responses but also participates in the global transcriptional regulation by controlling the transcription of other master regulators, such as sigH.

Abstract 28: Carboxyalkyl-pyrrole Phosphatidylethanolamine Adducts Are Present In Vivo And Induce Platelet Activation Via Toll-like Receptor

2013 ◽  
Vol 33 (suppl_1) ◽  
Author(s):  
Sudipta Biswas ◽  
Soumya Panigrahi ◽  
Alejandro Zimman ◽  
Eugene Podrez
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Platelet Activation ◽  
Platelet Reactivity ◽  
Biological Activities ◽  
Direct Interaction ◽  
Covalent Modification ◽  
Downstream Signaling

A prothrombotic state and increased platelet reactivity are common in pathophysiological conditions associated with oxidative stress. Lipid peroxidation, a major consequence of oxidative stress generates highly reactive products capable of modifying autologous proteins as well as lipids. Hydroxy-ω-oxoalkenoic acids and their carboxyalkylpyrrole (CAP) protein adducts are recently described products of lipid peroxidation with strong biological activity mediated by Toll like receptors (TLR). Phosphatidylethanolamine (PE) is the second most abundant phospholipid in the living organisms. While recent studies suggest that PE is a major target for covalent modification by reactive products of lipid peroxidation, the presence of such products in vivo, their biological activities and receptors involved are not established. We now report that CAP-PE adducts are present in vivo in circulation and are significantly elevated in plasma of hyperlipidemic apoE-/- mice. In vitro experiments demonstrated that CAP-PE adducts induce platelet integrin αIIbβ3 activation, P-selectin expression and promote platelet aggregation. Multiple complimentary approaches demonstrated that platelet activation by CAP-PE is mediated by TLR2 and TLR1. Furthermore, direct interaction of CAP-PE and TLR2 was demonstrated. CAP-PE induced assembly of TLR2/TLR1 receptor complex in platelets leading to downstream signaling via MyD88/TIRAP-dependent pathway. CAPs-PE induced signaling included phosphorylation and activation of IRAK4 and subsequent activation of TRAF6, Src family kinase, Syk and PLCγ2. Thus, our study identified carboxyalkylpyrrole adducts of phosphatidylethanolamine as novel end products accumulating in circulation in hyperlipidemia that can induce platelet activation via innate immunity signaling pathway.

scholarly journals Mutual Promotion of LAP2 and CAT2 Synergistically Regulates Plant Salt and Osmotic Stress Tolerance

2021 ◽  
Vol 12 ◽  
Author(s):  
Yu Zhang ◽  
Lin-Feng Wang ◽  
Ting-Ting Li ◽  
Wen-Cheng Liu
Keyword(s):  
Osmotic Stress ◽  
Stress Tolerance ◽  
Stress Responses ◽  
Plant Cells ◽  
Physical Interaction ◽  
Loss Of Function ◽  
Osmotic Stress Tolerance ◽  
Salt And Osmotic Stress

Almost all abiotic stresses induce reactive oxygen species (ROS) overaccumulation, causing oxidative damages to plant cells. Catalase (CAT) plays a vital role in plant oxidative stress tolerance by scavenging stress-induced excess H2O2; thus, the identification of factors regulating catalase function will shed light on the underlying regulatory mechanisms. Here, we identified leucine aminopeptidase 2 (LAP2) as a novel CAT2-interacting protein and showed a mutual promotion effect of the two proteins in plant stress responses. LAP2 has a physical interaction with CAT2 in plant cells. The loss-of-function mutant of LAP2, lap2-3, is hypersensitive to salt or osmotic stress with increased ROS accumulation and malondialdehyde content and decreased catalase activity. The lap2-3 mutant has less CAT2 protein levels as CAT2 protein stability is impaired in the mutant. Scavenging excess ROS by glutathione or overexpressing CAT2 in the lap2-3 mutant recovers its hypersensitive phenotype to salt or osmotic stress. Further study showed that CAT2 promotes LAP2 hydrolysis activity with leucine-4-methylcoumaryl-7-amides as a substrate in vivo and in vitro, and thus, similar to the lap2-3 mutant, the cat2-1 mutant also has lower γ-aminobutyric acid content than the wild type. Together, our study reveals mutual promotion effects of CAT2 and LAP2 in conferring plant salt and osmotic stress tolerance.

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