Reduced Hydroxyl Radical Research Articles

Carbon dioxide concentration on yield and functional properties of waterleaf

ABSTRACT Understanding the impact of carbon dioxide concentration on the yield and functional properties of waterleaf [Talinum triangulare (Jacq)] is necessary in the context of climate change, as it assesses the potential consequences of rising carbon dioxide levels on this leafy green’s growth and nutritional quality. In a controlled environment experiment, T. triangulare plants were exposed to 400, 600, 800, and 1000 ppm carbon dioxide levels. Plant development, yield, macro- and micro-nutrient composition, and number of bioactive substances were measured. Talinum triangulare grows best, has improved nutrient content, and produces more when carbon dioxide levels are 800 ppm. The 1000 ppm carbon dioxide showed a depreciative antioxidant value of T. triangulare. The secondary metabolites phenolics, flavonoids, and antioxidants (2,2’-Azino-bis 3-ethylbenzthiazoline-6-sulfonic acid, Ferric Reducing Antioxidant Property, 1,1-diphenyl-2-picrylhydrazyl, and Hydroxyl Radical Scavenging Ability) results indicated that <800 ppm of carbon dioxide increased antioxidant properties. Elevated carbon dioxide concentrations have the potential to enhance the growth and yield of T. triangulare. The T. triangulare grown under 800 ppm CO2 showed the best antioxidant properties. It can be recommended that greenhouses fortified with CO2 at 800 ppm CO2 can benefit to the growth, functionality, and nutritional properties of vegetables.

Bioactive compounds and antioxidant activity in various parts of Morus alba L. Cv. ichinose: a comparative analysis

Present investigation was undertaken to assess the composition of bioactive compounds within various parts of methanolic extracts from mulberry plants utilizing both High-Performance Liquid Chromatography (HPLC) and spectrophotometric methodologies. Furthermore, the antioxidant potential was evaluated through assays including 2,2-diphenyl-1-picrylhydrazyl (DPPH), Ferric Reducing Antioxidant Power (FRAP), β-carotene bleaching (BCBA), and Hydroxyl Radical Scavenging Activity (HRSA). This research incorporated the analysis of the fruit, root, shoot, and leaf of the mulberry (Morus alba L.) Cv. Ichinose. Findings from the investigation revealed that levels of total phenols (533.8 ± 15.6 mg/100 g) and flavonoids (232.3 ± 7.1 mg/100 g) were notably higher in fruit compared to root, while total ascorbic acid content (70.9 ± 3.1 mg/100 g) was significantly elevated in the leaf. The fruit exhibited a significantly higher concentration of total anthocyanins (142.5 ± 3.1 mg/100 g), whereas the leaf contained a substantial amount of total carotenoids (5.8 ± 0.3 mg/100 g). Predominant phenolic acids detected in mulberry included ferulic acid, m-coumaric acid, syringic acid, caffeic acid, chlorogenic acid, and gallic acid. Quercetin and isoquercetin were identified as the major flavonoids in mulberry fruits. In terms of anthocyanins, cyanidin-3-rutinoside (25.6 ± 2.3 mg/100 g) and cyanidin-3-glucoside (16.4 ± 2.1 mg/100 g) were the primary anthocyanins present in the fruit. The main carotenoid found in the leaf was beta-carotene, with levels reaching 2.1 ± 0.3 mg/100 g. Fruit displayed the highest antioxidant activity among all parts examined. Comparison of the EC50 values of fruit (EC50 = 174.2 ± 2.2 µg/mL), root (EC50 = 179.6 ± 2.3 µg/mL), and shoot (EC50 = 189.4 ± 2.1) suggested that these segments of the mulberry plant could potentially function as antioxidants and could exhibit a greater hydroxyl radical scavenging effect than standard antioxidants.

Phyto-chemical Profiling, Antimicrobial and Antioxidant Activity of Marine Brown Algae, Sargassum polycystum

Marine algae contain diverse bioactive compounds with pharmaceutical and nutraceutical importance. The present study was aimed at exploring one such alga, Sargassum polycystum, belonging to the phaeophyceae family. The seaweed was extracted with two different solvent systems and subjected to phytochemical analysis, antimicrobial and antioxidant studies. The extract showed wide variety of phytocomposition and was found to possess significant antimicrobial activity against bacterial and fungal pathogens. For antioxidant activities, DPPH assay, Hydroxyl radical scavenging assays, Phosphomolybdenum reduction and Fe3+ reducing power assays were carried out. The extract exhibited remarkable antioxidant activity in all the assays, especially in Fe3+ reducing power assay and hydroxyl radical scavenging, a maximum inhibition of 96.27 and 84.14% was observed, respectively. Also, the GC-MS analysis further confirmed the presence of isoflavone, a phenolic compound that signifies the role in antioxidant activity.

Ethanol leaf extracts of Anogeissus leiocarpus in antioxidants and hepatotoxic effects of Escherichia coli O157:H7 infected Swiss Mice.

Diseases caused by bacteria can be managed with medicinal plants with rightful dosage that will not affect body physiology and organs. This research aimed to evaluate the antioxidants and the effects of Anogeisus leiocarpus on liver function. Ethanol leaf extracts were processed for antioxidants and hepatotoxic effects using animal models. Group one (negative control) was given access to water and regular feed, group two (positive control) was dosed with 107 CFU/ml of Escherichia coli O157:H7, and groups 3-6 were dosed with 107 E. coli O157:H7 for 3 days and treated with extract concentrations of 12, 25, 50 and 100 mg/kg bw respectively for seven days. Higher ascorbic acid values in Ferric reducing antioxidant property (FRAP) and Hydroxyl radical scavenging (HRS) were recorded in the positive control (0.05 ± 0.01, 41 ± 0.05) than in the extract-treated (0.02 ± 0.14, 30 ± 0.02). Increase in DPPH (47 ± 0.1268 ± 0.05 %), Free radical scavenging property (FRAP) (0.03 ± 0.02-0.08 ± 0.14 %), and HRS (38 ± 0.14-68 ± 0.12 %) was observed in the extract. The lipid peroxidation (LPO) of the quote was 78.51 ± 2.16, GSH was 36.18 ± 3.18, and catalase was 78.42 ± 4.713. In the extract-treated, decreased values were recorded for LPO ((108.36 ± 1.12-70.19 ± 1.68 μM/g), while increased values were observed in Glutathione (GSH) (25.11 ± 2.64-33.62 ± 1.35 μM/g), and catalase (54.18 ± 2.14-60.25 ± 1.4 μM/g). The values of negative control for Aspartate aminotransferase (AST), Alanine aminotransferase (ALT), and Alkaline phosphate (ALP) were lesser than what was received in the extract treated. The plant's traditional medicine usage is effective at low dosage and could be a suitable candidate for drug development which will not affect the body's physiology and organs. The subjecting of A. leiocarpus ethanol leaf extract to antioxidants assays and its effect on liver function have further proved its value in folklore medicine.

Protective effect of methylene blue in iron-induced neurotoxicity

Iron deposits have been identified as an intriguing pathological finding in the brain. Although generally considered benign, and, to a certain degree, necessary for various biochemical processes and functions, recent research suggests that abnormal iron deposits may exert harmful effects on brain tissue. Excessive iron accumulation in the brain, due to an imbalance in iron homeostasis and exacerbated by endogenous hydrogen peroxide (H2O2), can contribute to neurodegenerative diseases like Alzheimer's and Parkinson's diseases. This occurs through the Fenton reaction, where iron and H2O2 produce highly reactive hydroxyl radicals (•OH), causing oxidative stress and damaging cellular components. This oxidative damage leads to neuronal dysfunction and death, promoting aggregation of misfolded proteins and the progression of neurodegenerative diseases.Methylene blue, a versatile medication used in methemoglobinemia treatment and diagnostics, shows promise in the prevention of possible brain damage from iron deposits. It may act by inhibiting the Fenton reaction, and reducing hydroxyl radical production. By reducing oxidative stress, methylene blue can mitigate iron-induced neurotoxicity in neurodegenerative diseases.We propose early treatment with methylene blue in patients with initial signs of neurodegenerative diseases and excessive iron deposits in the brain detected with Magnetic Resonance Imaging.

Antioxidant and hepatoprotective effects of Solanum villosum leaf extracts against acetaminophen-induced mouse model of hepatotoxicity

Solanum villosum is an indigenous vegetable and ethno-medicine source in Africa. Scientific validation of their medicinal potential is required. The current study aimed to assess the antioxidant and hepatoprotective effects of S. villosum leaf methanol extracts (SVE) against acetaminophen-induced mouse model. The SVE antioxidant activities were evaluated by ferric reducing antioxidant capacity and hydroxyl radical scavenging activities in vitro. Hepatoprotective activities were assessed by automated hematological analysis, chemical analysis and specific biochemical assays of liver homogenates. Mice were orally administered with SVE at 30, 100, 300 and 500 mg/kg body weight. Hepatotoxicity was induced by acetaminophen 300 mg/kg bw intraperitoneally while silymarin 25 mg/kg bw orally was a positive control. The SVE exhibited a clear concentration-dependent antioxidant activity. Subsequently, SVE treatment significantly (P≤0.05) lowered granulocyte count, while there was a significant increase in lymphocyte count in acetaminophen-treated mice. Further, SVE significantly lowered the activities of alanine transaminase, aspartate transaminase, and alkaline phosphatase, but significantly increased γ-glutamyl-transferase activity in treated mice compared to the controls. However, SVE led to insignificant change in total proteins. Additionally, SVE treatment led to a significant rise in superoxide dismutase and glutathione peroxidase activities but, an insignificant change in catalase activity. In conclusion, SVE confers liver protection by oxidative stress prevention, antioxidant enzyme activation, immuno-modulation and hepatic tissue preservation. The results also support indigenous use of S. villosum to protect patients against drug-induced liver damage and enhance immunity. Further, dietary supplements of S. villosum could be an adjunct therapy in acetaminophen-induced hepatotoxicity.

Clinical Use and Treatment Mechanism of Molecular Hydrogen in the Treatment of Various Kidney Diseases including Diabetic Kidney Disease.

As diabetes rates surge globally, there is a corresponding rise in the number of patients suffering from diabetic kidney disease (DKD), a common complication of diabetes. DKD is a significant contributor to chronic kidney disease, often leading to end-stage renal failure. However, the effectiveness of current medical treatments for DKD leaves much to be desired. Molecular hydrogen (H2) is an antioxidant that selectively reduces hydroxyl radicals, a reactive oxygen species with a very potent oxidative capacity. Recent studies have demonstrated that H2 not only possesses antioxidant properties but also exhibits anti-inflammatory effects, regulates cell lethality, and modulates signal transduction. Consequently, it is now being utilized in clinical applications. Many factors contribute to the onset and progression of DKD, with mitochondrial dysfunction, oxidative stress, and inflammation being strongly implicated. Recent preclinical and clinical trials reported that substances with antioxidant properties may slow the progression of DKD. Hence, we undertook a comprehensive review of the literature focusing on animal models and human clinical trials where H2 demonstrated effectiveness against a variety of renal diseases. The collective evidence from this literature review, along with our previous findings, suggests that H2 may have therapeutic benefits for patients with DKD by enhancing mitochondrial function. To substantiate these findings, future large-scale clinical studies are needed.

The Antidiabetic Activity of Combining the Aqueous Extracts of Vernonia amygdalina Leaves and Tamarindus indica Fruit Pulp in Streptozotocin-Induced Wistar Rats.

Background Many plants are used to reduce the side effects of diabetes mellitus. These plants (including Vernonia amygdalina andTamarindus indica) are rich in phytochemical compounds that have the ability to reduce glycemia and the effect of diabetes-related oxidative stress. In this study, we aimed to investigate the antioxidant and antidiabetic activities of combining V. amygdalina leaves and T. indica pulp extracts. Methodology We prepared a mixture by combining V. amygdalina leaves and T. indica pulp extracts, and we assessed antioxidant properties via the capacity of both extracts to reduce ferric ions, 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radicals, and hydroxyl radicals. We also assessed antidiabetic properties through the capacity of the extracts' combination to inhibit alpha-amylase. We evaluated crude fiber, total phenols content (TPC), and total flavonoid content (TFC). Results From our findings, the combination at a concentration of 200 μg/mgE showed that a percentage of 55.17±1.2 could reduce DPPH radicals, 0.366±0.012 could scavenge ferric ions, and 0.233±0.0022 could reduce hydroxyl radicals. With regard to secondary metabolites, we obtained 16.96±0.17 mEGA/gE for total phenol content, 1.74±0.045 mECAT/gE for total flavonoid content, and crude fiber content in our combination at 6.87±1%. These results were obtained with a significant difference at the 5% threshold. The extractcombination also showed an alpha-amylase inhibitory percentage of 23.56±4.6% at the concentration of 200 μg/mgE. Daily administration of the combination of extracts significantly lowered the fasting blood glucose, triglycerides, total cholesterol, LDL cholesterol, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, creatinine, and malondialdehyde. However, there was a significant increase in serum proteins and HDL cholesterol. We did not observe an antagonistic effect between our combination and glybenclamide. Conclusion Our formulation, therefore, presents antioxidant and antidiabetic activity and could be used for the management of diabetic patients.

Effect of Bi3+co-doping on the up-converting and photocatalytic properties of SrGd2O4:Yb3+/Ho3+ phase

In this investigation, samples of strontium-gadolinium-oxide (SrGd2O4) doped with different Yb3+ (2, 4 and 6 at%) and constant Ho3+ (1 at%) contents and co-doped with Bi3+ (2 at%) were prepared using the glycine-assisted sol–gel method. The pure orthorhombic SrGd2O4 phase, space group Pnma, was revealed using X-ray diffraction in all samples. Transmission electron microscopy discovered agglomerated clusters of spherical particles measuring approximately 150 nm in size. The inclusion of Bi3+ ions into the structure influenced the morphology since the formation of larger grains was observed, with sizes reaching up to ∼1.7 μm. The uniform distribution of all constitutive elements was confirmed by energy-dispersive X-ray spectroscopy. In all samples, up-conversion emission spectra revealed two dominant green (540 and 550 nm), red (671 nm), and infrared (758 nm) emission lines, due to the 5F4,5S2→5I8, 5F5→5I8, and 5F4,5S2 → 5I7 transitions, respectively. The sample co-doped with Bi3+ showed the most intense photoluminescent emissions, shorter luminescence decay, and the highest quantum yield. Additionally, a significant decrease in the energy band gap value was detected using diffuse reflectance spectroscopy for this sample. Methylene blue was used as a test pollutant to investigate its photocatalytic efficiency under simulated sunlight irradiation. The results show that Bi3+ co-doping deteriorates the photocatalytic efficiency of the SrGd2O4:Yb3+/Ho3+ phase by reducing hydroxyl radical formation.

Evaluation of in vitro enzyme inhibitory, anti-inflammatory, antioxidant, and antibacterial activities of Oldenlandia corymbosa L. and Oldenlandia umbellata L. whole plant extracts

BackgroundOldenlandia corymbosa and Oldenlandia umbellata are well-known medicinal plants in various traditional systems of medicine and used to treat bronchitis, asthma, tuberculosis, constipation, and leprosy. We evaluated the phytochemical content, antioxidant potential, enzyme inhibitory action, anti-inflammatory, and antibacterial activities of the whole plant extracts of O. corymbosa and O. umbellata due to their therapeutic importance. MethodsThe phytochemical analysis includes qualitative analysis and quantification of total phenolics, flavonoids, tannins, flavonols, proanthocyanidins, and vitamin E. Enzyme inhibitory assays were studied using α-amylase and α-glucosidase enzymes and anti-inflammatory activity was determined by egg albumin denaturation assay. Antioxidant potential was estimated using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis (3-ethyl benzothiozoline-6-sulfonic acid) diammonium salt (ABTS), ferric reducing antioxidant power (FRAP), hydroxyl radical, superoxide, nitric oxide, metal chelating, and phosphomolybdenum assays. Minimum inhibitory concentrations of extracts were studied against ten bacterial strains by the microdilution method. ResultsThe aqueous extract of O.umbellata showed a higher extract yield (5.0%). The highest amount of total phenolics and flavonoids were observed in the ethanolic extract of O.umbellata (77.23±0.46 mg GAE/g) and O.corymbosa (19.01±0.26 mg GAE/g). Ethanolic extract of O.umbellata (IC50 of 31.71±0.32 µg/mL) and aqueous extract of O.corymbosa (30.53±1.83 µg/mL) showed notable α-amylase inhibitory effect and petroleum ether extract of both plants observed good inhibition against α-glucosidase enzyme. Likewise, petroleum ether extract of O.umbellata (IC50 of 57.16±1.88 µg/mL) showed a moderate anti-inflammatory effect. In all extracts, considerable antioxidant potential was recorded specially with aqueous extract in the nitric oxide scavenging assay with an IC50 of 40.72±1.25 µg/mL. Ethanolic extract of O.umbellata and petroleum ether extract of O.corymbosa (MIC of 56.25 µg/mL) showed good antibiotic potency in lower concentrations which proves these two valuable herb's potential in herbal preparations. ConclusionsThe results of the study provide a basis for further studies aiming to evaluate the possibilities of using the O. umbellata and O. corymbosa as natural sources of antioxidants, enzyme inhibitory, and antibacterial agents. Further studies could be directed to exploit these plants in experimental animal models as potential pharmaceutical agents.

Naringin and Naringenin Polyphenols in Neurological Diseases: Understandings from a Therapeutic Viewpoint.

The glycosides of two flavonoids, naringin and naringenin, are found in various citrus fruits, bergamots, tomatoes, and other fruits. These phytochemicals are associated with multiple biological functions, including neuroprotective, antioxidant, anticancer, antiviral, antibacterial, anti-inflammatory, antiadipogenic, and cardioprotective effects. The higher glutathione/oxidized glutathione ratio in 3-NP-induced rats is attributed to the ability of naringin to reduce hydroxyl radical, hydroperoxide, and nitrite. However, although progress has been made in treating these diseases, there are still global concerns about how to obtain a solution. Thus, natural compounds can provide a promising strategy for treating many neurological conditions. Possible therapeutics for neurodegenerative disorders include naringin and naringenin polyphenols. New experimental evidence shows that these polyphenols exert a wide range of pharmacological activity; particular attention was paid to neurodegenerative diseases such as Alzheimer's and Parkinson's diseases, as well as other neurological conditions such as anxiety, depression, schizophrenia, and chronic hyperglycemic peripheral neuropathy. Several preliminary investigations have shown promising evidence of neuroprotection. The main objective of this review was to reflect on developments in understanding the molecular mechanisms underlying the development of naringin and naringenin as potential neuroprotective medications. Furthermore, the configuration relationships between naringin and naringenin are discussed, as well as their plant sources and extraction methods.

Synthesis and Biological Activity of Trolox Amide Derivatives

A series of Trolox amide derivatives were synthesized by modifying the carboxyl groups of Trolox. Thirty target compounds were obtained and characterized through nuclear magnetic resonance and mass spectrometry. Trolox derivatives were employed to explore the potential structure-antioxidant activity relationships. The antioxidant activities of these compounds were evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), ferric reducing antioxidant power (FRAP) and hydroxyl radical assays. DPPH scavenging activity test results illustrated that compounds exhibited scavenging activities similar to L-ascorbic acid and Trolox, with compounds 14a, 18a, 24a and 26a in particular exhibiting higher scavenging activities than L-ascorbic acid. The results demonstrated that compounds displayed ABTS scavenging activities similar to L-ascorbic acid and Trolox, with compounds 26a and 29a in particular having potency twofold higher. FRAP assay results indicated that compounds 11a, 19a, 25a, 29a and 30a had activity similar to Trolox. The results revealed that compounds 6a and 19a had similarly high hydroxyl radical-scavenging activities as Trolox. The results of α-glucosidase experiments uncovered that compounds 10a, 25a, 28a and 29a had excellent inhibitory activity, which was similar to that of acarbose and different from Trolox. The results of acetylcholinesterase and butyrylcholinesterase experiments demonstrated that some compounds had weak anticholinesterase activities. 26a and 29a are important Trolox derivatives with better biological activity profiles and deserve further study.

Imine resveratrol analogs (IRAs): The strong antioxidant that can protect lymphocytes from oxidative damage.

Imine resveratrol analogs (IRAs) are promising new agents that can have higher positive effects and, simultaneously, lower negative properties than resveratrol. In this study,three imine hydroxy derivatives (2-((4-hydroxyphenylimino) methyl) phenol [IRA1], 3-((4-hydroxyphenylimino) methyl) phenol [IRA2], and 4-((4-hydroxyphenylimino) methyl) phenol [IRA3]) were prepared and tested in several biological assays. They performed superior to resveratrol in several antioxidant and biological assays, showing high antioxidant capacity and low genotoxicity. Ferric reducing antioxidant power assay (FRAP) and hydroxyl radicals scavenging assay revealed good Fe3+ to Fe2+ reduction and strong inhibition of hydroxyl radical formation, respectively. High dosage (1 mmol/dm3 ) of IRA2 and IRA3 did not cause genotoxicity in human lymphocytes. Moreover, lymphocytes pretreated with all three IRAs accumulated only very few DNA breaks induced by H2 O2 than lymphocytes pretreated with resveratrol. Additionally, the number of detected DNA breaks appearing after removal of damaged DNA bases, 8-oxo-7,8-dihydroguanine (8-oxoG), did not dramatically increase in lymphocytes treated with IRA2. Thus, we concluded that IRAs, especially IRA2, are strong antioxidants with the ability to protect lymphocytes from oxidative damage.

Development and Characterization of Ulvan Polysaccharides-Based Hydrogel Films for Potential Wound Dressing Applications.

BackgroundUlvan is a natural polymer and type of sulfated polysaccharides from green seaweed that could have potential as a candidate for wound dressing material based on the support of its biopolymer characteristics such as antioxidant and antimicrobial activities.ObjectiveIn this study, we developed and prepared three different hydrogel films to explore the potency of ulvan for wound dressing application.MethodsUlvan hydrogel films were prepared by the facile method through ionic crosslinking with boric acid and added glycerol as a plasticizer. The films were evaluated in regard to swelling degree, water vapor transmission (WVTR), Fourier transform infrared (FTIR), powder x-ray diffractometry (P-XRD), scanning electron microscopy (SEM), mechanical properties, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), antimicrobial, and antioxidant activity.ResultsThe hydrogel films showed that the different concentration of ulvan in the formula affects the characteristics of the hydrogel film. The higher the concentration of ulvan in UHF, the higher the value of viscosity (201±13.45 to 689±62.23 cps for UHF5 to UHF10), swelling degree (82% to 130% for UHF5 to UHF10 at 1 h), moisture content (24%±1.94% to 18.4%±0.51 for UHF5 to UHF10), and the WVTR were obtained in the range 1856–2590g/m2/24h. Meanwhile, the SEM showed porous hydrogel film. Besides, all hydrogel films can reduce hydroxyl radicals and inhibit gram-positive and negative bacteria (Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Streptococcus epidermidis).ConclusionThe swelling behavior and WVTR of these films are great and could have potential as a wound dressing biomaterial, supported by their antimicrobial and antioxidant properties.

Dual roles of tau R peptides on Cu(II)/(I)-mediated reactive oxygen species formation.

Metal dyshomeostasis plays a critical role in the reactive oxygen species (ROS) formation and protein misfolding and aggregation; hence, contributing to neurodegeneration. Tau protein plays a key role in normal cellular function by maintaining microtubule formation in brain. The role of metal ions on tau protein biochemistry has not been systematically evaluated, but earlier reports indicated that metal ions modulate the complex biochemistry of this protein and its peptides. Herein, we evaluated interactions of biologically-relevant Cu(II) ions with the four repeat peptides of tau protein (R1 through R4) and their role on the formation of ROS, Cu(II) to Cu(I) reduction, and ultimately, peptide aggregation. The role of R peptides on ROS formation was characterized in the absence and presence of biological reducing agent, ascorbate by using UV-Vis and fluorescence spectroscopy. In the presence of the reducing agent, all Cu(II)-peptide complexes reduced hydroxyl radical (OH·), while only Cu(II)-R3 complex depleted the hydrogen peroxide (H2O2). In the absence of a reducing agent, only Cu(II)-R2 and Cu(II)-R3 complexes, which contain Cys and His residues, produced OH· and H2O2. Only R2 and R3 peptides, but not R1 and R4, reduced Cu(II) to Cu(I). The aggregation propensities of R peptides were modulated by Cu(II) and ascorbate, and were imaged by transmission electron microscopy. All metallo-peptides were characterized predominantly as singly charged mononuclear complexes by mass spectrometry. The data indicate that Cu(II)-peptide complexes may act as pro-oxidants or antioxidants and exhibit unique aggregation propensities under specific environmental conditions, with implications in the biological setting.

Activation of Nrf2 Pathway by Dimethyl Fumarate Attenuates Renal Ischemia-Reperfusion Injury

Dimethyl fumarate (DMF) is a novel antioxidant that selectively reduces hydroxyl radicals. This study aimed to investigate the potential role of DMF in the pathogenesis of renal ischemia-reperfusion injury (IRI) and the mechanisms involved. C57BL/6 wild-type mice were treated with DMF or a vehicle. Subsequently, renal IRI was induced in mice by a model of right kidney nephrectomy and left renal ischemia for 30 minutes followed by reperfusion for 24 hours. Sham operation and phosphate-buffered saline were used as controls. Serum and renal tissues were collected at 24 hours after IRI to evaluate the influence of DMF on the recovery of renal function after IRI. Blood urea nitrogen and serum creatinine levels were measured. Kidney cell apoptosis was evaluated using terminal deoxynucleotidyl transferase dUTP nick end labeling-positive staining. Interleukin 6 and tumor necrosis factor α cytokines in the kidney tissues were measured. Indicators of oxidative stress in the kidneys were detected. Finally, Nrf2-deficient mice were used to determine the protective role of the nuclear factor erythroid 2-related factor 2 (Nrf2)/hemeoxygenase-1 (HO-1) and NAD(P)H dehydrogenase quinone 1 (NQO1) signaling pathways induced by DMF using western blot assay. DMF significantly attenuated renal dysfunction in mice and showed reductions in the severity of renal tubular injury, cell necrosis, and apoptosis. Moreover, DMF significantly reduced the amount of key inflammatory mediators. Additionally, DMF attenuated the malondialdehyde levels 24 hours after IRI but upregulated the superoxide dismutase activities. Western blot assay showed that DMF significantly increased the protein levels of Nrf2, HO-1, and NQO-1. Importantly, these DMF-mediated beneficial effects were not observed in Nrf2-deficient mice. DMF attenuates renal IRI by reducing inflammation and upregulating the antioxidant capacity, which may be through Nrf2/HO-1and NQO1 signaling pathway.

Enhanced Fenton Reaction for Xenobiotic Compounds and Lignin Degradation Fueled by Quinone Redox Cycling by Lytic Polysaccharide Monooxygenases.

The Fenton reaction is considered to be of great significance in the initial attack of lignocellulose in wood-decaying fungi. Quinone redox cycling is the main way to induce the Fenton reaction in fungi. We show that lytic polysaccharide monooxygenases (LPMOs), through LPMO-catalyzed oxidation of hydroquinone, can efficiently cooperate with glucose dehydrogenase (GDH) to achieve quinone redox cycling. The LPMO/GDH system can enhance Fe3+-reducing activity, H2O2 production, and hydroxyl radical generation, resulting in a fueled Fenton reaction. The system-generated hydroxyl radicals exhibited a strong capacity to decolorize different synthetic dyes and degrade lignin. Our results reveal a potentially critical connection between LPMOs and the Fenton reaction, suggesting that LPMOs could be involved in xenobiotic compound and lignin degradation in fungi. This new role of LPMOs may be exploited for application in biorefineries.

Chemical compounds and antioxidant activity in caffeinated and decaffeinated green robusta coffee beans enriched with ginger extract

Some detrimental effects of decaffeination process are attributed to the stability of the chemical composition of green coffee beans, include reducing the antioxidant activity. Ginger (Zingiber officinale) is widely used as an ingredient for herbal beverage due to its well-known antioxidant activity. The aim of this study was to evaluate the effect of decaffeination process on the chemical compounds and antioxidant activity of green robusta coffee beans without or with ginger extract. The result disclosed that the total phenolic contents of decaffeinated- and caffeinated- coffee were significantly higher up to 1.13 and 3.13 mg GAE/mL, respectively, as the increase of ginger extract concentration of 30%. Of the highest concentration of ginger extract, the total flavonoid contents of decaffeinated- and caffeinated- coffee increased up to 2.55 and 13.41 mg QE/mL, respectively, as well as the melanoidin contents, rose until 0.53 nm (decaffeinated coffee) and 1.19 nm (caffeinated coffee). The analysis also found that the highest antioxidant activity determined by 2,2-Diphenyl-1-picrylhydrazyl was observed in the decaffeinated- and caffeinated- coffee (0.20 and 0.46 mmol TEAC/mL, respectively) with the addition of 30% ginger extract. When 30% ginger extract was added into the decaffeinated- and caffeinated- coffee, there was a significant improvement in the antioxidant activity tested by ferric reducing antioxidant power (0.27 and 0.77 mmol TEAC/mL, respectively) and hydroxyl radical scavenging assay (2.10 and 2.66 mmol TEAC/mL, respectively). Regardless of the concentration of ginger extract, this study reveals that decaffeinated coffee has lower antioxidant activity since a lower content of polyphenol, flavonoid, and melanoidin.

In-vitro Anti-lipid Peroxidation and Other Antioxidant Potentials of Gongronema latifolium Leaf Extract

Gongronema latifolium is a herbaceous plant consumed as a traditional folk medicine. The aim of this work is to evaluate the anti-lipid peroxidation activity and other antioxidant effects of the plant leaf extract of Gongronema latifolium using various in vitro models. Lipid peroxidation was first induced in egg yolk and bovine liver homogenate using the ascorbate-ferrous system and incubated with the plant extract at different concentrations. In another experiment, hydrogen peroxide was used to induce erythrocyte hemolysis and lipid peroxidation and those erythrocytes were incubated with the extract. Finally the potential ferrous reducing ability, hydroxyl radical and hydrogen peroxide scavenging activities of the plant extract were also analyzed. It revealed that the leaf extract significantly reduced chemically-induced lipid peroxidation in both homogenates when compared to quercetin. The extract also reduced both hydrogen peroxide-induced hemolysis and lipid peroxidation in erythrocytes. The extract also possessed significant abilities to reduce ferric ions, scavenge both hydroxyl radicals and hydrogen peroxide. In most cases, the responses were concentration-dependent (p &lt; 0.05). The findings are ascribed to the important phytochemicals which are antioxidant in nature hence the plant could be exploited both pharmacologically and neutraceutically.

Reduction of NF-κB Signals in Platelets and Prolongation of Platelet Plug Formation against High Shear Flow in Whole Blood on Human Subject by Columbianadin

Myocardial infarction and cerebral ischemic stroke during the process of arterial thrombosis are prominently causes of death worldwide. Platelets are anucleated cells and play a critical factor in these diseases. Columbianadin (CBN), a coumarin derivative from plants, inhibits effective platelet activation. In this study, platelet function analysis revealed that the closure time of the platelet plug in human whole blood significantly prolonged by CBN, whereas CBN did not pointedly prolong the bleeding time in mice. BAY11-7082 (an inhibitor of IκB kinase) and MG-132 (an inhibitor of proteasome) inhibited collagen-stimulated platelet aggregation and ATP-release in human platelets, BAY11-7082 exhibited a higher potency than MG-132. Moreover, CBN markedly reduced NF-κB activation (e.g., IκBα and p65 phosphorylation) and reversed IκBα degradation in activated platelets. We investigated intercellular signaling events between mitogen-activated protein kinases and NF-κB, and found that BAY11-7082 abolished JNK1/2 and ERK1/2 phosphorylation. Interestingly, SP600125 (an inhibitor of JNK) but not PD98059 (an inhibitor of ERK) had no effect in NF-κB activation in activated platelets. Moreover, CBN but not BAY11-7082 significantly reduced hydroxyl radical (HO●) formation in platelets. Therefore, we propose that CBN inhibits NF-κB activation in human platelets and could present a potent clinical treatment for thromboembolic diseases.