Superoxide Radical Scavenging Research Articles

Synthesis and antioxidant activity of gallic acid based fluorescent benzothiazole analogue: Photophysical, electrochemical, conceptual DFT, QTAIM and docking investigations

The present investigation reports on the synthesis of a novel 3,4,5-trihydroxy-N-(6‑methoxy benzo[d]thiazol-2-yl)benzamide (TMTB) molecule and employs elemental analysis, 1H NMR, 13C NMR, and mass spectrum methods to determine the structure of the desired product. The experimental and theoretical absorption and emission spectra of the molecules are used to study the photophysical properties of the TMTB molecule. We investigate the in vitro antioxidant activity of TMTB using DPPH and superoxide radical scavenging assays, as well as molecular docking experiments with the target NAD(P)H oxidase (PDB ID: 2CDU) protein. To ascertain the energies of the LUMO and HOMO levels, NLO behaviour, intermolecular charge transport facilitated by global chemical reactivity descriptors, molecular electrostatic potentials (MEP), and hyperpolarizability analyses, an investigation was carried out on their conceptual DFT and QTAIM analyses operating under B3LYP/6–31 G. The simulated DFT calculation shows that TMTB is highly polarizable in both the gas and solvent phases, with HOMO-LUMO energy gaps of 4.18 and 4.24 eV, respectively. Total first and second hyperpolarizability values for TMTB in the gas phase were determined to be 155.09 × 10–30 and 3611.59 × 10–36 esu, respectively, whereas in the DMSO phase the values were 556.15 × 10–30 and 6223.79 × 10–36 esu. Computational studies results corroborate the experimental findings. Based on the photophysical and computational findings, the newly reported TMTB molecule was determined to be a promising candidate for additional optimization and use in optoelectronic devices.

Optimization of the dosage of ZnO photocatalyst for the degradation of sunlight driven multi dose organic dye brilliant green

In this study, we prepared ZnO nanocrystals using a chemical precipitation approach with different precursor concentrations for optimization. The structural, optical, and morphological properties of the synthesized nanocrystals were analyzed. Sunlight-driven photocatalysis was investigated for its ability to degrade a low concentration (70 ppm) of brilliant green (BG) dye using the optimized ZnO at different dosages (0.05, 0.1, and 0.15 g). Among the different dosages of ZnO, it was noted that at a low catalyst concentration of 0.05 g, the degradation efficiency was only 58.47 % even after 120 min of light exposure. When the concentration increased to 0.1 g, the rate of degradation reached 95.33 % within 90 min. At a higher dosage of 0.15 g, only 86.26 % degradation was recorded within 90 min, indicating that the optimal catalyst dosage was 0.1 g. To investigate how the dye dosage affected the degradation efficiency of the catalyst, experiments were performed using higher dye concentrations of 100 and 120 ppm with 0.1 g of catalyst. As the dye concentration was increased, the degradation rate decreased. Tests were conducted using different scavengers, including EDTA (a hole scavenger), benzoquinone (a superoxide radical scavenger), and isopropyl alcohol (a hydroxyl radical scavenger), to determine which free radical was mainly breaking down BG. In the presence of EDTA, the degradation ability of the catalyst decreased to 35 %. When the superoxide radical scavenger benzoquinone was used, the degradation efficiency decreased to approximately 22 %. On the other hand, the hydroxyl radical scavenger IPA reduced the degradation efficiency to 13 %. Based on the above discussion, the synergistic effect of holes and superoxide radicals is mainly responsible for the degradation of brilliant green. To test the practical use of the ZnO catalyst, we conducted an experiment to assess its reusability. Even after the third cycle, the ZnO exhibits 94 % degradation, confirming its reusability.

Exploring Jiangshui-originated probiotic lactic acid bacteria as starter cultures: Functional properties and fermentation performances in pear juice

This study investigated the probiotic properties, functional activities and fermentation performances of Pediococcus pentosaceus JS91 (JS91) and Pediococcus pentosaceus JS96 (JS96). The results of probiotic properties showed that JS91 and JS96 possessed gastrointestinal tolerance, aggregation and antimicrobial activities. Functional activity results found that the cell-free supernatants of JS91 and JS96 showed good antioxidant activity. Meanwhile, the two strains exhibited cholesterol degrading ability. The fermentation performance results showed that JS91 and JS96 could produce acid, grow steadily in pear juice, decrease the pH value and increase the titratable acidity of fermented pear juice. Moreover, JS91 and JS96 could enhance the superoxide anion radical scavenging activity and total antioxidant capacity of the fermented pear juice. Sensory evaluation results showed that JS91 and JS96 could improve the overall acceptability of fermented pear juice. The present findings could provide valuable information for the application of JS91 and JS96 as functional starter cultures in fermented foods.

Antioxidant activity of Zuccagnia-type propolis: A combined approach based on LC-HRMS analysis of bioanalytical-guided fractions and computational investigation

This study reports a combined approach to assess the antioxidant activity of Zuccagnia-type propolis. Fractions exhibiting the highest antioxidant activities evidenced by DPPH, a β-carotene bleaching and superoxide radical scavenging activity-non-enzymatic assays, were processed by LC-HRMS/MS to characterize the relevant chemical compounds. A computational protocol based on the DFT calculations was used to rationalize the main outcomes. Among the 28 identified flavonoids, caffeic acids derivatives were in the fraction exhibiting the highest antioxidant activity, with 1-methyl-3-(4′-hydroxyphenyl)-propyl caffeic acid ester and 1-methyl-3-(3′,4′-dihydroxyphenyl)-propyl caffeic acid ester as major components. Results clearly showed roles of specific chemical motifs, which can be supported by the computational analysis.This is the first report ascribing the antioxidant ability of Zuccagnia-type propolis to its content in specific caffeic acid derivatives, a potential source of radical scavenging phytochemicals. The proposed protocol can be extended to the study of other plant-products to address the most interesting bioactive compounds.

Exploring the Potential of Invasive Species Sargassum muticum: Microwave-Assisted Extraction Optimization and Bioactivity Profiling.

Sargassum muticum (SM) poses a serious environmental issue since it is a fast-expanding invasive species occupying key areas of the European shoreline, disrupting the autochthonous algae species, and disturbing the ecosystem. This problem has concerned the general population and the scientific community. Nevertheless, as macroalgae are recognized as a source of bioactive molecules, the abundance of SM presents an opportunity as a raw material. In this work, response surface methodology (RSM) was applied as a tool for the optimization of the extraction of bioactive compounds from SM by microwave-assisted extraction (MAE). Five different parameters were used as target functions: yield, total phenolic content (TPC); and the antioxidant measurements of 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), and β-carotene bleaching (BC). After the optimal extraction conditions were determined (time = 14.00 min; pressure = 11.03 bar; ethanol = 33.31%), the chemical composition and bioactivity of the optimum extract was evaluated to appraise its antioxidant capability to scavenge reactive species and as a potential antibacterial, antidiabetic, antiproliferation, and neuroprotective agent. The results lead to the conclusion that MAE crude extract has bioactive properties, being especially active as an antiproliferation agent and as a nitric oxide and superoxide radical scavenger.

"Naringenin: A Promising Immunomodulator for Anti-Inflammatory, Neuroprotective, and Anti-Cancer Applications".

Inflammatory, immune, and neurodegenerative diseases constitute a category of persistent and debilitating conditions affecting millions worldwide, with inter-twined pathophysiological pathways. Recent research has spotlighted naturally occurring compounds like naringenin for potential therapeutic applications across multiple ailments. This review offers an encompassing exploration of naringenin's anti-inflamma-tory, immune-protective, and neuroprotective mechanisms, elucidating its pharmacological targets, signal transduction pathways, safety profile, and insights from clinical investigations. Data for this review were amassed through the scrutiny of various published studies via search engines such as PubMed and Google Scholar. Content from reputable publishers including Bentham Science, Taylor and Francis, Nature, PLOS ONE, among others, was referenced. Naringenin exhibits substantial anti-inflammatory effects by restraining the NF-κB signaling pathway. It activates Nrf2, renowned for its anti-inflammatory properties, inducing the release of hemeoxynase-1 by macrophages. Furthermore, naringenin treatment downregulates the expression of Th1 cytokines and inflammatory mediators. It also impedes xanthine oxidase, counteracts reactive oxygen species (ROS), scavenges superoxide radicals, mitigates the accessibility of oxygen-induced K+ erythrocytes, and reduces lipid peroxidation. Naringenin's antioxidant prowess holds promise for addressing neurological conditions. Extensive research has been undertaken to establish the anti-inflammatory, immunomodulatory, and neuroprotective attributes of naringenin across various medical domains, lending credence to its pharmacological utility. The principal obstacle to naringenin's adoption as a therapeutic agent remains the dearth of in vivo data. Efforts should focus on rendering naringenin delivery patient-friendly, economically viable, and technologically advanced.

In vitro antioxidant activity, QSAR, in silico toxicity prediction, molecular docking studies, and molecular dynamics of a series of N-ferrocenylmethylanilines as potent antioxidant agents

The superoxide anion radical scavenging activities of a series of twenty-eight ferrocenylmethylaniline derivatives were measured in an in vitro study followed by in silico studies which included quantitative structure-activity relationship (QSAR), toxicity prediction, molecular docking studies, and molecular dynamics simulations. Multilinear regression analysis was employed to establish a quantitative correlation between the scavenging activity of superoxide anion radicals and various structural properties. The QSAR model obtained underwent validation, demonstrating statistical significance with a squared fitting correlation coefficient (R2) of 0.934, an adjusted squared correlation coefficient (R2 adj) value of 0.849, and a cross-validation coefficient (Q2) value of 0.873. Additionally, the calculated Fisher ratio (F) value of 36.525 indicates the model's strong predictability. Toxicity perdition studies demonstrated that among the five most potent compounds, FMA27 and FMA12 were predicted to be non-toxic. The molecular Docking study revealed that compound FMA23 exhibited the least activity against the glutathione reductase enzyme, with the highest inhibitory concentration recorded at 4.16 × 10–6 M and the lowest docking scores observed at −7.34 kcal.mol-1. Interactions between the compound and the amino acid residues of glutathione reductase were primarily hydrophobic and π-cation in nature. Analysis of root mean square deviation (RMSD), radius of gyration (Rg), and root mean square fluctuation (RMSF), from molecular dynamics study, revealed stable fluctuations in protein backbone conformations, consistent compactness of the complex, and minimal fluctuations in most protein residues, respectively.

Investigation on the Potential of Some N-phenylalkanehydrazides as Superoxide Anion Radical Scavengers and Glutathione Peroxidase Binders with ADME Prediction: Comparison with Vitamin C

Objective: An investigation on the antioxidant activity and ADME properties of some N-phenylalkanehydrazides (NPhs) in comparison with ascorbic acid was carried out. Materials and Methods: The power of the compounds to scavenge the superoxide anion radical was examined using cyclic voltammetry. Furthermore, molecular docking was used to examine how NPhs bind to the antioxidant enzyme glutathione peroxidase (GPx). Finally, ADME properties were predicted using the SwissADME webserver. Results: The results showed that the studied compounds had significantly higher EC50 values than Vitamin C and displayed spontaneous binding with GPx with binding energy similar to ascorbic acid. Also, substantial values emerged from the predictive analysis of drug-likeness and bioavailability characteristics. Discussion: First, the EC50 of the compounds under study was determined by assessing the decrease in the anodic current peak intensity; this demonstrated significant radical scavenging activity. Next, the electrostatic way of binding with ROS radical and with antioxidant enzyme was disclosed by the binding free energies; however, the oxygen and nitrogen atoms in the compounds' structures might make many conventional hydrogen bonds with amino acids. Finally, NPh (a) followed all the rules for drug-likeness and bioavailability estimates, making it a promising moiety for synthesising new antioxidant chemicals. Conclusion: The current study is a hybrid of experimental and computational methods that complement each other perfectly.

Metabolomic insights and bioactive efficacies of Tragopogon dubius root fractions: Antioxidant and antiproliferative assessments

Tragopogon dubius is commonly consumed as a vegetable and used in traditional medicine for treating inflammatory skin conditions and cutaneous swelling. Despite known pharmacological properties of its leaves and roots, many of its biological characteristics and active phytochemicals remain unexplored. The present study investigates the phytochemical composition, antioxidant, and anticancer properties of methanolic root extracts and isolated fractions (TdRM-1 and TdRM-2) of T. dubius. Utilizing preparative thin-layer chromatography, the crude extract was successfully separated into TdRM-1 and TdRM-2, characterized by GC-MS and FTIR analysis, revealing a diverse range of bioactive compounds including terpenes, flavonoids, and phenolic acids. Qualitative phytochemical screening indicated the presence of carbohydrates, tannins, alkaloids, and other phytoconstituents. Advanced UPLC-ESI-QTOF-MS analysis identified 54 metabolites, significantly contributing to the chemical profiling of the extract. The antioxidant activities of the fractions were quantitatively assessed using ABTS, DPPH, and superoxide radical scavenging assays, where TdRM-2 exhibited superior activity with IC50 values ranging from 51.29 to 60.03 μg/mL. Anticancer potential was evaluated against A549, LN-18, and MCF-7 cancer cell lines, demonstrating that TdRM-2 significantly inhibited cell proliferation with GI50 values as low as 31.62 μg/mL for A549 cells. Additionally, fluorescence microscopy revealed that TdRM-2 induces apoptosis, indicated by changes in nuclear morphology and loss of mitochondrial membrane potential. Annexin V-FITC/PI double staining indicate that the TdRM-2 fractions from T. dubius can significantly inhibit the growth of A-549, LN-18, and MCF-7 cancer cell lines by inducing apoptosis These findings suggest that T. dubius root extracts, particularly the TdRM-2 fraction, hold promising therapeutic potential due to their significant antioxidant and anticancer activities, underpinned by their rich phytochemical composition. This study underscores the importance of T. dubius as a source of natural bioactive compounds with potential health benefits.

Novel antioxidant peptides from soybean protein by employing computational and experimental methods and their mechanisms of oxidative stress resistance

Antioxidant peptides have the potential to play a crucial role in mitigating and managing a variety range of diseases associated with oxidative stress. Soybean protein is an important source of antioxidant peptides. Here we employ computational and experimental methods to screen and identify five antioxidant peptides (Gly-Ala, Gly-Val-Pro-Tyr, Pro-His, Pro-Lys, and Ser-Gly-Pro) derived from soybean protein, and explore their potential targets and mechanisms of action. All five peptides demonstrated potent antioxidant activity, effectively scavenging superoxide radicals and protecting cells from H₂O₂-induced oxidative damage. These peptides exhibited multi-target effects on pathways implicated in oxidative stress, cardiovascular disease, and cancer. Notably, our results reveal that these peptides can stably interact with the key target nitric oxide synthase (NOS2) through Glu377, a critical residue of NOS2, thereby inhibiting its activity and potentially mitigating oxidative stress and inflammation. This study confirms the function of soybean peptide sequence that has not been previously disclosed, and provides a more specific theoretical basis for the development of natural antioxidant peptides.

LC-ESI-UHR-QqTOF-MS/MS profiling and anti-inflammatory potential of the cultivated Opuntia ficus-indica (L.) Mill. and the wild Opuntia stricta (Haw.) Haw. fruits from the Algerian region

Opuntia plants are abundant but still underexplored edible resources of the Algerian region. This work chemically characterizes extracts of different parts of the fruit of the commercial Opuntia ficus-indica (L.) Mill. and the wild Opuntia stricta (Haw.) Haw. growing in Bejaia, and evaluates their anti-inflammatory potential through different cell and cell-free bioassays. The LC-ESI-UHR-QqTOF-MS/MS analysis enabled the identification of 18 compounds, with azelaic acid and 1-O-vanilloyl-β-d-glucose reported here for the first time. Aqueous extracts of seeds were the most effective in scavenging superoxide anion radical (IC50 = 111.08 μg/mL) and presented the best anti-inflammatory potential in LPS-stimulated macrophages (IC50 = 206.30 μg/mL). The pulp of O. stricta suggested potential for addressing post-inflammatory hyperpigmentation, with piscidic and eucomic acids predicted with the strongest binding affinity towards tyrosinase, exhibiting higher scoring values than the reference inhibitor kojic acid. This pioneer study brings valuable perspectives for the pharmacological, nutritional and economic valorization of the wild O. stricta for functional foods.

In vitro and In vivo Antioxidant Effect of Mango, Coconut and Cotton Seed Oils on Hydrogen Peroxide- Induced Oxidative Stress in Wistar Rats

This study is aimed at determining the antioxidant activity of Mango kernel oil (MKO), Coconut oil (CCO) and Cotton seed oil (CSO) in vitro and in vivo. Antioxidant parameters demonstrated by five spectrophotometric methods such as: DPPH, FRAP, MCA, HRSA and SRSA was determined in the oils. Superoxide dismutase activity (SOD), catalase activity (CAT) and malondialdehyde (MDA) were evaluated in the serum of the Wistar rats. The antioxidant assay of the oils showed Coconut oil (75.67±0.21 %) was able to neutralize the DPPH radical more than the other oils followed by Cotton seed oil (38.70±0.23 %) and Mango kernel oil (31.56±0.24 %). Coconut oil exhibited the highest FRAP activity at (1.04 mMolFe2+) while the Cotton seed oil displayed significantly lower (P< 0.05) FRAP activity at (0.18±0.00 mMolFe2+). The Metal chelating activity (MCA) of Coconut oil (52.72±0.24 %) was found to be significantly higher than Mango and Cotton seed oils, Superoxide radical scavenging activity showed Coconut oil (62.36±0.01 %) having a relatively high ability to scavenge superoxide radicals better than the other oils with the standard glutathione being significantly higher (81.36±0.07 %). The result of the in vivo study showed the mean values for the SOD of MKO (118.10±5.39 IU/L), CCO (120.53±4.53 IU/L) and CSO (108.80±3.33 IU/L), CAT of MKO (108.93±11.60 IU/L), CCO (96.85±11.69 IU/L) and CSO (88.28±10.66 IU/L) and MDA of MKO (0.25±0.07 mmol/L), CCO (0.24±0.14 mmol/L) and CSO (0.31±0.02 mmol/L). The oils markedly reduced the amount of MDA while significantly increasing the activities of both CAT and SOD content.

Pigments profile and antioxidant potential of extremophile cyanobacteria isolated from the Mexican Volcanic Lake Chichonal

Cyanobacteria are ancient and prolific microorganisms for which the current knowledge remains limited. The present work constitutes the first report on the presence of the cyanobacteria Tolypothrix sp. LEGE 221228, Nostoc sp. LEGE 221229, Scytonema sp. LEGE 221230 and Drouetiella sp. LEGE 221231 in the volcanic crater lake in Chichonal (Chiapas-Mexico), and in the characterization of their pigments profile and antioxidant potential, through the application of biorefinery approaches. The identification of cyanobacteria species was achieved through advanced morphology-based methods for cyanobacterial taxonomy. The HPLC-PDA analysis of the cyanobacteria acetone extracts revealed β-carotene, echinenone and chlorophyll-a as the main pigments. Drouetiella sp. LEGE 221231 presented the highest β-carotene concentration (63.67 μg/mL), total carotenoids (87.92 μg/mL) and chlorophylls (20.88 μg/mL), closely followed by Tolypothrix sp. LEGE 221228 (with 51.37, 75.14 and 14.88 μg/mL, respectively), this being the first report on the carotenoid and chlorophylls profile of these strains. Aqueous extracts revealed the highest content of phycoerythrin in Tolypothrix sp. LEGE 221228 (50.61 mg/g) and of phycocyanin in Nostoc sp. LEGE 221229 (57.66 mg/g), standing out in superoxide anion radical scavenging, while the acetonic ones were more effective in scavenging nitric oxide radical. For both, Tolypothrix sp. LEGE 221228 was the most effective, presenting the lowest IC50 (53.75 and 57.68 μg/mL, respectively). Overall, the present study enriches the knowledge on biodiversity of cyanobacteria from underexplored environments, enhancing their potential biotechnological applications as producers of added value secondary metabolites with interest in food, pharmaceutical and cosmetic industries.

Isolation and characterization of feruloylated oligosaccharides from Phyllostachys acuta and in vitro antioxidant activity

Feruloylated oligosaccharides (FOs) generated by decomposing plant hemicellulose, offer a wide range of potential applications in both the food and biomedical areas. As a graminaceous plant, bamboo is rich in hemicellulose. However, the structural composition and activity studies of FOs from it were rarely reported. In this study, FOs from Phyllostachys acuta (pFOs) obtained by enzymatic hydrolysis were isolated by AmberliteXAD-2 and C18 SPE columns. Then, pFOs were qualitatively and quantitatively analyzed by UPLC-ESI-MS/MS after labeled by 3-Amino-9-ethyl-carbazole (AEC), and the chemical antioxidant activity of pFOs and effects of pFOs on H2O2-induced oxidative damage were investigated. Finally, 14 of pFOs isomers were distinguished and identified, of which 10 did not contain hexoses and 4 did, and the three most abundant pFO structures were 12 (Iso 7, F1A1X2H2-AEC, 29.04 %), 11 (Iso 6, F1A1X1H2-AEC, 17.96 %), and 4 (Iso 3-1, F1A1X3-AEC, 15.57 %). The results of antioxidant studies showed that pFOs possessed certain reducing power, scavenging DPPH radicals, scavenging superoxide anion radicals, and scavenging hydroxyl radicals. Among them, the ability to clear DPPH radicals was particularly significant. pFOs significantly reduced the viability of RAW264.7 cells after H2O2 induction, whereas pFOs had a significant protective effect (p < 0.001). pFOs increased the viability of T-AOC and SOD enzymes in oxidatively damaged cells, as well as had a significant inhibition effect on ROS elevation (p < 0.001). This study lays the foundation for the structural analysis and antioxidant activity evaluation of bamboo-derived feruloyl oligosaccharides for their application in food and pharmaceutical fields.

Phytochemical Analysis, Antioxidant and Anti Hyperlipidemic Activity of Nyctanthes arbor-tristis in Male Wistar Rats

The current study's objective was to assess the antihyperlipidemic, in vitro antioxidant, and qualitative and quantitative phytochemical analysis of Nyctanthes arbor-tristis flowers hydroalcoholic extract at 200 and 400 mg/kg in rats that were made hyperlipidemic by a high-fat diet. The Folins Ciocalteau reagent and the aluminium chloride method were used for the quantitative measurement of flavonoids and phenolics, respectively. Through phytochemical investigation, alkaloids, carbohydrates, glycosides, tannins, phenolic compounds, triterpenoids, and steroids were found in the hydroalcoholic extracts of N. arbor-tristis flowers. The hydroalcoholic extract flowers had a total phenolic content of 126.000 mg/gm, which was followed by flavonoids at 103.104 mg/gm. Hydroalcoholic extracts of flowers showed concentration-dependent antioxidant activity in vitro against DPPH and superoxide radical scavenging test technique. In this investigation, rats were given a high-fat diet as part of an experimental induction procedure. By lowering LDL and VLDL cholesterol levels and raising HDL levels, the HANAT therapy and the medication atorvastatin dramatically reduce body weight. grew When hydroalcoholic flower extracts were given orally to animals that had been forced to become hyperlipidaemic due to a high cholesterol diet, the levels of HDL cholesterol, triglycerides, low density lipoproteins, and very low-density lipoproteins were all much lower. The p value (p&lt;0.001) indicated that the results were significant. The triton-induced study results indicate that animals treated with HANAT at dose levels of 200 mg/kg and 400 mg/kg had considerably lower blood lipid parameters (p&lt;0.01) than the control group; however, the 400 mg/kg of HANAT group animals showed significantly higher serum lipid parameters (p&lt;0.001) than the control group. Additionally, a higher HDL level was noted at this time. Keywords: Nyctanthes arbor-tristis, Physicochemical analysis, Antioxidant activity, DPPH. Antihyperlipidemic activity

Porphyrin photosensitizers compatible with both aqueous and non-aqueous conditions: Acid dependent spectral, solubility and photocatalytic properties of meso-tetra(pyridyl)porphyrins

The aerobic photooxidation of 1,3-diphenylisobenzofuran (DPBF) as a specific singlet oxygen quencher was studied in the presence of meso-tetra(aryl)porphyrins (aryl = 2-pyridyl, 3-pyridyl and 4-pyridyl) and their diprotonated and hexaprotonated derivatives to investigate the influence of the position of pyridine nitrogen atom, solvent, core protonation (with HCl or dichloroacetic acid) and full protonation of the porphyrins on their photocatalytic activity and photooxidative stability. The pseudo-first order rate constants (kobs) for the oxidation of DPBF with singlet oxygen were determined to compare the relative activity of the photosensitizers. 1,4-benzoquinone as a scavenger of superoxide anion radical provided evidence for the absence of this species in these photocatalytic systems. The singlet oxygen quantum yields (φΔ) of the porphyrin photosensitizers were estimated by determining the initial rate constants for the oxidation of DPBF. H4T(2-Py)P(Cl)2 and H4T(2-Py)P(CHCl2COO)2 were the most efficient photosensitizers of the series of the meso-tetra(2-, 3- or 4-pyridyl)porphyrins and the protonated derivatives.

Angiotensin-I-converting enzyme and renin inhibitions by antioxidant shrimp shell protein hydrolysate and ultrafiltration peptide fractions

Protein hydrolysates with 20% and 30% degrees of hydrolysis (DH) were produced from alcalase hydrolysis of Pacific white shrimp shells. The study aimed to investigate the antioxidant and antihypertensive activities of these protein hydrolysates, focusing on peptide fractions of various molecular weights (MW) obtained through ultrafiltration. The 30% DH protein hydrolysate (SSPH) showed the highest antioxidant activities and was subjected to ultrafiltration to produce peptides of various molecular weights (MW) (F1:10–50, F2:5–10, F3:3–5, F4:1-3, and F5:<1 kDa). SSPH showed higher hydrophilic and non-essential amino acid content, among which alanine and aspartic acid were at higher levels. The obtained peptide fractions were analyzed for various antioxidant activities and inhibitory activities against angiotensin-converting enzyme and renin. F4 and F2 samples showed the highest DPPH (2.00 mM TE/g sample) and ABTS (60.68 mM TE/g sample) radical scavenging activities, respectively. Superoxide and hydrogen peroxide radical scavenging activity augmented with decreasing MW, aside from for F1, which showed higher activity than F2–F4 (p < 0.05). The highest ACE-inhibitory activity was found for the F2 fraction (44%–55%), and renin inhibitory activity increased with decreasing MW, in which F5 (12%–22%) was the most effective (p < 0.05). F5 showed 6 major peptides, among which KLVRGSKS and LPKKCLSARPG were the dominant sequences. Thus, this study suggests that shrimp shell protein isolate could be an alternative protein source for peptides with various antioxidant and antihypertensive activities, with potential applications in functional foods and nutraceuticals aimed at mitigating oxidative stress and hypertension.

Synergistic Performance of ZnO/SnO2 Nanocomposites: Synthesis, Characterization, and Applications in Photocatalysis and Superoxide Radical Scavenger

Synergistic Performance of ZnO/SnO2 Nanocomposites: Synthesis, Characterization, and Applications in Photocatalysis and Superoxide Radical Scavenger

Superoxide dismutase-contained solid lipid nanoparticles: Formulation development and In-vivo evaluation for second-degree burn wound healing in rats

IntroductionSuperoxide dismutase (SOD), a natural enzyme with high antioxidant activity, reduces injury and accelerates wound healing by scavenging superoxide radicals. This enzyme plays an important role in cellular defense against oxidative stress such as burn injury. The aim of this study was to load SOD into solid lipid nanoparticles for the treatment of rat burn wounds. MethodsSolid lipid nanoparticles were prepared by Solvent Emulsification Diffusion method and evaluated for particle size, enzyme activity and enzyme entrapment efficiency. Twenty-seven rats in 3 different groups were induced with deep second-degree burns and then treated with SOD-loaded solid lipid nanoparticles, solid lipid nanoparticles without enzyme, or SOD solution. After the treatment period, the wounds were evaluated macroscopically for the area of healing and microscopically for indices of re-epithelialization, granulation tissue and angiogenesis. ResultsThe optimized SOD-loaded solid lipid nanoparticles showed a particle size of 35–85 ± 2.41 nm, 78.4 ± 4.31 % entrapment efficiency and 90 % initial enzyme activity. Macroscopic examination showed that the best recovery rate belonged to the solid lipid nanoparticle group. Pathological studies also showed that angiogenesis and granulation tissue were significantly better in this group. Compared to the other two groups, SOD-loaded solid lipid nanoparticles showed a significant improvement in pathological factors, particularly angiogenesis and granulation tissue, as well as a faster reduction in the number of inflammatory cells. ConclusionBased on this study, solid lipid nanoparticles could be used as an effective delivery system for SOD in the treatment of second-degree burns.

Analysis of Quantitative Phytochemical Content and Antioxidant Activity of Leaf, Stem, and Bark of Gymnosporia senegalensis (Lam.) Loes.

To the best of our knowledge, there was no prior report providing valuable preliminary data through a demonstration of the quantitative phytochemical and antioxidant activity of Gymnosporia senegalensis. The total contents of phenols, flavonoid, flavanol, tannin, and saponin were evaluated from different fractions extracted from the leaf, stem, and bark of G. senegalensis by using standards such as gallic acid, quercetin, rutin, tannic acid, and saponin quillaja. The antioxidant potential was measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydrogen peroxide scavenging (H2O2), superoxide anion radical scavenging, metal chelating ferrous ion, ferric reducing antioxidant power (FRAP), and total antioxidant capacity (TAC). Data were subjected to half-inhibitory concentration (IC50) and one-way analysis of variance (ANOVA) at p < 0.05 as a significant value. The total phenol content was found to be highest in the chloroform extract of stem at 97.7 ± 0.02 mg GAE/g. The total flavonoid and flavonol contents in the aqueous extract were 97.1 ± 0.03 mg QE/g and 96.7 ± 0.07 mg RE/g, respectively. The total tannin content in the ethyl acetate extract of leaf was 97.5 ± 0.01 mg TAE/g, and the total saponin content in the methanol extract of stem was 79.1 ± 0.06 mg SQE/g. The antioxidant analysis indicated that IC50 and percentage (%) inhibition were dose-dependent and showed the highest antioxidant activity (40.9 ± 0.9 µg/mL) in methanol extract of leaf for DPPH, (88.8 ± 1.12 µg/mL) in the chloroform extract of stem for H2O2, (43.9 ± 0.15 µg/mL) in the aqueous extract of bark for superoxide anion radical scavenging activity, (26.9 ± 0.11 µg/mL) in the chloroform extract of leaf for the metal chelating ferrous ion activity, (7.55 ± 0.10 mg/mL) in the benzene extract of leaf for FRAP, and (2.97 ± 0.01 mg/mL) in the methanol extract of bark for TAC. These results show that G. senegalensis has great potential in antioxidant activities. The isolation and characterization of specific bioactive compounds and the in vivo applicability of such activity await further extensive studies for drug discovery and development.