Reevaluating the role of 1,10-phenanthroline in oxidative reactions involving ferrous ions and DNA damage

Immunomodulatory activities of polysaccharides isolated from Amauroderma rugosum (Blume and T. Nees) Torrend and their structural characterization

Amauroderma rugosum (Blume and T. Nees) Torrend is a traditionally well-known mushroom that is used for the treatment of cancer. In order to evaluate the pharmacological activities of A. rugosum polysaccharides, the mushroom powder was subjected to hot water extraction and pure polysaccharides (ARPs) were isolated by gel-filtration method. Three important APRs called ARP-1, ARP-2 and ARP-5 were identified with average molecular weights of 1494, 450, and 7 kDa respectively. Their antioxidant abilities were estimated by examining free radical scavenging potential against 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid radical (ABTS●+), 2,2-diphenyl-1-picrylhydrazyl radical (DPPH●), and hydroxyl radical. Immunomodulatory potentials of these ARPs were determined using murine macrophage cells. These polysaccharides exhibited high antioxidant abilities and stimulated mouse macrophages leading to the generation of tumour necrosis factor-α (TNF-α) and interleukin-6 (IL-6). Excellent activities were displayed by ARP-1 and APR-2. Gas chromatography and spectroscopic (FT-IR and NMR) methods were employed in order to carry out their structural characterisation. The two high molecular weight ARPs (ARP-1 and ARP-2) displayed β-(1 → 3)-D-glucan backbone structure with branching of β-(1 → 6)-d-glucopyranosyl. These observations suggest high potential of ARPs for immunotherapeutic applications.

Structural characterization of peroxyl radical oxidative products of antioxidant peptides from hydrolyzed proteins

This work aimed to characterize oxidative products of five unique antioxidant peptides (P1: YFDEQNEQFR, P2: GQLLIVPQ, P3: SPFWNINAH, P4: NINAHSVVY, P5: RALPIDVL) from hydrolyzed oat proteins. Peptides were reacted with 2,2'-Azobis(2-amidinopropane) dihydrochloride, a common peroxyl radical generator. Chromatographic data showed that peptide P3 was the most oxidized (67 ± 4 %) while also displaying the most ability to scavenge radicals in the oxygen absorbance capacity assay (ORAC) with an activity of 2.16 ± 0.09 μM Trolox equivalents/μM peptide. Structural characterization using mass spectrometry showed the presence of four oxidative products of P3, three of which were mono-oxygenated and the fourth di-oxygenated. The identification of these oxidative products is new and provides an opportunity to investigate their biological function. A good correlation (r = 0.889) between the degree of oxidation and the ORAC data, demonstrates the usefulness of using oxidative peptide data to predict their radical scavenging activities.

Design of flavonol-loaded cationic gold nanoparticles with enhanced antioxidant and antibacterial activities and their interaction with proteins

In this work, four structurally similar flavonols (galangin, kaempferol, quercetin and myricetin) were coated on the surface of (11-mercaptoundecyl)-N,N,N-trimethylammonium bromide (MUTAB)‑gold nanoparticles (AuNPs) by two-step phase transfer and self-assembly, and the cationic MUTAB- AuNPs coated with flavonols (flavonol-MUTAB-AuNPs) were designed. Free radical scavenging and antibacterial experiments show that flavonol-MUTAB-AuNPs greatly improve the scavenging effect on DPPH, hydroxyl and superoxide anion radicals, and significantly enhance the inhibition effect on Staphylococcus aureus and Escherichia coli compared with flavonols and AuNPs. Then γ-globulin, fibrinogen, trypsin and pepsin were selected as representative proteins and their interaction with flavonol-MUTAB-AuNPs were investigated by various spectroscopic techniques. The fluorescence quenching mechanism of these four proteins by flavonol-MUTAB-AuNPs is static quenching. The binding constants Ka between them are in the range of 103 to 106. The interaction between them is endothermic, entropy-driven spontaneous process, and the main non-covalent force is the hydrophobic interaction. The effect of flavonol-MUTAB-AuNPs on the structure of the four proteins were investigated using UV-vis absorption spectra, synchronous fluorescence spectra and circular dichroism spectra. These results offer important insights into the essence of the interaction between flavonol-MUTAB-AuNPs and γ-globulin/fibrinogen/trypsin/pepsin. They will contribute to the development of safe and effective flavonol-MUTAB-AuNPs in biomedical fields.

The Amoebicidal Activity of Diferrocenyl Derivatives: A Significant Dependence on the Electronic Environment

Amoebiasis is the second leading cause of death worldwide associated with parasitic disease and is becoming a critical health problem in low-income countries, urging new treatment alternatives. One of the most promising strategies is enhancing the redox imbalance within these susceptible parasites related to their limited antioxidant defense system. Metal-based drugs represent a perfect option due to their extraordinary capacity to stabilize different oxidation states and adopt diverse geometries, allowing their interaction with several molecular targets. This work describes the amoebicidal activity of five 2-(Z-2,3-diferrocenylvinyl)-4X-4,5-dihydrooxazole derivatives (X = H (3a), Me (3b), iPr (3c), Ph (3d), and benzyl (3e)) on Entamoeba histolytica trophozoites and the physicochemical, experimental, and theoretical properties that can be used to describe the antiproliferative activity. The growth inhibition capacity of these organometallic compounds is strongly related to a fine balance between the compounds' redox potential and hydrophilic character. The antiproliferative activity of diferrocenyl derivatives studied herein could be described either with the redox potential, the energy of electronic transitions, logP, or the calculated HOMO-LUMO values. Compound 3d presents the highest antiproliferative activity of the series with an IC50 of 23 µM. However, the results of this work provide a pipeline to improve the amoebicidal activity of these compounds through the directed modification of their electronic environment.

Examining Sporadic Cancer Mutations Uncovers a Set of Genes Involved in Mitochondrial Maintenance

Mitochondria are key organelles for cellular health and metabolism and the activation of programmed cell death processes. Although pathways for regulating and re-establishing mitochondrial homeostasis have been identified over the past twenty years, the consequences of disrupting genes that regulate other cellular processes, such as division and proliferation, on affecting mitochondrial function remain unclear. In this study, we leveraged insights about increased sensitivity to mitochondrial damage in certain cancers, or genes that are frequently mutated in multiple cancer types, to compile a list of candidates for study. RNAi was used to disrupt orthologous genes in the model organism Caenorhabditis elegans, and a series of assays were used to evaluate these genes' importance for mitochondrial health. Iterative screening of ~1000 genes yielded a set of 139 genes predicted to play roles in mitochondrial maintenance or function. Bioinformatic analyses indicated that these genes are statistically interrelated. Functional validation of a sample of genes from this set indicated that disruption of each gene caused at least one phenotype consistent with mitochondrial dysfunction, including increased fragmentation of the mitochondrial network, abnormal steady-state levels of NADH or ROS, or altered oxygen consumption. Interestingly, RNAi-mediated knockdown of these genes often also exacerbated α-synuclein aggregation in a C. elegans model of Parkinson's disease. Additionally, human orthologs of the gene set showed enrichment for roles in human disorders. This gene set provides a foundation for identifying new mechanisms that support mitochondrial and cellular homeostasis.

Anti-inflammatory effects and molecular mechanisms of bioactive small molecule garlic polysaccharide

Although garlic polysaccharides have been found to possess anti-inflammatory activities, anti-inflammatory study on small molecule water-soluble garlic polysaccharide (WSGP) is few. In this study, a novel WSGP with a molecular weight of 1853 Da was isolated by DEAE-52 and Sephadex G-100 column and the chemical composition was identified by monosaccharide composition and methylation analysis. Furthermore, the antioxidant effects of WSGP and the potential molecular mechanisms on LPS-induced inflammatory responses in RAW264.7 macrophage cells were investigated. The results showed that WSGP has strong antioxidant activity, such as DPPH, hydroxyl, superoxide anion, ABTS radical scavenging capacity, Fe²⁺ chelating ability and reducing power. Meanwhile, WSGP could considerably suppress the manufacturing of NO and the mRNA and protein expression degrees of IL-6, TNF-α, and IL-1β in LPS inspired RAW264.7 macrophages WSGP could significantly suppress the production of NO and the mRNA and protein expression levels of IL-1β, IL-6, and TNF-α in LPS stimulated RAW264.7 macrophage cells (p < 0.05). In addition, the phosphorylated IκB-α, p65, and STAT3 proteins were significantly increased in LPS-induced macrophages, while this trend was significantly reversed by WSGP treatment in a concentration-dependent manner (p < 0.05). Consequently, WSGP supplementation might reduce LPS-induced inflammatory responses by suppressing proinflammatory cytokines and NF-κB and STAT3 pathway activation. The finding of this research would give scientific guidelines for the judicious use of small molecular garlic polysaccharide in anti-inflammatory treatments.

Acetylcholinesterase and butyrylcholinesterase inhibitory activities of antioxidant peptides obtained from enzymatic pea protein hydrolysates and their ultrafiltration peptide fractions

This study optimized the enzymatic hydrolysis of yellow field pea proteins using alcalase (ACH), chymotrypsin (CHH), flavourzyme (FZH), pancreatin (PCH), pepsin (PEH), and trypsin (TPH) to obtain hydrolysates and ultrafiltered fractions (<1, 1-3, 3-5 and 5-10 kDa) that possess antioxidant plus acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitory activities. The hydrolysates exhibited varying degrees of radical scavenging and inhibition of linoleic acid peroxidation, as well as cholinesterase inhibition activities but the potency generally improved by >10% after UF separation into peptide fractions. ACH, FZH, and PEH exhibited significantly (p < .05) higher (20%-30% increases) radical scavenging activities than the other hydrolysates. The 1 and 3 kDa UF fractions of ACH, FZH, and PEH inhibited ~20%-30% AChE activity, while ACH, PCH, TPH, and PEH inhibited ~20%-40% BuChE activity. We conclude that the pea protein hydrolysates and their peptide fractions possess multifunctional properties with potential use against neurodegenerative disorders. PRACTICAL APPLICATIONS: Alzheimer's disease (AD) has multiple pathological pathways in addition to the loss of acetylcholine (ACh) catalyzed by acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). The presence of severe oxidative stress triggered by lipid peroxidation and formation of free radicals is a common trait in AD patients. The concept of AChE and BuChE inhibition as an approach toward AD amelioration involves the use of compounds with a similar structure to ACh, the natural substrate. Peptides derived from food proteins consist of ester bonds with structural similarity to ACh and theoretically possess the ability to interact with AChE and BuChE. Results from the present study imply that pea protein-derived peptides are potential candidates for use as inhibitors of AChE and BuChE activities, with application in the prevention and management of AD.

Perinatal exposure to glyphosate-based herbicides induced neurodevelopmental behaviors impairments and increased oxidative stress in the prefrontal cortex and hippocampus in offspring

Glyphosate is the organophosphate pesticide most widely used in the world. Recent studies correlate exposure to glyphosate and the emergence of neurodevelopmental disorders. Therefore, it was objective to propose a rat model of perinatal exposure to glyphosate-based herbicides (GBH) to study associated neurodevelopmental disorders. Behavioral aspects and brain pathways were assessed in the prepubertal phase. For this, maternal treatment occurred throughout the entire gestation period (from GD0) until weaning on postnatal day 22 (PND 22). Control group received oral gavage with 5 mL/kg of saline per day and GBH group received oral gavage with 50 mg/kg of GBH per day (n = 10 per group). Maternal behavior was evaluated in PND 2-6. Offspring were evaluated for quantification of ultrasonic vocalizations (PND 5); homing behavior test (PND 13); and hole board, social play behavior, open field, and object recognition tests (PND 28-32). Prefrontal cortex and hippocampus of the offspring were processed to evaluate oxidative stress. Maternal exposure to GBH impaired early social communication, olfactory discrimination, social play behavior, and the exploration of objects, in addition to increasing repetitive and stereotyped movements. GBH also increased oxidative stress. Therefore, perinatal GBH exposure induced behavioral and oxidative stress impairments in rats associated with neurodevelopmental disorders. The manifestations found in the offspring are in accordance with symptoms of autism spectrum disorder.

Antioxidant Activity, Functional Properties, and Cytoprotective Effects on HepG2 Cells of Tree Peony (Paeonia suffruticosa Andr.) Seed Protein Hydrolysate as Influenced by Molecular Weights Fractionation

In recent years, plant protein hydrolysates have gained increased attention due to their superior antioxidant activity and potential to prevent several chronic diseases associated with oxidative stress. This study aimed to investigate the antioxidant activity, functional properties, and cytoprotective effects of the tree peony seed protein hydrolysate (TPSPH) with different molecular weights (MWs). The antioxidant activities were evaluated by DPPH, hydroxyl radicals scavenging, Fe2+ chelating, and inhibition of the β-carotene oxidation abilities. The protective effects and mechanism against oxidative stress were determined using H2O2-stressed HepG2 cells. MW > 30 kDa of TPSPH showed the highest radical scavenging (DPPH IC50 = 0.04, hydroxyl IC50 = 0.89 mg/mL) and inhibition of β-carotene oxidation (80.07% at 2.0 mg/mL) activity. Moreover, MW > 30 kDa possessed high hydrophobicity, emulsifying capacity, and abundant antioxidant amino acids (28.22% of hydrophobic amino acids and 8.3% of aromatic amino acids). MW 5−10 kDa exhibited more effective protection against H2O2-induced HepG2 cells, by reducing reactive oxygen species (ROS), malonaldehyde (MDA), lactate dehydrogenase (LDH), and activating antioxidant enzymes (superoxide dismutase and catalase). These results indicated the potential application of TPSPH as an antioxidant in food and functional foods.

Antioxidant and Immunomodulatory Activities of Essential Oil Isolated from Anti-Upper Respiratory Tract Infection Formulation and Their Chemical Analysis

This study evaluates the in vitro antioxidant and immunomodulation activities of essential oils isolated from an anti-upper respiratory tract infection (URTI) formulation with a view to their therapeutic potential. The chemical components of the essential oil were analysed by gas chromatography-mass spectrometry (GC-MS). The antioxidative activity of the oils was investigated with regard to their ability to scavenge DPPH●, ABTS●+, and hydroxyl free radical (•OH). Their immunostimulatory activities were determined using murine macrophage cells. The main components of the oil with pharmacological and biological activities include 1,8-eucalyptol (42.9%), patchouli alcohol (19.9%), trans-erinolide (9.2%), and guaiacol (5%). The oils displayed high DPPH, ABTS, and hydroxyl radical scavenging activities and anti-inflammatory activities by reducing tumour necrosis factor-α (TNF-α) and interleukin-6 (IL-6) production. The results indicate that essential oils have the potential to be used in products for anti-URTI treatment.

Role of the Hydroxyl Radical-Generating System in the Estimation of the Antioxidant Activity of Plant Extracts by Electron Paramagnetic Resonance (EPR)

The scavenging activity of hydroxyl radicals, produced by the Fenton reaction, is commonly used to quantify the antioxidant capacity of plant extracts. In this study, three Fenton systems (Fe/phosphate buffer, Fe/quinolinic acid and Fe/phosphate buffer/quinolinic acid) and the thermal degradation of peroxydisulfate were used to produce hydroxyl radicals; the hydroxyl radical scavenging activity of plant extracts (ginger, blueberry juices and green tea infusion) and chemical compounds (EGCG and GA) was estimated by spin trapping with DMPO (5,5-dimethyl-1-pyrroline N-oxide) and EPR (Electron Paramagnetic Resonance) spectroscopy. Phosphate buffer was used to mimic the physiological pH of cellular systems, while quinolinic acid (pyridine-2,3-dicarboxylic acid) facilitates the experimental procedure by hindering the spontaneous oxidation of Fe(II). The EC₅₀ (the concentration of chemical compounds or plant extracts which halves the intensity of the DMPO-OH adduct) values were determined in all the systems. The results show that, for both the chemical compounds and the plant extracts, there is not a well-defined order for the EC₅₀ values determined in the four hydroxyl radical generating systems. The interactions of phosphate buffer and quinolinic acid with the antioxidants and with potential iron-coordinating ligands present in the plant extracts can justify the observed differences.

Structural Characterization and In-Vitro Antioxidant and Immunomodulatory Activities of Polysaccharide Fractions Isolated from Artemisia annua L

Arimisia annua L. is an important anticancer herb used in traditional Chinese medicine. The molecular basis underpinning the anticancer activity is complex and not fully understood, but the herbal polysaccharides, broadly recognised as having immunomodulatory, antioxidant and anticancer activities, are potential key active agents. To examine the functions of polysaccharides from A. annua, their immunomodulatory and antioxidant potentials were evaluated, as well as their structural characterization. The water-soluble polysaccharides (AAPs) were fractionated using size-exclusion chromatography to obtain three dominant fractions, AAP-1, AAP-2 and AAP-3, having molecular masses centered around 1684, 455 and 5.8kDa, respectively. The antioxidant potentials of the isolated polysaccharides were evaluated by measuring radical scavenging activities against DPPH● (2,2-diphenyl-1-picrylhydrazyl radical), ABTS●+ (2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid radical ion), and the OH● (hydroxyl radical). AAP-1 displayed high antioxidant activities against these radicals, which were 68%, 73% and 78%, respectively. AAP-2 displayed lower scavenging activities than the other two fractions. Immunostimulatory activities of AAPs were measured using mouse macrophages. The three polysaccharide fractions displayed significant antioxidant activities and stimulated the production of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). AAP-1 showed significant immunostimulatory activity (16-fold increase in the production of IL-6 compared to the control and 13-fold increase in the production of TNF-α) with low toxicity (>60% cell viability at 125 μg/mL concentration). Preliminary structural characterization of the AAPs was carried out using gas chromatography (GC) and FTIR techniques. The results indicate that AAP-1 and AAP-2 are pyranose-containing polysaccharides with β-linkages, and AAP-3 is a β-fructofuranoside. The results suggest that these polysaccharides are potential candidates for immunotherapy and cancer treatment.

Ferroin in dyes degradation by Fenton-like process: a chemical waste recycling perspective

Published literature describes the formation of the Fe (II)-phenanthroline complex (ferroin) as a stop way for Fenton processes, reducing radical yield. By contrast, this study presents evidence that ferroin can be activated by UVA in mildly acidic media in a photo-Fenton-like process. Because ferroin is the main waste from total iron determination in environmental samples, a recycling approach is suggested. Based on the best practices of waste management planning, an application of the proposed method for treating another chemical waste is presented. Titrimetric ammonia determination waste containing 2.67 mg L^-1 methyl red azo dye and 1.33 mg L^-1 methylene blue was degraded using the optimized experimental conditions: pH = 5.2-5.4; [H₂O₂] = 310 mg L^-1; [ferroin] = 1.4 mg L^-1; temperature = 36 ± 1 °C; reaction time = 165 min under UVA irradiation. Attenuation of most intense spectroscopic bands for the dyes achieved 94% (510 nm) and 96% (665 nm) reduction for methyl red and methylene blue, respectively, with degradation of ferroin itself. The present work brings empirical evidence that is possible to recycle ferroin as photo-Fenton-like process catalyst, as well as determine the best conditions for providing less acidic treated effluents with negligible suspended solid concentration, better than that obtained from classical photo-Fenton processes.

A Concise Review of Current In Vitro Chemical and Cell-Based Antioxidant Assay Methods

Antioxidants remain interesting molecules of choice for suppression of the toxic effects of free radicals in foods and human systems. The current practice involves the use of mainly synthetic molecules as potent antioxidant agents. However, due to the potential negative impact on human health, there is an intensive effort within the research community to develop natural alternatives with similar antioxidant efficacy but without the negative side effects of synthetic molecules. Still, the successful development of new molecules depends on the use of reliable chemical or cell culture assays to screen antioxidant properties. Chemical antioxidant assays include the determination of scavenging ability against free radicals such as DPPH, superoxide anion radicals, hydroxyl radicals, hydrogen peroxide, and nitric oxide. Other antioxidant tests include the ability of compounds to bind and sequester prooxidant metal cations, reduce ferric iron, and attenuate the rate of lipid oxidation. Ex vivo tests utilize cell cultures to confirm entry of the molecules into cells and the ability to quench synthetic intracellular free radicals or to stimulate the increased biosynthesis of endogenous antioxidants. In order to assist researchers in their choice of antioxidant evaluation methods, this review presents background scientific information on some of the most commonly used antioxidant assays with a comparative discussion of the relevance of published literature data to food science and human nutrition applications.

Antioxidant Activity Evaluation of Oviductus Ranae Protein Hydrolyzed by Different Proteases

As nutrition and a health tonic for both medicine and food, the protein content of Oviductus Ranae is more than 40%, making it an ideal source to produce antioxidant peptides. This work evaluated the effects of six different proteases (pepsin, trypsin, papain, flavourzyme, neutral protease and alcalase) on the antioxidant activity of Oviductus Ranae protein, and analyzed the relationship between the hydrolysis time, the degree of hydrolysis (DH) and the antioxidant activity of the enzymatic hydrolysates. The results showed that the antioxidant activity of Oviductus Ranae protein was significantly improved and the optimal hydrolysis time was maintained between 3-4 h under the action of different proteases. Among them, the protein hydrolysate which was hydrolyzed by pepsin for 180 min had the strongest comprehensive antioxidant activity and was most suitable for the production of antioxidant peptides. At this time, the DH, the DPPH radical scavenging activity, the absorbance value of reducing power determination and the hydroxyl radical scavenging activity corresponding to the enzymatic hydrolysate were 13.32 ± 0.24%, 70.63 ± 1.53%, 0.376 ± 0.009 and 31.96 ± 0.78%, respectively. Correlation analysis showed that there was a significant positive correlation between the hydrolysis time, the DH and the antioxidant activity of the enzymatic hydrolysates, further indicating that the hydrolysates of Oviductus Ranae protein had great antioxidant potential. The traditional anti-aging efficacy of Oviductus Ranae is closely related to the scavenging of reactive oxygen species, and its hydrolysates have better antioxidant capacity, which also provides support for further development of its traditional anti-aging efficacy.

In vitro antioxidant and antihypertensive properties of sesame seed enzymatic protein hydrolysate and ultrafiltration peptide fractions

The objective of this study was to determine the in vitro antioxidant and antihypertensive potentials of sesame seed protein hydrolysate and its membrane ultrafiltration peptide fractions in comparison to the unhydrolyzed protein. Sesame seed protein isolate (SESPI) was prepared from the defatted sesame seed meal and then hydrolyzed using consecutive additions of pepsin and pancreatin to yield sesame protein hydrolysate (SESPH). The SESPH was subjected to membrane ultrafiltration consecutively to obtain fractions with peptide sizes of <1, 1-3, 3-5, and 5-10 kDa, respectively, which were then assayed for in vitro antioxidant and antihypertensive properties. The results showed that protein hydrolysis and fractionation led to significant (p < .05) increases in the content of hydrophobic amino acids. Radical scavenging and metal ion chelation were also significantly (p < .05) enhanced by these treatments. Inhibition of linoleic acid oxidation was stronger with the 1.0 mg/ml of sesame peptide samples in comparison to the mild inhibitory effect exhibited by the 0.5 mg/ml of samples. The <1 kDa peptide fraction was the most active inhibitor (81%) against angiotensin converting enzyme, whereas the bigger peptides (>3-5 and 5-10 kDa) were the most effective (75%-85% ) inhibitors against renin. These sesame products could be used as therapeutic agents in the development of health enhancing foods for the prevention and management of chronic diseases. PRACTICAL APPLICATIONS: Bioactive peptides have been produced from plant protein sources through in vitro enzymatic activities. Sesame seed peptides have demonstrated multifunctional potential to act as antioxidative and antihypertensive agents that could be utilized as ingredients for the development of novel functional foods and nutraceuticals.

Morphological Profiling Identifies a Common Mode of Action for Small Molecules with Different Targets

Unbiased morphological profiling of bioactivity, for example, in the cell painting assay (CPA), enables the identification of a small molecule's mode of action based on its similarity to the bioactivity of reference compounds, irrespective of the biological target or chemical similarity. This is particularly important for small molecules with nonprotein targets as these are rather difficult to identify with widely employed target-identification methods. We employed morphological profiling using the CPA to identify compounds that are biosimilar to the iron chelator deferoxamine. Structurally different compounds with different annotated cellular targets provoked a shared physiological response, thereby defining a cluster based on their morphological fingerprints. This cluster is based on a shared mode of action and not on a shared target, that is, cell-cycle modulation in the S or G2 phase. Hierarchical clustering of morphological fingerprints revealed subclusters that are based on the mechanism of action and could be used to predict target-related bioactivity.

Modification of In Vitro and In Vivo Antioxidant Activity by Consumption of Cooked Chickpea in a Colon Cancer Model

Chickpea has been classified as a nutraceutical food due to its phytochemical compounds, showing antioxidant, anti-inflammatory, and anticancer activity. To investigate this, we evaluated the effect of cooking on the nutritional and non-nutritional composition and the in vitro and in vivo antioxidant activity of chickpea seed. The latter was determined by the variation in the concentration of nitric oxide (NO), oxidized carbonyl groups (CO), malondialdehyde (MDA), and the expression of 4-hydroxy-2-nonenal (4-HNE) in the colon of male BALB/c mice fed with a standard diet with 10 and 20% cooked chickpea (CC). We induced colon cancer in mice by administering azoxymethane/dextran sulfate sodium (AOM/DSS); for the evaluation, these were sacrificed 1, 7, and 14 weeks after the induction. Results show that cooking does not significantly modify (p < 0.05) nutritional compounds; however, it decreases the concentration of non-nutritional ones and, consequently, in vitro antioxidant activity. The in vivo evaluation showed that animals administered with AOM/DSS presented higher concentrations of NO, CO, MDA, and 4-HNE than those in animals without AOM/DSS administration. However, in the three evaluated times, these markers were significantly reduced (p < 0.05) with CC consumption. The best effect on the oxidation markers was with the 20% CC diet, demonstrating the antioxidant potential of CC.

Reclassifying Hepatic Cell Death during Liver Damage: Ferroptosis-A Novel Form of Non-Apoptotic Cell Death?

Ferroptosis has emerged as a new type of cell death in different pathological conditions, including neurological and kidney diseases and, especially, in different types of cancer. The hallmark of this regulated cell death is the presence of iron-driven lipid peroxidation; the activation of key genes related to this process such as glutathione peroxidase-4 (gpx4), acyl-CoA synthetase long-chain family member-4 (acsl4), carbonyl reductase [NADPH] 3 (cbr3), and prostaglandin peroxidase synthase-2 (ptgs2); and morphological changes including shrunken and electron-dense mitochondria. Iron overload in the liver has long been recognized as both a major trigger of liver damage in different diseases, and it is also associated with liver fibrosis. New evidence suggests that ferroptosis might be a novel type of non-apoptotic cell death in several liver diseases including non-alcoholic steatohepatitis (NASH), alcoholic liver disease (ALD), drug-induced liver injury (DILI), viral hepatitis, and hemochromatosis. The interaction between iron-related lipid peroxidation, cellular stress signals, and antioxidant systems plays a pivotal role in the development of this novel type of cell death. In addition, integrated responses from lipidic mediators together with free iron from iron-containing enzymes are essential to understanding this process. The presence of ferroptosis and the exact mechanisms leading to this non-apoptotic type of cell death in the liver remain scarcely elucidated. Recognizing ferroptosis as a novel type of cell death in the liver could lead to the understanding of the complex interaction between different types of cell death, their role in progression of liver fibrosis, the development of new biomarkers, as well as the use of modulators of ferroptosis, allowing improved theranostic approaches in the clinic.

Ultrasonic pretreatment improved the antioxidant potential of enzymatic protein hydrolysates from highland barley brewer's spent grain (BSG)

Highland barley brewer's spent grain (BSG), being China's brewing industry's major by-product is the focus of current research. The aim of the present study was to scrutinize the effects of ultrasound and heat pretreatments on enzymatic hydrolysis of highland barley BSG protein hydrolysates (HBSGPH) and evaluate the effect of enzymatic hydrolysis time on the antioxidant activity of hydrolysates by Alcalase. Different ultrasonic waves (40 and 50 kHz) and heat pretreatment temperatures (50 and 100 °C) were chosen and the pretreatment time was 15, 30, and 60 min. The obtained results revealed that the ultrasound pretreatment of highland barley BSG protein at 40 and 50 kHz has significantly (P < 0.05) enhanced about 57 and 67% of oxygen radical absorption capacity of obtained hydrolysate over the untreated substrate. The 1,1-diphenyl-2-picrylhdrazl (DPPH) radical scavenging activity (DRSA) 28%, metal chelating activity (MCA) 54%, superoxide radical scavenging activity (SRSA) 18%, and hydroxyl radical scavenging activity (HRSA) 25% of HBSGPH at 50 kHz were also improved (P < 0.05) significantly. HBSGPH from heat treatment at 100 °C showed no SRSA and HRSA scavenging activities but improved significantly (P < 0.05) about 27% ferric reducing antioxidant power (FRAP) assay values. In the present work, the resultant HBSGPH had stronger antioxidant properties with ultrasound pretreatment at 50 kHz and the enzymatic hydrolysis after 4 hr was facilitating the enzymatic release of antioxidant peptides from HBSGPH. PRACTICAL APPLICATION: Highland barley BSG is attracting toward natural food products due to its potent natural antioxidants to overcome the risk of diseases and are beneficial for human health.

In vitro antioxidant and angiotensin-converting enzyme inhibitory activity of fermented milk with different culture combinations

This study investigated the effects of Lactobacillus plantarum (Lp) and Bifidobacterium animalis ssp. lactis (Ba) in co-cultures with Streptococcus thermophilus (St) on changes in the acidification profile, proteolytic activity, peptide production, in vitro antioxidant activity, and angiotensin-converting enzyme (ACE) inhibitory properties of fermented milks during 21 d of storage at 4°C. The pH values and proteolysis in all batches showed a gradual decrease and increase during storage, respectively. The ACE-inhibitory activity and total antioxidant capacity of all co-fermented milk samples followed a similar pattern, with maximum values on d 6 of storage. The St starter, in conjunction with Ba or Lp or both, enhanced proteolysis, peptide generation, and ACE-inhibitory and antioxidant activity, but decreased pH values compared with St alone. The St-Ba-Lp samples showed higher DPPH^• (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity, hydroxyl radical scavenging activity, and total antioxidant capacity, but similar superoxide anion scavenging activity compared to St-Ba or St-Lp samples. The St-Ba samples showed higher DPPH^• radical scavenging activity but lower hydroxyl radical scavenging activity than St-Lp samples. In the ACE-inhibitory assays, the St-Lp samples exhibited relatively low activity among the co-fermented milks, digested or not. The presence of Ba and Lp in fermentation together did not affect ACE-inhibitory activity in undigested fermented milks compared with the presence of Ba alone, and St-Ba-Lp fermented milks demonstrated an increase in ACE-inhibitory activity after simulated gastrointestinal digestion in storage. Pepsin digestion largely improved ACE-inhibitory activity, except in St-Lp samples, in which the activity was reduced. Further hydrolysis by trypsin reduced final activity in digestion. This study suggests that co-cultured fermentation with probiotics improves in vitro antioxidant and ACE inhibition activity in fermented milks, and this effect is partly due to the higher proteolytic activity of probiotics.

Extraction of Cathepsin D-Like Protease from Neon Flying Squid (Ommastrephes bartramii) Viscera and Application in Antioxidant Hydrolysate Production

A protease from neon flying squid (Ommastrephes bartramii) viscera (SVCE3(f)) was partially purified by isoelectric solubilization/precipitation combined with ultra-membrane filtration (ISP-UMF). Two protein bands of 45 and 27 KDa were determined by SDS-PAGE assay. The protease characteristic of the protein band of 45 KDa was confirmed using casein zymography analysis. The result of UPLC-ESI-MS/MS suggested that the band of 45 KDa could be a cathepsin D-like protease. This cathepsin D-like protease showed an optimum pH of 3.0 and optimum temperature of 60 °C when casein was used as s substrate. Furthermore, its protease activity was stable at 30–50 °C and under a pH range of 1.0–5.0, maintaining about 60% of its initial activity. SVCE3(f) can digest half-fin anchovy (Setipinna taty) to generate antioxidant hydrolysates (HAHp-SEs). The degree of hydrolysis (DH) of HAHp-SEs increased along with the hydrolysis time and reached stability after 60 min of digestion. HAHp-SEs(30) with relatively lower DH exhibited the highest DPPH radical scavenging activity as compared with other HAHp-SEs. However, a stronger hydroxyl radical scavenging activity and greater reducing power were observed for HAHp-SEs that underwent higher DH. Accordingly, the partially purified cathepsin D-like protease of neon flying squid viscera using ISP-UMF could have potential application in antioxidant hydrolysates production.

The antityrosinase and antioxidant activities of flavonoids dominated by the number and location of phenolic hydroxyl groups

Background

Compounds with the ability to scavenge reactive oxygen species (ROS) and inhibit tyrosinase may be useful for the treatment and prevention from ROS-related diseases. The number and location of phenolic hydroxyl of the flavonoids will significantly influence the inhibition of tyrosinase activity. Phenolic hydroxyl is indispensable to the antioxidant activity of flavonoids. Isoeugenol, shikonin, baicalein, rosmarinic acid, and dihydromyricetin have respectively one, two, three, four, or five phenolic hydroxyls. The different molecular structures with the similar structure to l-3,4-dihydroxyphenylalanine (l-DOPA) were expected to the different antityrosinase and antioxidant activities.

Methods

This investigation tested the antityrosinase activity, the inhibition constant, and inhibition type of isoeugenol, shikonin, baicalein, rosmarinic acid, and dihydromyricetin. Molecular docking was examined by the Discovery Studio 2.5 (CDOCKER Dock, Dassault Systemes BIOVIA, USA). This experiment also examined the antioxidant effects of the five compounds on supercoiled pBR322 plasmid DNA, lipid peroxidation in rat liver mitochondria in vitro, and DPPH, ABTS, hydroxyl, or superoxide free radical scavenging activity in vitro.

Results

The compounds exhibited good antityrosinase activities. Molecular docking results implied that the compounds could interact with the amino acid residues in the active site center of antityrosinase. These compounds also exhibited antioxidant effects on DPPH, ABTS, hydroxyl, or superoxide free radical scavenging activity in vitro, lipid peroxidation in rat liver mitochondria induced by Fe²⁺/vitamin C system in vitro, and supercoiled pBR322 plasmid DNA. The activity order is isoeugenol < shikonin < baicalein < rosmarinic acid < dihydromyricetin. The results showed the compounds with more phenolic hydroxyls have more antioxidant and antityrosinase activities.

Conclusion

This was the first study of molecular docking for modeling the antityrosinase activity of compounds. This was also the first study of the protective effects of compounds on supercoiled pBR322 plasmid DNA, the lipid peroxidation inhibition activity in liver mitochondria. These results suggest that the compounds exhibited antityrosinase and antioxidant activities may be useful in skin pigmentation and food additives.

Electronic supplementary material

The online version of this article (10.1186/s13020-018-0206-9) contains supplementary material, which is available to authorized users.

Fluazifop-p-butyl, an aryloxyphenoxypropionate herbicide, diminishes renal and hepatic functions and triggers testicular oxidative stress in orally exposed rats

Fluazifop- p-butyl (FPB) is a selective aryloxyphenoxypropionate herbicide. Its phytotoxicity mechanism involves inhibition of lipid biosynthesis, free-radical generation, and oxidative stress in vulnerable plants. This study evaluates the impact of orally administered FPB on selected tissues in non-target animal model. Twenty-four male wistar rats (160–180g) were randomized into groups (I–IV). Group-I served as control, while animals in groups II, III, and IV received FPB at 18.75, 37.5, and 75 mg/kg body weight/day p.o., respectively, for 21 days. FPB caused significant ( p < 0.05) increase in plasma biomarkers of renal and hepatic function (urea, creatinine, bilirubin, alkaline phosphatase, alanine aminotransferase, and aspartate aminotransferase) when compared to control. Significant reductions in testicular ascorbic acid, glutathione, and activities of glutathione-S transferase, superoxide dismutase, and catalase were observed in FPB-treated animals when compared to control, in a dose-dependent manner. This was accompanied by increased testicular lipid peroxidation in the treated groups. Furthermore, a significant decrease in testicular acid phosphatase and γ-glutamyl transferase activities was also observed in the FPB-treated groups in a dose-dependent manner compared to control. However, testicular lactate dehydrogenase activity was significantly increased in the FPB-treated rats when compared to control. Additionally, histopathological studies revealed severe interstitial oedema and congestion of testicular blood vessels in the FPB-treated groups. Overall, data from this study suggest that FPB induced hepatotoxicity, nephrotoxicity, and oxidative stress-mediated alteration of testicular functions in rat.

Accelerated Catalytic Fenton Reaction with Traces of Iron: An Fe-Pd-Multicatalysis Approach

An accelerated catalytic Fenton (ACF) reaction was developed based upon a multicatalysis approach, facilitating efficient contaminant oxidation at trace levels of dissolved iron. Beside the Fe(II)/H2O2 catalyst/oxidant pair for production of OH-radicals, the ACF system contains Pd/H2 as catalyst/reductant pair for fast reduction of Fe(III) back to Fe(II) which accelerates the Fenton cycle and leads to faster contaminant degradation. By this means, the concentration of the dissolved iron catalyst can be reduced to trace levels (1 mg L(-1)) below common discharge limits, thus eliminating the need for iron sludge removal, which is one of the major drawbacks of conventional Fenton processes. ACF provides fast degradation of the model contaminant methyl tert-butyl ether (MTBE, C0 = 0.17 mM) with a half-life of 11 min with 1 mg L(-1) dissolved iron, 500 mg L(-1) H2O2, 5 mg L(-1) Pd (as suspended Pd/Al2O3 catalyst) and 0.1 MPa H2, pH 3. The effects of pH, H2 partial pressure and H2O2 concentration on MTBE degradation rates were studied. Results on kinetic deuterium isotope effect and quenching studies are in conformity with OH-radicals as main oxidant. The heterogeneous Pd/Al2O3 catalyst was reused within six cycles without significant loss in activity.

Preparation, characterization and in vitro antioxidative potential of synbiotic fermented dairy products

The present study, evaluates the antioxidative potential of two synbiotic dairy products viz. synbiotic lassi with honey and whey based synbiotic drink with inulin and orange juice, along with their physicochemical and microbiological activity during storage period. Antioxidative potential of raw ingredients and probiotic cultures used to prepare synbiotic products was also evaluated. Synbiotic lassi with honey was prepared using Streptococcus thermophilus MTCC 5460 (MD2) and Lactobacillus helveticus MTCC 5463 (V3) as probiotics and honey as prebiotic. For preparation of whey based synbiotic drink, Lactobacillus helveticus MTCC 5463 and inulin were used as probiotic and prebiotic, respectively and orange juice was also incorporated. Titratable acidity and pH of both synbiotic products followed a similar pattern of increase or decrease during storage. Furthermore, no major changes were observed in viability of probiotic cultures under storage conditions adapted. The hydroxyl radical scavenging activity of synbiotic lassi with honey was found to significantly decrease from 107.76 to 79.41 % at the end of storage whereas, the activity of whey based synbiotic drink was 100.32 % which declined sharply to 79.21 % on 7th day but further increased to 102.59 % on 14th day. The DPPH (α, α-Diphenyl-β-Picrylhydrazyl) radical scavenging activity of freshly prepared synbiotic lassi with honey was 28.43 % which decreased to 23.03 % on 7th day while for whey based synbiotic drink decreased from 26.85 % (0 day) to 17.12 % (7th day) and continued to decline. Moreover, probiotic strains used for synbiotic preparation also demonstrated good antioxidative activity.

Enzymatic protein hydrolysates from high pressure-pretreated isolated pea proteins have better antioxidant properties than similar hydrolysates produced from heat pretreatment

Isolated pea protein (IPP) dispersions (1%, w/v) were pretreated with high pressure (HP) of 200, 400, or 600 MPa for 5 min at 24 °C or high temperature (HT) for 30 min at 100 °C prior to hydrolysis with 1% (w/w) Alcalase. HP pretreatment of IPP at 400 and 600 MPa levels led to significantly (P<0.05) improved (>40%) oxygen radical absorption capacity (ORAC) of hydrolysates. 2,2-Diphenyl-1-picrylhydrazyl, superoxide radical and hydroxyl radical scavenging activities of pea protein hydrolysates were also significantly (P<0.05) improved (25%, 20%, and 40%, respectively) by HP pretreatment of IPP. Protein hydrolysates from HT IPP showed no ORAC, superoxide or hydroxyl scavenging activity but had significantly (P<0.05) improved (80%) ferric reducing antioxidant power. The protein hydrolysates had weaker antioxidant properties than glutathione but overall, the HP pretreatment was superior to HT pretreatment in facilitating enzymatic release of antioxidant peptides from IPP.

A novel hemp seed meal protein hydrolysate reduces oxidative stress factors in spontaneously hypertensive rats

This report shows the antioxidant effects of a hemp seed meal protein hydrolysate (HMH) in spontaneously hypertensive rats (SHR). Defatted hemp seed meal was hydrolyzed consecutively with pepsin and pancreatin to yield HMH, which was incorporated into rat feed as a source of antioxidant peptides. Young (8-week old) SHRs were divided into three groups (8 rats/group) and fed diets that contained 0.0%, 0.5% or 1.0% (w/w) HMH for eight weeks; half of the rats were sacrificed for blood collection. After a 4-week washout period, the remaining 20-week old SHRs were fed for an additional four weeks and sacrificed for blood collection. Plasma total antioxidant capacity (TAC) and superoxide dismutase (SOD), catalase (CAT) and total peroxides (TPx) levels were determined. Results showed that plasma TAC, CAT and SOD levels decreased in the older 20-week old SHRs when compared to the young SHRs. The presence of HMH in the diets led to significant (p < 0.05) increases in plasma SOD and CAT levels in both young and adult SHR groups; these increases were accompanied by decreases in TPx levels. The results suggest that HMH contained antioxidant peptides that reduced the rate of lipid peroxidation in SHRs with enhanced antioxidant enzyme levels and total antioxidant capacity.

Antioxidant capacity of hydrolyzed protein fractions obtained from an under-explored seed protein: Gingerbread plum (Neocarya macrophylla)

The antioxidant capacity of gingerbread plum kernel protein fraction (albumin, globulin and glutelin) hydrolysates (GPKH) was studied. Gingerbread plum kernel protein fractions were hydrolyzed through a combined action of two digestive enzymes (pespsin and trypsin). The hydrolyzed fractions were subjected to antioxidant test via several chemical assays such as: DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, hydroxyl radical-scavenging activity, reducing power and metal chelating activity. Total phenolic contents, amino acid composition and molecular weight distribution were also evaluated. The glutelin fraction hydrolysate showed the strongest antioxidative activity throughout the entire investigation: 79.09, 58.81, 52.08 % and 40.7 μg/mL GAE for DPPH, hydroxyl radical, chelating activity and total phenolics respectively. GPKH possess a molecular weight ranging from 300 to 4000 Da and also showed much more high reducing power than some common standards such as BHA and α-tocopherol indicating that, hydrolysates derived from gingerbread plum kernel protein could be a new antioxidants source.

In vitro antioxidant activity and in vivo antifatigue effect of layered double hydroxide nanoparticles as delivery vehicles for folic acid

Folic acid antioxidants were successfully intercalated into layered double hydroxides (LDH) nanoparticles according to a previous method with minor modification. The resultant folic acid-LDH constructs were then characterized by X-ray powder diffraction and transmission electron microscopy. The in vitro antioxidant activities, cytotoxicity effect, and in vivo antifatigue were examined by a series of assays. The results showed that folic acid-LDH antioxidant system can scavenge 1,1-diphenyl-2-picrylhydrazyl and hydroxyl free radicals and chelate pro-oxidative Cu²⁺. The in vitro cytotoxicity assays indicated that folic acid-LDH antioxidant system had no significant cytotoxic effect or obvious toxicity to normal cells. It also prolonged the forced swimming time of the mice by 32% and 51% compared to folic acid and control groups, respectively. It had an obvious effect on decreasing the blood urea nitrogen and blood lactic acid, while increasing muscle and hepatic glycogen levels. Therefore, folic acid-LDH might be used as a novel antioxidant and antifatigue nutritional supplement.

Evaluation of the in vitro antioxidant properties of a cod (Gadus morhua) protein hydrolysate and peptide fractions

Mechanically-deboned cod muscle proteins were sequentially hydrolysed using pepsin and a trypsin+chymotrypsin combination, which was followed by passing the digest through a 1 kDa equipped tangential flow filtration system; the permeate (<1 kDa peptides) was collected as the cod protein hydrolysate (CPH). Reversed-phase high performance liquid chromatography (RP-HPLC) was used to separate the CPH into four peptide fractions (CF1-CF4) and their in vitro antioxidant properties investigated. Results showed that most of the peptide fractions (CF2-CF4) displayed significantly higher (p<0.05) oxygen radical absorbance capacity values (698-942 μM Trolox equivalents, TE/g) and 2,2-diphenyl-1-picrylhydrazyl scavenging activities (17-32%) than those of CPH (613 μM TE/g and 19%, respectively). However, the unfractionated CPH displayed improved capability to scavenge superoxide and hydroxyl radicals as well as significantly higher (p<0.05) ferric iron reduction and chelation of iron than the RP-HPLC peptides. The CPH and peptide fractions displayed a dose-dependent inhibition of linoleic acid oxidation.