Chelating Capacity Research Articles

Effect of prolonged captivity on the hemolymph profile of Tachypleus gigas using the various anticoagulant formulations

Horseshoe crab (HSC) amebocyte cells degranulate to form a gel clot when in contact with endotoxins. This phenomenon is the basis of both the horseshoe crab immune system and the detection of endotoxin in biologicals. Horseshoe crab captive rearing has been suggested as a promising method for continuous amebocyte cell harvesting. Hence, we aimed to investigate the amebocyte cells quality in Tachypleus gigas pre and post bleeding under captivity. Wild and captive horseshoe crabs (5 months captivity) were fed with Meretrix meretrix (highly preferred diet by T. gigas) and bled in 6 anticoagulant formulations (A, B, C, D, E, and F). No profound difference in cell density was observed between captive and wild groups with the mean value of 0.883 × 107 a cells/mL and 0.917 × 107 cells/mL, respectively. Cell viability of the captive group was significantly lower than the wild group (F = 808.075, p < 0.001). Anticoagulant formulation greatly affected cell viability and cell morphology in captive and wild groups (p < 0.001). Amebocyte cells collected from the wild T. gigas using optimum anticoagulant (formula C) showed 0.6 × 107 cells/mL cell density and 86.9 % cell viability. Simultaneously, morphology analysis revealed the percentage of contracted, granular flattened, and degranulated flattened cells were 14.62 %, 71.39 %, and 14 %, respectively. The anticoagulant formulations showed varying capabilities in maintaining cell viability due to their buffering and chelating capacity. We postulate that selection of the best anticoagulant recipe is crucial to inaccurate blood profiling of horseshoe crabs. Prolonged captivity and single feed impact the quality of amebocyte cells in the crabs.

Isolation and Chelation Activity of Plant Phenolic Root Exudates As Potential Clinical Iron Chelators

Introduction:Hemoglobinopathies such as β-Thalassemia (Thal) and other genetic disorders such as neurodegeneration with brain iron accumulation have complications of iron overload, which can impair vital processes such as cardiac and neurological function. In Thal, ineffective erythropoiesis leads to elevated gastrointestinal iron absorption and in severe cases may necessitate blood transfusions exacerbating the condition. Iron chelating agents such as deferoxamine (DFO), deferiprone, and deferasirox must be used, but can have unwanted side effects. While effective in treating iron overload, the increased risk of side effects at higher doses highlights the importance of finding new potent iron-chelating agents, either as replacements or as adjuvants. Plant based treatments may be better tolerated by patients, offering an alternative therapeutic approach. Plant secondary metabolites secreted from roots under iron limiting conditions may provide a novel source for this bioactivity. Plants rich in phenolic compounds and those tolerating alkaline soils, which necessitate efficient mobilization of soil-precipitated iron, are our focus here. The aim of this project is to functionally and analytically characterize naturally occurring plant root exudates as possible clinical iron chelators.Methods : We cultivated Populus trichocarpa ( Poplar), Thuja plicata (Western red-cedar), and Lavendula X intermedia (Lavender) cuttings under iron normal and iron limiting conditions. From their roots, exudates were isolated to characterize and determine their effectiveness as iron chelators. Total phenolic concentrations of exudates were evaluated using Folin-Ciocalteu reagent. The ferrozine assay was used as a competition assay to characterize total iron binding ability of root exudates and standard chelators, which was sensitive enough to differentiate chelation effectiveness between DFO, EDTA, and isolated root exudates at 800 nM. Furthermore, known plant iron chelators chlorogenic acid (CA), a phenolic, and the more lipophilic β-thujaplicin (hinokitiol) were compared to DFO, then used tomodel root exudates in a cell culture bioassay. The bioassay was developed using monocytic THP-1 cells (as an RE system model) to quantify intra- and extracellular iron, comparing iron uptake in cells exposed to varying concentrations of iron chelators as a way of evaluating chelation strengths of crude root exudates, β-thujaplicin, and CA in comparison to DFO.Results:Total phenolic production in P. trichocarpa root exudates increased significantly (p < 0.05) in response to iron depletion after 12 hrs. Iron binding ability increased almost four-fold upon iron depletion. In the ferrozine competition assay, iron depleted root exudates inhibited iron binding by 15% whereas iron normal exudates inhibited by only 4%. Iron binding of root exudates was similar to EDTA (13% inhibition) and about half that of DFO (30% inhibition). In the THP-1 cell bioassay, DFO and CA showed comparable trends of chelation activity. Cells exposed to either 50 or 100 μM CA or DFO reduced intracellular iron by at least 47% or 89%, respectively. However, at 50 and 100 µM β-thujaplicin increased iron uptake by 82 to 86% respectively. Further testing of plant root exudates is ongoing.Conclusions: Exposing P. trichocarpa to an iron deficient environment resulted in plants that secreted root exudates with significantly higher level of phenolics and increased iron chelation ability. This was shown in the ferrozine competition assay where iron depleted root exudates showed higher binding affinity for iron when compared to the iron normal exudates resulting in an iron chelation ability similar to the known iron chelator EDTA. In the bioassay using THP-1 monocytic cells, testing the plant phenolic CA, there was reduction of intracellular iron comparable to DFO, whereas the lipophilic chelator β-thujaplicin increased cellular iron. Consequently, chelators such as CA exclude iron from being taken up by the cells, while more lipophilic chelators, like β-thujaplicin enable transport through membranes, and thus have the capacity to transport iron both into and out of cells. Thus, we have shown that plant root exudates can yield potential iron chelators and that in general plant phenolics have iron chelation capacity comparable to the classic iron chelator DFO. DisclosuresWalter:Apopharma: Research Funding.

Characterization of Bioactive and Antioxidant Composition of Mountain Tea (Sideritis montana ssp. montana): Microwave-Assisted Technology

The use of synthetic antioxidants has been restricted and even prohibited in some countries due to their toxic effects. This study aims to perform the biochemical assays representing the bioactive compounds in Sideritis montana L. ssp. montana L. known as mountain tea. The study specifically investigates the potential application of mountain tea in the food industry as a natural antioxidant. Different extraction procedures using various solvents are carried out to obtain phenolic compounds and antioxidant activities in plant matrices. In this study, the maceration method was used for the extraction procedure. Furthermore, the microwave-assisted extraction method was applied to shorten the extraction time and decrease the solvent quantity. Methanol was used as a solvent in both conventional and microwave-assisted extraction procedures. The samples were evaluated in terms of the total phenolic compounds, total flavonoids, antioxidant activities, and metal chelating capacity. The obtained results for classical extraction and microwave-assisted extraction methods were found to be 51 and 55 mg/g for TPC, 16.3 and 22 mg/g for TFC, 93 and 103 mg/g for FRAP, and 284 and 282 mg/g for MCC, respectively. The microwave-assisted extraction method produced higher concentrations of bioactive molecules as compared to the classical method. Microwave-assisted extraction was found to be superior to the conventional method in terms of effectiveness, extraction time, and solvent quantity. Besides, Sideritis montana ssp. montana is suggested in the food industry as a natural antioxidant instead of synthetic ones to prevent health-damaging effects.

In Vitro Antioxidant Activities of Methanol Extracts of Three Achillea Species from Turkey

In this study, total phenolics and flavonoid compounds of methanol extract concentrations of three medicinal plant, Asteraceae (Compositae) L. genus that are grown in Turkey and belong to the genus Achillea, were determined with the goal of measuring their antioxidant activities. Antioxidant capacity was measured by widely used iron reducing power, DPPH radical scavenging activity and metal chelating capacity. The antioxidant activities of the achillea extracts used in the study were compared with the standard antioxidants (BHA, BHT and α-tocopherol), which were frequently used as antioxidant food additives. According to the free radical scavenging activity antioxidant results, all the extracts exhibited higher DPPH radical scavenging activity than the standards used. The extract from A.boissieri showed remarkable 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity (68.51% at 37.5 μg/mL) comparable with synthetic antioxidants. The ferric reducing antioxidant power was found to be moderate in methanolic extract of Achillea species, whereas the chelating capacity of the extracts were found to be lower as compared to the standards. In addition, total phenolic, flavonoid and flavonol content of all extracts were measured spectrophotometrically and the results were expressed as "gallic acid equivalent" or "quercetin equivalent". The total phenolic content was expressed as equivalents of gallic acid and the results were observed to range from 11.86 to 23.63 mg/g dry extract weight. The total flavonoid concentrations of Achillea extracts were expressed as quercetin equivalent. Flavonoid content ranged from 15.05 to 29.70 mg/g. Total flavonol concentrations of the extracts were determined to be between 5.92 and 7.20 mg/g in terms of quercetin equivalent. This study showed that Achillea L. species, which has been used for treatment in Anatolia for years, can be used as a potential natural antioxidant source.

High Metal Chelating Properties from Rapeseed Meal Proteins to Counteract Lipid Oxidation in Foods: Controlled Proteolysis and Characterization

AbstractRapeseed meal proteins (RP) are enzymatically hydrolyzed using three individual proteases (Alcalase, Flavourzyme, and Prolyve) and the enzymatic mechanism is studied. Rapeseed hydrolysates are produced under controlled conditions and the Prolyve hydrolysate is separated by membrane filtration. Their capacity to reduce free radicals (by transfer of hydrogen or electron) or transition metals (by electron transfer) in the absence of an oxidizable substrate, their metal chelating capacity as well as the antioxidant performances in model (conjugated autoxidizable triene assay) are investigated. All hydrolysates show a reduction capacity (by transfer of hydrogen or electron) and antioxidant activities, in a dose‐dependent manner, which are however not significantly increased in comparison to the native proteins. A noteworthy metal chelating activity of the peptides produced with Prolyve is highlighted. These results indicate the potential of valorization of RP as a source of high metal chelating peptides to counteract lipid oxidation in foods. Practical applications: Over the last decade, the antioxidative potential of peptides from plant biomass has been evidenced by much research. Considering the myriad of possible sources and the diversity of technology and means to obtain peptides from protein materials, it is reasonable to expect more applications. Concomitantly, preventing lipid oxidation, especially with the polyunsaturated fat‐based products, is a major concern in sectors such as agri‐food and cosmetic. Although the efficacy of synthetic antioxidants is recognized, both consumers and manufacturers are looking for more innovative, healthy, environmental‐friendly processes and quality products. In this context, a controlled proteolysis of proteins from plant by‐products can be used as a sustainable strategy to produce antioxidant peptides. Among them, new peptides released from rapeseed proteins with Prolyve can provide interesting metal chelators to counteract lipid oxidation in foods.

Effects of simultaneous dual-frequency divergent ultrasound-assisted extraction on the structure, thermal and antioxidant properties of protein from Chlorella pyrenoidosa

The aim of this study was to investigate the effects of simultaneous dual-frequency divergent ultrasound-assisted extraction (SDFUE) on the yield, structure, thermal and antioxidant activities of protein from Chlorella pyrenoidosa (CPP). Based on single factor experiments, the extraction conditions were optimized by response surface methodology (RSM). Under optimal conditions, ultrasonic power of 360 W, extraction temperature of 45 °C, 3% (w/v) alkali concentration and ultrasonic time of 20 min, the maximal extraction rate of CPP was 52.36 ± 0.31%, significantly higher than that of hot water extraction (HWE). In addition, the amino acid composition, the secondary and tertiary structure of CPP were significantly changed due to the unfolding of protein molecules and the exposure of hydrophobic groups. Moreover, the thermal property of CPP was more stable, the denaturation temperature and the heat required for denaturation were increased. Besides, the antioxidant properties of CPP (6 mg/mL) extracted by SDFUE showed that, the maximum 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity was 86.96 ± 0.33%, maximum 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity was 59.07 ± 0.31%, maximum Fe2+ chelating capacity was 34.37 ± 0.43%, and the maximum 2-Phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO) radical scavenging activity at pH 4.5 was 66.24 ± 0.98%, which were all improved obviously compared with that of HWE, PTIO trapping assay demonstrated that electron transfer (ET) was mainly involved in the antioxidant process of CPP. These findings revealed that ultrasound-assisted extraction not only increased the yield of CPP, but also enhanced its thermal and antioxidant properties, which was related to the changes of CPP structure. This work might break the traditional single-frequency ultrasonic extraction model and provide a reference for the utilization of ultrasonic extraction in the field of Chlorella pyrenoidosa as bioactive materials.

Molecular Interaction and Evolution of Jasmonate Signaling With Transport and Detoxification of Heavy Metals and Metalloids in Plants.

An increase in environmental pollution resulting from toxic heavy metals and metalloids [e.g., cadmium (Cd), arsenic (As), and lead (Pb)] causes serious health risks to humans and animals. Mitigation strategies need to be developed to reduce the accumulation of the toxic elements in plant-derived foods. Natural and genetically-engineered plants with hyper-tolerant and hyper-accumulating capacity of toxic minerals are valuable for phytoremediation. However, the molecular mechanisms of detoxification and accumulation in plants have only been demonstrated in very few plant species such as Arabidopsis and rice. Here, we review the physiological and molecular aspects of jasmonic acid and the jasmonate derivatives (JAs) in response to toxic heavy metals and metalloids. Jasmonates have been identified in, limiting the accumulation and enhancing the tolerance to the toxic elements, by coordinating the ion transport system, the activity of antioxidant enzymes, and the chelating capacity in plants. We also propose the potential involvement of Ca2+ signaling in the stress-induced production of jasmonates. Comparative transcriptomics analyses using the public datasets reveal the key gene families involved in the JA-responsive routes. Furthermore, we show that JAs may function as a fundamental phytohormone that protects plants from heavy metals and metalloids as demonstrated by the evolutionary conservation and diversity of these gene families in a large number of species of the major green plant lineages. Using ATP-Binding Cassette G (ABCG) transporter subfamily of six representative green plant species, we propose that JA transporters in Subgroup 4 of ABCGs may also have roles in heavy metal detoxification. Our paper may provide guidance toward the selection and development of suitable plant and crop species that are tolerant to toxic heavy metals and metalloids.

Chelating Fabrics Prepared by an Organic Solvent-Free Process for Boron Removal from Water.

A chelating fabric was prepared by graft polymerization of glycidyl methacrylate (GMA) onto a nonwoven fabric, followed by attachment reaction of N-methyl-D-glucamine (NMDG) using an organic solvent-free process. The graft polymerization was performed by immersing the gamma-ray pre-irradiated fabric into the GMA emulsion, while the attachment reaction was carried out by immersing the grafted fabric in the NMDG aqueous solution. The chelating capacity of the chelating fabric prepared by reaction in the NMDG aqueous solution without any additives reached 1.74 mmol/g, which further increased to above 2.0 mmol/g when surfactant and acid catalyst were added in the solution. The boron chelation of the chelating fabric was evaluated in a batch mode. Fourier transform infrared spectrophotometer (FTIR) was used to characterize the fabrics. The chelating fabric can quickly chelate boron from water to form a boron ester, and a high boron chelating ability close to 18.3 mg/g was achieved in the concentrated boron solution. The chelated boron can be eluted completely by HCl solution. The regeneration and stability of the chelating fabric were tested by 10 cycles of the chelation-elution operations. Considering the organic solvent-free preparation process and the high boron chelating performance, the chelating fabric is promising for the boron removal from water.

Changes in stability and in vitro digestion of egg-protein stabilized emulsions and β-carotene gels in the presence of sodium tripolyphosphate.

Egg proteins are effective emulsifiers and gelators in food systems. However, the physicochemical stability and control release properties of egg-protein stabilized emulsions and gels need to be further improved. The potential of sodium tripolyphosphate (St) to improve the functionality of egg proteins was evaluated. The emulsions with St had smaller particle sizes and higher zeta potential, leading to better physical stability. Furthermore, the oxidation stability increased with increasing St contents, possibly due to its metal chelating capacity and the improved emulsifying activity of whole-egg dispersions. Phosphate had a positive impact on the chemical stability of β-carotene in whole-egg liquids and gels, decreasing the degradation during thermal treatment. The gel made with St was firm and broke down slowly, leading to a low rate of digestion and β-carotene release in simulated gastric fluid. This study shows that St is useful to improve the egg proteins stabilized emulsions and gels, which is applicable in the development of emulsion-based food grade gel products. © 2021 Society of Chemical Industry.

Influence of organic acids on pentlandite bioleaching by Acidithiobacillus ferrooxidans LR.

Bioleaching is a bio-hydrometallurgical process of solubilizing metals from low-grade sulfide ores by microbial action employing chemolithoautotrophic microorganisms capable of promoting redox reactions. Organic acids have been applied in bioleaching once can act in two different ways; providing hydrogen ions for mineral acidolysis and complexing metals due to their chelating capacity. This study investigates the synergy of different organic acids (acetic, ascorbic, citric, lactic, and oxalic) and Acidithiobacillus ferrooxidans LR pentlandite bioleaching. The addition of oxalic acid had a positive effect on the Ni extraction during pentlandite biological-chemical leaching after 15days, and the yields observed were 45.6% (26.5mg Ni/g ore). The yields for Co extraction were meager, and Co extraction values were found to only 2.8% (1.6mg Co/g ore) in the presence of citric acid. A design of experiments with mixtures was used to evaluate the interaction of organic acids in bioleaching. According to simplex-centroid experiments, only citric acid presented a statistically significant effect and has contributed in a synergistic form in pentlandite biological-chemical leaching in the presence of A. ferrooxidans. This study provides a new synergistic bioleaching system to improve Ni and Co extraction from sulfide ores.

Effects of polysaccharide charge density on the structure and stability of carboxymethylcellulose-casein nanocomplexes at pH 4.5 prepared with and without a pH-cycle

Carboxymethylcellulose (CMC) can stabilize acidic casein dispersions but the CMC charge density effect has not been studied. The objective of the present work was to study the structure and stability of CMC-casein nanocomplexes at pH 4.5 using CMC with the degree of substitution (DS) of 0.7, 0.9, and 1.2. Dispersions were prepared at 1%w/v casein and casein:CMC mass ratios from 5:1 to 1:1 with and without a pH-cycle. The calcium chelating capacity of CMC was strengthened as the DS increased, which enhanced the partial disassociation of casein micelles and therefore improved the dispersion clarity. The lowest dispersion turbidity was observed at a casein:CMC mass ratio of 3:1 for all three kinds of CMC, and the pH-cycle, by alkalizing dispersion pH to 11.3 followed by acidifying to pH 4.5, further lowered the dispersion turbidity. Electrostatic attraction was the mechanism of complex formation at pH 4.5, and the CMC on the complex surface was critical to the stability against aggregation. Furthermore, increasing the DS of CMC resulted in smaller complexes and clearer dispersions. Particularly, the dispersions with a CMC:casein mass ratio of 3:1 after the pH-cycle had the absorbance at 600 nm of 1.25, 0.85, and 0.57, and the mean hydrodynamic diameter of 379, 392, and 188 nm at the DS of 0.7, 0.9, and 1.2 respectively; the increased DS also increased the stability of complexes against aggregation and precipitation at elevated ionic strengths, from 50 mM to 200 mM NaCl. The present findings may broaden the application of caseins in acidic systems.

Chemical profile, antioxidant and anti-inflammatory properties of Miconia albicans (Sw.) Triana (Melastomataceae) fruits extract

Ethnopharmacological relevanceMiconia albicans (Sw.) Triana has been widely used in Brazilian popular medicine for the treatment of several diseases. Aerial parts are used as an infusion to treat arthrosis and arthritis, to relieve rheumatic and stomach pains, and intestinal disorders due to its anti-inflammatory, anti-mutagenic anti-nociceptive, digestive and hepatoprotective properties. Aim of the studyThis study aimed to characterize the of M. albicans (Sw.) Triana fruits extract (MAFRE) chemical profile and to evaluate its antioxidant, anti-inflammatory and antitumor activities, as well as its toxicity. Materials and methodsMaceration with methanol as liquid extractor was used to prepare MAFRE. M. albicans (Sw.) Triana fruits chemical composition was characterized by UHPLC-QTOF-MS/MS and GC-FID (fatty acid methyl esters composition from lyophilized fruits). MAFRE antioxidant potential was evaluated in vitro using a combination of assays: Folin-Ciocalteu reducing capacity, DPPH• and ABTS radical scavenging ability and ferric reducing antioxidant power (FRAP). In vitro antiproliferative activity was investigated in four human tumor cell lines (U251, 786-0, HT29 and MDA-MB-231) while the effect on the non-tumor cell viability was assessed in the VERO cell line using the on-step MTT assay. In addition, in vivo anti-inflammatory effect was assessed by Croton oil-induced ear edema in mice followed by myeloperoxidase (MPO) activity evaluation. ResultsThirty-five compounds were identified by UHPLC-QTOF-MS/MS. Among it flavonoids derived from quercetin (8), myricetin (1), kaempferol (2), terpenoids (6) and other compounds (18). GC-FID analysis identified and quantified nine fatty acids: palmitic, stearic, arachidic, behenic, elaidic, oleic, eicosenoic, and linoleic acids. The most abundant fatty acids were polyunsaturated fatty acids (5.33 ± 0.17 mg g-1), followed by saturated fatty acids (2.38 ± 0.07 mg g-1) and monounsaturated fatty acids (1.74 ± 0.09 mg g-1). The extract revealed high content of phenolic compounds (43.68 ± 0.50 mg GAE/g of extract), potent antioxidant, and ferrous chelating capacities. Morever, it proved to be non-toxic to the VERO cells, not affecting cells viability (95% of viable cells). No antiproliferative effect against human tumor cell lines were found. Furthermore, MAFRE significantly (p<0.05) reduced ear edema (≈35%) and MPO activity (84.5%) having a statistical effect similar to traditional steroidal and non-steroidal anti-inflammatory drugs. ConclusionsTaken together, the results evidenced that M. albicans fruit extract has antioxidant properties, a higher concentration of phenolic compounds, flavonoids, fatty acids, and also topical anti-inflammatory activity with low toxicity of extract on VERO cells. Through the ethnomedicinal study, these findings supporting the popular use of M. albicans, but also highlight that not only aerial parts and leaves deserve attention, but the fruits also have anti-inflammatory proprieties and can be a source of phenolic compounds and other substances with potential health benefices.

Determination of Biological Activity and Active Substances of Thecocarpus Carvifolius (BOISS.) Hedge &amp; Lamond

We have studied the antioxidant activity and analyzed active substances of the aqueous and methanol extracts of endemic species Thecocarpus carvifolius Hedge and Lamond. The antioxidant activity was identified and assessed using the DPPH, FRAP and iron chelating capacity assay. Active substances were detection, total phenolic, flavonoids and volatile compounds were analyzed. According to DPPH analyzes, the inhibition percentage was 48.57% for aqueous extract and 76.34% for methanol extract. The FRAP reduction capacity was determined as 3.32 mg/mL for aqueous extract and 11.75 mg/mL FESO4 for methanol extract. The total concentrations of phenolics and flavonoids were calculated as 64.08 – 35.29 μg/mL and 146.84 – 555.66 μg/mL in aqueous and methanol extracts, respectively. Finally, five volatile compounds were detected in methanol extracts. The results indicated that the endemic species of T. carvifolius can be evaluated as a natural antioxidant plant.

Bioactive Compounds and Biochemical and Antioxidant Properties of Selected Minor Indigenous Fruits in Bangladesh

Minor fruits are a potential source of antinutrients, but there is no complete primary data source in the Bangladeshi context. Therefore, the present study was undertaken to acquire documentation for a database of the composition of selected minor fruits. The total phenolic (TPH), vitamin C, total carotene, and ß-carotene contents and antioxidant activity of selected minor fruits were determined by 1,1-diphenyl-2picryl hydrazyl (DPPH) scavenging and reducing power assays (RPA). Phenolic compounds were assessed using high-performance liquid chromatography coupled with a photodiode array detector and autosampler. Results revealed that minor fruits contain different phytochemicals, particularly TPH, ascorbic acid, total flavonoid (TF), ß-carotene, total carotenoid (TC), and total anthocyanin content (TAC); values ranged, respectively, 0.23-176.50 mg GAE/g, 16.67-664.92 mg/100 g, 2.26-150.02 mg QE/100 g, 1.41-6897.57 µg/100 g, 1.26-98.24 mg/100 g and 1.15-47.46 mg/100 g. In the parameters antioxidant activity, total antioxidant capacity, DPPH, reducing power capacity (RPC), ferric reducing antioxidant power (FRAP), metal chelating capacity (MCC), nitric oxide (NO), and free radical scavenging activity, IC50 ranged 0.01-278.24 µg of ascorbic acid/mg of extract, 39.70-250.00%, 3.21-634.00%, 0.02-1817.88 µM Fe2SO4/100g, 22.29-210.43%, 0.02-70.50%, and 4.98-856.70 µg/g, respectively. Among the identified and quantified phenolic acids, leading examples were gallic acid (279.06 mg/100 g), vanilic acid (43.77 mg/100 g), Þ-courmaric acid (178.96 mg/100 g), ferulic acid (20.44 mg/100 g), and lutein (91.13 µg/100 g) in aonla, day fruit, elephant apple, and bilimbi. Moreover, all selected minor fruits are rich sources of bioactive, biochemical, and antioxidant compounds with potential for use in therapeutic applications.

Shielding effect on oxidative stress and immune modulating potential of Himalayan Musk Rose (Rosa brunonii Lindl.)

Rosa brunonii Lindl., a wildly growing species of rose is used widely by the folklore of the Himalayan region for various food and traditional medicinal purposes. The present study aims to evaluate the protective effects against oxidative stress markers and immunomodulation of Rosa brunonii Lindl. The crude extracts (chloroform, methanol, and aqueous) and subsequent fractions (chloroform, ethyl acetate, acetone, methanol, and aqueous) of both the leaves and flowers were evaluated for antioxidant potential (DPPH free radicals scavenging, chelation capacity on ferrous ions, FRAP activity, and reducing activity), DNA protection (DNA strand nicking) and immunomodulatory potential (humoral antibody titre) and cell-mediated (DTH immune responses and lymphocytic proliferation). The antioxidant study indicated that among all, methanol fraction (leaves) possessed remarkable antioxidant potential with the highest DPPH free radical scavenging (IC50 32.3±1.15 µg/mL), chelation capacity on ferrous ions (66±0.22%), reducing power (EC50124.4±0.17 µg/mL), FRAP (3996±2.17 µM/g dry wt.) as well as highest amounts of total phenols (250±0.54 GAE mg/g dry wt.) and flavonoids (344±1.76 QE mg/g dry wt.). Moreover, a significant reduction in plasmid DNA damage was also observed. Immunomodulatory results of methanol fraction (flowers) at 100 µg/mL showed maximum stimulation with 125% on humoral response, 166% on cell-mediated response and significant suppressive effect on mitogen-induced lymphocytic proliferation. The active constituent identified in methanol fraction (leaves) through RP-HPLC analysis was myricetin and from methanol fraction (flowers) was p-coumaric acid. This study concluded that the leaves of R. brunonii are a rich source of natural antioxidants and immune-modulating agents which can be further explored for establishing their pharmacological potential.

Impact of in vitro gastrointestinal digestion on peptide profile and bioactivity of cooked and non-cooked oat protein concentrates

Oat (Avena sativa) is one of the most cultivated and consumed cereals worldwide. Recognized among cereals for its high protein content (12%–24%), it makes it an excellent source of bioactive peptides, which could be modified during processes such as heating and gastrointestinal digestion (GID). This work aims to evaluate the impact of heat treatment on the proteolysis of oat proteins and on the evolution of antioxidant peptide released during in vitro static GID, in terms of comparative analysis between cooked oat protein concentrate (COPC) and non-heated oat protein concentrate (OPC) samples. The protein extraction method and cooking procedure used showed no detrimental effects on protein quality. After GID, the proportion of free amino acids/dipeptides (<0.2 ​kDa) reached >40% for both samples (OPC and COPC), thus producing peptides with low molecular weight and enhanced bioactivity. Furthermore, during GID, the amino acid profile showed an increase in essential, positively-charged, hydrophobic and aromatic amino acids. At the end of GID, the reducing power of OPC and COPC increased >0.3 and 8-fold, respectively, in comparison to the non-digested samples; while ABTS•+ and DPPH• showed a >20-fold increase. Fe2+ chelating capacity of OPC and COPC was enhanced >4 times; similarly, Cu2+ chelation showed a >19-fold enhancement for OPC and >10 for COPC. β-carotene bleaching activity was improved 0.8 times in OPC and >9 times in COPC; the oxygen radical antioxidant capacity assay increased 2 times in OPC and >4.7 times in COPC, respectively. This study suggests that OPC after cooking and GID positively influenced the nutritional and bioactive properties of oat peptides. Thus, COPC could be used as a functional food ingredient with health-promoting effects, as hydrothermal treatment is frequently used for this type of cereals.

Synthesis and biological evaluation of 1,3,5-triazine-substituted ureido benzenesulfonamides as antioxidant, acetylcholinesterase and butyrylcholinesterase inhibitors

A series of twenty 1,3,5-triazine-substituted ureido benzenesulfonamides 2 (a-e) and 3 (a-o) were re-synthesized and assayed for antioxidant properties by using several different methods including 1,1-diphenyl-2-picryl hydrazyl (DPPH) free radical scavenging assay, 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cation radical decolarization assay, metal chelating and cupric reducing antioxidant capacity (CUPRAC) methods. The inhibitory effects of compounds on acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes have been also demonstrated. All compounds showed a greater antioxidant capacity against ABTS assay by having a more potent activity than the standards BHT, BHA and α-TOC. In general, all compounds were non susceptible to against AChE enzyme. On the other hand, several lead compounds were obtained from the current series against BChE enzyme. More specifically, compound 3m showed great inhibition profile against BChE with % inhibition value of 93.77, which is better than the standard drug galantamine (% inhibition value of 87.86).

A Review of Recent Studies on the Antioxidant Activities of a Third-Millennium Food: Amaranthus spp.

Amaranth (Amaranthus spp.) plant commonly refers to the sustainable food crop for the 21st century. The crop has witnessed significant attention in recent years due to its high nutritional value and agronomic advantages. It is a relatively well-balanced cosmopolitan food that is a protector against chronic diseases. Usually, the antioxidant activities of amaranth are held responsible for its defensive behavior. Antioxidant activity of plants, generally, is attributed to their phytochemical compounds. The current interest, however, lies in hydrolysates and bioactive peptides because of their numerous biological functions, including antioxidant effect. While the importance of bioactive peptides has been progressively recognized, an integrated review of recent studies on the antioxidant ability of amaranth species, especially their hydrolysates and peptides has not been generated. Hence, in this review, we summarize studies focused on the antioxidant capacity of amaranth renewal over the period 2015–2020. It starts with a background and overall image of the amaranth-related published reviews. The current research focusing on in vitro, in vivo, and chemical assays-based antioxidant activity of different amaranth species are addressed. Finally, the last segment includes the latest studies concerning free radical scavenging activity and metal chelation capacity of amaranth protein hydrolysates and bioactive peptides.

Antarctic fungus proteases generate bioactive peptides from caseinate

The extracellular serine protease produced by Acremonium sp. L1-4B isolated from the Antarctic continent, was purified and used for the proteolysis of bovine and caprine sodium caseinate. Protein hydrolysates were evaluated in vitro to determine their antioxidant and antihypertensive potential, and later characterized by mass spectrometry. Bovine and caprine hydrolysates produced over 24 h showed a higher content of copper chelation (25.8 and 31.2% respectively), also at this time the ABTS+• scavenging was 65.2% (bovine sample) and 67.5% (caprine sample), and bovine caseinate hydrolysate (8 h) exhibited higher iron chelation capacity (43.1%). Statistically (p < 0.05), caprine caseinate hydrolysates showed relatively higher antioxidant potential in this study. All hydrolysates showed antihypertensive potential; however peptides released from caprine caseinate after 8 h of hydrolysis were able to inhibit 75% of angiotensin-converting enzyme (ACE) activity. Nano-ESI-Q-TOF-MS/MS analysis prospected a total of 23 different peptide sequences in the bovine hydrolysate fraction, originated from the αS1- and β-casein chain, whilst in caprine hydrolysate, 31 sequences were detected, all from β-casein. The low molecular weight bovine and caprine hydrolysates obtained in this research have the potential to act in the prevention of disorders caused by oxidative reactions and in the regulation of blood pressure. These findings support the development of new functional food and nutraceutical formulations.

Miracle Fruit Leaf Extract: Antioxidant Activity Evaluation, Constituent Identification, and Medical Applications

A systematic study was carried out on the antioxidants in miracle fruit leaf extract. The total phenols, total flavonoids, saponins and the antioxidant activities of the extract were evaluated using the 2,2′-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azino-bis-3-ethyl-benzotiazolin-6-sulfonic acid (ABTS), metal chelating capacity (MCC) and ferric reducing antioxidant power (FRAP) assays. The results showed that the leaves contained high phenol concentrations of 90.0 ± 4.78 mg gallic acid equivalent/g dry weight, total flavonoids at 33.0 ± 1.92 mg rutin equivalent/g dry weight, and saponins at 27.8 ± 1.64 mg oleanolic acid equivalent/g dry weight. The extract possessed excellent free radical scavenging ability and high antioxidant capacities. Furthermore, eighteen polyphenol and flavonoid constituents in the extract were identified by using ultra-high performance liquid chromatography-diode array detector-tandem mass spectrometry (UPLC-DAD-MSn) method and standard chemicals. The constituents were gallic acid, 5-O-caffeoylquinic acid, 3-O-p-coumaroylquinic acid, 5-O-p-coumaroylquinic acid, 3-O-feruloylquinic acid, 4-O-caffeoylquinic acid, 4-O-p-coumaroylquinic acid dimer, 4-O-p-coumaroylquinic acid, 4-O-feruloylquinic acid, 4-O-feruloylquinic acid, rutin, myricetin-3-O-rhamnoside, quercetin-3-D-galactoside, quercetin-3-glucoside, kaempferol-3-O-glucoside, quercetin-3-rhamnoside, myricetin-O-galloylrhamnoside and quercetin-3-O-(2′′-galloyl)-rhamnoside.Eight constituents were quantified with values from 0.12 to 4.13 mg·g‒1. The extract of miracle fruit leaves was also used in an anti-Alzheimer's disease model for potential medical applications. The assay indicated that the extract provided apparent inhibition for the paralysis of Caenorhabditis elegans at a concentration of 0.02 mg·mL‒1. This work demonstrated that miracle fruit leaves are rich in bioactive antioxidants with potential for drug and functional product development.