Azinobis - ( 3-ethylbenzthiazoline-6-sulphonate Research Articles

Antioxidant Peptides Derived from Millet Bran Promote Longevity and Stress Resistance in Caenorhabditis elegans.

Millet bran as a by-product of millet grain processing remains a reservoir of active substances. In this study, functional millet bran peptides (MBPE) were obtained from bran proteins after alcalase hydrolysis and ultrafiltration. The activity of MBPE was assessed in vitro and in the model organism Caenorhabditis elegans (C. elegans). In vitro, compared to unhydrolyzed proteins, MBPE significantly enhanced the 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-Azinobis-(3-ethylbenzthiazoline-6-sulphonate (ABTS) and hydroxyl radicals scavenging activity, and the scavenging rate of MBPE with 15,000 U/g alcalase reached 42.79 ± 0.31%, 61.38 ± 0.41 and 45.69 ± 0.84%, respectively. In C. elegans, MBPE at 12.5µg/mL significantly prolonged the lifespan by reducing lipid oxidation, oxidative stress, and lipofuscin levels. Furthermore, MBPE increased the activities of the antioxidant enzymes. Genetic analyses showed that MBPE-mediated longevity was due to a significant increase in the expression of daf-16 and skn-1, which are also involved in xenobiotic and oxidative stress responses. In conclusion, this study found that MBPE had antioxidant and life-prolonging effects, which are important for the development and utilization of millet bran proteins as resources of active ingredients.

Effects of Polygonatum sibiricum on Physicochemical Properties, Biological Compounds, and Functionality of Fermented Soymilk.

The purpose of this study was to investigate the effects of Polygonatum sibiricum (P. sibiricum) on microbial fermentation, physicochemical properties, and functional properties of fermented soymilk. Three types of fermented soymilk were prepared. The first type was fermented directly from regular soymilk (fermented soymilk, FSM), and the other two were fermented after adding P. sibiricum (P. sibiricum fermented soymilk, P-FSM) or P. sibiricum polysaccharides (P. sibiricum polysaccharides fermented soymilk, PP-FSM). The differences in physical and chemical indexes such as pH value, acidity, and water-holding capacity were mainly compared, and the differences in the contents of functional components such as total phenols, total flavonoids, soy isoflavones, γ-aminobutyric acid, and organic acids were compared. The functionalities of the three samples in terms of antioxidant activity were evaluated, and the relevance of each active substance was explored. Compared with the FSM group, the addition of P. sibiricum and P. sibiricum polysaccharides could not only significantly promote the fermentation of Lactobacillus but also significantly improve the stability of the finished products during storage and prolong the shelf life of the finished product. The conversion rates of glycoside soybean isoflavones in the PP-FSM and P-FSM groups were 73% and 69%, respectively, which were significantly higher than those in the FSM group (64%). At the end of fermentation, the γ-aminobutyric acid contents of the PP-FSM and P-FSM groups were 383.66 ± 1.41 mg/L and 386.27 ± 3.43 mg/L, respectively, while that of the FSM group was only 288.66 ± 3.94 mg/L. There were also great differences in the content and types of organic acids among the three samples, especially lactic acid and acetic acid. By comparing the antioxidant capacity of DPPH (1,1-Diphenyl-2-picrylhydrazyl free radical), AB-TS (2,2'-Azinobis-3-ethylbenzthiazoline-6-sulphonate), and iron chelation, it was found that both PP-FSM and P-FSM were superior to FSM, and the antioxidant capacity had a certain correlation with the contents of total phenols and total flavonoids.

Effect of Flowering Stages on the Content of Active Ingredients and Antioxidant Capability of Bletilla striata Flowers.

Bletilla striata (Thunb.) Reichb.f. is a perennial herb with abundant active ingredients. Previous research mainly focused on its tubers, however, the study on flowers, especially the variation of active ingredient contents at different flowering stages, was rarely seen. This study analyzed the total phenols, flavonoids, polysaccharides, anthocyanins, and cyanidin-3-O-glucoside content of B. striata flowers which were in cultivated in Herb Garden of Zhejiang A&F University and collected in May, 2019, in order to investigate the changes in active ingredients and antioxidant capacity among different flowering stages (bud, initial, and full bloom). Changes in radical scavenging capability of DPPH (1,1-Diphenyl-2-picrylhydrazyl radical), ABTS (2,2'-azinobis(3-ethylbenzthiazoline-6-sulphonate)), and hydroxy were analyzed. Significant differences in active ingredient content of flowers were detected among different flowering stages. The total phenolic content increased continuously during the entire flowering stage. The contents of total flavonoid, total polysaccharide, and cyanidin-3-O-glucoside reached peaks at the initial blooming stage and then fell as the flowering process continued. The antioxidant activity in initial stage was the highest than in any other flowering stages. Therefore, we conclude that the initial blooming stage is the best harvesting stage of B. striata flowers. This study provides a robust basis for the harvest and utilization of B. striata flowers in food, medical, and cosmetic industries.

A Composition Analysis and an Antibacterial Activity Mechanism Exploration of Essential Oil Obtained from Artemisia giraldii Pamp.

The goal of this work was to use the GC-MS technique to explore the chemical components of Artemisia giraldii Pamp essential oil (AgEo) and to uncover its antibacterial activity, specifically the antibacterial mechanism of this essential oil. There were a total of 63 chemical constituents in the AgEo, monoterpenes (10.2%) and sesquiterpenes (30.14%) were found to be the most common chemical components, with camphor (15.68%) coming in first, followed by germacrene D. (15.29%). AgEo displayed significant reducing power and good scavenging ability on hydroxyl radicals, 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radicals, and 2,2'-Azinobis-(3-ethylbenzthiazoline-6-sulphonate (ABTS) radicals, according to antioxidant data. The diameter of the inhibition zone (DIZ) of AgEo against S. aureus and E. coli was (14.00 ± 1.00) mm and (16.33 ± 1.53) mm, respectively; the minimum inhibitory concentration (MIC) of AgEo against E. coli and S. aureus was 3 μL/mL and 6 μL/mL, respectively; and the minimum bactericidal concentration (MBC) of AgEo against E. coli and S. aureus was 6 μL/mL and 12 μL/mL, respectively. The antibacterial curve revealed that 0.5MIC of AgEo may delay bacterial growth while 2MIC of AgEo could totally suppress bacterial growth. The relative conductivity, alkaline phosphatase (AKP) activity, and protein concentration of the bacterial suspension were all higher after the AgEo treatment than in the control group, and increased as the essential oil concentration was raised. In addition, the cell membrane ruptured and atrophy occurred. The study discovered that AgEo is high in active chemicals and can be used as an antibacterial agent against E. coli and S. aureus, which is critical for AgEo's future research and development.

Efficient removal of sulfonamides and tetracyclines residues by the laccase-mediator system employing a novel laccase from Lysinibacillus fusiformis

The laccase-mediator system (LMS) is an important solution to eliminate veterinary residues. In this study, a novel laccase from Lysinibacillus fusiformis (Lyfu-Lac) showed promising removal efficiency towards sulfonamides and tetracyclines residues in the presence of syringic acid (SA) and 2'-Azinobis-3-ethylbenzthiazoline-6-sulphonate (ABTS). The optimum temperature of Lyfu-Lac against ABTS was 80 °C, which is much higher than that of most laccases. At 40 °C, more than 85% of sulfamethazine (SMZ), sulfamethoxazole (SMX), and sulfadiazine (SDZ) were removed by the Lyfu-Lac-SA system after 12 h. Meanwhile, tetracycline (TC), and oxytetracycline (OTC) were significantly reduced to 0% and 16.9% by the Lyfu-Lac-ABTS system after 6 h. Based on the analysis of transformation products (TPs), a two-step reaction was reasonably proposed in the removal of sulfonamides: (i) the oxidation of mediators by Lyfu-Lac to radicals, (ii) the adductive reaction between radicals and sulfonamides. Moreover, the removal mechanism of tetracyclines was proposed, including the cleavage of the N-N bond after the adductive reaction between ABTS radicals and tetracyclines.

Distribution of free and bound phenolic compounds, β-glucan, and araboxylan in fractions of milled hulless barley

To study the effect of milling process on active compounds in hulless barley, the β-glucan, araboxylan, the free and bound forms of phenolic compounds and antioxidant activities were evaluated. The results showed that total araboxylan content (9.64 g/100 g → 2.35 g/100 g) decreased significantly (P < 0.05) from the outer to the inner layer, while the β-glucan content first increased significantly going towards the inner layers and showed a gradual decrease moving toward the endosperm. Total free and bound forms of total phenolics and total flavonoids decreased by 91% and 95% with the increase of the degree of milling and anthocyanins mostly existed in the outer layers. The total DPPH (2,2-Diphenyl-1-picrylhydrazyl) and ABTS (2,2′-Azinobis-(3-ethylbenzthiazoline-6-sulphonate)) antioxidant activities decreased by 90% and 97% from the outer to the inner layers. Both free and bound forms of 21 phenolic compounds decreased significantly (P < 0.05) with increased milling and were mostly in the outermost layer. Moreover, eight diferulic acids were reported for the first time in hulless barley, and ferulic acid was the most abundant monomeric phenolic acid, with 8-O-4′ diferulic acid being the most abundant diferulic acid and chrysoeriol-7-O-glucouronide being the dominant flavonoid. Therefore, a lower degree milling is recommended for the higher retainment of bioactive compounds during daily processing.

Optimization of Extraction of Bioactive Peptides from Monkfish (Lophius litulon) and Characterization of Their Role in H2O2-Induced Lesion.

Background: Marine fish meat has been widely used for the extraction of bioactive peptides. This study was aimed to optimize the preparation of monkfish muscle peptides (LPs) using response surface methodology (RSM) and explore the antioxidant activities of <1 kDa LPs. Methods: Peptides were prepared from the muscles of monkfish (Lophius litulon), and five proteases were tested to hydrolyze muscle proteins. The hydrolysate that was treated using neutrase showed the highest degree of hydrolysis (DH) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activities. Results: The optimized conditions were as follows: water/material ratio of 5.4:1, a time span of 5 h, pH of 7.0, enzyme concentration of 2000 U/g, and temperature of 45 °C; the maximum DPPH scavenging activity and DH were 92.861% and 19.302%, respectively. LPs exhibited appreciable antioxidant activities, including DPPH radical, hydroxyl radical, 2,2′-azinobis-3-ethylbenzthiazoline-6-sulphonate (ABTS) radical, and superoxide anion scavenging activities. LPs attenuated H2O2-related oxidative injury in RAW264.7 cells, reduced the reactive oxygen species (ROS) and malondialdehyde (MDA) levels, and increased the superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) levels. Conclusion: We concluded that LPs could be an ideal source of bioactive peptides from monkfish and also have pharmaceutical potential.

Polyphenol composition and antioxidant potential of mint leaves

Soluble and insoluble/bound phenolic compounds and an aqueous infusion of two mint species (Medina and Hasawi), were tested for their total phenolic content, 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonate (ABTS) and 1,1-diphenyl-2picrylhydrazyl (DPPH) radical scavenging activity, iron (III) reduction, iron (II) chelating and oxygen radical absorbance capacity (ORAC). Furthermore, the potency of the mint extracts in the inhibition of radical-induced DNA scission, human low-density lipoprotein (LDL) cholesterol oxidation, formation of thiobarbituric acid reactive substances (TBARS) in a cooked ground meat system and LPS (lipopolysaccharide)-stimulated cyclooxygenase-2 (COX-2) expression in J774A.1 mouse macrophage cells were monitored. Results showed that the soluble phenolics had a higher phenolic content and antioxidant activity than the insoluble-bound extracts and aqueous infusions in most of the assays. Both varieties exhibited notable antioxidant activities and inhibition of LDL cholesterol oxidation, DNA scission and COX-2 gene expression at transcriptional level. However, Medina mint was a more potent antioxidant than the Hasawi mint. High performance liquid chromatography with online tandem electrospray ionization mass spectrometry (HPLC/ESI-MS/MS) analysis of the extracts revealed that rosmarinic acid was the major phenolic compound present in both mint samples.Graphical abstract

Phenolic composition, antioxidant and anticholinesterase properties of the three mushrooms Agaricus silvaticus Schaeff., Hydnum rufescens Pers. and Meripilus giganteus (Pers.) Karst. in Tunisia

Mushrooms have been used both for food and medicine purposes for centuries. This paper provides a chemical study of Agaricus silvaticus Schaeff., Hydnum rufescens Pers. and Meripilus giganteus (Pers.) Karst. extracts and an evaluation of their antioxidant and anticholinesterase activities.Chemical investigations allowed as to note that the highest flavonoids and polyphenols contents are represented respectively in the ethyl acetate extract of A. silvaticus (47.06 ± 2.4 mg catechin g−1) and the methanolic extract of H. rufescens (32.54 ± 1.9 mg catechin g−1). While the highest amount of tannins (98.2 ± 4.8 mg catechin g−1) is present in M. giganteus ethyl acetate extract.The antioxidant activity was evaluated using 1,1-Diphenyl-2-Picrylhydrazyl (DPPH), 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulphonate (ABTS), Ferric-Reducing Antioxidant Power (FRAP) and Catalase Activity Assay (CAT). The ethyl acetate extract of H. rufescens showed the highest antioxidant activity (IC50 = 0.852 ± 0.003 mg mL−1) by the DPPH method as well as a significant catalase activity (448.430 ± 0.002 μmol H2O2 degraded/min/protein).The anticholinesterasic activity showed 63.10% inhibition against butyrylcholinesterase by the methanolic extract of H. rufescens at the concentration of at 10 mg mL−1. The cholinesterase inhibition decreases with the concentrations decrease until its total disappearance at a concentration of 0.312 mg mL−1.

Ionic Liquid⁻Ultrasound-Based Extraction of Biflavonoids from Selaginella helvetica and Investigation of Their Antioxidant Activity.

As a new and green solvent, ionic liquids (ILs) have received more attention during the green extraction and separation process for natural medicines. In this paper, IL-ultrasound-assisted extraction (IL-UAE) of total biflavonoids (TBFs) from Selaginella helvetica was firstly developed, and different ILs were employed and compared. Based on single-factor experiment, solid–liquid ratio (1:10–1:14 g/mL), IL concentration (0.6–1.0 mmol/mL), and extract temperature (40–60 °C) were further explored, according to response surface methodology (RSM), with TBF yields as the index. Moreover, antioxidant activity of TBF extract was analyzed by four methods, i.e., 2,2-di(4-tert-octylphenyl)-1-picrylhydrazyl (DPPH) and 2,2′-azinobis-(3-ethylbenzth-iazoline-6-sulphonate (ABTS) free radical scavenging assay, ferric ion reducing power assay, and chelation of ferrous ions assay. The results indicated that [C6mim]PF6 had a high selectivity and efficiency. Moreover, important parameters for the extraction process were investigated and optimized. Through parameter optimization (0.8 mmol/L, 250 W, 40 min, 1:12.7 g/mL, and 47 °C), a yield of 18.69 mg/g biflavonoids was obtained from the extract of S. helvetica. Compared with ethanol-UAE, heat-reflux extraction, Soxhlet extraction, and percolation extraction, IL-UAE could not only obtain higher yield in a shorter time, but also reduce the solvent consumption. In addition, TBF extract showed potential antioxidant activity based on the above four antioxidant methods. In short, IL-UAE was first employed to develop a novel and green extraction method for TBF content, and this experiment provides valuable references for further utilization of S. helvetica.

A potentially functional yogurt co-fermentation with Gnaphalium affine

A potentially functional yogurt co-fermentation with Gnaphalium affine was prepared and its quality and antioxidant properties were investigated. According to the classic procedure, a novel yogurt was successfully prepared with Gnaphalium affine extract (EGA). During the storage period, the pH value and titratable acidity of yogurt showed no obvious changes compared with control. However, the texture properties of yogurt, such as firmness, adhesiveness, cohesiveness and springiness, could be effectively improved. Moreover, the yogurt possessed the lower syneresis susceptibility and higher viability of Lactobacillus bulgaricus and Streptococcus thermophilus than the control. Furthermore, the yogurt showed remarkable antioxidant potential to scavenge 2, 2′-azinobis-3-ethylbenzthiazoline-6-sulphonate (ABTS), 1,1-diphenyl-2-picrylhydrazyl (DPPH), superoxide and hydroxyl radicals. Meanwhile, the yogurt could enhance the activities of antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px), and it could also lead to a significant decrease of malondialdehyde (MDA) level in animal serums. The current results suggest that the yogurt co-fermentation with EGA possesses high quality properties and remarkable antioxidant potential, and thus has the great potential to be used as a novel functional food product in food industry.

Changes in structure and antioxidant activity of β-lactoglobulin by ultrasound and enzymatic treatment

Effects of ultrasound (20–40% amplitudes at 45–55 °C) and enzymatic (pepsin and trypsin) treatment on structure and antioxidant activity of β-lactoglobulin were studied. Changes in structure of β-lactoglobulin were investigated using spectroscopy techniques and changes in antioxidant activity were measured by chemical and cellular-based assays. Ultrasound treatment had considerable impact on the structure of β-lactoglobulin and increased the susceptibility of β-lactoglobulin to both pepsin and trypsin proteolysis. Intrinsic fluorescence intensity of β-lactoglobulin was increased by ultrasound and then decreased after following enzymatic treatment. Compared with control, the β-lactoglobulin after ultrasound and enzymatic treatments showed significantly higher oxygen scavenging activities in Caco-2 cells models, ABTS (2, 2′-Azinobis-3-ethylbenzthiazoline-6-sulphonate) radical scavenging activity and oxygen radical absorbance capacity (p < 0.05). Results indicated that ultrasound treatment increased the proteolysis of β-lactoglobulin by both pepsin and trypsin and improved the antioxidant activity of the protein and its proteolytic products.

Enrichment, purification and in vitro antioxidant activities of polysaccharides from Umbilicaria esculenta macrolichen

Umbilicaria esculenta as an edible macrolichen possesses nutritional properties, such as antioxidant, immune-boosting, and lipid peroxidation inhibitory properties. A new enrichment and separation technology for the polysaccharides from Umbilicaria esculenta (UEP) with AB-8 resin was established, and its adsorption data were well fitted to the pseudo-second-order kinetic model and the Langmuir isotherm, with a process of monolayer coverage of UEP onto it. After purification by DEAE (diethylaminoethyl) Cellulose-52 chromatography, two polysaccharide fractions (UEP-1, UEP-2) were obtained and characterized. UEP-1 was composed of mannose, rhamnose, glucose and galactose in a molar ratio of 0.59:3.12:93.09:3.20 with a molecular weight of 124.7kD, while UEP-2 comprised mannose and glucose in a molar ratio of 20.66:79.34 with a molecular weight of 249.4kD. With DPPH (2, 2-diphenyl-1-picrylhydrazyl), ABTS (2,2′-Azinobis-(3-ethylbenzthiazoline-6-sulphonate), superoxide anion, and hydroxyl scavenging capacities as indices, their antioxidative assays in vitro indicated that the polysaccharides exhibited the very strong scavenging activities in a concentration-dependent manner. It was worth expecting that UEP could be developed as a novel potential functional component in food industries.

Optimization of Ionic Liquid-Assisted Extraction of Biflavonoids from Selaginella doederleinii and Evaluation of Its Antioxidant and Antitumor Activity

As new green solvents, ionic liquids (ILs) have been generally applied in the extraction and separation of natural product. In this study, microwave assisted extraction based on IL (IL-MAE) was firstly employed to extract total biflavonoids from Selaginella doederleinii. Based on single-factor experiment, microwave power (300–700 W), extract time (30–50 min) and extract temperature (40–60 °C) on total bioflavonoids and antioxidant activities of the extracts were further investigated by a Box-Behnken design of response surface methodology (RSM) selecting total bioflavonoids yields and IC50 of radical scavenging as index. Besides antioxidant activity of the extract was evaluated by a 2,2-diphenyl-1-picrylhydarzyl (DPPH) and 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulphonate (ABTS) radical scavenging assay, ferric reducing power assay and chelation of ferrous ions assay, and then anticaner activity was also researched against A549 cell line and 7721 cell line. The results illustrated that three factors and their interactions could be well suited for second-order polynomial models (p < 0.05). Through process parameters, optimization of the extract (460 W, 40 min, and 45 °C) and detection of bioactivity, the yield of total bioflavonoids was 16.83 mg/g and IC50 value was 56.24 μg/mL, respectively, indicating the extract has better anti-oxidation effect and antitumor activity. Furthermore, IL-MAE was the most efficient extracting method compared with MAE and Soxhlet extraction, which could improve extraction efficiency in a shorter time and at a lower temperature. In general, ILs-MAE was first adopted to establish a novel and green extraction process on the yields of total biflavonoids from S. doederleinii. In addition, the extract of containing biflavones showed potent antioxidant and anticancer capacity as a utilized valuable bioactive source for natural medicine.

First Evaluation of the Biologically Active Substances and Antioxidant Potential of Regrowth Velvet Antler by means of Multiple Biochemical Assays

We investigated the biologically active substances contained in RVA (regrowth velvet antler) by comparing the composition of biologically active substances and antioxidant potential of different antler segments. RVA was subjected to extraction using DW (distilled water). RVA was divided into 3 segments: T-RVA (top RVA), M-RVA (middle RVA), and B-RVA (base RVA). The T-RVA section possessed the greatest amounts of uronic acid (36.251 mg/g), sulfated GAGs (sulfated glycosaminoglycans) (555.76 mg/g), sialic acid (111.276 mg/g), uridine (0.957 mg/g), uracil (1.084 mg/g), and hypoxanthine (1.2631 mg/g). In addition, the T-RVA section possessed the strongest antioxidant capacity as determined by DPPH, H2O2(hydrogen peroxide), hydroxyl, and ABTS (2,2′-azinobis-3-ethylbenzthiazoline-6-sulphonate) radical scavenging activity as well as FRAP (ferric reducing antioxidant power) and ORAC (oxygen radical absorbance capacity). The values of those were 53.44, 23.09, 34.12, 60.31, and 35.81 TE/μM at 1 mg/mL and 113.57 TE/μM at 20 μg/mL. These results indicate that the T-RVA section possesses the greatest amount of biologically active substances and highest antioxidant potential. This is the first report on the biologically active substances and antioxidant potential of RVA.

Partial purification and characterization of ligninolytic enzymes produced by Pleurotus ostreatus during solid state fermentation

The production of ligninolytic enzymes including laccase, manganese peroxidase and lignin peroxidase from Pleurotus ostreatus was studied under different parameters using solid state fermentation. Maximum production of enzymes was observed after 7 days in solid state fermentation (SSF) medium containing 5 g wheat straw (66% w/w moisture) in a still culture SSF. Different parameters had a significant effect on enzyme production. Maximum laccase (455.11 U/mL), manganese peroxidase (210.77 U/mL) and lignin peroxidase (54.50 U/mL) were produced when wheat straw (5 g) at 66% moisture (w/w) was used with 4 mL inoculum at pH 4.5 and 30°C in the presence of 1% (v/v) glycerol as carbon source, 0.2% w/w urea as nitrogen source, 1% (w/v) 2, 2 azinobis 3-ethylbenzthiazoline 6 sulphonate (ABTS) as an inducer for laccase and 1% (w/v) MnSO 4 for manganese peroxidase,1% (w/v) CuSO 4 as metal ion for laccase and Mn + for manganese peroxidase. Both enzymes laccase and manganese peroxidase produced by Pleurotus ostreatus were partially purified by ammonium sulphate precipitation followed by gel filtration chromatography. Additionally, the protein content of the recovered supernatants was also noted. Purification results showed an increase in purity up to 3.37 and 3.07 fold for laccase and manganese peroxidase, respectively. The Michaelis constant, KM was 62 and 33 µM for laccase and manganese peroxidase, respectively. Lignin peroxidase was not produced during solid state fermentation of ligniocellulosic material by P. ostreatus because this fungus is a laccase producer. The activators ABTS and MnSO 4 proved good for laccase and MnP production. This shows that SSF parameters had a significant influence on catalytic activity of ligninolytic enzymes produced by P. ostreatus under still conditions.