Azino-bis(3-ethylbenzothiazoline-6-sulfonic Acid) Diammonium Salt Research Articles

Optical Biosensors Based on Nitrogen‐Doped Graphene Functionalized with Magnetic Nanoparticles

Nanocomposites from nitrogen‐doped graphene (NG) and magnetic nanoparticles (MNPs) are prepared via an edge‐functionalized ball milling approach, followed by a coprecipitation method. Catalytic peroxidase‐like activity of the resulting MNP/NG is investigated. The as‐synthesized MNP/NG nanocomposites are used to catalyze the colorimetric reaction between hydrogen peroxide (H2O2) and 2,2′‐azino‐bis(3‐ethylbenzo‐thiazoline‐6‐sulfonic acid) diammonium salt (ABTS). Typical absorption peaks associated with the oxidation of ABTS are found to increase linearly with increasing H2O2 concentrations up to 10.0 × 10−3 m with a detection limit of 17.1 × 10−6 m. Rapid detection of H2O2 with the use of MNP/NG is confirmed further by a glucose biosensor. Concentrations of glucose could be monitored by detection of H2O2 since H2O2 is generated during oxidation of glucose by glucose oxidase (GOx). The absorption intensity increases significantly with increasing glucose amounts up to 18.0 × 10−3 m glucose, with a detection limit of 59.7 × 10−6 m, indicating a high performance for glucose detection.

Antioxidant properties and UPLC-MS/MS profiling of phenolics in jacquemont's hazelnut kernels (Corylus jacquemontii) and its byproducts from western Himalaya.

A rapid and selective analytical method was developed to simultaneously quantify seven polyphenolic compounds (gallic acid, catechin, epicatechin, quercetin, kaempferol, syringic acid and p-coumaric acid). 15 phenolics of diverse groups in 80% ethanolic extracts of jacquemont's hazelnut (Corylus jacquemontii) kernels and its byproducts from western Himalaya using ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) were identified. The developed analytical method showed excellent linearity, repeatability and accuracy. Total phenols concentrations were found to be 4446, 1199 and 105 mg gallic acid equivalent (GAE)/Kg of dried extract for jacquemont's hazelnut skin, hard shell and kernels respectively. Antioxidant potential of defatted, raw jacquemont's hazelnut skin, hard shell and kernel extracts assessed by 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), 2,2'-diphenyl-1-picrylhydrazyl (DPPH) methods were increased in a dose-dependent manner. The IC50 values were observed as 23.12, 51.32, 136.46 and 45.73, 63.65, 169.30μg/ml for jacquemont's hazelnut skin, hard shell, kernels by DPPH and ABTS assays, respectively. The high phenolic contents in jacquemont's hazelnut skin contributed towards their free radical scavenging capacities.

In vitro synergistic antioxidant activity of honey-Mentha spicata combination

The beneficial health effects including antioxidant properties of mint (Mentha spicata) and honey have been extensively studied. However, there is no data about the effect of their associated use. In this study the total phenolic and flavonoid contents of individual extracts of mint and honey and their combination were determined. The antioxidant activity was investigated by using reducing power, 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2´-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid diammonium salt (ABTS), and chelating power methods. The results showed that individual extracts contained important quantity of phenolics and flavonoids and their combination was found to produce best antioxidant activity. A positive correlation between the phenolic/flavonoid contents and antioxidant activity, especially with free radical scavenging ability and chelating power, was observed. These findings suggest that combined mixture of honey and mint could be used as promising additive foods.

Antioxidant Contents and Antioxidant Activities of White and Colored Potatoes (Solanum tuberosum L.).

This study was performed to evaluate and compare the antioxidant substance content and antioxidant activities of white (Superior) and colored (Hongyoung, Jayoung, Jasim, Seohong, and Jaseo) potatoes. The potatoes were extracted with 80% ethanol and were evaluated for the total polyphenol, flavonoid, and anthocyanin contents and for 1,1-diphenyl- 2-picrylhydrazyl (DPPH)/2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activity, reducing power, and ferrous metal ion chelating effect. The total polyphenol, flavonoid, and anthocyanin contents of Hongyoung and Jayoung were higher than white and other colored potatoes. All colored potato extracts, except for Jaseo and Seohong, showed higher ABTS radical scavenging activities than the general white potato extract. Hongyoung and Jayoung had the highest ABTS and DPPH radical scavenging activities. Optical density values for the reducing power of Jayoung and Jaseo at concentration of 2 mg/mL were 0.148 and 0.090, respectively. All colored potato extracts had lower ferrous metal ion chelating effect than the white potato. A significant (P<0.05) positive correlation was observed between total polyphenol content and total flavonoid content (r=0.919), anthocyanin content (r=0.992), and ABTS radical scavenging activity (r=0.897). Based on these results, this research may be useful in developing the Hongyoung and Jayoung cultivars with high antioxidant activities.

Self-validating lab-on-a-chip for monitoring enzyme-catalyzed biological reactions

This paper reports on a miniaturized and highly integrated lab-on-a-chip (LoC) combining both optical and electrochemical transduction modes for self-validating determination of biological analytes that undergo enzyme-catalyzed-reactions. This LoC monolithically integrates a biofunctionalized microfluidic mixer, also working as bioreactor, together with a measurement chamber, both fabricated in polydimethylsiloxane (PDMS) and applied for enzyme-mediated detection of glucose in continuous flow regime. The measurement chamber combines a multiple internal reflection (MIR) photonic cuvette and a tailor-made electrochemical cell, where gold electrode areas are defined by a silicon oxide passivation layer. Having separated mixing/reaction and measurement chambers greatly facilitates the functionalization process during the microsystem fabrication and the further calibration/rinsing steps carried out during the microsystem performance. A cascade bi-enzymatic reaction involving glucose oxidase (GOx) and horseradish peroxidase (HRP) together with azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) mediator is applied to carry out the glucose dual detection. The optical and electrochemical properties of the ABTS enable simultaneous absorbance and amperometric measurements, without cross-talk. The system requires low sample volumes below 15μL and presents tunable analytical properties that can be adjusted by varying the flow rate. Linear ranges extending up to 1.6mM and 2mM glucose and limits of detection of 0.23±0.02mM and 0.064±0.001mM are achieved with the optical and electrochemical detection approaches, respectively, when operating simultaneously at 10μL/min flow rate. The high degree of integration results in a minimization of dead volumes, reagent consumption and response time, providing with a high performance self-validating structure ideal for biomedical applications.

Synthesis and Antioxidant Activity of Alkyl Nitroderivatives of Hydroxytyrosol.

A series of alkyl nitrohydroxytyrosyl ether derivatives has been synthesized from free hydroxytyrosol (HT), the natural olive oil phenol, in order to increase the assortment of compounds with potential neuroprotective activity in Parkinson’s disease. In this work, the antioxidant activity of these novel compounds has been evaluated using Ferric Reducing Antioxidant Power (FRAP), 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), and Oxygen Radical Scavenging Capacity (ORAC) assays compared to that of nitrohydroxytyrosol (NO2HT) and free HT. New compounds showed variable antioxidant activity depending on the alkyl side chain length; compounds with short chains (2–4 carbon atoms) maintained or even improved the antioxidant activity compared to NO2HT and/or HT, whereas those with longer side chains (6–8 carbon atoms) showed lower activity than NO2HT but higher than HT.

Antioxidant Capacity and Phenolic Contents of Three &lt;i&gt;Quercus&lt;/i&gt; Species

The antioxidant capability and phenolic contents of ethanol extracts (free phenolics) and ethyl acetate extracts (bound phenolics) of three Quercus species were estimated in this work. The antioxidant activities were examined by 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) free radical, reducing power and b-carotene bleaching methods. HPLC was employed to detect major phenolic acids. The leaf extract of Q. salicina contained maximum total phenolics while the highest total flavonoid content was found in the leaf extract of Q. serrata. The antioxidant activities varied among three species. Bark extract of Q. salicina was the most potential and it was closed to levels of the standard antioxidative dibutyl hydroxytoluene (BHT). The bark extract of Q. serrata also showed promising antioxidant activities despite their eminence was negligibly lower than Q. salicina. Stronger antioxidant activities of free phenolics than those of the bound phenolics may be attributed to higher quantities of free phenolics in the barks of Quercus species, however total flavonoids may not contribute a critical role. By HPLC analysis, thirteen phenolic acids were detected in the leaf and bark extracts. Of them, Q. salicina showed maximum in number (ten compounds) and quantities of detected phenolic acids. Ellagic, chlorogenic and benzoic acids were dominant in Quercus species. Findings of this study revealed that leaves and barks of three Quercus species are rich source of antioxidants, and Q.salicina is the most promising and should be elaborated to exploit its pharmaceutical properties.

Impacts of redox-mediator type on trace organic contaminants degradation by laccase: Degradation efficiency, laccase stability and effluent toxicity

This study compares the effectiveness of seven redox-mediating compounds namely, 1-hydrozybenzotriazole (HBT), N-hydroxyphthalimide (HPI), 2,2,6,6-Tetramethyl-1-piperidinyloxy (TEMPO), violuric acid (VA), syringaldehyde (SA), vanillin (VA), and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), which follow distinct oxidation pathways, for the degradation of trace organic contaminants (TrOCs). These redox-mediators were investigated for improved degradation of four TrOCs showing resistance to degradation by crude laccase from the white-rot fungus Pleurotus ostreatus. ABTS and VA achieved the highest degradation of the phenolic compounds (i.e., oxybenzone and pentachlorophenol), whereas the non-phenolic compounds (i.e., naproxen and atrazine) were best removed using VA or HBT. This implies that the non-phenolic compounds are more effectively removed by the radical species generated by the NOH type mediators (i.e., VA and HBT), while removal of the phenolic compounds may depend more on the stability and the redox potential of the radicals generated from the mediator, irrespective of the type. Notably, enzyme stability was greatly affected by the NOH type mediators but it was compensated by their rapid degradation capacity. Overall, VA and HBT (NOH type) appear to be the best mediators for enhanced degradation of the selected compounds without causing significant toxicity in the effluent.

Antioxidant Capacity and Phenolic Contents of Three &lt;i&gt;Quercus&lt;/i&gt; Species

The antioxidant capability and phenolic contents of ethanol extracts (free phenolics) and ethyl acetate extracts (bound phenolics) of three Quercus species were estimated in this work. The antioxidant activities were examined by 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) free radical, reducing power and b-carotene bleaching methods. HPLC was employed to detect major phenolic acids. The leaf extract of Q. salicina contained maximum total phenolics while the highest total flavonoid content was found in the leaf extract of Q. serrata. The antioxidant activities varied among three species. Bark extract of Q. salicina was the most potential and it was closed to levels of the standard antioxidative dibutyl hydroxytoluene (BHT). The bark extract of Q. serrata also showed promising antioxidant activities despite their eminence was negligibly lower than Q. salicina. Stronger antioxidant activities of free phenolics than those of the bound phenolics may be attributed to higher quantities of free phenolics in the barks of Quercus species, however total flavonoids may not contribute a critical role. By HPLC analysis, thirteen phenolic acids were detected in the leaf and bark extracts. Of them, Q. salicina showed maximum in number (ten compounds) and quantities of detected phenolic acids. Ellagic, chlorogenic and benzoic acids were dominant in Quercus species. Findings of this study revealed that leaves and barks of three Quercus species are rich source of antioxidants, and Q.salicina is the most promising and should be elaborated to exploit its pharmaceutical properties.

Quercetin and curcumin in nanofibers of polycaprolactone and poly(hydroxybutyrate‐co‐hydroxyvalerate): Assessment of in vitro antioxidant activity

ABSTRACTPolymeric nanofibers are materials that can be used as scaffolds in tissue engineering. Quercetin and curcumin are antioxidants because of scavenge free radicals and chelate metal ions properties, protecting tissues of lipid peroxidation. The objective of this study was to develop a scaffold with potential antioxidant activity that was produced from nanofibers consisting of polycaprolactone (PCL) and a blend of PCL/poly(hydroxybutyrate‐co‐hydroxyvalerate) (PHB‐HV) with the addition of quercetin or curcumin as the bioactive compound. Curcumin and quercetin were integrated into the solution at a concentration of 3%. The electrospun nanofibers were characterized using calorimetry and thermogravimetric analysis, and the addition of bioactive compounds did not alter the thermal properties of the biomaterial. The antioxidant activity of scaffolds with the active compounds was evaluated by hydrate 2,2‐diphenyl‐2‐picrylhydrazyl (DPPH) and 2,2′‐azinobis (3‐ethylbenzothiazoline‐6‐sulfonic acid) diammonium salt (ABTS) methods. The scaffolds with PCL and PCL/PHB‐HV blend with quercetin exhibited higher antioxidant activity than curcumin with both methods. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43712.

Estimated daily intake of phenolics and antioxidants from green tea consumption in the Korean diet

To estimate daily intake of total phenolics and flavonoids from green tea and the contribution of green tea to the antioxidant intake from the Korean diet, 24 commercial brands of green tea were selected and analyzed. Data from the Korea National Health and Nutrition Examination Survey (KNHANES) from 2008 and 2011 indicate that the green tea consumption in these 2 years was 2.8 g/tea drinker/day and 2.9 g/tea drinker/day, respectively. Based on data derived from direct measurements of green tea phenolics and the dataset of the 2008 KNHANES, we estimated the daily per tea drinker phenolics intake to be 172 mg gallic acid equivalents (GAE), the total flavonoids to be 43 mg catechin equivalents (CE) and the total antioxidants to be 267 mg vitamin C equivalents (VCE; 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay) and 401 mg VCE (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) assay). In 2011, we estimated the daily per tea drinker total phenolics intake to be 246 mg GAE, the total flavonoids to be 60 mg CE and the antioxidants to be 448 mg VCE (DPPH assay) and 630 mg VCE (ABTS assay). The daily intake of total phenolics, total flavonoids and antioxidants from green tea consumption increased from 2008 to 2011.

Biochemical Characteristics of Three Laccase Isoforms from the Basidiomycete Pleurotus nebrodensis.

The characterization of three laccase isoforms from Pleurotus nebrodensis is described. Isoenzymes Lac1, Lac2 and Lac3 were purified to homogeneity using ion exchange chromatography on DEAE-cellulose, CM-cellulose and Q-Sepharose and a gel filtration step on Superdex 75. The molecular weights of the purified laccases were estimated to be 68, 64 and 51 kDa, respectively. The isoenzymes demonstrated the same optimum pH at 3.0 but slightly different temperature optima: 50–60 °C for Lac1 and Lac3 and 60 °C for Lac2. Lac2 was always more stable than the other two isoforms and exposure to 50 °C for 120 min caused 30% loss in activity. Lac2 was relatively less stable than the other two isoforms when exposed to the pH range of 3.0–8.0 for 24 h, but inactivation only occurred initially, with around 70% residual activity being maintained during the whole process. Oxidative ability towards aromatic compounds varied substantially among the isoforms and each of them displayed preference toward some substrates. Kinetic constants (Km, Kcat) were determined by using a 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) assay, with Lac3 showing the best affinity and Lac2 displaying the highest catalytic efficiency. Amino acid sequences from peptides derived from digestion of isoenzymes showed great consistency with laccases in the databases.

Comparative Phytochemical Analyses and in-vitro Antioxidant Activity of Aqueous and Ethanol Extracts of Simarouba glauca (Paradise Tree)

Aims: The study was conducted to evaluate the phytochemical and antioxidant potentials of ethanol and aqueous leaf extracts of Simarouba glauca vis-a-vis standard antioxidants. Study Design: True experimental study. Place and Duration of Study: Department of Biochemistry, University of Benin, Benin City. Nigeria, between August and October 2015. Methodology: Samples were harvested, air dried, pulverized and extracted with aqueous and absolute ethanol; freeze dried at the National energy commission centre, University of Benin. Total phenol content was determined by Folin-ciocalteau method, tannin determined according to Folin and Denis methods while flavonoids content was determined according to the methods described by Ebrahimzadeh et al. DPPH radical scavenging activity was conducted based on the ability of 1,1-diphenyl-2-picrylhydrazyl (DPPH), a stable free radical, to decolorize in the presence of antioxidants. Reducing power activity of extracts was conducted based on test samples extract’ Original Research Article Osagie-Eweka et al.; EJMP, 13(3): 1-11, 2016; Article no.EJMP.24736 2 ability to reduce ferricyanide to ferrocyanide indicated in the colour change. Total antioxidant activity of ethanol and aqueous leaf extracts was determined based on the ability of the sample to reduce the ferric-tripyridyltriazine (Fe (III)-TPTZ) complex to ferrous tripyridyltriazine (Fe(II)-TPTZ) at low pH. Hydroxyl radical activity of extracts was conducted on the principle based on the ability of test samples to reduce H2O2 in the presence of 1,10-phenanthroline. Trolox equivalent antioxidant activity of extracts was conducted based on the ability of test sample to scavenge 2,2’azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical generated based on the principle of decolourization. Nitric oxide (NO.) radical scavenging activity of S, glauca leaf extracts was estimated based on the ability of test samples to scavenge radicals generated by the reaction of naphthylethylenediamine dihydrochloride. Butylated hydroxytuolene (BHT), Ascorbate, Quercetin and Trolox were standard antioxidant. Results: DPPH radical scavenging activity yielded aqueous and ethanol extracts IC50 values of 3.2144 and 4.9100 μg/ml respectively. Reducing power activity yielded (aqueous and ethanol extracts) EC50 of values 60.3233 and 60.1000 μg/ml respectively. Total antioxidant activity yielded (ethanol and aqueous extracts) IC50 values of 52.4320 and 68.8201 μg/ml respectively. Hydroxyl radical activity yielded (ethanol and aqueous extracts) IC50 values of 49.3130 and 50.2341 μg/ml respectively. Trolox equivalent antioxidant activity yielded (ethanol and aqueous extracts) IC50 values of 45.2015 and 52.0721 μg/ml respectively. Nitric oxide scavenging activity yielded aqueous IC50 value of 14.2102 μg/ml but ethanol extract yielded no inhibition concentration at 50 percent. Conclusion: The study showed that aqueous and ethanol leaf extracts of S. glauca demonstrated substantial amount of biochemically valuable phytochemicals and antioxidant potential capable of scavenging reactive oxygen species.

In vitro Antioxidant Activities and Polyphenol Contents of Seven Commercially Available Fruits.

Background:Fruits are considered one of the richest sources of natural antioxidants. Their consumption has been linked to the prevention of oxidative stress-induced diseases.Objective:In this study, in vitro antioxidant activities of blueberry, jackfruit, blackberry, black raspberry, red raspberry, strawberry, and California table grape extracts were evaluated.Materials and Methods:Antioxidant activities were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant potential (FRAP), 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), nitric oxide (NO), superoxide anion (O2−) scavenging assays, and ferric reducing power.Results:Black raspberry extract had the highest phenolic (965.6 ± 2.9 mg gallic acid equivalents [GAE]/g), flavonoid (186.4 ± 1.7 mg quercetin equivalents/g), and proanthocyanidin (2677 ± 71.1 mg GAE/g) contents. All fruit extracts exhibited increasing radical scavenging activities with increased concentrations. At 100 μg/ml, red raspberry extract showed the highest ferric reducing power (A700 =0.3 ± 0.0052) and FRAP activity (A593 =11.43 mM Fe2+/g). Black raspberry extract (100 μg/ml) exhibited the highest DPPH activity (A517 =89.03 ± 0.0471). Jackfruit extract (100 μg/ml) had the highest ABTS (A734 =35.6 ± 0.613), NO (A540 =81.7 ± 0.2), and O2− radical scavenging (A230 =55.5 ± 0.2) activities. Positive correlations were observed between IC50 values for different radical scavenging activities and different polyphenolics. Red raspberry extract had the highest Pearson's coefficient values (0.952–1) between total phenolics, flavonoids, and proanthocyanidins and DPPH and superoxide radical scavenging activities.Conclusions:The antioxidant rich fruits in this study are good source of functional food and nutraceuticals that have the potential to improve human health.SUMMARY All fruit extracts exhibited increasing radical scavenging activities with increased concentrationsBlack raspberry extract is enriched in total phenols, flavonoids, and proanthocyanidins and showed the highest 2,2-diphenyl-1-picrylhydrazyl scavenging activity and red raspberry extract showed the highest ferric reducing power and ferric reducing antioxidant potential activityJackfruit extract exhibited the highest 2,2′azino-bis (3-ethylbenzothiazoline-6-sulfonicacid) diammonium salt, nitric oxide, O2- scavenging activitiesPositive correlations were observed between IC50 values for different radical scavenging activities and different polyphenolics. Abbreviations Used: Abs: Absorbance, ABTS: 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt, BHT: Butylated hydroxytoluene, DPPH: 2,2-diphenyl-1-picrylhydrazyl, DW: Dry weight, FRAP: Ferric reducing antioxidant potential, FW: Fresh weight, GAE: Gallic acid equivalents, NADH: β-nicotinamide adenine dinucleotide hydrate, NFL: The National Food Laboratories, NO: Nitric oxide, ONPG: ortho-nitrophenyl-β-galactoside, PBS: Phosphate buffered saline, PMS: Phenazine methosulfate, QE: Quercetin equivalents, ROS: Reactive oxygen species, SD: Standard deviation, SOD: Superoxide dismutase, TCA: Trichloroacetic acid, TPTZ: 2,4,6-tris(2-pyridyl)-s-triazine, Trolox: (±)-6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid.

쪽의 항산화 및 항염증 활성에 대한 연구

Objectives : Persicaria tinctoria belongs to the Polygonaceae family and it has been used as the natural dye traditionally. Also, it is well known that the Persicaria tinctoria is used for treating the following symptoms such as fever, inflammation and edema. The purpose of this study is to investigate the effective source of antioxidants and anti-inflammatory agent from various parts of Persicaria tinctoria. Methods : We investigated the antioxidative and anti-inflammatory properties of the Persicaria tinctoria extracts. Antioxidant activities were measured by 1,1-diphenyl-2picrylhydrazyl (DPPH), 2, 2'-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activity, Fe chelating activity and Reducing power of Persicaria tinctoria extracts. And its inhibitory effect against oxidative DNA damage was evaluated in non-cellular system using φX-174 RF I plasmin DNA. The anti-inflammatory effect of Persicaria tinctoria was measured by using the inhibitory efficacy for the amount of nitric-oxide (NO) produced in LPS induced RAW264.7 cells. Results : The extracts from stem part showed better DPPH scavenging activity compared to those of the leaf and root extracts. Their IC50s were measured as 7.17, 144.40 and 165.07 ug/ml, respectively. These results were similar to that of ABTS radical scavenging assay and reducing power. Also, Persicaria tinctoria showed the protective effects of DNA damage against oxidative stress and anti-inflammatory effect by suppression of NO production in LPS induced RAW264.7 cells. Conclusions : These results showed that various parts of Persicaria tinctoria can be used as an effective source of antioxidants and anti-inflammatory agents via antioxidative activities and anti-inflammatory effect.

Study on Antioxidant and Anti-inflammatory Activities of Persicaria tinctoria

Objectives : Persicaria tinctoria belongs to the Polygonaceae family and it has been used as the natural dye traditionally. Also, it is well known that the Persicaria tinctoria is used for treating the following symptoms such as fever, inflammation and edema. The purpose of this study is to investigate the effective source of antioxidants and anti-inflammatory agent from various parts of Persicaria tinctoria. Methods : We investigated the antioxidative and anti-inflammatory properties of the Persicaria tinctoria extracts. Antioxidant activities were measured by 1,1-diphenyl-2picrylhydrazyl (DPPH), 2, 2'-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activity, Fe chelating activity and Reducing power of Persicaria tinctoria extracts. And its inhibitory effect against oxidative DNA damage was evaluated in non-cellular system using φX-174 RF I plasmin DNA. The anti-inflammatory effect of Persicaria tinctoria was measured by using the inhibitory efficacy for the amount of nitric-oxide (NO) produced in LPS induced RAW264.7 cells. Results : The extracts from stem part showed better DPPH scavenging activity compared to those of the leaf and root extracts. Their IC50s were measured as 7.17, 144.40 and 165.07 ug/ml, respectively. These results were similar to that of ABTS radical scavenging assay and reducing power. Also, Persicaria tinctoria showed the protective effects of DNA damage against oxidative stress and anti-inflammatory effect by suppression of NO production in LPS induced RAW264.7 cells. Conclusions : These results showed that various parts of Persicaria tinctoria can be used as an effective source of antioxidants and anti-inflammatory agents via antioxidative activities and anti-inflammatory effect.

In vitro antioxidant activity, phenolic content and profile of Cystoseira barbata from Romanian Black Sea

The Romanian Black Sea has abundant seaweed resources, but little effort has been done to screen their biological potential. The aim of the present study was to assess the in vitro antioxidant activity, phenolic content and profile of Cystoseira barbata (Stackhouse) C. Agardh, Cystoseiraceae, a brown alga inhabiting the costal line of Romanian Black Sea. The 70% acetone extract from C. barbata was investigated by HPLC-DAD-ESI-MSn. Total phenolic content was determined by Folin-Ciocalteu method. The antioxidant activity was assessed using four methods (2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical cation scavenging assay, reducing power and 15-lipoxygenase inhibition assay); gallic acid and caffeic acid were used as positive controls. Several phlorotannins (fucodiphloroethol, fucophloroethols with six, seven and eight phloroglucinol units with [M+H]+ at m/z 499, 747, 871 and 995, respectively) were tentatively identified on the basis of their characteristic MS fragmentation pattern. A total phenolic content of 236.03 ± 1.20 mg gallic acid equivalents/g extract was determined. In all antioxidant assays, the activity of the extract increased significantly in a concentration dependent manner. The EC50 values in the DPPH, ABTS and reducing power assays were 88.5 ± 0.3, 13.9 ± 0.2 and 17.6 ± 0.0 µg/mL, respectively. The extract showed high 15-lipoxygenase inhibition capacity (EC50= 47.3 ± 1.5 µg/mL), when compared with positive controls (EC50= 39.0 ± 0.7 µg/mL for gallic acid and 25.5 µg/mL for caffeic acid). The remarkable antioxidant activity of C. barbata suggests its potential use in the food and pharmaceutical industries.

Electrochemical Characterization of Graphene and MWCNT Screen-Printed Electrodes Modified with AuNPs for Laccase Biosensor Development.

The aim of this work is to show how the integration of gold nanoparticles (AuNPs) into multi-wall-carbon-nanotubes (MWCNTs) based screen-printed electrodes and into graphene-based screen-printed electrodes (GPHs) could represent a potential way to further enhance the electrochemical properties of those electrodes based on nanoparticles. Laccase from Trametes versicolor (TvL) was immobilized over MWCNTs and GPH previously modified with AuNPs (of 5 and 10 nm). The characterization of the modified electrode surface has been carried out by cyclic voltammetry. The results showed that the use of AuNPs for modification of both graphene and MWCNTs screen-printed electrode surfaces would increase the electrochemical performances of the electrodes. MWCNTs showed better results than GPH in terms of higher electroactive area formation after modification with AuNPs. The two modified nanostructured electrodes were successively proven to efficiently immobilize the TvL; the electrochemical sensing properties of the GPH- and MWCNT-based AuNPs-TvL biosensors were investigated by choosing 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic-acid diammonium salt (ABTS), catechol and caffeic acid as laccase mediators; and the kinetic parameters of the laccase biosensor were carefully evaluated.

Antagonistic Antioxidant Effect in Butylated Hydroxytoluene/Butylated Hydroxyanisole Mixture

The widespread use of antioxidants in food processing industries, especially oil and oil-based ones, has great economic advantages. Butylated hydroxyanisole (BHA, E 320) and butylated hydroxytoluene (BHT, E 321) are synthetic antioxidants still widely used in foods. The present study shows and discusses the antioxidant properties of these two antioxidants individually and their mixtures differing in concentration of the components. The results, obtained by 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays, show the antagonistic antioxidant effect of BHT/BHA mixture on free radical scavenging. The observed effect is explained by quicker consumption of ABTS cation radicals by BHA or by regeneration of BHA by BHT in the presence of DPPH radical. Practical Applications Butylated hydroxyanisole (BHA, E 320) and butylated hydroxytoluene (BHT, E 321) are synthetic antioxidants still widely used in foods. There are many examples of food products, in which these antioxidants are applied together. The International Agency for Research on Cancer, part of the World Health Organization, considers BHA and BHT to be possibly carcinogenic to humans. For this reason, it is important to learn more about the antioxidant properties of these two antioxidants and their mixtures. Detailed information about antioxidant effect of BHT/BHA mixture on free radical scavenging is presented in this paper. In the light of obtained results, the necessity of applying of BHT/BHA mixture in food preservation seems strongly disputable.

모링가의 항산화 효과에 미치는 중저분자 키토산의 영향

The aim of this study is to elucidate the antibacterial activity of medium molecular weight chitosan (MMWC) along with keeping antioxidant activity of Moringa oleifera leaves extracts, which has shown the significant antioxidant activity. Antioxidant activity of the extracts as either free or ingredient in edible food was investigated in vitro by radical scavenging assays with 2,2-Diphenyl-1-picrylhydrazyl (DPPH), 2,2’-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) and 2,4,6-Tris(2-pyridyl)-s-triazine (FRAP). The results showed that extracts has showed high antioxidant activity while added in edible food as like a muk, although when it was added in muk as food additives, its original activity was reduced slightly. In addition, in the presence of MMWC with ranging from 3 to 8-kDa in muk, various improvements including antibacterial effect and stability of structure of muk were observed. Taken together, specified size of chitosan seems to be a good candidate playing a key role to maintain the antioxidant and antibacterial activities in functional foods.