scholarly journals Oxidative Degradation of High-Molar-Mass Hyaluronan: Effects of Some Indole Derivatives to Hyaluronan Decay

2020 ◽  
Vol 21 (16) ◽  
pp. 5609
Author(s):  
Katarína Valachová ◽  
Mojmír Mach ◽  
Ladislav Šoltés
Keyword(s):  
Molar Mass ◽  
Radical Scavenging ◽  
Oxidative Degradation ◽  
Protective Effects ◽  
Indole Derivatives ◽  
High Molar Mass ◽  
Positive Effects ◽  
Ic50 Value ◽  
Ic50 Values ◽  
Effective Compound

Indole derivatives such as isatin (a natural compound), cemtirestat, stobadine, and its derivatives (synthetic compounds) are known to have numerous positive effects on human health due to regulation of oxidative status. The aim of the study was to assess radical scavenging capacities of these compounds and explore their potential protective effects against reactive oxygen species formed during Cu(II) ions and ascorbate-induced degradation of high-molar-mass hyaluronan. Based on the IC50 values determined by the ABTS assay, the most effective compound was SM1M3EC2·HCl reaching the value ≈ 11 µmol/L. The lowest IC50 value reached in the DPPH assay was reported for cemtirestat ≈ 3 µmol/L. Great potency of inhibition of hyaluronan degradation was shown by cemtirestat, followed by isatin even at low concentration 10 µmol/L. On the other hand, stobadine·2HCl had also a protective effect on hyaluronan degradation, however at greater concentrations compared to cemtirestat or isatin. SME1i-ProC2·HCl reported to be a less effective compound and SM1M3EC2·HCl can be considered almost ineffective compared to stobadine·2HCl. In conclusion, our results showed that both isatin and cemtirestat were capable of attenuating the degradation of high-molar-mass hyaluronan due to their ability to complex/sequester cupric ions.

Dithiols as more effective than monothiols in protecting biomacromolecules from free-radical-mediated damage: in vitro oxidative degradation of high-molar-mass hyaluronan

2014 ◽  
Vol 68 (10) ◽  
Author(s):  
Mária Baňasová ◽  
Katarína Valachová ◽  
Ivo Juránek ◽  
Ladislav Šoltés
Keyword(s):  
Free Radical ◽  
Molar Mass ◽  
Radical Scavenging ◽  
Oxidative Degradation ◽  
Free Radical Scavenging ◽  
Dpph Assay ◽  
High Molar Mass ◽  
High Concentrations ◽  
Free Radical Scavenging Activities

AbstractOxidative stress and the resulting damage to cellular and extracellular components has been observed in a variety of degenerative processes, including degenerative joint disorders, where high-molar-mass hyaluronan (HA) is often found to be massively degraded. The present study sought to test the hypothesis that dithiols are more effective in protecting biomacromolecules from free-radicalmediated damage than monothiols. The materials/thiols tested included bucillamine (BUC), dithioerythritol (DTE), dithiothreitol (DTT) and glutathione (GSH), as a reference, for their effectiveness in protecting HA from oxidative degradation induced in vitro. Since HA degradation results in a decrease in its dynamic viscosity, rotational viscometry was applied to follow HA oxidative degradation. The free-radical-scavenging activities of the thiols tested were determined by 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) and di(phenyl)-(2,4,6-trinitrophenyl)iminoazanium (DPPH) assays. It was found that all the dithiols in the concentration range tested protected HA from the oxidative degradation. On the other hand, monothiol GSH exerted protection only at high concentrations (10 μmol L−1 and 100 μmol L−1) and 1 μmol L−1 of GSH even exhibited a prodegradative effect. The ABTS assay revealed free-radical scavenging activities in the following order: BUC, DTT, DTE, GSH, and that of the DPPH assay: BUC, DTE, DTT, GSH. In conclusion, it was demonstrated that dithiols may be more effective than monothiols in affording biomacromolecule protection from oxidative degradation.

scholarly journals Protective effects of manganese(II) chloride on hyaluronan degradation by oxidative system ascorbate plus cupric chloride

2010 ◽  
Vol 3 (1) ◽  
pp. 26-34 ◽  
Author(s):  
Katarína Valachová ◽  
Grigorij Kogan ◽  
Peter Gemeiner ◽  
Ladislav Šoltés
Keyword(s):  
Ascorbic Acid ◽  
Synovial Fluid ◽  
Molar Mass ◽  
Oxidative Degradation ◽  
Joint Inflammation ◽  
Transition Metal Ions ◽  
Cupric Chloride ◽  
Protective Effects ◽  
High Molar Mass ◽  
Oxidative System

Protective effects of manganese(II) chloride on hyaluronan degradation by oxidative system ascorbatepluscupric chlorideThe degradation of several high-molar-mass hyaluronan samples was investigated in the presence of ascorbic acid itself and further by an oxidative system composed of ascorbic acid plus transition metal ions, i.e. Fe(II) or Cu(II) ions. The latter oxidative system imitates conditions in a joint synovial fluid during early phase of acute joint inflammation and can be used as a model for monitoring oxidative degradation of hyaluronan under pathophysiological conditions. The system Cu(II)plusascorbate (the Weissberger oxidative system) resulted in a more significant decrease of hyaluronan molar mass compared to the oxidative system Fe(II) plus ascorbate. Addition of manganese(II) chloride was found to decrease the rate of the oxidative damage of hyaluronan initiated by ascorbate itself and by the Weissberger system.

scholarly journals Comparison of Phenolic Contents and Scavenging Activities of Miang Extracts Derived from Filamentous and Non-Filamentous Fungi-Based Fermentation Processes

Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1144
Author(s):  
Aliyu Dantani Abdullahi ◽  
Pratthana Kodchasee ◽  
Kridsada Unban ◽  
Thanawat Pattananandecha ◽  
Chalermpong Saenjum ◽  
...  
Keyword(s):  
Filamentous Fungi ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Protective Effects ◽  
Tea Leaves ◽  
Antioxidant Power ◽  
Phenolic Contents ◽  
Ic50 Values ◽  
Ferric Reducing Antioxidant Power ◽  
The Impact

The study investigated the impact of the fermentation process on the phenolic contents and antioxidant and anti-inflammatory activities in extracts of Miang, an ethnic fermented tea product of northern Thailand. The acetone (80%) extraction of Miang samples fermented by a non-filamentous fungi-based process (NFP) and filamentous fungi-based process (FFP) had elevated levels of total polyphenols, total tannins, and condensed tannins compared to young and mature tea leaves. The antioxidant studies also showed better the half-maximal inhibitory concentration (IC50) values for fermented leaves in both 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity assays as well as improved ferric reducing antioxidant power (FRAP) compared to young and mature tea leaves. Extracts of NFP and FFP samples at concentrations of 50 and 100 ppm showed better protective effects against hydrogen peroxide (H2O2)-induced intracellular reactive oxygen species (ROS) production in HT-29 colorectal cells without exerting cytotoxicity. Additionally, lipopolysaccharide (LPS)-induced production of nitric oxide (a proinflammatory mediator as well as a reactive nitrogen species) was also inhibited by these fermented Miang extracts with an IC50 values of 17.15 μg/mL (NFP), 20.17 μg/mL (FFP), 33.96 μg/mL (young tea leaves), and 31.33 μg/mL (mature tea leaves). Therefore, both NFP-Miang and FFP-Miang showed the potential to be targeted as natural bioactive functional ingredients with preventive properties against free radical and inflammatory-mediated diseases.

Antioxidative properties of Sambacus nigra extracts

2015 ◽  
Vol 69 (9) ◽  
Author(s):  
Dominika Topoľská ◽  
Katarína Valachová ◽  
Peter Rapta ◽  
Stanislav Šilhár ◽  
Elena Panghyová ◽  
...  
Keyword(s):  
Acute Inflammation ◽  
Radical Scavenging ◽  
Oxidative Degradation ◽  
Protective Effects ◽  
Radical Scavenging Capacity ◽  
Scavenging Capacity ◽  
Diammonium Salt ◽  
Dose Dependent ◽  
Oxidative System

AbstractPotential protective effects of elderberry (Sambucus nigra) extracts against oxidative degradation of hyaluronan (HA) were detected in vitro. To induce free-radical-mediated HA degradation, Weissberger’s biogenic oxidative system, which mimics the situation of acute inflammation, was applied. Time- and dose-dependent changes of dynamic viscosity of the HA solutions in the presence and absence of two elderberry extracts produced in 2006 and 2012 were recorded by rotational viscometry (RV). Radical scavenging capacity of both extracts was investigated by the spectrocolorimetric ABTS [2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt] assay and the “inverted” ABTS assay. Oxygen consumption of the system oxidizing HA either in the absence or presence of the elderberry extracts was determined. The results of RV revealed that an addition of the newer extract (2012) promoted the inhibition of HA degradation more markedly compared to the older extract (2006). The same effect of both extracts on ABTS

Manganese Porphyrins as Pro-Oxidants in High-Molar-Mass Hyaluronan Oxidative Degradation

2020 ◽  
pp. 223-241
Author(s):  
Katarína Valachová ◽  
Peter Rapta ◽  
Ines Batinic-Haberle ◽  
Ladislav Šoltés
Keyword(s):  
Molar Mass ◽  
Oxidative Degradation ◽  
High Molar Mass ◽  
Manganese Porphyrins

scholarly journals 2,2-Diphenyl-1-picrylhydrazil radical scavenging activity of extracts from roots and leaves of Searsia burchellii

Food Research ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 235-239
Author(s):  
M.S. Mpopo ◽  
M.K. Pillai ◽  
S.B. Mekbib
Keyword(s):  
Ascorbic Acid ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Positive Control ◽  
Scavenging Activity ◽  
Methanolic Extracts ◽  
Ic50 Value ◽  
Ic50 Values ◽  
Water Fractions ◽  
Radical Scavenging Assay

Searsia burchellii finds therapeutic applications in traditional medicine. Methanolic extracts, hexane, chloroform, ethyl acetate and methanol/water fractions of methanolic extracts and water extracts were obtained separately from the roots and leaves of Searsia burchellii by the combination of maceration, hot solvent extraction and solvent-solvent partition techniques. These extracts were evaluated for their antioxidant activity using 2,2- diphenyl-1-picrylhydrazil radical scavenging assay (DPPH). The extracts from roots and their fractions showed radical scavenging activity ranging from 6.60±4.50 to 63.27±1.93% at various concentrations. Similarly, the extracts from leaves and their fractions showed radical scavenging activity ranging from 3.32±0.95 to 64.91±0.15% at various concentrations. Ascorbic acid served as positive control which showed radical scavenging activity ranging from 53.62±2.80 to 60.82±0.62% at various concentrations. The IC50 values of these extracts and fractions were found to be < 200 to > 3000 µg/mL. The IC50 value of ascorbic acid was found to be <200 µg/mL. From this study, we concluded that extracts and their fractions from S. burchellii showed promising radical scavenging activity.

scholarly journals ANTIOXIDANT ACTIVITIES OF HYDROLYSATES ORIGINATED FROM SOYBEAN AND SOY MILK RESIDUE

2018 ◽  
Vol 55 (5A) ◽  
pp. 134
Author(s):  
Ngo Minh Ngoc
Keyword(s):  
Antioxidant Activity ◽  
Protein Content ◽  
Manufacturing Industry ◽  
Antioxidant Activities ◽  
Proteolytic Enzymes ◽  
Radical Scavenging ◽  
Soy Milk ◽  
Dpph Radical ◽  
Ic50 Value ◽  
Ic50 Values

Soybean (Glycine max) and soy milk residue (okara) are protein-rich materials. Soybean possesses the highest protein content among different types of beans (protein content of soybean varies from 40–42 %). Soy milk residue, a by-product of the soy milk manufacturing industry, contains approximately 27 % protein (by dry weight). A number of recent studies have investigated the improvement of functional properties of protein contained in soybean and okara by fermentation or by the use of proteolytic enzymes. The aim of this study was to evaluate the antioxidant activities of soybean and okara hydrolysates obtained by the fermentation with Aspergillus oryzae or by using proteolytic enzymes (neutrase and flavourzyme). DPPH radical scavenging assay was used to determine the antioxidant activities of hydrolysates. The concentration of peptides required to scavenge DPPH radical by 50 % (IC50 value) was used to evaluate the antioxidant activity of peptides produced obtained from hydrolysates. The results showed that when fermented with A. oryzae, the okara hydrolysate had higher antioxidant activity than the soybean hydrolysate, with IC50 values of 0.447 mg/ml and 3.95 mg/ml, respectively. The hydrolyzed okara obtained from hydrolysis using Neutrase had higher antioxidant activity than the one obtained from hydrolysis using Flavourzyme, with IC50 values of0.200 mg/ml and 0.407 mg/ml, respectively. Different peptide fractions obtained from the hydrolysates using cut-off membrane (10 kDa, 3 kDa and 1 kDa) possessed different antioxidant activities. The < 1 kDa peptide fraction exhibited the highest antioxidant activity with an IC50 value of 0.158 mg/ml.

scholarly journals In-vitro Antioxidant and Cytotoxicity Studies of Annona squamosa Linn.

1970 ◽  
Vol 2 (1) ◽  
pp. 32-36
Author(s):  
Israt Jahan Biva ◽  
Md Mynol Islam Vhuiyan ◽  
Moni Rani Saha ◽  
Muhammad Shahidul Islam ◽  
Shammy Sarwar
Keyword(s):  
Radical Scavenging ◽  
Pharmaceutical Sciences ◽  
Annona Squamosa ◽  
Soluble Extract ◽  
Phenolic Contents ◽  
Cytotoxicity Studies ◽  
Ic50 Value ◽  
Vincristine Sulphate ◽  
Ic50 Values

n-Hexane, chloroform and methanol soluble extracts of the leaves of Annona squamosa were screened fortheir possible antioxidant activitiy by DPPH free radical scavenging and cytotoxicity by brine shrimp lethalitybioassay. In DPPH radical scavenging assay, methanol soluble extract was found to be the most potent withan IC50 value of 103.5 μg/ml. The amount of total phenolics was also found to the highest in the methanolsoluble extract (283.16 ± 8.90 mg/g), followed by chloroform soluble extract (216.90 ± 4.48 mg/g). Here BHTand ascorbic acid were used as standards with IC50 values 8.2 μg/ml and 25 μg/ml respectively. In the brineshrimp lethality bioassay, the most significant cytotoxicity was observed with chloroform soluble extract withan LC50 of 4.16 μg/ml where vincristine sulphate was used as standard (LC50 0.29 μg/ml).Key Words: Annona squamosa; DPPH; Folin-Ciocalteu Reagent; Phenolic Contents; Brine ShrimpDOI: 10.3329/sjps.v2i1.5813Stamford Journal of Pharmaceutical Sciences Vol.2(1) 2009: 32-36

scholarly journals QSAR Model of Indeno[1,2-b]indole Derivatives and Identification of N-isopentyl-2-methyl-4,9-dioxo-4,9-Dihydronaphtho[2,3-b]furan-3-carboxamide as a Potent CK2 Inhibitor

Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 97 ◽  
Author(s):  
Samer Haidar ◽  
Christelle Marminon ◽  
Dagmar Aichele ◽  
Abdelhamid Nacereddine ◽  
Wael Zeinyeh ◽  
...  
Keyword(s):  
Molecular Modeling ◽  
Qsar Model ◽  
Biological Evaluation ◽  
Indole Derivatives ◽  
Ic50 Value ◽  
Ic50 Values ◽  
Synthesis And Biological Evaluation ◽  
Ck2 Inhibitors ◽  
Ck2 Inhibitor

Casein kinase II (CK2) is an intensively studied enzyme, involved in different diseases, cancer in particular. Different scaffolds were used to develop inhibitors of this enzyme. Here, we report on the synthesis and biological evaluation of twenty phenolic, ketonic, and para-quinonic indeno[1,2-b]indole derivatives as CK2 inhibitors. The most active compounds were 5-isopropyl-1-methyl-5,6,7,8-tetrahydroindeno[1,2-b]indole-9,10-dione 4h and 1,3-dibromo-5-isopropyl-5,6,7,8-tetrahydroindeno[1,2-b]indole-9,10-dione 4w with identical IC50 values of 0.11 µM. Furthermore, the development of a QSAR model based on the structure of indeno[1,2-b]indoles was performed. This model was used to predict the activity of 25 compounds with naphtho[2,3-b]furan-4,9-dione derivatives, which were previously predicted as CK2 inhibitors via a molecular modeling approach. The activities of four naphtho[2,3-b]furan-4,9-dione derivatives were determined in vitro and one of them (N-isopentyl-2-methyl-4,9-dioxo-4,9-dihydronaphtho[2,3-b]furan-3-carboxamide) turned out to inhibit CK2 with an IC50 value of 2.33 µM. All four candidates were able to reduce the cell viability by more than 60% after 24 h of incubation using 10 µM.

scholarly journals ANTIOXIDANT ACTIVITIES OF HYPERICUM FURSEI L.

2014 ◽  
Vol 44 (1) ◽  
pp. 19-23
Author(s):  
B. S. ALIPOUR ◽  
M. A. EBRAHIMZADEH ◽  
B. ESLAMI ◽  
Z. RAHMANI
Keyword(s):  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Scavenging Activity ◽  
Ic50 Value ◽  
Ic50 Values ◽  
Chelating Ability ◽  
Dpph Radical Scavenging ◽  
Gallic Acid Equivalent

In this study, antioxidant activities of H. fursei were investigated. Different model were used for assay. IC50 for DPPH radical-scavenging activity was 7.5±1.2 μg ml-1. The IC50 value for BHA was 92.9±4.5 µg ml-1. The extract showed very good reducing power that was comparable with vitamin C (p> 0.05) but showed weak nitric oxide scavenging activity and Fe2+ chelating ability. Extract showed good activity in scavenging of H2O2. Inhibition was 99.1% at 800 μg ml-1. The IC50 values for extract and BHA were 333.1±14.7 and 52.0±4.5 μg ml-1, respectively. Total phenol compounds, by the Folin Ciocalteu method, was 274±9.6 mg gallic acid equivalent/g of extract and the total flavonoid content, by AlCl3 method was 23.9 ± 1.4 mg quercetin equivalent/g of extract. Antioxidant activity may be attributed to the presence of phenols and flavonoids in the extract.

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