Příspěvek upozorňuje na vztahy mezi výsledky instrumentálního měření barevnosti a výsledky stanovení antioxidační aktivity medů (zejména metodou DPPH a FRAP). Dostatečně těsné korelace ukazují, že po jejich ověření, doplnění regresní analýzou a kalibrací mohou najít uplatnění při rychlém stanovení antioxidační aktivity medů.

The paper highlights the relationships between the results of instrumental colour measurement and the results of the determination of the antioxidant activity of honey (especially by DPPH and FRAP). The sufficiently close correlations show that once verified, supplemented by regression analysis and calibration, they may find application in the rapid determination of the antioxidant activity of honey.

• Klíčová slova
• měření barevnosti,
• MeSH
• antioxidancia analýza   MeSH
• barva MeSH
• chemické techniky analytické MeSH
• korelace dat MeSH
• med * analýza   MeSH

In the food industry, in the process of creating new agricultural plant products, and in the testing of anti-cancer drugs there is often a need to assay multiple samples of low molecular weight antioxidants, plant samples and foods rich in antioxidants, with minimal additional costs and low degrees of uncertainty. With these demands in mind, we decided to study the fully automated assay of antioxidants using not only automated sample measurements but also automated processing of samples and application of reagents. The automated pipetting system epMotion 5075 and the automated spectrophotometer BS 400 were chosen for the assay purposes. Five methods were introduced for the automation: 2-diphenyl-1-picrylhydrazyl (DPPH) test, ferric reducing antioxidant power (FRAP) method, 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) based test, N,N-dimethyl-1,4-diaminobenzene (DMPD) based test and the free radicals method. Samples containing one of the four antioxidants (standard rutin, quercitrin, ferulic and gallic acid) in a range 1–1000 μg/ml were used throughout. All of the tested methods were found suitable for implementation in an automated assay. However, some of them, such as the ABTS test failed to assay all tested antioxidants. The coefficients of determination were also unequal. From the analytical point of view, FRAP methods provided the most reliable results in the automated assay; because of the capacity of the method, approximately 240 samples per hour (one sample per 15 seconds) can be assayed using the automated protocol. We were encouraged by the data received and we expect further interest in the practical performance of such automation. As a mean of testing the robustness of our method, in the next step of our study, oxidative status was assessed in model cell lines derived from prostate cancer (PC-3, PNT1A and 22RV1) that were cultured on ellipticine (0, 0.5, 1, 1.5, 2, 2.5, 5, 7.5, 10, 15 μmol/l) supplemented agar. Antioxidant activity was assessed (DPPH, ABTS, FRAP, DMPD, FR) and calculated on the phenolic antioxidant level (rutin, quercitrin, ferulic and gallic acid), and thus an estimation was formulated of the oxidative stress as a result of the impact of anti-cancer drugs. It can be demonstrated that the new method has wide applicability.

• MeSH
• antioxidancia analýza   MeSH
• antitumorózní látky chemie   metabolismus   toxicita   MeSH
• chemické techniky analytické metody   přístrojové vybavení   statistika a číselné údaje   MeSH
• elipticiny analýza   chemie   metabolismus   MeSH
• financování organizované MeSH
• FRAP MeSH
• kalibrace MeSH
• kyselina gallová analýza   chemie   MeSH
• kyseliny kumarové analýza   chemie   MeSH
• laboratorní automatizace metody   přístrojové vybavení   MeSH
• léky antitumorózní - screeningové testy metody   statistika a číselné údaje   MeSH
• luminiscenční měření MeSH
• nádorové buněčné linie MeSH
• oxidační stres účinky léků   MeSH
• quercetin analogy a deriváty   analýza   chemie   MeSH
• reprodukovatelnost výsledků MeSH
• rutin analýza   chemie   MeSH
• spektrofotometrie metody   přístrojové vybavení   statistika a číselné údaje   MeSH
• viabilita buněk účinky léků   MeSH
• volné radikály analýza   MeSH
• vztahy mezi strukturou a aktivitou MeSH
• Publikační typ
• hodnotící studie MeSH
• statistiky MeSH
• tabulky MeSH

Antioxidant activity of 18 fruit and vegetable juices was determined using DPPH (2,2-diphenyl-1-picrylhydrazyl), FRAP (ferric reducing antioxidant potential), PCL (photochemiluminiscence) methods. Correlations between the results of individual methods and the total phenolics and anthocyanin contents were evaluated. Water and methanol extracts were applied in the determinations. In both water and methanol extracts, a significant correlation between the results of all the three methods was found. However, the correlation between the results of PCL and total phenolics content is poor. No correlation between the results of ACW and ACL was found. Antioxidant activity in the tested juices decreased in the order: blueberry > red cabbage > raspberry > sour cherry > strawberry > beetroot. Celery, carrot and cucumber are poor sources of antioxidants. The orders found by various methods do not differ significantly; DPPH, FRAP and ACL methods are interchangeable for this purpose. For complete information on antioxidant activity, application of more methods following different effects is necessary.

• MeSH
• antioxidancia MeSH
• fenoly MeSH
• klinické laboratorní techniky MeSH
• ovoce MeSH
• zelenina MeSH

A new natural flavonoid patuletin 3'-beta-xylofuranoside was isolated from Leuzea carthamoides leaves. The antioxidant activity of this compound was evaluated by the DPPH radical assay and ferric reducing antioxidant power (FRAP) assay, and the results were compared with those for trolox and quercetin. DPPH radical scavenging activity of the tested compounds was expressed by the parameter EC50: patuletin 3'-beta-xylofuranoside (56.0 microM), trolox (27.8 microM), and quercetin (25.3 microM). The ferric reducing activity of the compounds was demonstrated as FRAP values at 4 and 60 min: patuletin 3'-beta-xylofuranoside (28.4 microM, 35.8 microM), trolox (19.3 microM, 20.2 microM), and quercetin (54.3 microM, 79.9 microM). The structure/activity relationship of the flavonoid is also discussed. The results indicate significant antioxidant potency of patuletin 3'-beta-xylofuranoside.

• MeSH
• antioxidancia chemie   izolace a purifikace   farmakologie   MeSH
• flavonoidy chemie   izolace a purifikace   farmakologie   MeSH
• hmotnostní spektrometrie s elektrosprejovou ionizací MeSH
• Leuzea chemie   MeSH
• magnetická rezonanční spektroskopie MeSH
• spektrofotometrie ultrafialová MeSH
• vztahy mezi strukturou a aktivitou MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Sarcosine is currently one of the most discussed markers of prostate cancer. It is involved in amino acid metabolism and methylation processes that occur during the progression of prostate cancer. In this study, we monitored the effect of the addition of sarcosine (0; 10; 250; 500; 1,000 and 1,500 µM) in a time-dependent manner (0-72 h) on the PC-3 prostate cancer cell line. For the assessment of cell viability, the commonly used MTT test was employed. Furthermore, ion-exchange liquid chromatography was used for the determination of sarcosine content in the PC-3 cells. We also determined metallothionein (MT) levels by chip capillary electrophoresis and Brdicka reaction in the cells treated with sarcosine. Sarcosine levels in the cells increased in a concentration-dependent manner levels increased from only 270 nM with the lowest applied concentration of sarcosine (10 µM) to 106 µM with the highest applied concentration of sarcosine (1,500 µM). There was a marginal change observed in the MT concentration. Finally, the antioxidant activity of the PC-3 cells was determined using five different spectrophotometric methods [2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing ability of plasma (FRAP), free radicals, N,N-dimethyl-p-phenylenediamine (DMPD) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS)]. A significant negative correlation was observed between DPPH and FRAP (r=-0.68 at p<0.001) and between DMPD and ABST (r=-0.64 at p<0.001). Additionally, as regards the correlation between MT and DPPH, a significant positive trend (r=0.62 at p<0.001) was observed.

• MeSH
• lidé MeSH
• metalothionein metabolismus   MeSH
• nádorové biomarkery farmakologie   fyziologie   MeSH
• nádorové buněčné linie MeSH
• nádory prostaty MeSH
• sarkosin farmakologie   fyziologie   MeSH
• scavengery volných radikálů metabolismus   MeSH
• viabilita buněk MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The study investigated the active and intelligent properties of films based on furcellaran (FUR), gelatin hydrolysate (GELH) and rosemary extract (from fresh leaves (FRE) and dry leaves (DRE)). Rosemary extracts were blended with FUR/GELH film forming solution at different three concentrations (5, 10, 20%). Analyzing the ζ-potential dependences of complexation polysaccharide-protein hydrolysate, we selected optimal ratio for the film formation. The introduction of rosemary extracts into FUR/GELH films increased thickness, water content and tensile strength. The UV barrier properties of tested films improved with the addition of rosemary extracts into FUR/GELH matrix. The antioxidant activity (DPPH and FRAP) did not improved with the addition of FRE but significantly increased with the addition of DRE, reaching 88% of DPPH inhibition and 207 of μmol Trolox/g of dried film of FRAP value. The color changes in different pH were observed, however, the fish spoilage test showed that those films are not suitable as intelligent films for monitoring freshness of this type of food product. Among all films tested, FUR/GELH film with 20% DRE exhibited the best performance. The obtained results suggested that FUR/GELH films with 20% DRE could be used as a promising active food packing material.

• MeSH
• algináty chemie   MeSH
• antioxidancia chemie   farmakologie   MeSH
• biokompatibilní materiály chemie   farmakologie   MeSH
• fyzikální jevy MeSH
• kůže chemie   MeSH
• obaly potravin MeSH
• proteinové hydrolyzáty chemie   MeSH
• rostlinné extrakty chemie   MeSH
• rostlinné gumy chemie   MeSH
• rozmarýn chemie   MeSH
• ryby MeSH
• spektrální analýza MeSH
• želatina chemie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

AIMS: This study aimed to explore the antioxidant properties and neuroprotective effects of Esc-1GN. MAIN METHODS: FRAP assay and ABTS, DPPH, and NO radicals radical scavenging assays were performed to investigated the Antioxidant activities of Esc-1GN in vitro. Hydrogen peroxide (H2O2)-induced cell damage model was used to determine the neuroprotective effects of Esc-1GN. Carrageenan-injected inflamed paw model was performed to analysis the antioxidant and anti-inflammatory properties of Esc-1GN in vivo. KEY FINDINGS: Esc-1GN scavenged the ABTS, DPPH, and NO radicals and reduced Fe3+ in a concentration-dependent manner. Moreover, Esc-1GN exhibited neuroprotective activity by decreasing malondialdehyde and reactive oxygen species accumulation, restoring endogenous antioxidant enzyme activity, and inhibiting H2O2-induced cell cycle arrest and apoptosis in PC12 cells. Esc-1GN significantly reversed the dysregulation of MAPK, AKT and NF-κB signaling caused by H2O2. In vivo, Esc-1GN decreased MDA, COX-2, NO, TNF-α, IL-6, and Il-1β levels and increased SOD, CAT activity and GSH level in carrageenan-injected inflamed paw tissues. SIGNIFICANCE: These findings suggest that Esc-1GN might serve as a potential antioxidant agent with therapeutic potential in human neurodegenerative diseases.

• MeSH
• antioxidancia farmakologie   MeSH
• MAP kinasový signální systém MeSH
• myši MeSH
• neuroprotektivní látky farmakologie   MeSH
• protoonkogenní proteiny c-akt metabolismus   MeSH
• signální transdukce * MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

In recently, there has been a great interest in natural antioxidants as bioactive components of food, nutraceuticals or potential drugs against several diseases. In our study, 88 extracts from various parts of plants from European Asteraceae and Cichoriaceae were assayed for radical scavenging activity by means of DPPH (1,1-diphenyl-2-picryl hydrazyl radical) test using the SIA (Sequential injection analysis) method developed for this purpose in our laboratory. DPPH radical scavenging activity of all tested plant extracts was evaluated according to the IC(50) parameter. 29 extracts exhibited IC(50) value lower than 0.1 mg/mL. The leaves of Leuzea carthamoides (IC(50) = 0.046 mg/mL) were chosen as the most promising sample for a subsequent phytochemical study, which resulted in isolation of seven natural compounds, namely, 4',5,7-trihydroxy-6-methoxyflavone (hispidulin) (1), 5, 7, 3', 4'- tetrahydroxyflavanone (eriodictyol) (2), 3',4',5,7-pentahydroxy-6-methoxyflavonol (patuletin) (3), eriodictyol-7-beta-glucopyranoside (4), 6-hydroxykaempferol-7-O-(6''-O-acetyl-beta-D-glucopyranoside) (5), 4-hydroxybenzoic acid (6) and 3,4-dihydroxybenzoic acid (protocatechuic acid) (7). Antioxidant activity of the isolated compounds was evaluated by DPPH test and ferric reducing antioxidant power (FRAP) test and compared with trolox and quercetin. Both tests evaluated the flavonoid (5) as the most active antioxidant. This result was confirmed by comparison with known data concerning the structure/activity relationships of flavonoids.

• MeSH
• antioxidancia farmakologie   chemie   MeSH
• Asteraceae chemie   MeSH
• bifenylové sloučeniny MeSH
• biologické přípravky farmakologie   chemie   MeSH
• chromany (dihydrobenzopyrany) chemie   izolace a purifikace   MeSH
• financování organizované MeSH
• hydraziny MeSH
• Leuzea chemie   MeSH
• molekulární struktura MeSH
• pikráty MeSH
• preklinické hodnocení léčiv MeSH
• quercetin chemie   izolace a purifikace   MeSH
• Rhodophyta chemie   MeSH
• rostlinné extrakty farmakologie   chemie   izolace a purifikace   MeSH
• vztahy mezi strukturou a aktivitou MeSH
• Geografické názvy
• Evropa MeSH

The peumo (Cryptocarya alba) is a native fruit from central Chile that belongs to the Lauraceae family. To characterize the development and the potential health benefits of this edible fruit, quality and physiological parameters, along with antioxidant capacity, were evaluated during three clearly defined developmental stages of the fruit in two seasons. The most distinguishable attributes of ripe fruit were the change in size and color. Low CO2 production and no detectable ethylene levels suggested non-climacteric behavior of the peumo fruit. Peumo demonstrate a significant increase in their antioxidant capacity per 1 g of fresh weight (FW) of the sample, from small to ripe fruit. Higher values in ripe fruit (FRAP: 37.1-38.3 µmol FeSO4/gFW, TEAC: 7.9-8.1 mmol TE/gFW, DPPH: 8.4-8.7 IC50 μg/mL, and ORAC: = 0.19-0.20 mmol TE/gFW) were observed than those in blueberry fruit (FRAP: 4.95 µmol FeSO4/gFW, TEAC: 1.25 mmol TE/gFW, DPPH: 11.3 IC50 μg/mL, and ORAC: 0.032 mmol TE/ gFW). The methanol extracts of ripe fruit displayed the presence of polyphenol acids and quercetin, an ORAC value of 0.637 ± 0.061 mmol TE per g dried weight (DW), and a high cellular antioxidant and anti-inflammatory potential, the latter exceeding the effect of quercetin and indomethacin used as standard molecules. Also, the assay of isolated rat aorta with endothelium-dependent relaxation damage demonstrated that the peumo extract induced vascular protection, depending on its concentration under a high glucose condition. These results demonstrate that these endemic fruits have a good chance as ingredients or foods with functional properties.

• Publikační typ
• časopisecké články MeSH

Silymarin, an extract from milk thistle (Silybum marianum) fruits, is consumed in various food supplements. The metabolism of silymarin flavonolignans in mammals is complex, the exact structure of their metabolites still remains partly unclear and standards are not commercially available. This work is focused on the preparation of sulfated metabolites of silymarin flavonolignans. Sulfated flavonolignans were prepared using aryl sulfotransferase from Desulfitobacterium hafniense and p-nitrophenyl sulfate as a sulfate donor and characterized by high-resolution mass spectrometry (HRMS) and nuclear magnetic resonance (NMR). Their 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and N,N-dimethyl-p-phenylenediamine (DMPD) radical scavenging; ferric (FRAP) and Folin⁻Ciocalteu reagent (FCR) reducing activity; anti-lipoperoxidant potential; and effect on the nuclear erythroid 2-related factor 2 (Nrf2) signaling pathway were examined. Pure silybin A 20-O-sulfate, silybin B 20-O-sulfate, 2,3-dehydrosilybin-20-O-sulfate, 2,3-dehydrosilybin-7,20-di-O-sulfate, silychristin-19-O-sulfate, 2,3-dehydrosilychristin-19-O-sulfate, and silydianin-19-O-sulfate were prepared and fully characterized. Sulfated 2,3-dehydroderivatives were more active in FCR and FRAP assays than the parent compounds, and remaining sulfates were less active chemoprotectants. The sulfated flavonolignans obtained can be now used as authentic standards for in vivo metabolic experiments and for further research on their biological activity.

• MeSH
• antioxidancia chemie   MeSH
• flavonolignany chemie   MeSH
• hmotnostní spektrometrie MeSH
• magnetická rezonanční spektroskopie MeSH
• molekulární struktura MeSH
• ostropestřec mariánský chemie   MeSH
• ovoce chemie   MeSH
• potravní doplňky MeSH
• rostliny chemie   ultrastruktura   MeSH
• scavengery volných radikálů chemie   MeSH
• sírany chemie   MeSH
• Publikační typ
• časopisecké články MeSH