scholarly journals Antioxidative Properties of Bee Pollen Extracts Examined by EPR Spectroscopy

2012 ◽  
Vol 56 (1) ◽  
pp. 23-31 ◽  
Author(s):  
Anna Rzepecka-Stojko ◽  
Barbara Pilawa ◽  
Paweł Ramos ◽  
Jerzy Stojko
Keyword(s):  
Free Radicals ◽  
Antioxidant Capacity ◽  
Epr Spectroscopy ◽  
Antioxidant Properties ◽  
Antioxidative Effect ◽  
Paramagnetic Resonance ◽  
Bee Pollen ◽  
Antioxidative Properties ◽  
Ethanol Extracts ◽  
Dpph Scavenging

Antioxidative Properties of Bee Pollen Extracts Examined by EPR Spectroscopy Bee pollen is a valuable and highly recognized source of exogenous antioxidants. The aim of these studies was to determine the antioxidant capacity of three types of bee pollen extracts: ethanol extracts of bee pollen, pepsin extracts of bee pollen and ethanol extracts of pepsin-digested bee pollen. Their antioxidant properties were determined with the use of electron paramagnetic resonance (EPR) and their ability to quench DPPH free radicals was estimated. The EPR results showed that ethanol extracts of pepsin-digested bee pollen (EEPP) had the highest antioxidative effect and the highest free radical DPPH scavenging potential. The pepsin extracts of bee pollen (PEP) had the weakest antioxidant capacity. The ability to quench DPPH free radicals was also the weakest one for this extract. An average antioxidative effect was recorded for ethanol extracts of bee pollen (EEP).

Investigation of Antioxidant Activity of Pomegranate Juices by Means of Electron Paramagnetic Resonance and UV-Vis Spectroscopy

2015 ◽  
Vol 98 (4) ◽  
pp. 866-870 ◽  
Author(s):  
Violetta Kozik ◽  
Krystyna Jarzembek ◽  
Agnieszka Jędrzejowska ◽  
Andrzej Bąk ◽  
Justyna Polak ◽  
...  
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Free Radical ◽  
Epr Spectroscopy ◽  
Antioxidant Properties ◽  
Free Radical Scavenger ◽  
Pomegranate Juice ◽  
Radical Scavenger ◽  
Paramagnetic Resonance ◽  
Vis Spectroscopy ◽  
Electron Paramagnetic

Abstract Pomegranate fruit (Punica granatum L.) is a source of numerous phenolic compounds, and it contains flavonoids such as anthocyanins, anthocyanidins, cyanidins, catechins and other complexes of flavonoids, ellagitannins, and hydrolyzed tannins. Pomegranate juice shows antioxidant, antiproliferative, and anti-atherosclerotic properties. The antioxidant capacity (TEAC) of the pomegranate juices was measured using electron paramagnetic resonance (EPR) spectroscopy and 1,1-diphenyl-2-picrylhydrazyl (DPPH•) as a source of free radicals, and the total phenolic (TP) content was measured using UV-Vis spectroscopy. All the examined pomegranate juices exhibited relatively high antioxidant properties. The TEAC values determined by means of EPR spectroscopy using Trolox (TE) as a free radical scavenger were in the range of 463.12 to 1911.91 μmol TE/100 mL juice. The TP content measured by the Folin-Ciocalteu method, using gallic acid (GA) as a free radical scavenger, widely varied in the investigated pomegranate juice samples and ranged from 1673.62 to 5263.87 mg GA/1 L juice. The strongest antioxidant properties were observed with the fresh pomegranate juices obtained from the fruits originating from Israel, Lebanon, and Azerbaijan. Correlation analysis of numerical data obtained by means of EPR spectroscopy (TEAC) and UV-Vis spectroscopy (TP) gave correlation coefficient (r) = 0.90 and determination coefficient (r2) = 0.81 (P <0.05).

Exercise-induced brachial artery vasodilation: role of free radicals

2007 ◽  
Vol 292 (3) ◽  
pp. H1516-H1522 ◽  
Author(s):  
Russell S. Richardson ◽  
Anthony J. Donato ◽  
Abhimanyu Uberoi ◽  
D. Walter Wray ◽  
Lesley Lawrenson ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Free Radicals ◽  
Brachial Artery ◽  
Epr Spectroscopy ◽  
Vascular Function ◽  
Paramagnetic Resonance ◽  
Healthy State ◽  
Total Antioxidant ◽  
Exercise Induced

Originally thought of as simply damaging or toxic “accidents” of in vivo chemistry, free radicals are becoming increasingly recognized as redox signaling molecules implicit in cellular homeostasis. Indeed, at the vascular level, it is plausible that oxidative stress plays a regulatory role in normal vascular function. Using electron paramagnetic resonance (EPR) spectroscopy, we sought to document the ability of an oral antioxidant cocktail (vitamins C, E, and α-lipoic acid) to reduce circulating free radicals, and we employed Doppler ultrasound to examine the consequence of an antioxidant-mediated reduction in oxidative stress on exercise-induced vasodilation. A total of 25 young (18–31 yr) healthy male subjects partook in these studies. EPR spectroscopy revealed a reduction in circulating free radicals following antioxidant administration at rest (∼98%) and as a consequence of exercise (∼85%). Plasma total antioxidant capacity and vitamin C both increased following the ingestion of the antioxidant cocktail, whereas vitamin E levels were not influenced by the ingestion of the antioxidants. Brachial artery vasodilation during submaximal forearm handgrip exercise was greater with the placebo (7.4 ± 1.8%) than with the antioxidant cocktail (2.3 ± 0.7%). These data document the efficacy of an oral antioxidant cocktail in reducing free radicals and suggest that, in a healthy state, the aggressive disruption of the delicate balance between pro- and antioxidant forces can negatively impact vascular function. These findings implicate an exercise-induced reliance upon pro-oxidant-stimulated vasodilation, thereby revealing an important and positive vascular role for free radicals.

scholarly journals Electron Paramagnetic Resonance Study of Thermally Treated Bismuth Subgallate

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Paweł Ramos ◽  
Barbara Pilawa
Keyword(s):  
Free Radicals ◽  
Free Radical ◽  
Epr Spectroscopy ◽  
Electron Paramagnetic Resonance Study ◽  
Strong Interactions ◽  
Paramagnetic Resonance ◽  
Model Free ◽  
Different Temperatures ◽  
Bismuth Subgallate ◽  
Thermal Sterilization

Complex of bismuth, an anti-inflammatory drug, was studied by EPR spectroscopy. The aim of this study was to determine concentrations and properties of free radicals formed during thermal sterilization of bismuth subgallate according to pharmacopoeia norms to optimize its sterilization process. Different temperatures (160°C, 170°C, and 180°C) and times (120 minutes, 60 minutes, and 30 minutes) of sterilization were used. Interactions of bismuth subgallate with DPPH, the model free radical reference, were checked.g-Factors, amplitudes (A), integral intensities (I), and linewidths (ΔBpp) were obtained. Integral intensities were obtained by double integration of the first-derivative EPR lines. The influence of microwave power in the range of 2.2–70 mW on shape and parameters of the EPR spectra was examined. Thermal sterilization produced free radicals in bismuth subgallate in all tested cases. Strong interactions with free radicals were pointed out for all the analysed samples containing bismuth independent of sterilization conditions. Optimal conditions of thermal sterilization for bismuth subgallate with the lowest free radical formation are temperature 170°C and time of heating 60 minutes. Strong dipolar interactions exist in thermally sterilized bismuth subgallate. EPR spectroscopy is a useful method of examination of thermal sterilization conditions.

scholarly journals Association between Serum Uric Acid Levels, Nutritional and Antioxidant Status in Patients on Hemodialysis

Nutrients ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2600 ◽  
Author(s):  
Etna Domínguez-Zambrano ◽  
José Pedraza-Chaverri ◽  
Ana Laura López-Santos ◽  
Omar Noel Medina-Campos ◽  
Cristino Cruz-Rivera ◽  
...  
Keyword(s):  
Uric Acid ◽  
Nutritional Status ◽  
Antioxidant Capacity ◽  
Antioxidant Status ◽  
Antioxidant Properties ◽  
Dialysis Session ◽  
Scavenging Activity ◽  
Protein Nitrogen ◽  
Dpph Scavenging Activity ◽  
Dpph Scavenging

Purpose: To determine the relationship between uric acid (UA) and nutritional and antioxidant status in hemodialysis (HD) patients, given that hyperuricemia could be an indicator of good nutritional status possibly because of the antioxidant properties of UA. Methods: Cross-sectional study with 93 patients on HD. Hyperuricemia was considered as UA ≥6.0 mg/dL in females and ≥7.0 mg/dL in males. Nutritional variables were registered. Blood samples were taken before the dialysis session to determine oxidative damage as plasma malondialdehyde (MDA) content, and antioxidant capacity measuring 2,2-diphenyl-piclrylhidrazil radical (DPPH●) scavenging activity and oxygen radical absorbance capacity (ORAC) value. Results: Patients with hyperuricemia had higher creatinine (11.9 vs. 10.5 mg/dL; p = 0.004), potassium (5.5 vs. 5.0 mg/dL; p = 0.014) levels; phase angle (5.8 vs. 4.9; p = 0.005), protein consumption (normalized protein nitrogen appearance, nPNA, 1.03 vs. 0.83; p = 0.013) than normouricemic patients. DPPH● scavenging activity was higher in hyperuricemic subjects (1.139 vs. 1.049 mM Trolox equivalents; p = 0.007); likewise, hyperuricemic subjects had less oxidant damage measured by MDA (10.6 vs. 12.7 nmol/mL; p = 0.020). Subjects with normouricemia were at higher risk of having a reactance to height (Xc/H) ratio less than 35 (OR 2.79; 95% CI, 1.1–7.017, p = 0.028); nPNA < 1.0 (OR 3.78; 95% CI, 1.4–10.2, p = 0.007), diagnosis of cachexia (OR 2.95; 95% CI, 1156–7.518, p = 0.021), potassium levels <5 (OR 2.97; 95% CI, 1.136–7.772, p = 0.023) and PA < 5.5° (OR 3.38; 95% CI, 1.309–8.749, p = 0.012.) Conclusions: Patients with hyperuricemia had higher antioxidant capacity and better nutritional status. Purines and protein restrictions in HD patients with hyperuricemia need to be reviewed individually for each patient. More studies are needed to stablish a cut point of UA levels in renal population.

scholarly journals Total polyphenol content and antioxidant capacity of allium plants and their correlation with antibacterial and antifungal activity

2021 ◽  
pp. 85-97
Author(s):  
S. S. Satorov ◽  
F. D. Mirzoeva
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Capacity ◽  
Antioxidant Properties ◽  
Biologically Active ◽  
Diffusion Method ◽  
Active Components ◽  
Total Polyphenols ◽  
Disk Diffusion Method ◽  
Ethanol Extracts ◽  
Antibacterial And Antifungal

Aim. To determine the total polyphenols and antioxidant capacity and their correlation with antimicrobial and fungicidal properties in some species of the genus Allium growing in Tajikistan.Materials and methods. The objects of the study were 15 kinds of the Amaryllidaceae family. Antibacterial onions were studied by the disk diffusion method against 4 types of microorganisms (test strains) and 1 type of yeast fungus. In the presence of total polyphenols, the content in μg of Gallic acid (GA) per ml of plant extract was measured. To determine the antioxidant activity, a solution of ABTS K2S2O8 was used. Trolox was used as a standard.Results. The maximum content of total polyphenols is characterized by ethanol extracts of A. Carolinianum, A. altaicum, A. elatum, A. oschaninii, A. ramosum, A. hymenorhisum. At the same time, their lowest amount was found in the bulbs of A. longicuspis. A. shoenoprasum, which is statistically significantly lower than in all the above-listed species of this plant group. The extracts from the stems of A. carolinianum, A. elatum, and A. pamiricum had the highest antioxidant effect. There is a direct weak correlation between biologically active components with antimicrobial and fungicidal activity in A. oshaninii and A. suworowii, depending on the altitude gradient.Conclusions. The results allow suggesting that the above-ground and underground parts of some wild-growing endemic species of the genus Allium have different degrees of antioxidant activity due to total polyphenols. The content of total polyphenols and the antioxidant capacity of extracts obtained from various plants in different in large ranges. In some cases, there are direct correlations between the content of polyphenols, antioxidant properties, antimicrobial and fungal properties.

scholarly journals Effect of UV Irradiation on Interactions ofα-Lipoic Acid with Free Radicals

2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
Paweł Ramos ◽  
Piotr Pepliński ◽  
Barbara Pilawa
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Free Radicals ◽  
Uv Irradiation ◽  
Lipoic Acid ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Antioxidant Properties ◽  
Resonance Spectroscopy ◽  
Paramagnetic Resonance ◽  
Pharmacological Substance ◽  
Electron Paramagnetic

Changes of antioxidant properties ofα-lipoic acid (LA) after UV irradiation were studied. LA is the typical drug used in diabetic neuropathy. Quenching of free radicals is an important factor of therapy by using this substance.α-Lipoic acid is exposed to UV irradiation during the storage. The aim of our studies was to examine the effect of UV irradiation on the interactions of LA with free radicals. Theα-lipoic acid was irradiated by UVA 315–400 nm light during 10 to 110 minutes by intervals of 10 minutes. The electron paramagnetic resonance spectroscopy was used as the experimental technique. The antioxidant properties of LA were spectroscopically confirmed. The strong effect of UV irradiation on interactions ofα-lipoic acid with free radicals was observed. It was pointed out that interactions of LA with free radicals decrease after its exposition on UV. The interactions of LA with free radicals were higher after the sample irradiation during 10 minutes than for the samples irradiated longer (20–110 minutes). The results are important for problems connected with photomedicine; they pointed out thatα-lipoic acid should not be stored on UV exposition. Application of electron paramagnetic resonance spectroscopy to characterize interactions of pharmacological substance with free radicals was confirmed.

Identification of free radicals in pyrolysis oil and their impact on bio-oil stability

RSC Advances ◽  
2014 ◽  
Vol 4 (56) ◽  
pp. 29840-29846 ◽  
Author(s):  
Jiajia Meng ◽  
Tatyana I. Smirnova ◽  
Xiao Song ◽  
Andrew Moore ◽  
Xueyong Ren ◽  
...  
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Free Radicals ◽  
Loblolly Pine ◽  
Epr Spectroscopy ◽  
Oil Stability ◽  
Pyrolysis Oil ◽  
Paramagnetic Resonance ◽  
Bio Oil ◽  
Electron Paramagnetic

The existence of radicals in pyrolysis oil generated from loblolly pine in three different reactor systems was verified with electron paramagnetic resonance (EPR) spectroscopy.

scholarly journals Antioxidant activity and free radicals of roasted herbal materials

2017 ◽  
Vol 63 (2) ◽  
pp. 34-41 ◽  
Author(s):  
Elżbieta Wojtowicz ◽  
Aldona Krupska ◽  
Renata Zawirska-Wojtasiak
Keyword(s):  
Antioxidant Activity ◽  
Free Radicals ◽  
Free Radical ◽  
Raw Materials ◽  
Antioxidant Properties ◽  
Sea Buckthorn ◽  
Total Phenolic ◽  
Paramagnetic Resonance ◽  
Phenolic Contents ◽  
Roasting Process

Summary Introduction: Novel raw materials are being constantly searched for chicory coffee, which thanks to their specific composition can influence human health, thus promoting properties and of course the attractive aroma. Prior to their addition herbs – sea buckthorn (Hippophaë rhamnoides L.), rowanberry (Sorbus aucuparia L.), lovage roots (Levisticum officinale Koch) and dandelion (Taraxacum officinale coll.) – are roasted, which may change their antioxidant properties and generate free radicals with pro-oxidative properties. Objective: The characteristic of antioxidant activity of roasted herbal raw materials (sea buckthorn fruits, rowanberry, lovage roots and dandelion roots) for the production of chicory coffee and to determine the level of free radicals formed under the influence of roasting. Methods: Total phenolic contents were determined before and after the roasting process using the Folin-Ciocalteu phenol reagent and antioxidant activity by ABTS and DPPH assays. Free radicals were examined using electron paramagnetic resonance (EPR) spectroscopy. Results: The roasted materials were good sources of bioactive compounds, estimated at the total phenolic levels from 23.9 to 38.8 mg GAE/g. The highest antioxidant activity by ABTS and DPPH at 109.6 and 71.0 mg Tx/g was determined in roasted sea buckthorn. Free radicals were present in both the raw and roasted herbal materials. Roasted materials were characterised by markedly higher free radical concentrations when compared with the corresponding samples. The lowest free radical concentrations were recorded for roasted sea buckthorn fruits (0.031 × 1015 spin/g). Conclusion: Despite a high content of compounds with potent antioxidant activity, free radicals were present in novel roasted herbal materials. The formation of both antioxidant molecules and free radicals during the roasting process demonstrates that the two processes were not inversely related.

Effect of Different Drying Processes on the Physicochemical and Antioxidant Properties of Thinned Young Apple

2015 ◽  
Vol 11 (2) ◽  
pp. 207-219 ◽  
Author(s):  
Weiqi Chen ◽  
Yurong Guo ◽  
Juan Zhang ◽  
Xiaorui Zhang ◽  
Yonghong Meng
Keyword(s):  
Antioxidant Capacity ◽  
Large Scale ◽  
Antioxidant Properties ◽  
Food Resource ◽  
Reducing Power ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Scale Production ◽  
Large Scale Production ◽  
Trolox Equivalent ◽  
Dpph Scavenging

Abstract In China, there are about 1.6 million tons of thinned young apples (TYAs) every year after blossoming and fruit thinning. These resulting fruits, in reality, could be utilized as agricultural and food resource. This study was undertaken to evaluate the influence on physical properties, bioactive attributes of TYAs that were subjected to chosen drying techniques. In general, significant differences (p < 0.05) exist in physical appearance and polyphenol. Antioxidant capacity was also investigated on the basis of assay for Trolox equivalent antioxidant capacity (TEAC) by 2,2ʹ-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), reducing power and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) scavenging ability. Judging from the results, it was concluded that hot air drying at 60℃ is appropriate for large-scale production; furthermore, vacuum freeze drying tends to manufacture high-value up-market TYA products that are available to give the best results for dehydrated fruits. It is suggested that TYA has great potential in the food industry as functional ingredient.

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