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  1. 8 Acta Biochimica Polonica

  2. 5 Annales Academiae Medicae Silesiensis

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  1. 8 Pilawa B.

  2. 7 Ramos P.

  3. 2 Czarnocki Z.

  4. 2 Grochowska-Niedworok E.

  5. 2 Pepliński P.

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1
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EPR examination of free radicals thermally formed invaselinum flavum

100%
Ramos P., Pilawa B.
Nukleonika
|
2015
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vol. 60
|
issue 3
443-447
EN
The popular pharmaceutical base used in pharmacy – vaselinum flavum – was studied by an X-band (9.3 GHz) EPR spectrometer in the range of microwave power of 2.2–70 mW. The samples were sterilized in hot air oven at temperatures: 160°C (120 min), 170°C (60 min), and 180°C (30 min). The aim of this work was to determine properties and free radical concentrations in vaselinum flavum thermally sterilized at different conditions. The changes in free radical system in vaselinum flavum during storage were analyzed. Free radicals were found in all the heated samples. The lowest free radical concentration was obtained for vaselinum flavum heated at 180°C for 30 min; so these parameters are proposed for the thermal sterilization of this pharmaceutical base. Interactions with oxygen decreased free radical concentration in vaselinum flavum during storage. Strong quenching of free radicals in vaselinum flavum was observed after 2 days for the samples sterilized at temperatures 160 and 180°C. Such an effect for vaselinum flavum heated at temperature 170°C was observed later, 13 days after sterilization. Fast spin-lattice relaxation processes exist in thermally sterilized vaselinum flavum. The EPR lines of heated vaselinum flavum were homogeneously broadened. EPR spectroscopy and its use for examining the thermal sterilization process in pharmacy was confirmed.
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Spin traps in the detection of free radicals in the blood of patients with ischemia

100%
Krzyminiewski R., Kruczynski Z., Stepien A., Dobosz B.
Polish Journal of Medical Physics And Engineering
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2009
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vol. 15
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issue 1
47-54
EN
Electron Paramagnetic Resonance and a nitrosobenzene spin trap were used to investigate free radicals in the human blood after angioplasty treatment. The nitrosobenzene anion radical was determined using EPR measurements and quantum-mechanical calculations. Differences were observed in the concentration of free radicals before and after angioplasty treatment. These results were compared with myocardium damage parameters (CPK, MB and TnT).
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Interaction between magnetic agglomerates and an extended free radicals network studied by magnetic resonance

100%
Guskos N., Zolnierkiewicz G., Typek J., Guskos A., Berczynski P., Petridis D.
Open Physics
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2012
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vol. 10
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issue 1
166-171
EN
Solids containing an extended network of free radicals have been prepared and studied by magnetic resonance techniques in the 4–290 K temperature range. One solid contained additionally a small amount of magnetic γ-Fe2O3 in the form of nanoparticle agglomerates. The solid without agglomerates displayed only a narrow, single resonance line centered at g eff = 2.0043. The magnetic resonance measurements of the solid with γ-Fe2O3 agglomerates gave a spectrum composed of two lines attributed to two different magnetic centers: a narrow line due to free radicals and a broad line arising from magnetic iron oxide agglomerates. In the high temperature range the integrated intensities of both lines decreased with decreasing temperature. The resonance field of the broad line shifted to lower magnetic fields upon lowering the temperature with the gradient ΔH r/ΔT = 2.3 G/K, while the narrow line shifted towards higher magnetic fields. The linewidth of the broader line increased with decreasing temperature while for the narrow lines in both samples this change was small. The magnetic iron oxide clusters produce a magnetic field which acts on the free radicals network and its strength depends essentially on the concentration of clusters. The reorientation process in the free radicals network is more intense in the sample without magnetic clusters.
4
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Influence of Vitamin E Given Intraperitoneally to Prevent Peritoneal Adhesions in Rats

100%
Makarska J., Sosada K., Stępien T., Bucki B., Żurawiński W.
Polish Journal of Surgery
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2010
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vol. 82
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issue 10
547-552
EN
The aim of the study was to evaluate the influence of vitamin E administered intraperitoneally on the prevention of peritoneal adhesion formation in rats on the basis of macroscopic and microscopic assessment of the adhesions.Material and methods. Experimental studies were performed on 50 Sprague-Dawley male rats, which were randomly divided into 5 groups, 10 rats in a group. Experimental group I (EI) included 10 rats which had peritoneal adhesions provoked by scraping of the wall of cecum and parietal peritoneum followed by intraperitoneal administration of vitamin E in the dose of 100 mg/kg body weight. Experimental group II (EII) included 10 rats which had peritoneal adhesions provoked by surgery, without administration of vitamin E. Control Group I (CI) included 10 rats which had the abdominal cavity opened without provoking peritoneal adhesions, and vitamin E was administered. Control Group II (CII) included 10 rats which had peritoneal adhesions provoked by surgery, and then lipid based solution was administered intraperitoneally. Control Group III (CIII) included 10 rats which had the abdominal cavity only opened and closed.Groups EI, CI and CII were the subject of the drugs intraperitoneal re-injection in first, second and third day after surgery. The animals were killed during the 8th postoperative day. Macroscopic examination of peritoneal adhesions using the classification reported by Nair was performed and samples for microscopic examination were excised.Results. In group EI peritoneal adhesions were formed in 60% rats (40% weak and 20% solid). In group EII peritoneal adhesions were found in all animals (30% weak and 70% solid). Reduction of the inflammatory response and less severe fibrosis were observed in animals with intraperitoneal administration of vitamin E.Conclusion. In the study, vitamin E administered intraperitoneally to rats decreased the intensity and extensiveness of peritoneal adhesions, which was confirmed by macroscopic and microscopic examinations.
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Inhibitory effect of resveratrol on free radical generation in blood platelets

100%
Olas B., Żbikowska H. M., Wachowicz B., Krajewski T., Buczyński A., Magnuszewska A.
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EN
Resveratrol (3,4',5-trihydroxystilbene), a compound found in many plants, has been shown to prevent coronary heart diseases and to exert a variety of antiinflammatory and anticancerogenic effects. It is effective in lowering the level of serum lipids and in inhibiting platelet aggregation. We evaluated the effect of trans-resveratrol on the production of free radicals in pig blood platelets and showed that resveratrol inhibited the production of different reactive oxygen species (O^·_2H^2O^2, singlet oxygen and organic radicals) measured by the luminol-dependent chemiluminescence in resting platelets (P < 0.05). Resveratrol inhibited also the generation of radicals in platelets activated by thrombin (P < 0.05). Treatment of platelets with resveratrol at concentrations of 6.25 and 12.5 μg/ml caused a statistically insignificant increase in the production of O^·-_2 in these cells, as measured by reduction of cytochrome c; however, at higher doses (25, 50 and 100 μg/ml) resveratrol distinctly reduced the generation of O^·-_2 in platelets (P < 0.05). We suggest that free radicals play an important role in the reduced reactivity of blood platelets induced by resveratrol.
6
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Can angiotensin-converting enzyme inhibitors interfere with the free radicals? Measurement of antioxidant capacity using DPPH radical reduction examined by UV-VIS method

100%
Ramos P., Juszczak A., Szczołko W., Pilawa B., Stanisz B. J.
Acta Poloniae Pharmaceutica - Drug Research
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2019
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vol. 76
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issue 2
233-239
EN
A negative impact of radicals on human’s health is responsible for growing research interest in antioxidant properties of substances, which protect organisms from the damaging influence of these reactive species. Angiotensin-converting enzyme inhibitors (ACE-I) are the most popular drugs used in cardiovascular diseases. There are a lot of clinical reports that ACE-I have antioxidant properties, due to the fact, that prolonged use improves conditions of patients with neurodegenerative disorders and slow inflammatory processes. The paper shows the antioxidant properties of a selected ACE-I: cilazapril, ramipril, imidapril, lisinopril, perindopril, and quinapril. Among numerous methods for antioxidant activity estimation, DPPH reduction is the most popular and commonly used one due to its ease, speed, sensitivity and the usage of stable radicals. UV-Vis spectrophotometry was used to examine interactions of chosen ACE-I with model-free radicals. Absorption of UV-Vis spectra of DPPH (reference), and DPPH interacting with the tested ACE-I were compared. For all tested ACE-I kinetics of their interaction with DPPH, up to 30 minutes, were obtained. The strongest interaction with DPPH was observed for imidapril and cilazapril and the lowest interaction for lisinopril. Studies have shown usefulness UV-Vis spectrophotometry for obtaining information on interactions of ACE-I with model-free radicals.
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Interactions of dietary carotenoids with singlet oxygen (1O2) and free radicals: potential effects for human health

100%
Böhm F., Edge R., George Truscott T.
Acta Biochimica Polonica
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2012
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vol. 59
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issue 1
27-30
EN
The dietary carotenoids provide photoprotection to photosynthetic organisms, the eye and the skin. The protection mechanisms involve both quenching of singlet oxygen and of damaging free radicals. The mechanisms for singlet oxygen quenching and protection against free radicals are quite different - indeed, under some conditions, quenching of free radicals can lead to a switch from a beneficial anti-oxidant process to damaging pro-oxidative situation. Furthermore, while skin protection involves β-carotene or lycopene from a tomato-rich diet, protection of the macula involves the hydroxyl-carotenoids (xanthophylls) zeaxanthin and lutein. Time resolved studies of singlet oxygen and free radicals and their interaction with carotenoids via pulsed laser and fast electron spectroscopy (pulse radiolysis) and the possible involvement of amino acids are discussed and used to (1) speculate on the anti- and pro-oxidative mechanisms, (2) determine the most efficient singlet oxygen quencher and (3) demonstrate the benefits to photoprotection of the eye from the xanthophylls rather than from hydrocarbon carotenoids such as β-carotene.
8
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Effect of microwave power on EPR spectra of thermally sterilizedeucerinum anhydricum

88%
Ramos P., Pepliński P., Pilawa B.
Nukleonika
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2015
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vol. 60
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issue 3
439-442
EN
Free radicals formed during thermal sterilization of eucerinum anhydricum – the pharmaceutical base were examined by an X-band (9.3 GHz) spectrometer. Eucerinum anhydricum was sterilized at different physical conditions according to the Polish Pharmacopeia norms. The samples were heated at temperatures: 160°C (120 min), 170°C (60 min), and 180°C (30 min). The aim of this study is to compare free radical concentration and effect of microwave power on EPR spectra of eucerinum anhydricum base thermally sterilized at different temperatures and periods of time. The effect of time storage on the free radicals in the heated samples was tested. Free radical concentrations in the sample stored 15 min strongly decreased with the increasing of sterilization temperature, probably as the result of recombination. Storage caused strong decrease of free radical concentrations in the samples, probably as the result of interactions with oxygen. It was observed to be independent of sterilization conditions from 2 days of storage and longer. Because of the lowest free radical concentration, for eucerinum anhydricum thermal sterilization at 180°C for 30 min is recommended. The sterilized samples should be stored at inert atmosphere without oxygen molecules. Fast spin-lattice relaxation processes existed in sterilized eucerinum anhydricum. The character of changes of amplitudes and linewidths of EPR lines with increasing of microwave power was the same for different storage times. The parameters of thermal sterilization and storage time influenced free radical concentration in eucerinum anhydricum, but magnetic spin-lattice interactions were unchanged. The usefulness of EPR spectroscopy in optimization of thermal sterilization process of eucerinum anhydricum was confirmed.
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Effect of UV irradiation on free radicals in synthetic melanin and melanin biopolymer fromSepia officinalis– EPR examination

88%
Zdybel M., Pilawa B.
Nukleonika
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2015
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vol. 60
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issue 3
483-488
EN
Free radicals in synthetic melanin and melanin from Sepia officinalis were studied by electron paramagnetic resonance (EPR) spectroscopy. The effect of time of ultraviolet (UV) irradiation on free radicals in these melanins was tested. The samples were exposed to UV during 15, 30, and 60 minutes. EPR spectra were measured with microwaves from an X-band (9.3 GHz) in the range of microwave power of 2.2–70 mW. The performed EPR examinations indicate that high concentrations (~1021–1022 spin/g) of o-semiquinone free radicals with g factors of 2.0039–2.0045 exist in all the tested samples. For nonirradiated samples, free radical concentration was higher in natural melanin than in synthetic melanin. UV irradiation caused the increase of free radical concentrations in synthetic melanin samples and this effect depends on the time of irradiation. The largest free radical formation in the both melanins was obtained for 60 min of UV irradiation. Free radical concentrations after the UV irradiation of melanins during 30 min were lower than during irradiation by 15 min, and probably this effect was the result of recombination of the radiatively formed free radicals. EPR lines of the tested samples broadened with increasing microwave power, so these lines were homogeneously broadened. The two types of melanins differed in the time of spin-lattice relaxation processes. Slower spin-lattice relaxation processes exist in melanin from Sepia officinalis than in synthetic melanin. UV irradiation did not change the time of spin-lattice relaxation processes in the tested melanins. The performed studies confirmed the usefulness of EPR spectroscopy in cosmetology and medicine.
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Human Tissue Investigations Using PALS Technique - Free Radicals Influence

88%
Jasińska B., Zgardzińska B., Chołubek G., Pietrow M., Gorgol M., Wiktor K., Wysogląd K., Białas P., Curceanu C., Czerwiński E., Dulski K., Gajos A., Głowacz B., Hiesmayr B., Jodłowska-Jędrych B., Kamińska D., Korcyl G., Kowalski P., Kozik T., Krawczyk N., Krzemień W., Kubicz E., Mohammed M., Pawlik-Niedźwiecka M., Niedźwiecki S., Pałka M., Raczyński L., Rudy Z., Sharma N., Sharma S., Shopa R., Silarski M., Skurzok M., Wieczorek A., Wiktor H., Wiślicki W., Zieliński M., Moskal P.
Acta Physica Polonica A
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2017
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vol. 132
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issue 5
1556-1558
EN
The positron annihilation lifetime spectroscopy was applied to the samples of the human uterine leiomyomas and the normal myometrium tissues taken from the selected place of the uterus during a surgery. The method indicated differences in values of the measured positron annihilation lifetime spectroscopy parameters (lifetimes and intensities) between healthy and diseased tissue samples. The additional measurements were performed either in darkness or in presence of visible light which influenced the free radicals present in both kind of tissues and, as a result, made changes in free annihilation and o-Ps decay lifetime and intensity values.
11
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Comparison of the antioxidant potential of some herbal teas produced from ecological and traditional crops

88%
Wira D., Zielonka-Brzezicka J., Muzykiewicz-Szymańska A., Klimowicz A.
Acta Universitatis Lodziensis. Folia Biologica et Oecologica
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2021
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vol. 17
97-103
EN
The growing public awareness of the dangers regarding chemicals used in traditional agriculture has led to consumers seeking valuable and contaminant-free products. Ecological agriculture has become synonymous with high health value and product safety. The aim of this study was to evaluate the antioxidant activity and the total polyphenolic content of infusions of herbal tea bags and loose teas from traditional crops, as well as infusions of loose teas from ecological crops. Raw material comprised dried flowers of Matricaria chamomilla and Tilia cordata, as well as dried leaves of Urtica dioica, Melissa officinalis and Mentha piperita. Herbal infusions were prepared using three brewing times: 5, 10 and 20 min. The analysis of antioxidant potential was performed using in vitro methods such as DPPH, ABTS and FRAP. The polyphenolic content was determined using the Folin-Ciocalteu method. The antioxidant activity of the studied tea infusion depended on the method by which the plants were cultivated and the brewing time. The ecological agriculture conditions seem not to stimulate the synthesis of antioxidants. However, the possibility to obtain other beneficial properties of the studied plants is an indication to carry out ecological cultivation.
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Melatonin and its metabolites: new findings regarding their production and their radical scavenging actions

88%
Reiter R. J., Tan D.-x., Pilar Terron M., Flores L. J., Czarnocki Z.
Acta Biochimica Polonica
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2007
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vol. 54
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issue 1
1-9
EN
This review summarizes some of the recent findings concerning the long-held tenet that the enzyme, N-acetyltransferase, which is involved in the production of N-acetylserotonin, the immediate precursor of melatonin, may in fact not always control the quantity of melatonin generated. New evidence from several different laboratories indicates that hydroxyindole-O-methyltransferase, which O-methylates N-acetylserotonin to melatonin may be rate-limiting in some cases. Also, the review makes the point that melatonin's actions are uncommonly widespread in organs due to the fact that it works via membrane receptors, nuclear receptors/binding sites and receptor-independent mechanisms, i.e., the direct scavenging of free radicals. Finally, the review briefly summarizes the actions of melatonin and its metabolites in the detoxification of oxygen and nitrogen-based free radicals and related non-radical products. Via these multiple processes, melatonin is capable of influencing the metabolism of every cell in the organism.
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Preparation of N-aryl-ketonitrone spin traps

88%
Hassan I., Lauricella R., Tuccio B.
Open Chemistry
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2006
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vol. 4
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issue 2
338-350
EN
The syntheses of seven N-aryl-C,C-dialkoxycarbonylnitrones 1–7, six of which were original, were achieved from the appropriate aryl-nitroso compounds. These ketonitrones were found to trap efficiently carbon-centred free radicals in aqueous media, yielding stable aminoxyl radicals whose EPR spectra lasted several days. The two penta-deuterated compounds 6 and 7 were also found to be efficient at trapping methoxyl radical. Their various spin adducts showed simple three line signals, very sensitive to the polarity of the environment. This study represents the very first use of linear ketonitrones as spin traps.
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Metformin reduces NAD(P)H oxidase activity in mouse cultured podocytes through purinergic dependent mechanism by increasing extracellular ATP concentration

75%
Piwkowska A., Rogacka D., Jankowski M., Angielski S.
Acta Biochimica Polonica
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2013
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vol. 60
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issue 4
607-612
EN
Hyperglycemia affects the functioning numbers of podocytes and leads to a gradual decline of renal function. The normalization of glucose level is a principle therapeutic goal in diabetic patients and metformin is a popular hypoglycemic drug used in type 2 diabetes mellitus. Metformin activates AMP-activated kinase (AMPK) and decreases NAD(P)H oxidase activity in podocytes leading to reduction of free radical generation. Similar effects are observed after activation of P2 receptors. Therefore, we investigated whether metformin increases extracellular ATP concentration and affects the activities of NAD(P)H oxidase and AMPK through P2 receptors. Experiments were performed on cultured mouse podocytes. NAD(P)H oxidase activity was measured by chemiluminescence and changes in AMPK activity were estimated by immunoblotting against AMPKα-Thr172-P. Metformin increased extracellular ATP concentration by reduction of ecto-ATPase activity, decreased NAD(P)H oxidase activity and increased AMPK phosphorylation. A P2 receptor antagonist, suramin (300 µM), prevented metformin action on NAD(P)H oxidase and AMPK phosphorylation. The data suggests a novel mechanism of metformin action, at least in podocytes. Metformin, which increases extracellular ATP concentration leads to activation of P2 receptors and consequent modulation of the podocytes' metabolism through AMPK and NAD(P)H oxidase which, in turn, may affect podocyte functioning.
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Malondialdehyde (MDA) – product of lipid peroxidation as marker of homeostasis disorders and aging

75%
Całyniuk B., Grochowska-Niedworok E., Walkiewicz K. W., Kawecka S., Popiołek E., Fatyga E.
Annales Academiae Medicae Silesiensis
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2016
|
vol. 70
224-228
EN
Malondialdehyde (MDA) found in the body comes from two sources: food consumed and lipid peroxidation occurring in the tissues. The formation of MDA and the scale and rate of lipid oxidation in the tissues of living organisms is influenced by a number of endo- and exogeneous factors. The products of lipid peroxidation, in particular MDA, exhibit cytotoxic, mutagenic and carcinogenic properties. They can also inhibit enzymes associated with defending cells against oxidative stress. Not only do the occurring processes contribute to the development of many diseases, but they are also a part of the aging process. The body defends itself to some extent against the effects of free radicals by trapping and neutralising them. The main source of antioxidants is food products of plant origin. Lifestyle, the components of which are diet and physical activity, is an important element in preserving health understood as physical and psychological well-being. Dietary habits and a diet rich in antioxidants are modifiable factors which not only prevent age-associated diseases, but also delay aging processes.
PL
Dialdehyd malonowy (MDA) w organizmie człowieka pochodzi z dwóch źródeł: spożywanego pokarmu i peroksydacji lipidów występujących w tkankach. Powstawanie MDA, a także wielkość i szybkość utleniania lipidów w tkankach organizmów żywych, zależy od wielu czynników endo- i egzogennych. Produkty peroksydacji lipidów, szczególnie MDA, wykazują właściwości cytotoksyczne, mutagenne i rakotwórcze. Mogą one również hamować enzymy związane z obroną komórki przed stresem oksydacyjnym. Mogą nie tylko przyczyniać się do rozwoju wielu chorób, ale stanowią również część procesu starzenia się. Organizm broni się w pewnym stopniu przed działaniem wolnych rodników, neutralizując je. Głównym źródłem przeciwutleniaczy jest żywność – produkty pochodzenia roślinnego. Styl życia, na który składają się dieta i aktywność fizyczna, jest ważnym elementem w zachowaniu zdrowia rozumianego jako dobre samopoczucie fizyczne i psychiczne. Nawyki żywieniowe i dieta bogata w przeciwutleniacze są modyfikowalnymi czynnikami, które nie tylko zapobiegają chorobom związanym z wiekiem, ale także opóźniają procesy starzenia.
16
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EPR study of free radicals formed in fusidic acid and neomycin under UV irradiation

75%
Pierzchała E., Ramos P., Pilawa B.
Acta Poloniae Pharmaceutica - Drug Research
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2019
|
vol. 76
|
issue 2
215-223
EN
Free radicals in UV irradiated antibiotics used in dermatology were examined. Concentrations of free radicals in fusidic acid and neomycin, were determined. EPR spectra of the tested antibiotics were measured by electron paramagnetic resonance spectrometer with magnetic modulation of 100 kHz and numerical acquisition system the Rapid Scan Unit. The influence of microwave powers in the range of 2.2-70 mW on the spectra was obtained. Amplitudes (A) and linewidths (ΔBpp) of the EPR spectra, were analysed. The EPR spectra were homogeneously broadened. Fast spin-lattice relaxation processes existed in UV irradiated fusidic acid and neomycin, which EPR spectra were not saturated up to 70 mW. The influence of the time of UV irradiation on free radicals in the samples was observed. The samples were irradiated by UVA (315-400 nm) in the 30, 60, and 90 minute period. Free radical concentrations in the tested antibiotics exposed to UV were proportional to the amplitudes (A) of the EPR spectra. The highest amplitudes (A) were observed for the UV irradiated antibiotics during 60 minutes. The higher amplitudes (A) characterized fusidic acid than neomycin. Fusidic acid and neomycin used to treat bacterial infection of skin under UV irradiation may produce free radical toxic effects. The stronger photosensitivity characterized fusidic acid relatively to neomycin. EPR spectroscopy is the useful method to examine free radicals formed in antibiotics during photolysis.
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Peroxidation of proteins and lipids in suspensions of liposomes, in blood serum, and in mouse myeloma cells.

75%
Gebicki J. M., Du J., Collins J., Tweeddale H.
Acta Biochimica Polonica
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2000
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vol. 47
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issue 4
901-911
EN
There is growing evidence that proteins are early targets of reactive oxygen species, and that the altered proteins can in turn damage other biomolecules. In this study, we measured the effects of proteins on the oxidation of liposome phospholipid membranes, and the formation of protein hydroperoxides in serum and in cultured cells exposed to radiation-generated hydroxyl free radicals. Lysozyme, which did not affect liposome stability, gave 50% protection when present at 0.3 mg/ml, and virtually completely prevented lipid oxidation at 10 mg/ml. When human blood serum was irradiated, lipids were oxidized only after the destruction of ascorbate. In contrast, peroxidation of proteins proceeded immediately. Protein hydroperoxides were also generated without a lag period in hybrid mouse myeloma cells, while at the same time no lipid peroxides formed. These results are consistent with the theory that, under physiological conditions, lipid membranes are likely to be effectively protected from randomly-generated hydroxyl radicals by proteins, and that protein peroxyl radicals and hydroperoxides may constitute an important hazard to biological systems under oxidative stress.
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Melatonin as an antioxidant: biochemical mechanisms and pathophysiological implications in humans.

75%
Reiter R. J., Tan D.-x., Mayo J. C., Sainz R. M., Leon J., Czarnocki Z.
Acta Biochimica Polonica
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2003
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vol. 50
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issue 4
1129-1146
EN
This brief resume enumerates the multiple actions of melatonin as an antioxidant. This indoleamine is produced in the vertebrate pineal gland, the retina and possibly some other organs. Additionally, however, it is found in invertebrates, bacteria, unicellular organisms as well as in plants, all of which do not have a pineal gland. Melatonin's functions as an antioxidant include: a), direct free radical scavenging, b), stimulation of antioxidative enzymes, c), increasing the efficiency of mitochondrial oxidative phosphorylation and reducing electron leakage (thereby lowering free radical generation), and 3), augmenting the efficiency of other antioxidants. There may be other functions of melatonin, yet undiscovered, which enhance its ability to protect against molecular damage by oxygen and nitrogen-based toxic reactants. Numerous in vitro and in vivo studies have documented the ability of both physiological and pharmacological concentrations to melatonin to protect against free radical destruction. Furthermore, clinical tests utilizing melatonin have proven highly successful; because of the positive outcomes of these studies, melatonin's use in disease states and processes where free radical damage is involved should be increased.
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Free radical formation in salicylic acid and heating parameters – application of EPR, UV-Vis, TGA and colorimetry examination to optimize thermal sterilization

75%
Ramos P., Pilawa B.
Acta Poloniae Pharmaceutica - Drug Research
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2020
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vol. 77
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issue 3
431-441
EN
Salicylic acid heated at different temperatures and times was examined by an X-band (9.3 GHz) EPR spectroscopy, UV-Vis spectrophotometry, TGA and colorimetry test to optimize its thermal sterilization process. Free radical formation (~1018 spin/g) during thermal sterilization of salicylic acid according to the pharmaceutical norms at temperature 120oC and time of 120 minutes was compared with those for heating at the new tested temperatures and times: 130oC and 60 minutes, and 140oC and 30 minutes. It was obtained that the relatively lower free radical concentrations characterized salicylic acid heated at temperatures (times): 120oC (120 minutes), and 130oC (60 minutes), than at temperature (time) 140oC (30 minutes). So treatment at temperature 120oC during 120 minutes, and temperature 130oC during 60 minutes, were recommended as the optimal for thermal sterilization of salicylic acid. Salicylic acid should not be sterilized at temperature 140oC during 30 minutes, because of the highest free radical formation. Free radical systems of thermally treated salicylic acid revealed complex character. Fast spin-lattice relaxation processes existed in heated salicylic acid. Strong dipolar interactions characterized all the heated salicylic acid samples. EPR spectroscopy, UV-Vis spectrophotometry, thermogravimetry, and color measurement may be helpful besides microbiological analysis to optimize thermal sterilization conditions of salicylic acid.
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An Esr Study of Free Radicals Scavenging by Red Tea

75%
Wosiński S., Jurga J., Kruczyński Z., Górski R., Sobieralski K., Siwulski M.
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vol. 19
|
issue 1
47-54
EN
Herbal tea is known to exhibit the scavenging of free radicals responsible for cellular damage. We studied the effect of water treated with reverse osmotic filter equipped with a special dielectric ceramic composite on the antioxidant activity of red tea. Methanol solution of DPPH was added to the tea extract and the RT decay of DPPH free radicals was studied by ESR spectroscopy. Red tea brewed from tap water treated with the composite filter was found to exhibit higher radical scavenging efficiency in comparison with that of the tea brewed from tap water, mineral water and reverse osmosis water.
PL
Herbata ziołowa jest znana z własności wymiatania rodników odpowiedzialnych za uszkodzenia komórkowe. Zbadano wpływ wody poddanej filtracji metodą odwróconej osmozy z zastosowaniem dielektrycznego kompozytu ceramicznego na aktywność antyoksydacyjną czerwonej herbaty. Do ekstraktu herbaty dodawano metanolowego roztworu DPPH i badano metodą EPR zanik czasowy wolnych rodników DPPH. Czerwona herbata zaparzana na wodzie wodociągowej traktowanej filtrem kompozytowym wykazywała większą zdolność wymiatania rodników w porównaniu z herbatą zaparzaną na wodzie wodociągowej, wodzie mineralnej i wodzie z odwróconej osmozy.
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