scholarly journals UV-induced change in quercetin antioxidant activity toward benzophenone initiated lipid peroxidation

2012 ◽  
Vol 77 (11) ◽  
pp. 1571-1588 ◽  
Author(s):  
Jelena Zvezdanovic ◽  
Dejan Markovic ◽  
Dragan Cvetkovic ◽  
Jelena Stanojevic
Keyword(s):  
Lipid Peroxidation ◽  
Antioxidant Activity ◽  
Uv Irradiation ◽  
Energy Input ◽  
Incident Light ◽  
Methanol Solution ◽  
Suppression Effect ◽  
Peroxidation Processes ◽  
Uv Photons ◽  
Uv C

The aim of this work is to estimate the degradation and change in antioxidant activity of quercetin in the presence of two different mixtures of phospholipids in methanol solution, under continuous UV-irradiation from three different sub-ranges (UV-A, UV-B and UV-C), in the presence and in the absence of selected UV-absorbing photosensitizer, benzophenone. Quercetin is employed to control lipid peroxidation process generated by UV-irradiation, by absorbing part of the UV-incident light, or/and by scavenging the involved, created free radicals. The results show that quercetin undergoes to irreversible destruction, highly dependent on UV-photons energy input, more expressed in the presence than in the absence of benzophenone. In the same time quercetin expresses suppression effect on lipid peroxidation processes in UV-irradiated phospholipid mixtures in both cases - absence or presence of benzophenone (more or less effective, respectively). In UV-C-irradiated mixtures, benzophenone photosensitizing function is significantly reduced due to its strong absorption in the same UV-C spectral range, therefore affecting less antioxidant activity of the remained quercetin.

scholarly journals Effects of continuous UV-irradiation on the antioxidant activities of quercetin and rutin in solution in the presence of lecithin as the protective target

2011 ◽  
Vol 76 (7) ◽  
pp. 973-985 ◽  
Author(s):  
Dragan Cvetkovic ◽  
Dejan Markovic ◽  
Dragana Cvetkovic ◽  
Blaga Radovanovic
Keyword(s):  
Lipid Peroxidation ◽  
Uv Irradiation ◽  
Energy Input ◽  
Antioxidant Activities ◽  
Antioxidant Action ◽  
First Order ◽  
First Order Kinetics ◽  
Uv Photons ◽  
Uv C

The stabilities and antioxidant action of two selected flavonoids, quercetin and rutin, dissolved in methanol and water, toward continuous UV-irradiation from three different sub-ranges (UV-A, UV-B and UV-C) were studied. The flavonoids underwent degradation (bleaching) following first-order kinetics. The bleaching rates were highly dependent on the energy input of the involved UV-photons. The antioxidant activities of the two flavonoids on UV-induced lecithin lipid peroxidation were studied by the TBA-MDA test, and appeared to be also affected by the continuous UV irradiation. The energy input of the incident UV-photons again played a major governing role, but an impact of the flavonoids structures cannot be neglected.

scholarly journals A marginal contribution of selected carotenoids to the supression of UV-irradiation-induced lecithin peroxidation in hexane solution

2007 ◽  
Vol 72 (3) ◽  
pp. 235-250 ◽  
Author(s):  
Dragan Cvetkovic ◽  
Dejan Markovic
Keyword(s):  
Lipid Peroxidation ◽  
Free Radicals ◽  
Uv Irradiation ◽  
Marginal Contribution ◽  
Lipid Peroxidation Process ◽  
Uv Photons ◽  
Uv C ◽  
Hexane Solution

The aim of this work was to study the anticipated antioxidant role of four selected carotenoids in mixtures with lecithin lipoidal compounds in hexane solution, under continuous UV-irradiation in three different ranges (UV-A, UV-B and UV-C). Two carotenes (b-carotene and licopene) and two xantophylls (lutein and neoxanthin) were employed to control the lipid peroxidation process generated by UV-irradiation, by scavenging the involved free radicals. The results show that while carotenoids undergo a substantial, structural dependent destruction (bleaching), which is highly dependent on energy of the UV-photons, their contribution to the expected suppression of lecithin peroxidation is of marginal importance, not exceeding a maximum of 20%. The marginal antioxidant behaviour has been attributed to a highly unordered hexane solution, where the scavenging action of the carotenoids becomes less competitive.

scholarly journals Bleaching of chlorophylls by UV irradiation in vitro: The effects on chlorophyll organization in acetone and n-hexane

2008 ◽  
Vol 73 (3) ◽  
pp. 271-282 ◽  
Author(s):  
Jelena Zvezdanovic ◽  
Dejan Markovic
Keyword(s):  
Uv Irradiation ◽  
Photosynthetic Pigments ◽  
Energy Input ◽  
First Order ◽  
First Order Kinetics ◽  
Uv Photons ◽  
The Stability ◽  
Major Factors

The stability of chlorophylls toward UV irradiation was studied by Vis spectrophotometry in extracts containing mixtures of photosynthetic pigments in acetone and n-hexane. The chlorophylls underwent destruction (bleaching) obeying first-order kinetics. The bleaching was governed by three major factors: the energy input of the UV photons, the concentration of the chlorophylls and the polarity of the solvent, implying different molecular organizations of the chlorophylls in the two solvents.

scholarly journals UV-effects on antioxidant activity of selected carotenoids in the presence of lecithin estimated by DPPH test

2008 ◽  
Vol 73 (11) ◽  
pp. 1051-1061 ◽  
Author(s):  
Dragan Cvetkovic ◽  
Dejan Markovic
Keyword(s):  
Antioxidant Activity ◽  
Ultraviolet Radiation ◽  
Energy Input ◽  
High Energy ◽  
Antioxidant Action ◽  
Dpph Radical ◽  
Dpph Test ◽  
Uv Photons

The effects of ultraviolet radiation (UV) on the antioxidant action of three selected carotenoids (?-carotene, lycopene and lutein) in the presence of a lipoidal lecithin mixture were studied by the DPPH (1,1-diphenyl-2-picrylhydrazyl) test. The test is based on the measurement of the decrease of the free DPPH radical absorbance at 517 nm caused by the antioxidant action of carotenoids, which appeared to be strongly affected by UV-action. The high-energy input of the involved UV-photons plays a major governing role.

scholarly journals Parameters of Lipid Peroxidation and Antioxidant Protection in Men with Pathological Spermogram Variants

2019 ◽  
Vol 4 (1) ◽  
pp. 14-18
Author(s):  
Nadezhda A. Kurashova ◽  
Ekaterina A. Kudeyarova ◽  
Ekaterina O. Kuznetsova
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Antioxidant Activity ◽  
Antioxidant Defense ◽  
Antioxidant Defense System ◽  
Total Antioxidant Activity ◽  
Antioxidant Protection ◽  
Defense System ◽  
Total Antioxidant ◽  
Peroxidation Processes

Background.Today infertile marriage is not only a serious medical, but also a socio-demographic and economic problem. Male factor contributes averagely to half of the cases of the disease in couples. Such factors as high levels of reactive oxygen species and oxidative stress have been reported to compromise the process of spermatogenesis and sperm function in men. Oxidative stress is a significant risk factor for male infertility. A pro-oxidant testicular environment may alter the expression profile of functional sperm proteins and result in poor sperm quality.Aims.To study the characteristics of the intensity of the processes of lipoperoxidation and antioxidant status in the ejaculate of men with different variants of spermograms.Materials and methods.We examined 69 men with primary infertility and 155 fertile men. The content of lipid peroxidation components and antioxidant protection was determined by spectrophotometric method.Results.The results of the study in men with infertility and asthenozoospermia showed decreased total antioxidant activity of sperm by 50 % and α-tocopherol by 52 %, and in men with infertility and oligozoospermia, decreased total antioxidant activity of sperm by 47 % and α-tocopherol by 41 %.Conclusions.The analysis indicates a change in the parameters of the system of lipid peroxidation – antioxidant defense system and confirms the development of oxidative stress in them. Depending on the pathological state of the ejaculate in men of reproductive age, lipid peroxidation processes have their own characteristics. In men with oligozoospermia, peroxidation processes occur more intensively. Activation of lipid peroxidation – antioxidant defense system processes can be both a consequence and a cause of various metabolic changes in the human body.

scholarly journals Benzophenone Suppression of Quercetin Antioxidant Activity towards Lipids under UV-B Irradiation Regime: Detection by HPLC Chromatography

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Jelena S. Stanojević ◽  
Dejan Z. Marković ◽  
Jelena B. Zvezdanović
Keyword(s):  
Lipid Peroxidation ◽  
Antioxidant Activity ◽  
Spectrophotometric Method ◽  
Methanol Solution ◽  
The Other ◽  
Lipid Mixture ◽  
Irradiation Regime

Quercetin, a well-known flavonoid antioxidant, has been employed to control benzophenone-sensitized peroxidation of the lipid mixture in methanol solution, induced by continuous UV-B irradiation. Surprisingly, the detected quercetin antioxidant activity was almost negligible. The presented data suggests that the reason is not in its own UV-B-induced degradation but rather in its interrelationship with benzophenone during UV-B stress. On the other side of this relationship, benzophenone anticipated sensitizing role towards lipids; that is, the initiation of lipid peroxidation has been affected as well. These results, obtained by HPLC chromatography, partly confirm but partly relativize to some extent recent results obtained with the same system by spectrophotometric method.

scholarly journals Prognostic value of lipid peroxidation changes in acute poisoning with household drugs “bath salts”

2019 ◽  
Vol 100 (4) ◽  
Author(s):  
D B Sumnaya ◽  
A V Iksanov ◽  
V Yu Shkarednykh ◽  
V A Sadova ◽  
M V Kuleshova
Keyword(s):  
Lipid Peroxidation ◽  
Antioxidant Activity ◽  
Blood Serum ◽  
Antioxidant System ◽  
Bath Salts ◽  
Acute Period ◽  
Clinical Hospital ◽  
Lipid Peroxidation Products ◽  
Peroxidation Processes ◽  
Biochemical Features

Aim. To study the state of lipid peroxidation processes in case of psychodisleptic poisoning of the “bath salt” type and to determine the clinical and biochemical markers of a favorable and complicated course of the acute period of poisoning. Methods. In 347 patients with acute household poisoning (“bath salts”) admitted to the toxicology department of the Chelyabinsk Regional Clinical Hospital №3, the clinical and biochemical features of the acute period of psychodisleptic poisoning (“bath salts”) were studied in a favorable and unfavorable course. Blood and urine samples were taken from all patients, which later underwent chemical and toxicological studies by gas chromatography-mass spectrometry. Also, lipid peroxidation and antioxidant activity were determined in selected blood samples. Lipid peroxidation products were detected in heptane-isopropanol extracts of biological material by spectrophotometry. The intensity of Fe2+-ascorbate-induced lipid peroxidation was determined in E.I. L'vovskaya's modification. The study of patients' samples was carried out in the biochemical laboratory of the regional clinical hospital №3, at the Department of Biochemistry of the Ural state university of physical culture and the South Ural state medical university of Chelyabinsk. Results. Patients with “bath salts” poisoning in the acute period showed an elevated content of all categories of peroxidation products in the blood serum — by 1.51–1.70 times more than in the control group of healthy people. A decrease in antioxidant activity values I and II by 1.13–1.31 times was also found. With favorable outcomes of poisoning, the level of activation of lipid peroxidation processes decreased with an adequate increase in the activity of the antioxidant system by 1.5–1.6 times. The activation of lipid peroxidation processes in the blood serum accompanied by a decrease in the activity of antioxidant system led to an unfavorable course of the disease and the development of cerebral edema in 18 patients which was fatal. Conclusion. The clinical and biochemical features of the course of the acute period of poisoning with “bath salts” revealed by us suggest adverse outcomes of the disease with a tendency to an increase in the content of serum lipid peroxidation products in the course of the disease (instead of reducing them) along with a reduction of antioxidant activity; these indicators should be compensated by the use of antioxidant therapy.

scholarly journals Irreversible UV-induced quercetin and rutin degradation in solution, studied by UV-spectrophotometry and HPLC chromatography

2012 ◽  
Vol 77 (3) ◽  
pp. 297-312 ◽  
Author(s):  
Jelena Zvezdanovic ◽  
Jelena Stanojevic ◽  
Dejan Markovic ◽  
Dragan Cvetkovic
Keyword(s):  
Rate Constants ◽  
Energy Input ◽  
Degradation Products ◽  
Formation Rate ◽  
Uv Spectrophotometry ◽  
First Order ◽  
First Order Kinetics ◽  
Uv Photons ◽  
Rutin Degradation ◽  
Uv C

Irreversible degradation of quercetin and rutin, dissolved in methanol and water, induced by continuous UV-irradiation from two different sub-ranges (UV-B and UV-C) has been studied in this work. The degradation of both flavonoids is related to formation of UV-induced degradation products: both processes follow first-order kinetics. The degradation and products formation rate constants are both dependent on the involved UV-photons energy input in both solvents.

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