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 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 Stability of carotenoids toward UV-irradiation in hexane solution

2008 ◽  
Vol 73 (1) ◽  
pp. 15-27 ◽  
Author(s):  
Dragan Cvetkovic ◽  
Dejan Markovic
Keyword(s):  
Free Radical ◽  
Uv Irradiation ◽  
First Order ◽  
Chemical Structures ◽  
First Order Kinetics ◽  
Uv C ◽  
Hexane Solution

The stabilities of four selected carotenoids dissolved in hexane, two carotenes and two xanthophylls, toward UV-irradiation of three different ranges (UV-A, UV-B and UV-C) were studied in this work. The carotenoids underwent bleaching via a probable free radical mediated mechanism following first-order kinetics. The bleaching rates were highly dependent on the input of the involved photons and, although not consistently, on the chemical structures of the investigated compounds. For the two xanthophylls, a possible role of oxygen associated with their bleaching cannot be neglected.

Role of Free Radicals and Lipid Peroxidation in Gastric Mucosal Injury Induced by Ischemia-Reperfusion in Rats

1989 ◽  
Vol 24 (sup162) ◽  
pp. 55-58 ◽  
Author(s):  
S. Ueda ◽  
T. Yoshikawa ◽  
S. Takahashi ◽  
H. Ichikawa ◽  
M. Yasuda ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Free Radicals ◽  
Ischemia Reperfusion ◽  
Mucosal Injury ◽  
Gastric Mucosal Injury

scholarly journals Oxidative Stress and Cancer: Chemopreventive and Therapeutic Role of Triphala

Antioxidants ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 72 ◽  
Author(s):  
Sahdeo Prasad ◽  
Sanjay K. Srivastava
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Free Radicals ◽  
Signaling Pathways ◽  
Multiple Cell ◽  
Multiple Signaling ◽  
Immense Potential ◽  
Cell Signaling Pathways ◽  
Radioprotective Agent

Oxidative stress, caused by the overproduction of free radicals, leads to the development of many chronic diseases including cancer. Free radicals are known to damage cellular biomolecules like lipids, proteins, and DNA that results in activation of multiple signaling pathways, growth factors, transcription factors, kinases, inflammatory and cell cycle regulatory molecules. Antioxidants, which are classified as exogenous and endogenous, are responsible for the removal of free radicals and consequently the reduction in oxidative stress-mediated diseases. Diet and medicinal herbs are the major source of antioxidants. Triphala, which is a traditional Ayurvedic formulation that has been used for centuries, has been shown to have immense potential to boost antioxidant activity. It scavenges free radicals, restores antioxidant enzymes and non-enzyme levels, and decreases lipid peroxidation. In addition, Triphala is revered as a chemopreventive, chemotherapeutic, immunomodulatory, and radioprotective agent. Accumulated evidence has revealed that Triphala modulates multiple cell signaling pathways including, ERK, MAPK, NF-κB, Akt, c-Myc, VEGFR, mTOR, tubulin, p53, cyclin D1, anti-apoptotic and pro-apoptotic proteins. The present review focuses on the comprehensive appraisal of Triphala in oxidative stress and cancer.

Protective role of edible clam Paphia malabarica (Chemnitz) against lipid peroxidation and free radicals

2013 ◽  
Vol 38 (2) ◽  
pp. 138-144 ◽  
Author(s):  
Ravindra Tanaji Pawar ◽  
Smita Suresh Nagvenkar ◽  
Tanaji Gajanan Jagtap
Keyword(s):  
Lipid Peroxidation ◽  
Free Radicals ◽  
Protective Role

Protective role of DLa-lipoic acid against adriamycin-induced cardiac lipid peroxidation

2003 ◽  
Vol 22 (5) ◽  
pp. 249-254 ◽  
Author(s):  
A V Balachandar ◽  
K P Malarkodi ◽  
P Varalakshmi
Keyword(s):  
Lipid Peroxidation ◽  
Free Radicals ◽  
Lipoic Acid ◽  
Antioxidant Property ◽  
Protective Role ◽  
Cytoprotective Activity ◽  
Male Wistar Rats ◽  
Cellular Defence ◽  
Antitumour Drug

The cytoprotective activity of a-lipoic acid against free radical toxicity manifested during adriamycin (ADR)induced cardiotoxicity has been investigated. ADR is a potent antitumour drug known to cause severe cardiotoxicity. Although ADR generates free radicals, the role of these radicals in the development of cardiac toxicity is still not well understood. In the present study, we evaluated the influence of chronic ADR treatment on the cellular defence mechanism against free radicals and the effect of a-lipoic acid supplementation on ADR-induced cardiotoxicity in male Wistar rats. The increase in lipid peroxidation (LPO) and activities of serum myocardial enzymes, namely lactate dehydrogenase (LDH) and creatinephosphokinase, associated with the decrease in activities of enzymatic (SOD, CAT, GPx, G6PD and GR) and non-enzymatic (GSH, Vit C and Vit E) antioxidants levels were the salient features observed in ADR-induced cardiotoxicity. Lipoic acid pretreated groups showed significant increase in activities of both enzymatic and non-enzymatic antioxidant levels. These observations highlight the antioxidant property ofa-lipoic acid and its cytoprotective action against ADR-induced cardiotoxicity.

scholarly journals The role of aldehyde oxidase in ethanol-induced hepatic lipid peroxidation in the rat

1990 ◽  
Vol 268 (3) ◽  
pp. 579-583 ◽  
Author(s):  
S Shaw ◽  
E Jayatilleke
Keyword(s):  
Lipid Peroxidation ◽  
Free Radicals ◽  
Liver Injury ◽  
Xanthine Oxidase ◽  
Aldehyde Oxidase ◽  
Ethanol Metabolism ◽  
Dependent Manner ◽  
Hepatic Lipid ◽  
Hepatic Lipid Peroxidation

Hepatic lipid peroxidation has been implicated in the pathogenesis of alcohol-induced liver injury, but the mechanism(s) by which ethanol metabolism or resultant free radicals initiate lipid peroxidation is not fully defined. The role of the molybdenum-containing enzymes aldehyde oxidase and xanthine oxidase in the generation of such free radicals was investigated by measuring alkane production (lipoperoxidation products) in isolated rat hepatocytes during ethanol metabolism. Inhibition of aldehyde oxidase and xanthine oxidase (by feeding tungstate at 100 mg/day per kg) decreased alkane production (80-95%), whereas allopurinol (20 mg/kg by mouth), a marked inhibitor of xanthine oxidase, inhibited alkane production by only 35-50%. Addition of acetaldehyde (0-100 microM) (in the presence of 50 microM-4-methylpyrazole) increased alkane production in a dose-dependent manner (Km of aldehyde oxidase for acetaldehyde 1 mM); menadione, an inhibitor of aldehyde oxidase, virtually inhibited alkane production. Desferrioxamine (5-10 microM) completely abolished alkane production induced by both ethanol and acetaldehyde, indicating the importance of catalytic iron. Thus free radicals generated during the metabolism of acetaldehyde by aldehyde oxidase may be a fundamental mechanism in the initiation of alcohol-induced liver injury.

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