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Messedi M, Guidara W, Grayaa S, Khrouf W, Snoussi M, Bahloul Z, Bonnefont-Rousselot D, Lamari F, Ayadi F. Selected plasma oxysterols as a potential multi-marker biosignature panel for Behçet's Disease. J Steroid Biochem Mol Biol 2022; 221:106122. [PMID: 35588947 DOI: 10.1016/j.jsbmb.2022.106122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 04/29/2022] [Accepted: 05/02/2022] [Indexed: 10/18/2022]
Abstract
Clinical, genetic, and medical evidence has shown the inflammatory vasculitis aspect of Behçet's Disease (BD). Whereas oxysterols are vital factors in inflammation and oxidative stress, it is still unknown whether they are involved in the pathophysiology of BD. The current study aims to explore the profile of oxysterols in plasma of BD patients. Thirty patients diagnosed with BD and forty healthy controls matched for age and gender were included. Results showed that the cholestane-3β,5α,6β-triol, 27-hydroxycholesterol (27-OHC) and cholestanol levels were higher in BD than controls. In addition, plasma levels of 7-ketocholesterol (7-KC) and 25-hydroxycholesterol (25-OHC) were lower in BD patient. However, levels of 24S-hydroxycholesterol (24-OHC) did not significantly differ. For BD patients, the plasma 7-KC level was negatively correlated with the BD activity index (BDAI) while 27-OHC was positively correlated with high-sensitivity C-reactive protein (hs-CRP) in patients with active course of the disease. According to ROC analysis, a remarkable increase in the area under the curve (AUC) with a higher sensitivity (Se) and specificity (Sp) for 7-KC, 25-OHC and 27-OHC combined markers was observed. The present study indicated that the identification of the predictive value of these three-selected biomarkers related to oxidative stress and inflammation in patients should lead to a better identification of the etiological mechanism of BD.
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Affiliation(s)
- Meriam Messedi
- Research Laboratory "Molecular Basis of Human Diseases", LR19ES13, Sfax Medicine School, University of Sfax, Tunisia.
| | - Wassim Guidara
- Research Laboratory "Molecular Basis of Human Diseases", LR19ES13, Sfax Medicine School, University of Sfax, Tunisia
| | - Sahar Grayaa
- Research Laboratory "Molecular Basis of Human Diseases", LR19ES13, Sfax Medicine School, University of Sfax, Tunisia
| | - Walid Khrouf
- Service de Biochimie Métabolique, AP-HP.Sorbonne Université, Hôpitaux Universitaires Pitié-Salpêtrière-Charles Foix, DMU BioGeM, Paris F-75013, France
| | - Mouna Snoussi
- Internal medicine department, Hedi Chaker Hosptital, Sfax, Tunisia
| | - Zouhir Bahloul
- Internal medicine department, Hedi Chaker Hosptital, Sfax, Tunisia
| | - Dominique Bonnefont-Rousselot
- Service de Biochimie Métabolique, AP-HP.Sorbonne Université, Hôpitaux Universitaires Pitié-Salpêtrière-Charles Foix, DMU BioGeM, Paris F-75013, France; Université de Paris, CNRS, Inserm, UTCBS, Paris F-75006, France
| | - Foudil Lamari
- Service de Biochimie Métabolique, AP-HP.Sorbonne Université, Hôpitaux Universitaires Pitié-Salpêtrière-Charles Foix, DMU BioGeM, Paris F-75013, France
| | - Fatma Ayadi
- Research Laboratory "Molecular Basis of Human Diseases", LR19ES13, Sfax Medicine School, University of Sfax, Tunisia
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Phung AS, Bannenberg G, Vigor C, Reversat G, Oger C, Roumain M, Galano JM, Durand T, Muccioli GG, Ismail A, Wang SC. Chemical Compositional Changes in Over-Oxidized Fish Oils. Foods 2020; 9:foods9101501. [PMID: 33092165 PMCID: PMC7590219 DOI: 10.3390/foods9101501] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 10/12/2020] [Accepted: 10/16/2020] [Indexed: 02/07/2023] Open
Abstract
A recent study has reported that the administration during gestation of a highly rancid hoki liver oil, obtained by oxidation through sustained exposure to oxygen gas and incident light for 30 days, causes newborn mortality in rats. This effect was attributed to lipid hydroperoxides formed in the omega-3 long-chain polyunsaturated fatty acid-rich oil, while other chemical changes in the damaged oil were overlooked. In the present study, the oxidation condition employed to damage the hoki liver oil was replicated, and the extreme rancidity was confirmed. A detailed analysis of temporal chemical changes resulting from the sustained oxidative challenge involved measures of eicosapentaenoic acid/docosahexaenoic acid (EPA/DHA) omega-3 oil oxidative quality (peroxide value, para-anisidine value, total oxidation number, acid value, oligomers, antioxidant content, and induction time) as well as changes in fatty acid content, volatiles, isoprostanoids, and oxysterols. The chemical description was extended to refined anchovy oil, which is a more representative ingredient oil used in omega-3 finished products. The present study also analyzed the effects of a different oxidation method involving thermal exposure in the dark in contact with air, which is an oxidation condition that is more relevant to retail products. The two oils had different susceptibility to the oxidation conditions, resulting in distinct chemical oxidation signatures that were determined primarily by antioxidant protection as well as specific methodological aspects of the applied oxidative conditions. Unique isoprostanoids and oxysterols were formed in the over-oxidized fish oils, which are discussed in light of their potential biological activities.
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Affiliation(s)
- Austin S. Phung
- Department of Chemistry, University of California, Davis, CA 95616, USA;
| | - Gerard Bannenberg
- Global Organization for EPA and DHA Omega-3s (GOED), Salt Lake City, UT 84105, USA;
- Correspondence: (G.B.); (S.C.W.)
| | - Claire Vigor
- Institut des Biomolécules Max Mousseron (IBMM), UMR 5247, CNRS, Université de Montpellier, ENSCM, 34093 Montpellier, France; (C.V.); (G.R.); (C.O.); (J.-M.G.); (T.D.)
| | - Guillaume Reversat
- Institut des Biomolécules Max Mousseron (IBMM), UMR 5247, CNRS, Université de Montpellier, ENSCM, 34093 Montpellier, France; (C.V.); (G.R.); (C.O.); (J.-M.G.); (T.D.)
| | - Camille Oger
- Institut des Biomolécules Max Mousseron (IBMM), UMR 5247, CNRS, Université de Montpellier, ENSCM, 34093 Montpellier, France; (C.V.); (G.R.); (C.O.); (J.-M.G.); (T.D.)
| | - Martin Roumain
- Louvain Drug Research Institute, Université Catholique de Louvain, 1200 Brussels, Belgium; (M.R.); (G.G.M.)
| | - Jean-Marie Galano
- Institut des Biomolécules Max Mousseron (IBMM), UMR 5247, CNRS, Université de Montpellier, ENSCM, 34093 Montpellier, France; (C.V.); (G.R.); (C.O.); (J.-M.G.); (T.D.)
| | - Thierry Durand
- Institut des Biomolécules Max Mousseron (IBMM), UMR 5247, CNRS, Université de Montpellier, ENSCM, 34093 Montpellier, France; (C.V.); (G.R.); (C.O.); (J.-M.G.); (T.D.)
| | - Giulio G. Muccioli
- Louvain Drug Research Institute, Université Catholique de Louvain, 1200 Brussels, Belgium; (M.R.); (G.G.M.)
| | - Adam Ismail
- Global Organization for EPA and DHA Omega-3s (GOED), Salt Lake City, UT 84105, USA;
| | - Selina C. Wang
- Department of Food Science and Technology, University of California, Davis, CA 95616, USA
- Correspondence: (G.B.); (S.C.W.)
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Brahmi F, Vejux A, Sghaier R, Zarrouk A, Nury T, Meddeb W, Rezig L, Namsi A, Sassi K, Yammine A, Badreddine I, Vervandier-Fasseur D, Madani K, Boulekbache-Makhlouf L, Nasser B, Lizard G. Prevention of 7-ketocholesterol-induced side effects by natural compounds. Crit Rev Food Sci Nutr 2018; 59:3179-3198. [DOI: 10.1080/10408398.2018.1491828] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Fatiha Brahmi
- Team ‘Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism’, Lab. Bio-PeroxIL, Université de Bourgogne Franche-Comté, Dijon, France
- Lab. Biomathématique, Biochimie, Biophysique et Scientométrie, Faculté des Sciences de la Nature et de la Vie, Université de Bejaia, Bejaia, Algeria
| | - Anne Vejux
- Team ‘Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism’, Lab. Bio-PeroxIL, Université de Bourgogne Franche-Comté, Dijon, France
| | - Randa Sghaier
- Team ‘Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism’, Lab. Bio-PeroxIL, Université de Bourgogne Franche-Comté, Dijon, France
- Lab-NAFS ‘Nutrition - Functional Food & Vascular Health’, LR12ES05, Université de Monastir, Monastir, Tunisia
- Faculty of Medicine, Lab. Biochemistry, Sousse, Tunisia
| | - Amira Zarrouk
- Lab-NAFS ‘Nutrition - Functional Food & Vascular Health’, LR12ES05, Université de Monastir, Monastir, Tunisia
- Faculty of Medicine, Lab. Biochemistry, Sousse, Tunisia
| | - Thomas Nury
- Team ‘Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism’, Lab. Bio-PeroxIL, Université de Bourgogne Franche-Comté, Dijon, France
| | - Wiem Meddeb
- Team ‘Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism’, Lab. Bio-PeroxIL, Université de Bourgogne Franche-Comté, Dijon, France
- LMMA/IPEST, Faculty of Science, University of Carthage, Bizerte, Tunisia
| | - Leila Rezig
- Team ‘Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism’, Lab. Bio-PeroxIL, Université de Bourgogne Franche-Comté, Dijon, France
- ESIAT, Lab. Conservation et Valorisation des Aliments, Tunis, Tunisia
| | - Amira Namsi
- Team ‘Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism’, Lab. Bio-PeroxIL, Université de Bourgogne Franche-Comté, Dijon, France
- University Tunis El Manar, Faculty of Science of Tunis, Laboratory of Functional Neurophysiology and Pathology, Tunis, Tunisia
| | - Khouloud Sassi
- Team ‘Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism’, Lab. Bio-PeroxIL, Université de Bourgogne Franche-Comté, Dijon, France
- Lab. Onco-Hematology, Faculty de Medicine of Tunis, Université de Tunis El Manar, Tunis, Tunisia
| | - Aline Yammine
- Team ‘Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism’, Lab. Bio-PeroxIL, Université de Bourgogne Franche-Comté, Dijon, France
- Bioactive Molecules Research Lab, Faculty of Sciences, Lebanese University, Beirut, Lebanon
| | - Iham Badreddine
- Team ‘Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism’, Lab. Bio-PeroxIL, Université de Bourgogne Franche-Comté, Dijon, France
- Lab. ‘Valorisation des Ressources Naturelles et Environnement’, Université Ibn Zohr, Taroudant, Morocco
| | | | - Khodir Madani
- Lab. Biomathématique, Biochimie, Biophysique et Scientométrie, Faculté des Sciences de la Nature et de la Vie, Université de Bejaia, Bejaia, Algeria
| | - Lila Boulekbache-Makhlouf
- Lab. Biomathématique, Biochimie, Biophysique et Scientométrie, Faculté des Sciences de la Nature et de la Vie, Université de Bejaia, Bejaia, Algeria
| | - Boubker Nasser
- Lab. Neuroscience and Biochemistry, Université Hassan 1er, Settat, Morocco
| | - Gérard Lizard
- Team ‘Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism’, Lab. Bio-PeroxIL, Université de Bourgogne Franche-Comté, Dijon, France
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Argan Oil-Mediated Attenuation of Organelle Dysfunction, Oxidative Stress and Cell Death Induced by 7-Ketocholesterol in Murine Oligodendrocytes 158N. Int J Mol Sci 2017; 18:ijms18102220. [PMID: 29065513 PMCID: PMC5666899 DOI: 10.3390/ijms18102220] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 10/18/2017] [Accepted: 10/20/2017] [Indexed: 02/07/2023] Open
Abstract
Argan oil is widely used in Morocco in traditional medicine. Its ability to treat cardiovascular diseases is well-established. However, nothing is known about its effects on neurodegenerative diseases, which are often associated with increased oxidative stress leading to lipid peroxidation and the formation of 7-ketocholesterol (7KC) resulting from cholesterol auto-oxidation. As 7KC induces oxidative stress, inflammation and cell death, it is important to identify compounds able to impair its harmful effects. These compounds may be either natural or synthetic molecules or mixtures of molecules such as oils. In this context: (i) the lipid profiles of dietary argan oils from Berkane and Agadir (Morocco) in fatty acids, phytosterols, tocopherols and polyphenols were determined by different chromatographic techniques; and (ii) their anti-oxidant and cytoprotective effects in 158N murine oligodendrocytes cultured with 7KC (25-50 µM; 24 h) without and with argan oil (0.1% v/v) or α-tocopherol (400 µM, positive control) were evaluated with complementary techniques of cellular and molecular biology. Among the unsaturated fatty acids present in argan oils, oleate (C18:1 n-9) and linoleate (C18:1 n-6) were the most abundant; the highest quantities of saturated fatty acids were palmitate (C16:0) and stearate (C18:0). Several phytosterols were found, mainly schottenol and spinasterol (specific to argan oil), cycloartenol, β-amyrin and citrostadienol. α- and γ-tocopherols were also present. Tyrosol and protocatechic acid were the only polyphenols detected. Argan and extra virgin olive oils have many compounds in common, principally oleate and linoleate, and tocopherols. Kit Radicaux Libres (KRL) and ferric reducing antioxidant power (FRAP) tests showed that argan and extra virgin olive oils have anti-oxidant properties. Argan oils were able to attenuate the cytotoxic effects of 7KC on 158N cells: loss of cell adhesion, cell growth inhibition, increased plasma membrane permeability, mitochondrial, peroxisomal and lysosomal dysfunction, and the induction of oxiapoptophagy (OXIdation + APOPTOsis + autoPHAGY). Altogether, our data obtained in 158N oligodendrocytes provide evidence that argan oil is able to counteract the toxic effects of 7KC on nerve cells, thus suggesting that some of its compounds could prevent or mitigate neurodegenerative diseases to the extent that they are able to cross the blood-brain barrier.
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Abstract
Cholesterol is one of the oxidizable lipids constituting biomembranes and plasma lipoproteins. Cholesterol hydroperoxides (Chol-OOH) are the primary products if cholesterol is subjected to attack by reactive oxygen species. In particular, singlet molecular oxygen reacts with cholesterol to yield cholesterol 5α-hydroperoxide as the major hydroperoxide species. Chol-OOH may accumulate in biological systems because of its resistance to glutathione-dependent enzymatic detoxification reactions. Their degradation products (including hydroxycholesterol and 7-ketocholesterol) participate in the pathophysiological functions of oxysterols. Highly reactive cholesterol 5,6-secosterol present in atherosclerotic lesions can be derived from the degradation of cholesterol 5α-hydroperoxide. Chol-OOH themselves may affect the lipid rafts of biomembranes, thereby leading to the modification of signal transduction pathways.
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Affiliation(s)
- Junji Terao
- Institute of Health Biosciences, University of Tokushima Graduate School, Tokushima, 770-8503, Japan,
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6
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A review on the role of nutraceuticals as simple as se(2+) to complex organic molecules such as glycyrrhizin that prevent as well as cure diseases. Indian J Clin Biochem 2013; 29:119-32. [PMID: 24757291 DOI: 10.1007/s12291-013-0362-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2013] [Accepted: 06/30/2013] [Indexed: 10/26/2022]
Abstract
Nutraceuticals are nutritional medicines which are present in edible food items. Most of them are antioxidants with various other biological properties viz, anti inflammatory, anti atherogenic, anticancer, anti viral, anti aging properties etc. They are as simple as minerals like Se(2+) to complex organic molecules such as glycyrrhizin (Ca(2+), K(+) salts of glycyrrhizic acid). They can prevent as well as cure various diseases. Most of the medical people are not aware of the importance of the nutraceuticals as such matters are not part of their text books. Many still think that vitamins are the major nutritional medicines. Actually other dietary principles like terpenes, carotenes, phytosterols, polyphenols, flavanoids, di and poly sulphides, their sulfoxides and their precursor amino acids are necessary to scavenge free radicals in the body which are reactive oxygen species to protect and maintain the vitamin levels in the body. They down regulate the activities of those enzymes which are increased in diseases and they increase those that remove oxidants and detoxify carcinogens. They are immune boosters too. Recently glucosinolates, non toxic alkaloids, certain proteins and even fiber are included in the list of nutraceuticals.
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Mitić T, Shave S, Semjonous N, McNae I, Cobice DF, Lavery GG, Webster SP, Hadoke PWF, Walker BR, Andrew R. 11β-Hydroxysteroid dehydrogenase type 1 contributes to the balance between 7-keto- and 7-hydroxy-oxysterols in vivo. Biochem Pharmacol 2013; 86:146-53. [PMID: 23415904 PMCID: PMC3694296 DOI: 10.1016/j.bcp.2013.02.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Revised: 02/01/2013] [Accepted: 02/04/2013] [Indexed: 01/19/2023]
Abstract
11β-Hydroxysteroid dehydrogenase 1 (11βHSD1; EC 1.1.1.146) generates active glucocorticoids from inert 11-keto metabolites. However, it can also metabolize alternative substrates, including 7β-hydroxy- and 7-keto-cholesterol (7βOHC, 7KC). This has been demonstrated in vitro but its consequences in vivo are uncertain. We used genetically modified mice to investigate the contribution of 11βHSD1 to the balance of circulating levels of 7KC and 7βOHC in vivo, and dissected in vitro the kinetics of the interactions between oxysterols and glucocorticoids for metabolism by the mouse enzyme. Circulating levels of 7KC and 7βOHC in mice were 91.3 ± 22.3 and 22.6 ± 5.7 nM respectively, increasing to 1240 ± 220 and 406 ± 39 nM in ApoE−/− mice receiving atherogenic western diet. Disruption of 11βHSD1 in mice increased (p < 0.05) the 7KC/7βOHC ratio in plasma (by 20%) and also in isolated microsomes (2 fold). The 7KC/7βOHC ratio was similarly increased when NADPH generation was restricted by disruption of hexose-6-phosphate dehydrogenase. Reduction and oxidation of 7-oxysterols by murine 11βHSD1 proceeded more slowly and substrate affinity was lower than for glucocorticoids. in vitro 7βOHC was a competitive inhibitor of oxidation of corticosterone (Ki = 0.9 μM), whereas 7KC only weakly inhibited reduction of 11-dehydrocorticosterone. However, supplementation of 7-oxysterols in cultured cells, secondary to cholesterol loading, preferentially slowed reduction of glucocorticoids, rather than oxidation. Thus, in mouse, 11βHSD1 influenced the abundance and balance of circulating and tissue levels of 7βOHC and 7KC, promoting reduction of 7KC. In health, 7-oxysterols are unlikely to regulate glucocorticoid metabolism. However, in hyperlipidaemia, 7-oxysterols may inhibit glucocorticoid metabolism and modulate signaling through corticosteroid receptors.
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Affiliation(s)
- Tijana Mitić
- Endocrinology, University/British Heart Foundation Centre for Cardiovascular Science, The Queen's Medical Research Institute, University of Edinburgh, Edinburgh, EH16 4TJ, UK.
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Mak JCW. Potential role of green tea catechins in various disease therapies: progress and promise. Clin Exp Pharmacol Physiol 2012; 39:265-73. [PMID: 22229384 DOI: 10.1111/j.1440-1681.2012.05673.x] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Green tea (from the plant Camellia sinensis), a beverage whose consumption started 5000 years ago in China, has important biological and pharmacological properties. The beneficial effects of green tea have been attributed to the presence of phenolic compounds that are powerful anti-oxidants and free iron scavengers. Of all the catechins found in green tea, namely (-)-epicatechin-3-gallate, (-)-epigallocatechin, (-)-epicatechin and (-)-epigallocatechin-3-gallate (EGCG), EGCG is the most abundant and powerful. It is widely believed that green tea may protect against death from all causes, especially cardiovascular diseases (coronary heart disease and stroke) owing to the presence of catechins associated with green tea consumption. Other health benefits include various types of cancer chemoprevention, weight loss and protective effects against neurodegenerative diseases (Alzheimer's disease and Parkinson's disease). Thus far, numerous pharmacological activities regulating disease-specific molecular targets have been reported in vitro for EGCG concentrations in the micromolar range, which are physiologically irrelevant. Although most of the studies have shown benefits with two to three cups of green tea per day, the optimal dose has not yet been established to enable any solid conclusions to be drawn regarding the various health benefits of green tea or its constituents in humans. With Phase I trials providing information on the safety profile and pharmacokinetics of EGCG, the window of opportunity is wider to undertake well-controlled long-term human studies to enable a full understanding of the protective effects of green tea catechins on various parameters in different settings.
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Affiliation(s)
- Judith C W Mak
- Departments of Medicine and Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong, China.
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Evidence of cell damage induced by major components of a diet-compatible mixture of oxysterols in human colon cancer CaCo-2 cell line. Biochimie 2012; 95:632-40. [PMID: 23092829 DOI: 10.1016/j.biochi.2012.10.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2012] [Accepted: 10/15/2012] [Indexed: 01/29/2023]
Abstract
Cholesterol oxidation products, termed oxysterols, have been shown to be more reactive than unoxidized cholesterol, possessing marked pro-inflammatory and cytotoxic effects in a number of cells and tissues. Oxysterols, absorbed with the diet as products of cholesterol auto-oxidation, have recently been suggested to potentially interfere with homeostasis of the mucosal intestinal epithelium, by promoting and sustaining irreversible damage. However, the treatment of colon cancer cells with a diet-compatible mixture of oxysterols does not elicit the same responses than individual components added to the cells at the same concentrations at which they are present in the mixture. Sixty μM oxysterol mixture showed a slight pro-apoptotic effect on human colon cancer CaCo-2 cell line, evaluated in terms of caspase-3 and caspase-7 activation; conversely, 7α-hydroxycholesterol, 7β-hydroxycholesterol and 5α,6α-epoxycholesterol were identified to be able to induce a significant pro-apoptotic effect if added to cell culture singly; 7β-hydroxycholesterol had stronger action than other compounds. The enhanced production of reactive oxygen species through up-regulation of the colonic NADPH-oxidase isoform NOX1 appeared to be the key event in oxysterol-induced apoptosis in these colon cancer cells. As regards pro-inflammatory effects of oxysterols, IL-8 and MCP-1 were evaluated for their chemotactic activity. Only MCP-1 production was significantly induced by 7β-hydroxycholesterol, as well as by cholesterol and oxysterol mixture. However, oxysterol-induced inflammation appeared to be NOX1-independent, suggesting a secondary role of this enzyme in inducing inflammation in colon cancer cells. A selective cell death induced by specific oxysterols against colon cancer cells, mainly exploiting their ability to activate NOX1 in generating oxidative reactions, might represent a promising field of investigation in colorectal cancer, and might bring new insights on strategies in anticancer therapy.
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Bubonja-Sonje M, Giacometti J, Abram M. Antioxidant and antilisterial activity of olive oil, cocoa and rosemary extract polyphenols. Food Chem 2011. [DOI: 10.1016/j.foodchem.2011.02.071] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Spickett CM, Wiswedel I, Siems W, Zarkovic K, Zarkovic N. Advances in methods for the determination of biologically relevant lipid peroxidation products. Free Radic Res 2010; 44:1172-202. [PMID: 20836661 DOI: 10.3109/10715762.2010.498476] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Lipid peroxidation is recognized to be an important contributor to many chronic diseases, especially those of an inflammatory pathology. In addition to their value as markers of oxidative damage, lipid peroxidation products have also been shown to have a wide variety of biological and cell signalling effects. In view of this, accurate and sensitive methods for the measurement of lipid peroxidation products are essential. Although some assays have been described for many years, improvements in protocols are continually being reported and, with recent advances in instrumentation and technology, highly specialized and informative techniques are increasingly used. This article gives an overview of the most currently used methods and then addresses the recent advances in some specific approaches. The focus is on analysis of oxysterols, F(2)-isoprostanes and oxidized phospholipids by gas chromatography or liquid chromatography mass spectrometry techniques and immunoassays for the detection of 4-hydroxynonenal.
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Affiliation(s)
- Corinne M Spickett
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK.
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Mascia C, Maina M, Chiarpotto E, Leonarduzzi G, Poli G, Biasi F. Proinflammatory effect of cholesterol and its oxidation products on CaCo-2 human enterocyte-like cells: effective protection by epigallocatechin-3-gallate. Free Radic Biol Med 2010; 49:2049-57. [PMID: 20923702 DOI: 10.1016/j.freeradbiomed.2010.09.033] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Revised: 09/24/2010] [Accepted: 09/28/2010] [Indexed: 10/19/2022]
Abstract
Cholesterol and its oxidation products, namely oxysterols, have very recently been shown to potentially interfere with homeostasis of the human digestive tract, by promoting and sustaining irreversible damage of the colonic epithelial layer. This report concerns the strong proinflammatory action that a dietary oxysterol mixture and, to a lesser extent, an identical concentration of unoxidized cholesterol exert on CaCo-2 colonic epithelial cells by up-regulating both expression and synthesis of interleukin 8. The oxysterol mixture and its most effective component, 7β-hydroxycholesterol, are also shown to markedly enhance the expression of key inflammatory and chemotactic cytokines in colonic epithelial cells, more efficiently than unoxidized cholesterol. The sterols' proinflammatory effect seems to be mediated by enhanced activation of NOX1, because it is prevented by pretreatment of the cells with DPI, a selective inhibitor of this oxidase. Importantly, NOX1 hyperactivation by the oxysterol mixture or cholesterol was fully prevented by CaCo-2 cell preincubation with epigallocatechin-3-gallate. Consistently, supplementation with this compound fully protected colonic epithelial cells against overexpression of inflammatory and chemotactic genes induced by the sterols investigated.
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Affiliation(s)
- Cinzia Mascia
- Department of Clinical and Biological Sciences, University of Turin at San Luigi Gonzaga Hospital, Turin, Italy
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Carvalho JFS, Silva MMC, Moreira JN, Simões S, Sá e Melo ML. Sterols as Anticancer Agents: Synthesis of Ring-B Oxygenated Steroids, Cytotoxic Profile, and Comprehensive SAR Analysis. J Med Chem 2010; 53:7632-8. [PMID: 20931970 DOI: 10.1021/jm1007769] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- João F. S. Carvalho
- Center for Pharmaceutical Studies, University of Coimbra, Portugal
- Faculdade de Farmácia, Universidade de Coimbra, 3000-548 Coimbra, Portugal
| | - M. Manuel Cruz Silva
- Center for Pharmaceutical Studies, University of Coimbra, Portugal
- Faculdade de Farmácia, Universidade de Coimbra, 3000-548 Coimbra, Portugal
| | - João N. Moreira
- Center for Neuroscience and Cell Biology, University of Coimbra, Portugal
- Faculdade de Farmácia, Universidade de Coimbra, 3000-548 Coimbra, Portugal
| | - Sérgio Simões
- Center for Neuroscience and Cell Biology, University of Coimbra, Portugal
- Faculdade de Farmácia, Universidade de Coimbra, 3000-548 Coimbra, Portugal
| | - M. Luisa Sá e Melo
- Center for Pharmaceutical Studies, University of Coimbra, Portugal
- Faculdade de Farmácia, Universidade de Coimbra, 3000-548 Coimbra, Portugal
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14
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Huang MH, Chu HL, Juang LJ, Wang BS. Inhibitory effects of sweet potato leaves on nitric oxide production and protein nitration. Food Chem 2010. [DOI: 10.1016/j.foodchem.2009.12.068] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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15
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Li Y, Wu X, Lee TB, Isbell EK, Parish EJ, Gorden AEV. An effective method for allylic oxidation of Delta5-steroids using tert-butyl hydroperoxide. J Org Chem 2010; 75:1807-10. [PMID: 20141120 DOI: 10.1021/jo902637k] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An allylic oxidation method for Delta(5)-steroids using TBHP as oxidant with a 2-quinoxalinol salen Cu(II) complex as catalyst is reported. A variety of Delta(5)-steroidal substrates are selectively oxidized to the corresponding enones. Excellent yields are achieved (up to 99% under optimized conditions) while significantly reducing reaction times required as compared to other current methods.
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Affiliation(s)
- Yuancheng Li
- Department of Chemistry and Biochemistry, College of Science and Mathematics, Auburn Univeristy, Auburn, Alabama 36849-5319, USA
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16
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Biasi F, Mascia C, Astegiano M, Chiarpotto E, Nano M, Vizio B, Leonarduzzi G, Poli G. Pro-oxidant and proapoptotic effects of cholesterol oxidation products on human colonic epithelial cells: a potential mechanism of inflammatory bowel disease progression. Free Radic Biol Med 2009; 47:1731-41. [PMID: 19778604 DOI: 10.1016/j.freeradbiomed.2009.09.020] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2009] [Revised: 09/14/2009] [Accepted: 09/17/2009] [Indexed: 12/13/2022]
Abstract
With the aim of investigating whether cholesterol oxidation products could contribute to the pathogenesis of the intestinal epithelial barrier dysfunction that occurs in human inflammatory bowel disease (IBD), differentiated versus undifferentiated CaCo-2 cells, an accepted model for human intestinal epithelial cells, were challenged with a dietary-representative mixture of oxysterols. Only differentiated colonic cells were susceptible to the proapoptotic action of the oxysterol mixture, checked both by enzymatic and by morphological methods, mainly because of a very low AKT phosphorylation pathway compared to the undifferentiated counterparts. Enhanced production of reactive oxygen species by a colonic NADPH oxidase hyperactivation seemed to represent the key event in oxysterol-induced up-regulation of the mitochondrial pathway of programmed death of differentiated CaCo-2 cells. These in vitro findings point to the pro-oxidant and cytotoxic potential of cholesterol oxidation products, of both dietary and endogenous origin, as an important mechanism of induction and/or worsening of the functional impairment of enteric mucosa that characterizes IBD.
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Affiliation(s)
- Fiorella Biasi
- Department of Clinical and Biological Sciences, University of Turin at San Luigi Gonzaga Hospital, 10043 Orbassano (Turin), Italy
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17
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Balázs Z, Nashev LG, Chandsawangbhuwana C, Baker ME, Odermatt A. Hexose-6-phosphate dehydrogenase modulates the effect of inhibitors and alternative substrates of 11beta-hydroxysteroid dehydrogenase 1. Mol Cell Endocrinol 2009; 301:117-22. [PMID: 19010388 DOI: 10.1016/j.mce.2008.10.021] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2008] [Revised: 10/09/2008] [Accepted: 10/09/2008] [Indexed: 11/23/2022]
Abstract
Intracellular glucocorticoid reactivation is catalyzed by 11beta-hydroxysteroid dehydrogenase 1 (11beta-HSD1), which functions predominantly as a reductase in cells expressing hexose-6-phosphate dehydrogenase (H6PDH). We recently showed that the ratios of cortisone to cortisol and 7-keto- to 7-hydroxy-neurosteroids are regulated by 11beta-HSD1 and very much depend on coexpression with H6PDH, providing cosubstrate NADPH. Here, we investigated the impact of H6PDH on the modulation of 11beta-HSD1-dependent interconversion of cortisone and cortisol by inhibitors and alternative substrates. Using HEK-293 cells expressing 11beta-HSD1 or coexpressing 11beta-HSD1 and H6PDH, we observed significant differences of 11beta-HSD1 inhibition by natural and pharmaceutical compounds as well as endogenous hormone metabolites. Furthermore, we show potent and dose-dependent inhibition of 11beta-HSD1 by 7-keto-DHEA in differentiated human THP-1 macrophages and in HEK-293 cells overexpressing 11beta-HSD1 with or without H6PDH. In contrast, 7-ketocholesterol (7-KC) did not inhibit 11beta-HSD1 in HEK-293 cells, even in the presence of H6PDH, but inhibited 11beta-HSD1 reductase activity in differentiated THP-1 macrophages (IC(50) 8.1+/-0.9microM). 7-Keto-DHEA but not 7-KC inhibited 11beta-HSD1 in HEK-293 cell lysates. In conclusion, cellular factors such as H6PDH can significantly modulate the effect of inhibitors and alternative 7-oxygenated substrates on intracellular glucocorticoid availability.
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Affiliation(s)
- Zoltán Balázs
- Division of Molecular and Systems Toxicology, Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland
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18
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Wamil M, Andrew R, Chapman KE, Street J, Morton NM, Seckl JR. 7-oxysterols modulate glucocorticoid activity in adipocytes through competition for 11beta-hydroxysteroid dehydrogenase type. Endocrinology 2008; 149:5909-18. [PMID: 18755798 DOI: 10.1210/en.2008-0420] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Obesity is associated with an increased risk of diabetes type 2, dyslipidemia, and atherosclerosis. These cardiovascular and metabolic abnormalities are exacerbated by excessive dietary fat, particularly cholesterol and its metabolites. High adipose tissue glucocorticoid levels, generated by the intracellular enzyme 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1), are also implicated in the pathogenesis of obesity, metabolic syndrome, and atherosclerosis. 11beta-HSD1 also interconverts the atherogenic oxysterols 7-ketocholesterol (7KC) and 7beta-hydroxycholesterol (7beta-HC). Here, we report that 11beta-HSD1 catalyzes the reduction of 7KC to 7beta-HC in mature 3T3-L1 and 3T3-F442A adipocytes, leading to cellular accumulation of 7beta-HC. Approximately 73% of added 7KC was reduced to 7beta-HC within 24 h; this conversion was prevented by selective inhibition of 11beta-HSD1. Oxysterol and glucocorticoid conversion by 11beta-HSD1 was competitive and occurred with a physiologically relevant IC(50) range of 450 nm for 7KC inhibition of glucocorticoid metabolism. Working as an inhibitor of 11beta-reductase activity, 7KC decreased the regeneration of active glucocorticoid and limited the process of differentiation of 3T3-L1 preadipocytes. 7KC and 7beta-HC did not activate liver X receptor in a transactivation assay, nor did they display intrinsic activation of the glucocorticoid receptor. However, when coincubated with glucocorticoid (10 nm), 7KC repressed, and 7beta-HC enhanced, glucocorticoid receptor transcriptional activity. The effect of 7-oxysterols resulted from the modulation of 11beta-HSD1 reaction direction, and could be ameliorated by overexpression of hexose 6-phosphate dehydrogenase, which supplies reduced nicotinamide adenine dinucleotide phosphate to 11beta-HSD1. Thus, the activity and reaction direction of adipose 11beta-HSD1 is altered under conditions of oxysterol excess, and could impact upon the pathophysiology of obesity and its complications.
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Affiliation(s)
- Malgorzata Wamil
- Endocrinology Unit, Centre for Cardiovascular Science, The Queen's Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh EH16 4TJ, United Kingdom
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19
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Schindhelm RK, Alssema M, Diamant M, Teerlink T, Dekker JM, Kok A, Kostense PJ, Nijpels G, Heine RJ, Scheffer PG. Comparison of two consecutive fat-rich and carbohydrate-rich meals on postprandial myeloperoxidase response in women with and without type 2 diabetes mellitus. Metabolism 2008; 57:262-7. [PMID: 18191058 DOI: 10.1016/j.metabol.2007.09.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2007] [Accepted: 09/28/2007] [Indexed: 11/22/2022]
Abstract
Patients with type 2 diabetes mellitus (DM2) have an increased risk of cardiovascular disease (CVD). Myeloperoxidase (MPO), expressed in leukocytes and released upon activation, is associated with CVD and endothelial dysfunction. Postprandial leukocyte recruitment and activation with subsequent MPO release may contribute to atherosclerosis and CVD. We hypothesized that MPO may increase in the postprandial state because of postprandial leukocyte recruitment and/or activation, especially in subjects with DM2. One hundred postmenopausal women, aged 50 to 65 years (66 with normal glucose metabolism [NGM] and 34 with DM2), received 2 consecutive fat-rich meals and 2 consecutive carbohydrate-rich meals on separate occasions. Blood samples were taken before (t = 0) and at 2, 4, and 8 hours after breakfast; lunch was given at t = 4. Plasma MPO concentration was measured by sandwich enzyme-linked immunosorbent assay. The number of leukocytes in fasting blood samples was higher in DM2 compared with NGM (6.1 +/- 1.4 and 5.4 +/- 1.2 x 10(9)/L, respectively; P < .05). Baseline MPO concentration did not significantly differ between NGM and DM2 (51.4 +/- 12.9 and 54.5 +/- 18.4 mug/L, respectively; P = .39). Baseline MPO was positively associated with leukocytes (r = 0.20, P < .05) and inversely associated with high-density lipoprotein cholesterol (r = -0.22, P < .05). Leukocytes increased from 5.0 +/- 1.5 to 6.1 +/- 1.5 x 10(9)/L and from 5.8 +/- 1.4 to 6.6 +/- 1.4 x 10(9)/L in NGM and DM2, respectively (both P < .01), after the fat-rich meals. In contrast to our hypothesized increase in MPO, we found a significant decrease in MPO in NGM (both meal types) and DM2 (fat-rich meals only). Our findings provide no support to our initial hypothesis that meal-induced release of MPO might be a mechanism that contributes to CVD risk.
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Affiliation(s)
- Roger K Schindhelm
- Department of Endocrinology/Diabetes Center, VU University Medical Center, 1007 MB Amsterdam, The Netherlands
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20
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Javitt NB. Oxysterols: novel biologic roles for the 21st century. Steroids 2008; 73:149-57. [PMID: 18068744 DOI: 10.1016/j.steroids.2007.10.004] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2007] [Revised: 09/17/2007] [Accepted: 10/12/2007] [Indexed: 01/17/2023]
Abstract
A major focus for the 21st century are the sterol intermediates in cholesterol synthesis and their metabolites. No longer considered inactive way stations in their transformation to cholesterol, both physiologic and pathophysiologic studies, though early in their development, indicate novel biologic roles for these sterols, and their oxysterol metabolites that bypass cholesterol, the expected end product. A major impetus for further inquiry is the recognition that in genetically determined errors in cholesterol synthesis such as Smith-Lemil-Opitz syndrome, the phenotypic effects on the developing fetus are not solely attributable to the lack of cholesterol but the accumulation of 7-dehydrocholesterol and its 27-hydroxy metabolite. This view is now supported by a new mouse model, the double knockout Insig1 & 2 (insulin-induced genes 1 & 2) in which lack of the protein product results in a greater production of lanosterol compared to cholesterol during fetal life with severe dysmorphic consequences. Further support can be derived from in vitro studies of the Sonic hedgehog signaling pathway, essential for normal morphogenesis in the central nervous system and perhaps other organs, which may require the local presence of oxysterols for full expression. Future studies that can delineate the specific role of a sterol intermediate or its metabolite require a paradigm shift away from the generic use of oxysterols as a class of compounds to a focus on specific sterols that can be expected in tissues and techniques for mimicking the local environment. Another class of oxysterols are those arising by photoxidation, now considered to be an expected event generated by the photons of visible blue light and therefore pari passu with normal vision. The sequence of events from peroxides of cholesterol to hydroxy and keto derivatives is the signature of singlet oxygen as opposed to free radicals and other mechanisms for generating reactive oxygen species. Perhaps surprisingly, the retina expresses CYP 27A1 and CYP 46A1, enzymes with broad substrate specificity for ring-modified sterols, implying that, in addition to a rich blood supply for disposing of potentially toxic oxysterols, they can be detoxified locally. Recognition that the retina has nuclear receptors similar to those found in other tissues raises the possibility that the sterols that are generated may function in their traditional role as ligands for modulating gene expression but other, nonligand, activities can be expected since other proteins such as the oxysterol-binding proteins exist and are considered to have biologic activities. To critically evaluate these potentially new biologic roles for oxysterols a need exists for the synthesis and utilization of the expected naturally occurring metabolites rather than available surrogates that may not be truly representative of their tissue effects and to utilize analytical techniques that can identify their existence at the expected concentrations in tissues.
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Affiliation(s)
- Norman B Javitt
- Department of Pediatrics and Medicine, NYU School of Medicine, 550 First Avenue, New York, NY 10016, United States.
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21
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Steffen Y, Gruber C, Schewe T, Sies H. Mono-O-methylated flavanols and other flavonoids as inhibitors of endothelial NADPH oxidase. Arch Biochem Biophys 2008; 469:209-19. [DOI: 10.1016/j.abb.2007.10.012] [Citation(s) in RCA: 215] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2007] [Revised: 10/19/2007] [Accepted: 10/19/2007] [Indexed: 02/07/2023]
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22
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Choi H, Doyle MP. Optimal TBHP allylic oxidation of Delta5-steroids catalyzed by dirhodium caprolactamate. Org Lett 2007; 9:5349-52. [PMID: 18027961 PMCID: PMC2596589 DOI: 10.1021/ol7025284] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Dirhodium caprolactamate is the most efficient catalyst for the oxidation of Delta5-steroids to 7-keto-Delta5-steroids by 70% tert-butyl hydroperoxide in water (T-HYDRO). Isolated product yields range from 38 to 87%.
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Affiliation(s)
- Hojae Choi
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742
| | - Michael P. Doyle
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742
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23
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24
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Minami Y, Yokoi S, Setoyama M, Bando N, Takeda S, Kawai Y, Terao J. Combination of TLC Blotting and Gas Chromatography–Mass Spectrometry for Analysis of Peroxidized Cholesterol. Lipids 2007; 42:1055-63. [PMID: 17701239 DOI: 10.1007/s11745-007-3099-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2007] [Accepted: 07/04/2007] [Indexed: 10/23/2022]
Abstract
We have established a sensitive and convenient method for analysis of cholesterol hydroperoxides (Chol-OOHs) as trimethylsilyloxyl derivatives using diphenylpyrenylphosphine (DPPP)-thin-layer chromatography (TLC) blotting and gas chromatography-electron ionization-mass spectrometry/selected-ion monitoring (GC-EI-MS/SIM). Chol-OOH standards were prepared by photosensitized oxidation and azo radical-induced peroxidation of cholesterol. Trimethylsilyloxyl derivatives of cholesterol 5alpha-hydroperoxide (Chol 5alpha-OOH), cholesterol 7alpha-hydroperoxide (Chol 7alpha-OOH), and cholesterol 7beta-hydroperoxide (Chol 7beta-OOH) could be separated from one another in the SIM chromatogram using a fragment ion with elimination of trimethylsilanol from the molecular ion. This method was used to characterize peroxidized cholesterol from azo radical-exposed human low-density lipoprotein and UVA-irradiated human keratinocytes in the presence of hematoporphyrin. Finally, we succeeded in the quantification of each Chol-OOH isomer present in hairless mouse skin with and without UVA irradiation by use of beta-sitosterol hydroperoxide as internal standard. The accumulation of Chol 5alpha-OOH with Chol 7alpha/betaOOH in the skin indicates that singlet molecular oxygen ((1)O(2)) participated in the peroxidation of skin cholesterol, because Chol 5alpha-OOH is known to be a (1)O(2) specific cholesterol peroxidation product. We concluded that the combination of DPPP-TLC blotting and GC-EI-MS/SIM is useful for quantifying peroxidized cholesterol in biological samples and confirming the participation of (1)O(2) in oxidative stress.
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Affiliation(s)
- Yuko Minami
- Department of Food Science, Graduate School of Nutrition and Bioscience, The University of Tokushima, Tokushima, 770-8503, Japan
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25
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Steffen Y, Schewe T, Sies H. (-)-Epicatechin elevates nitric oxide in endothelial cells via inhibition of NADPH oxidase. Biochem Biophys Res Commun 2007; 359:828-33. [PMID: 17560937 DOI: 10.1016/j.bbrc.2007.05.200] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2007] [Accepted: 05/31/2007] [Indexed: 10/23/2022]
Abstract
Dietary (-)-epicatechin is known to improve bioactivity of (*)NO in arterial endothelium of humans, but the mode of action is unclear. We used the fluorophore 4,5-diaminofluorescein diacetate to visualize the (*)NO level in living human umbilical vein endothelial cells (HUVEC). Untreated cells showed only a weak signal, whereas pretreatment with (-)-epicatechin (10 microM) or apocynin (100 microM) elevated the (*)NO level. The effects were more pronounced when the cells were treated with angiotensin II with or without preloading of the cells with (*)NO via PAPA-NONOate. While (-)-epicatechin scavenged O2(*-), its O-methylated metabolites prevented O2(*-) generation through inhibition of endothelial NADPH oxidase activity, even more strongly than apocynin. From the effect of 3,5-dinitrocatechol, an inhibitor of catechol-O-methyltransferase (COMT), on HUVEC it is concluded that (-)-epicatechin serves as 'prodrug' for conversion to apocynin-like NADPH oxidase inhibitors. These data indicate an (*)NO-preserving effect of (-)-epicatechin via suppression of O2(*-)-mediated loss of (*)NO.
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Affiliation(s)
- Yvonne Steffen
- Institut für Biochemie und Molekularbiologie I, Heinrich-Heine-Universität Düsseldorf, D-40001 Düsseldorf, Germany
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26
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Abstract
Genesis of plaque lesion as atherosclerosis is based on the involvement of endothelium and smooth muscle cells
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Affiliation(s)
- Lawrence M Agius
- Department of Pathology, St Luke's Hospital, Tal-Virtu, Rabat RBT09, Malta.
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