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Detopoulou P, Demopoulos CA, Antonopoulou S. Micronutrients, Phytochemicals and Mediterranean Diet: A Potential Protective Role against COVID-19 through Modulation of PAF Actions and Metabolism. Nutrients 2021; 13:nu13020462. [PMID: 33573169 PMCID: PMC7911163 DOI: 10.3390/nu13020462] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 01/23/2021] [Accepted: 01/26/2021] [Indexed: 01/08/2023] Open
Abstract
The new coronavirus disease 2019 (COVID-19) pandemic is an emerging situation with high rates of morbidity and mortality, in the pathophysiology of which inflammation and thrombosis are implicated. The disease is directly connected to the nutritional status of patients and a well-balanced diet is recommended by official sources. Recently, the role of platelet activating factor (PAF) was suggested in the pathogenesis of COVID-19. In the present review several micronutrients (vitamin A, vitamin C, vitamin E, vitamin D, selenium, omega-3 fatty acids, and minerals), phytochemicals and Mediterranean diet compounds with potential anti-COVID activity are presented. We further underline that the well-known anti-inflammatory and anti-thrombotic actions of the investigated nutrients and/or holistic dietary schemes, such as the Mediterranean diet, are also mediated through PAF. In conclusion, there is no single food to prevent coronavirus Although the relationship between PAF and COVID-19 is not robust, a healthy diet containing PAF inhibitors may target both inflammation and thrombosis and prevent the deleterious effects of COVID-19. The next step is the experimental confirmation or not of the PAF-COVID-19 hypothesis.
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Affiliation(s)
- Paraskevi Detopoulou
- Department of Clinical Nutrition, General Hospital Korgialenio Benakio, 11526 Athens, Greece;
| | - Constantinos A. Demopoulos
- Laboratory of Biochemistry, Faculty of Chemistry, National & Kapodistrian University of Athens, 16121 Athens, Greece;
| | - Smaragdi Antonopoulou
- Laboratory of Biology, Biochemistry and Microbiology, Department of Nutrition and Dietetics, School of Health Science and Education, Harokopio University, 70 El. Venizelou Street, 17671 Athens, Greece
- Correspondence: ; Tel.: +30-210-954-9230; Fax: +30-210-957-7050
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Theoharides TC, Antonopoulou S, Demopoulos CA. Coronavirus 2019, Microthromboses, and Platelet Activating Factor. Clin Ther 2020; 42:1850-1852. [PMID: 32883529 PMCID: PMC7430296 DOI: 10.1016/j.clinthera.2020.08.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 08/10/2020] [Accepted: 08/11/2020] [Indexed: 12/20/2022]
Abstract
Recent articles have reported elevated markers of coagulation, endothelial injury, and microthromboses in lungs from deceased patients with coronavirus 2019 (COVID-19). Platelets are critical in the formation of thrombi, and their most potent trigger is platelet activating factor (PAF). PAF is produced by cells involved in host defense, and its biological actions bear similarities with COVID-19 disease manifestations, including pulmonary microthromboses and inflammation, possibly via activation of mast cells. The histamine1 receptor antagonist rupatadine was developed to have anti-PAF activity and inhibits activation of human mast cells in response to PAF. Rupatadine could be repurposed for COVID-19 prophylaxis.
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Affiliation(s)
- Theoharis C Theoharides
- Laboratory of Molecular Immunopharmacology and Drug Discovery, Department of Immunology, Tufts University School of Medicine, Boston, MA, USA; School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, MA, USA; Department of Internal Medicine, Tufts University School of Medicine and Tufts Medical Center, Boston, MA, USA.
| | - Smaragdi Antonopoulou
- Laboratory of Biology, Biochemistry and Microbiology, Department of Nutrition and Dietetics, School of Health Science and Education, Harokopio University, Athens, Greece
| | - Constantinos A Demopoulos
- Laboratory of Biochemistry, Faculty of Chemistry, National & Kapodistrian University of Athens, Athens, Greece
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Consumption of plant extract supplement reduces platelet activating factor-induced platelet aggregation and increases platelet activating factor catabolism: a randomised, double-blind and placebo-controlled trial. Br J Nutr 2019; 121:982-991. [PMID: 30940217 DOI: 10.1017/s0007114519000308] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Platelet-activating factor (PAF) is a potent mediator of inflammation that plays a crucial role in atherosclerosis. The purpose of this study was to evaluate the effect of a dietary supplement containing mainly plant extracts on PAF actions and metabolism in healthy volunteers. A double-blind, placebo-controlled, 8 weeks' duration study was performed. Healthy volunteers were randomly allocated into the supplement or the placebo group and fifty-eight of them completed the study. The supplement contained plant extracts (Aloe gel, grape juice, Polygonum cuspidatum) and vitamins. The activities of PAF metabolic enzymes: the two isoforms of acetyl-CoA:lyso-PAF acetyltransferase, cytidine 5'-diphospho-choline:1-alkyl-2-acetyl-sn-glycerol cholinephosphotransferase (PAF-cholinephosphotransferase) and platelet-activating factor-acetylhydrolase (PAF-AH) in leucocytes and lipoprotein associated phospholipase-A2 in plasma were measured along with several markers of endothelial function. Platelet aggregation against PAF, ADP and thrombin receptor activating peptide was measured in human platelet-rich plasma by light transmission aggregometry. No difference was observed on soluble vascular cell adhesion molecule-1, sP-selectin and IL-6 levels at the beginning or during the study period between the two groups. Concerning PAF metabolism enzymes' activity, no difference was observed at baseline between the groups. PAF-AH activity was only increased in the supplement group at 4 and 8 weeks compared with baseline levels. In addition, supplement consumption led to lower platelet sensitivity against PAF and ADP compared with baseline levels. However, a trial effect was only observed when platelets were stimulated by PAF. In conclusion, supplementation with plant extracts and vitamins ameliorates platelet aggregation primarily against PAF and secondarily against ADP and affects PAF catabolism by enhancing PAF-acetylhydrolase activity in healthy subjects.
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Lordan R, Tsoupras A, Zabetakis I. The Potential Role of Dietary Platelet-Activating Factor Inhibitors in Cancer Prevention and Treatment. Adv Nutr 2019; 10:148-164. [PMID: 30721934 PMCID: PMC6370273 DOI: 10.1093/advances/nmy090] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 09/11/2018] [Accepted: 10/10/2018] [Indexed: 12/11/2022] Open
Abstract
Cancer is the second leading cause of mortality worldwide. The role of unresolved inflammation in cancer progression and metastasis is well established. Platelet-activating factor (PAF) is a key proinflammatory mediator in the initiation and progression of cancer. Evidence suggests that PAF is integral to suppression of the immune system and promotion of metastasis and tumor growth by altering local angiogenic and cytokine networks. Interactions between PAF and its receptor may have a role in various digestive, skin, and hormone-dependent cancers. Diet plays a critical role in the prevention of cancer and its treatment. Research indicates that the Mediterranean diet may reduce the incidence of several cancers in which dietary PAF inhibitors have a role. Dietary PAF inhibitors such as polar lipids have demonstrated inhibitory effects against the physiological actions of PAF in cancer and other chronic inflammatory conditions in vitro and in vivo. In addition, experimental models of radiotherapy and chemotherapy demonstrate that inhibition of PAF as adjuvant therapy may lead to more favorable outcomes. Although promising, there is limited evidence on the potential benefits of dietary PAF inhibitors on cancer prevention or treatment. Therefore, further extensive research is required to assess the effects of various dietary factors and PAF inhibitors and to elucidate the mechanisms in prevention of cancer progression and metastasis at a molecular level.
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Affiliation(s)
- Ronan Lordan
- Department of Biological Sciences, University of Limerick, Limerick, Ireland
| | - Alexandros Tsoupras
- Department of Biological Sciences, University of Limerick, Limerick, Ireland
| | - Ioannis Zabetakis
- Department of Biological Sciences, University of Limerick, Limerick, Ireland
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5
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Vlachogianni IC, Fragopoulou E, Stamatakis GM, Kostakis IK, Antonopoulou S. Platelet Activating Factor (PAF) biosynthesis is inhibited by phenolic compounds in U-937 cells under inflammatory conditions. Prostaglandins Other Lipid Mediat 2015; 121:176-83. [PMID: 26358846 DOI: 10.1016/j.prostaglandins.2015.09.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 09/03/2015] [Accepted: 09/03/2015] [Indexed: 11/24/2022]
Abstract
Interleukin 1 beta (IL-1β) induced platelet activating factor (PAF) synthesis in U-937 cells through stimulation of acetyl-CoA:lysoPAF-acetyltransferase (lyso PAF-AT) at 3 h and DTT-independentCDP-choline-1-alkyl-2-acetyl-sn-glycerol cholinophosphotransferase (PAF-CPT) at 0.5 h. The aim of this study was to investigate the effect of tyrosol (T), resveratrol (R) and their acetylated derivatives(AcDs) which exhibit enhanced bioavailability, on PAF synthesis in U-937 after IL-1β stimulation. The specific activity of PAF enzymes and intracellular levels were measured in cell homogenates. T and R concentration capable of inducing 50% inhibition in IL-1β effect on lyso PAF-AT was 48 μΜ ± 11 and 157 μΜ ± 77, for PAF-CPT 246 μΜ ± 61 and 294 μΜ ± 102, respectively. The same order of concentration was also observed on inhibiting PAF levels produced by IL-1β. T was more potent inhibitor than R (p<0.05). AcDs of T retain parent compound inhibitory activity, while in the case of R only two AcDs retain the activity. The observed inhibitory effect by T,R and their AcDs, may partly explain their already reported beneficial role.
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Affiliation(s)
- Ioanna C Vlachogianni
- Department of Nutritional Science and Dietetics, Harokopio University, Athens, Greece
| | - Elizabeth Fragopoulou
- Department of Nutritional Science and Dietetics, Harokopio University, Athens, Greece
| | | | - Ioannis K Kostakis
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, National and Kapodistrian University of Athens, Greece
| | - Smaragdi Antonopoulou
- Department of Nutritional Science and Dietetics, Harokopio University, Athens, Greece.
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Xanthopoulou M, Asimakopoulos D, Antonopoulou S, Demopoulos C, Fragopoulou E. Effect of Robola and Cabernet Sauvignon extracts on platelet activating factor enzymes activity on U937 cells. Food Chem 2014; 165:50-9. [DOI: 10.1016/j.foodchem.2014.05.085] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Revised: 04/10/2014] [Accepted: 05/15/2014] [Indexed: 10/25/2022]
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The influence of cholinergic agents on histamine release from HMC-1 human mast cell line stimulated with IgG, C-reactive protein and compound 48/80. Life Sci 2012; 91:1053-7. [DOI: 10.1016/j.lfs.2012.08.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Revised: 07/30/2012] [Accepted: 08/02/2012] [Indexed: 11/21/2022]
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Chang J, Hsu Y, Kuo P, Kuo Y, Chiang L, Lin C. Increase of Bax/ Bcl-XL ratio and arrest of cell cycle by luteolin in immortalized human hepatoma cell line. Life Sci 2005; 76:1883-93. [PMID: 15698865 DOI: 10.1016/j.lfs.2004.11.003] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2004] [Accepted: 11/05/2004] [Indexed: 02/06/2023]
Abstract
Luteolin is a common constituent of many kinds of fruits and vegetables. It possesses the anti-neoplastic activities against several human cancers, but its activity against hepatocellular carcinoma (HCC) is seldom mentioned. To evaluate the activity against HCC and to provide information about the mechanism, we tested luteolin against five human hepatoma cell lines, namely HepG2, SK-Hep-1, PLC/PRF/5, Hep3B, and HA22T/VGH, with XTT assay and flow cytometry. The results showed that luteolin inhibited PLC/PRF/5, Hep3B and HA22T/VGH at a concentration of 1 microg/ml, but it needed 5 microg/ml to inhibit HepG2 and 10 microg/ml for SK-Hep1 (P <0.05). The inhibitive concentrations of 50% (IC50) of luteolin were between 7.29 microg/ml and 32.59 microg/ml, which were comparable with those of 5-FU (15.35 microg/ml to 32.84 microg/ml). The least effective cell line as affected by luteolin (SK-Hep1) was the most effective one when treating with 5-FU. The least effective cell line as affected by 5-FU (HA22T/VGH) was effectively affected by luteolin. It seemed that luteolin had some complementary activity to 5-FU against these HCC cell lines. The luteolin-treated PLC/PRF/5 cells exhibited typical changes of apoptosis with a characteristic DNA laddering pattern on gel electrophoresis. Luteolin also activated casepase-3, increased Bax protein with a concomitant decrease in Bcl-XL level. Increase in Bax/ Bcl-XL ratio and activation of caspase-3 supported the apoptotic finding on gel electrophoresis. Luteolin also induced cell cycle arrest at G0/G1 phase. We suggested that luteolin might exhibit anti-HCC activity as efficient as 5-FU by the mechanism of not only cell cycle arrest but also apoptosis.
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Affiliation(s)
- Jungsan Chang
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, No. 100 Shih-Chuan 1st Road, Kaohsiung 807, Taiwan
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Ueda Y, Oku H, Iinuma M, Ishiguro K. Effects on blood pressure decrease in response to PAF of Impatiens textori MIQ. Biol Pharm Bull 2004; 26:1505-7. [PMID: 14519965 DOI: 10.1248/bpb.26.1505] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A 35% EtOH extract of flowers of Impatiens textori MIQ. showed an inhibitory effect on blood pressure decrease in response to platelet activating factor (PAF) measured with a blood pressure monitoring system. Bioassay-guided fractionation of the 35% EtOH extract (IT) led to isolation of the flavones apigenin (1) and luteolin (3), which significantly inhibited blood pressure decrease in response to PAF. Their compounds and apigenin 7-glucoside (2), chrysoeriol (4), quercetin (5), quercetin 3-glucoside (6), kaempferol (7), kaempferol 3-glucoside (8) and kaempferol 3-rhamnosyldiglucoside (9) were also isolated from the flowers of I. textori for the first time. This study revealed that the flowers of I. textori might be a possible anti-allergy agent.
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Affiliation(s)
- Yoshimi Ueda
- School of Pharmaceutical Sciences, Mukogawa Women's University, Nishinomiya, Japan
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Tonks AJ, Tonks A, Morris RHK, Jones KP, Jackson SK. Regulation of platelet-activating factor synthesis in human monocytes by dipalmitoyl phosphatidylcholine. J Leukoc Biol 2003; 74:95-101. [PMID: 12832447 DOI: 10.1189/jlb.1202601] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Platelet-activating factor (PAF) has a major role in inflammatory responses within the lung. This study investigates the effect of pulmonary surfactant on the synthesis of PAF in human monocytic cells. The pulmonary surfactant preparation Curosurf significantly inhibited lipopolysaccharide (LPS)-stimulated PAF biosynthesis (P<0.01) in a human monocytic cell line, Mono mac-6 (MM6), as determined by (3)H PAF scintillation-proximity assay. The inhibitory properties of surfactant were determined to be associated, at least in part, with the 1,2-dipalmitoyl phosphatidylcholine (DPPC) component of surfactant. DPPC alone also inhibited LPS-stimulated PAF biosynthesis in human peripheral blood monocytes. DPPC treatment did not affect LPS-stimulated phospholipase A(2) activity in MM6 cell lysates. However, DPPC significantly inhibited LPS-stimulated coenzyme A (CoA)-independent transacylase and acetyl CoA:lyso-PAF acetyltransferase activity. DPPC treatment of MM6 cells decreased plasma membrane fluidity as demonstrated by electron paramagnetic resonance spectroscopy coupled with spin labeling. Taken together, these findings indicate that pulmonary surfactant, particularly the DPPC component, can inhibit LPS-stimulated PAF production via perturbation of the cell membrane, which inhibits the activity of specific membrane-associated enzymes involved in PAF biosynthesis.
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Affiliation(s)
- Amanda J Tonks
- Department of Haematology, University of Wales College of Medicine, Cardiff, United Kingdom.
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Balestrieri ML, Castaldo D, Balestrieri C, Quagliuolo L, Giovane A, Servillo L. Modulation by flavonoids of PAF and related phospholipids in endothelial cells during oxidative stress. J Lipid Res 2003; 44:380-7. [PMID: 12576520 DOI: 10.1194/jlr.m200292-jlr200] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
PAF-dependent transacetylase (TA) modifies the functions of platelet-activating factor (PAF), a potent inflammatory lipid, either by transferring the acetyl group from PAF to lysophospholipids (TAL activity), or to sphingosine (TAS activity) or by hydrolyzing PAF (acetylhydrolase activity). In stimulated endothelial cells (EC), TAL activity contributes to the synthesis of acyl-PAF, an acyl analog of PAF, that antagonizes PAF functions and is regulated by the cellular redox state. In this study, we investigated the possible involvement of TA in the flavonoid antioxidant mechanism(s) during oxidative stress in EC induced by hydrogen peroxide. The treatment of EC with H2O2 resulted in 4-fold increase of the acetyl-CoA acetyltransferase activity (AT), that is responsible for PAF biosynthesis, while the TAL activity increased only by 53%. However, the preincubation of H2O2-treated EC with the flavonoids hesperedin, naringin, and quercetin strongly inhibited AT activity and activated TAL by 290%, 340%, and 250%, respectively. The induction of TAL activity resulted in enhanced biosynthesis of 1-acyl-2-[3H]acetyl-PAF in intact EC and was related to the flavonoid structure. These findings suggest that TAL is involved in the flavonoid anti-inflammatory action by enhancing the production of acyl-PAF.
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Abstract
Flavonoids are plant pigments that are synthesised from phenylalanine, generally display marvelous colors known from flower petals, mostly emit brilliant fluorescence when they are excited by UV light, and are ubiquitous to green plant cells. The flavonoids are used by botanists for taxonomical classification. They regulate plant growth by inhibition of the exocytosis of the auxin indolyl acetic acid, as well as by induction of gene expression, and they influence other biological cells in numerous ways. Flavonoids inhibit or kill many bacterial strains, inhibit important viral enzymes, such as reverse transcriptase and protease, and destroy some pathogenic protozoans. Yet, their toxicity to animal cells is low. Flavonoids are major functional components of many herbal and insect preparations for medical use, e.g., propolis (bee's glue) and honey, which have been used since ancient times. The daily intake of flavonoids with normal food, especially fruit and vegetables, is 1-2 g. Modern authorised physicians are increasing their use of pure flavonoids to treat many important common diseases, due to their proven ability to inhibit specific enzymes, to simulate some hormones and neurotransmitters, and to scavenge free radicals.
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Affiliation(s)
- Bent H Havsteen
- Department of Biochemistry, University of Kiel, Olshausenstrasse 40, D-24098, Kiel, Germany.
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Oku H, Ishiguro K. Antipruritic and antidermatitic effect of extract and compounds of Impatiens balsamina L. in atopic dermatitis model NC mice. Phytother Res 2001; 15:506-10. [PMID: 11536380 DOI: 10.1002/ptr.964] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We examined the effects of a 35% ethanol extract (IB) from the petals of Impatiens balsamina L. and the principal active compounds from IB on chronic and serious pruritus and the development of dermatitis using NC mice, a model of atopic dermatitis. IB at 100 mg/kg significantly inhibited serious scratching behaviour in the NC mouse with established dermatitis when administered i.v. 1 h before, or p.o. 24 h before the measurement. A 10 microg/kg dose of kaempferol 3-rutinoside and 2-hydroxy-1,4-naphthoquinone (lawsone) isolated from IB also inhibited scratching behaviour in the NC mouse with established dermatitis. When 4-week-old NC mice with no symptoms were administered orally 100 mg/kg/day of IB until 13 weeks of age, protection was also noted against scratching behaviour during the development of dermatitis. IB was effective for the prevention and treatment of atopic dermatitis.
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Affiliation(s)
- H Oku
- School of Pharmaceutical Sciences, Mukogawa Women's University, Koshien Kyuban-cho, Nishinomiya, 663-8179, Japan
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Effects of flavonoids on gastrointestinal disorders. ACTA ACUST UNITED AC 2001. [DOI: 10.1016/s1572-5995(01)80019-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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15
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Abstract
In this review properties of lipid acetyltransferase enzymes are outlined. The three activities of interest are lyso PAF acetyltransferase (acetyl CoA: 1-alkyl-sn-glycero-3-phosphocholine acetyltransferase), AGP acetyltransferase (acetyl CoA: 1-alkyl sn-glycero-3-phosphate acetyltransferase) and a transacetylase activity that can transfer acetyl groups from PAF to lipid acceptors in the formation of 1-alkenyl-2-acetyl-sn-glycero-3-phosphoethanolamine and N-acetyl sphingosine (C2 ceramide). This review focuses on the role of acetyltransferases and transacetylases within the metabolism of platelet-activating factor and specifically addresses characteristics of the enzymes, including subcellular localization, substrate selectivity, and enzymatic regulation.
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Affiliation(s)
- R R Baker
- Department of Biochemistry, University of Toronto, Canada
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Abstract
A blood pressure monitoring system was developed for studying antagonist effects against platelet activating factor (PAF), a chemical mediator of anaphylactic hypotension. Using this system, we were able to determine the inhibitory effects of a 35% ethanol extract (IB) from the petals of Impatiens balsamina L. against PAF-induced hypotension and the active principal compounds from IB. One mechanism of the antianaphylactic effects of IB was characterized as PAF-antagonist effects.
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Affiliation(s)
- H Oku
- School of Pharmaceutical Sciences, Mukogawa Women's University, Koshien Kyuban-cho, Nishinomiya, 663-8179, Japan
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Virgili F, Kobuchi H, Packer L. Procyanidins extracted from Pinus maritima (Pycnogenol): scavengers of free radical species and modulators of nitrogen monoxide metabolism in activated murine RAW 264.7 macrophages. Free Radic Biol Med 1998; 24:1120-9. [PMID: 9626566 DOI: 10.1016/s0891-5849(97)00430-9] [Citation(s) in RCA: 120] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Nitrogen monoxide (NO) has diverse physiological roles and also contributes to the immune defense against viruses, bacteria, and other parasites. However, excess production of NO is associated with various diseases such arthritis, diabetes, stroke, septic shock, autoimmune, chronic inflammatory diseases, and atheriosclerosis. Cells respond to activating or depressing stimuli by enhancing or inhibiting the expression of the enzymatic machinery that produce NO. Thus, maintenance of a tight regulation of NO production is important for human health. Phytochemicals have been traditionally utilized in ways to treat a family of pathologies that have in common the disregulation of NO production. Here we report the scavenging activity of Pycnogenol (the polyphenols containing extract of the bark from Pinus maritima) against reactive oxygen and nitrogen species, and its effects on NO metabolism in the murine macrophages cell line RAW 264.7. Macrophages were activated by the bacterial wall components lipopolysaccharide (LPS) and interferon (IFN-gamma), which induces the expression of large amounts of the enzyme nitric oxide synthase (iNOS). Preincubation of cells with physiological concentrations of Pycnogenol significantly decreased NO generation. It was found that this effect was due to the combination of several different biological activities, i.e., its ROS and NO scavenging activity, inhibition of iNOS activity, and inhibition of iNOS-mRNA expression. These data begin to provide the basis for the conceptual understanding of the biological activity of Pycnogenol and possibly other polyphenolic compounds as therapeutic agents in various human disorders.
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Affiliation(s)
- F Virgili
- Department of Molecular and Cell Biology, University of California, Berkeley 94720-3200, USA
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