The BAP test and the global assessment of oxidative stress ... - Medial

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Antioxidants play a relevant role in the biochemical homeostasis of our body by defendingour cells and tissues against potentially toxic chemical oxidants species, including free radicals andreactive oxygen species (ROS).Therefore, in the light to prevent/to treat the possible unwanted effects of oxidative stress,many peoples currently take antioxidant supplements with the aim to restore and/or to maintainan optimal level of antioxidant defense effectiveness.However recent studies and clinical experience suggest that any antioxidant supplementshould be taken only after a biochemical evidence of its deficiency. Indeed high doses of someantioxidants may result pro-oxidant.On these basis, in order to establish the clinical indications for antioxidant treatment and toavoid concomitantly the unwanted side effects of unneeded supplements, some years ago theItalian researcher Mauro Carratelli developed a new test, i. e. the BAP test, where the initials meanBiological Antioxidant Potential. This test is based on the ability of a plasma blood sample toreduce ferric ions to ferrous ions as a FRAP assay (ferric reducing ability of plasma). Howevercompared to the classical FRAP assay firstly described by Benzie, BAP test appears quicker andsimpler to perform. Moreover according to the novel concept of global oxidative stress assessment,the BAP test showed able to integrate the results of the d-ROMs test, which allows the assessmentof serum/plasma total oxidant capacity.The aim of the present book was to describe the principle, the validation and the clinicalapplication of BAP test in Human and Veterinary Medicine.We acknowledge the help of all Authors of clinical and experimental studies reported in thisbook and, particularly, Mauro Carratelli, the “inventor” of BAP test.Dr. Eugenio Luigi Iorio, MD, PhDThe President of InternationalObservatory of Oxidative Stress4www.fras4evolvo.it
1. IntroductionThe blood of Vertebrates contains severalcompounds/activities which are able, takentogether, to oppose the oxidant potential ofoxidant chemical species, like the reactiveoxygen species (ROS) (1).Virtually, any “endogenous” compound (i.e. albumin, transferrin, ceruloplasmin, bilirubin,uric acid, reduced glutathione, etc.) or“exogenous” biomolecule (i. e. tocopherols,carotens, ubiquinol, ascorbate, methionine,flavonoids, polyphenols, etc.) which is able togive equivalent reducing units (e. g. electrons)is able also to block the potential damage ofROS. Indeed, the reactivity of a free radical isjust the result of a lack of electrons (2).Of course, any injury to such “blood barrierto oxidation” – e. g. exposure either toradiations, or xenobiotics or infectious agents –can result in oxidative tissue damage and,therefore, in early aging and in the so-calledoxidative stress related diseases (e. g.atherosclerosis, arterial hypertension, stroke,myocardial infarction, diabetes, arthritis,dementia, colitis, pancreatitis, respiratorydiseases, cancer, infections, etc.) (3).The velocity of these processes can beslowed down not only by specificpharmacotherapies (e. g. antihypertensive orlipid-lowering drugs), but also by modifyingsome lifestyles (e. g. diet, exercise, etc.) and,when indicated, by the intake of compoundswith antioxidant activity (4).However, before any medical intervention,the antioxidant effectiveness of plasma barrierto oxidation should be assessed, in order tolimit the eventual intake of antioxidants only topatients showing a reduced antioxidant plasmaactivity (5). In fact, an uncontrolled intake ofantioxidants has been shown to induce aparadoxical unwanted pro-oxidant action (6,7).Therefore, the assessment of antioxidantactivity of plasma/serum blood is the first stepof any medical intervention aimed to redressthe oxidative balance in oxidative stress relatedconditions.Over the last few years, a number of testsbased on different chemical principles has beenproposed in order to assess the wholeantioxidant activity of plasma or serum blood(5, 8-18).In this subject, one of the most knowexamples of oxidation in Nature is the changeof iron from ferrous to ferric form, as it happenin the generation of the rust. Therefore onecan consider as antioxidant a solution, such theserum/blood plasma, which is able to bringback the iron from its ferric form to the ferrousform.In other words from the merely analyticalpoint of view, the effectiveness of antioxidantplasma barrier can be evaluated by testing itsability to reduce a specific substrate, i. e. byassessing its ability to give oxidant agents (e.g. free radicals) to one or more electrons.For this purpose, several chemicalreducing-oxidizing couples are available. Forinstance, transition metals (i e. iron) exhibitthe property to receive one electron thusshifting from the oxidized state (Fe 3+ ) toreduced state (Fe 2+ ). Such agents can work as“meters” in tests aimed to assess antioxidantpower of biological systems. Indeed, the socalled“plasma antioxidant power” is ultimatelya measure of the reducing or “electron-giving”activity of blood plasma.On the other hand, some compounds sharethe ability to change their absorbance justwhen bound to compounds able to switch fromthe oxidized to reduced state. For instance,some thiocyanates are able to reversibly shiftfrom colored to uncolored derivatives, in thepresence of ferric or ferrous salts, respectively(19). Such “chromogens” can work as excellent“detectors” when coupled with adequate“oxidizing/reducing meters” in a test designedto assess antioxidant activity of biologicalsamples.Indeed, when a ferric salt is dissolved in auncolored solution containing a particularthiocyanate derivative, the resulting solutionbecomes red, as a function of the ferric ionsconcentration. This phenomenon is ascribableto the formation of a complex between ferricsalt and thiocyanate. Further adding of a smallamount of blood plasma will reduce ferric ions5www.fras4evolvo.it
Page 1 and 2: Eugenio Luigi IorioA short reviiewR
Page 3: Table of ContentsPreface and acknow
Page 7 and 8: different analytical approach (e. g
Page 9 and 10: On the other hand, in experimental
Page 12 and 13: In particular, 140 Labrador Retriev
Page 14 and 15: µEq/L25002000150010005000Before di
Page 16 and 17: 8. Clinical studies on AnimalsGrowi
Page 18 and 19: absorption of nutrients, etc.). In
Page 20 and 21: 21. Benzie IFF, Strain JJ. The ferr
Page 22 and 23: 53. Carratelli M, Iorio EL, Bianchi
Page 24: F R A S 4 EVOLVO SYSTEMFREE RADICAL

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