Noninvasive electrochemical antioxidant activity estimation: saliva analysis

摘要

Monitoring of the oxidant/antioxidant slate of the biological objects plays an important role in the detection of serious diseases in the early stages,the choice of therapy and evaluation of its effectiveness.This parameter is very important for understanding the processes occurring at the interfaces(biointerfaces)in living organisms,in particular,lipid bilayers of cell membranes and cellular organelles(mitochondria),etc.Under normal conditions and in physiological concentrations,active oxygen/nitrogen forms(ROS/ANA)are involved in the growth,differentiation,development,and death of cells,as well as in a number of other bioregulation processes,as natural signaling molecules.With an excessive generation of ROS/ANA oxidative stress develops,the result of which is the processes of oxidative destruction,occurring mainly on the biointerface and leading to apoptosis of cells and the appearance of pathological conditions.Disbalance between reactive oxygen/nitrogen(ROS/RNS)generation and activity of the antioxidant defense system is the cause of oxidative stress(OS)appearing.Antioxidant activity(AOA)of biological objects,as an integral parameter,is an indicator of the OS intensity.The paper presents a hybrid version of electrochemical methods for the determination of AOA,including a chemical signal-forming reaction that precedes or proceeds simultaneously with the recording of an analytical signal.The source of information on AOA(analytical signal)is:-the electrode potential shift that is observed when the sample is introduced into the mediator system-the mixture of 0.01 M K3[Fe(CN)6] +0.0001 M K4[Fe(CN)6](potentiomelric variant);;-the increment of K4[Fe(CN)6] oxidation current.resulting from the interaction of the AO.containing in the sample,with the oxidized form of the mediator system-10~(-2)M L3[Fe(CN)6] previously introduced into the solution(chronoamperometric version).The method is applied to the analysis of saliva as a noninvasive alternative to invasive sampling blood fractions investigation.The existence of a relationship between oral diseases and the internal state of the body gives reason to believe that saliva's AOA can serve as a source of information on common health problems.Recovery of antioxidant standard addition introduced into analyzed sample is not less than 85.0% in chronoamperometry and 85.3% in ehronopotentiornetry.Reproducibility(Sr≤8.87%).The values of Student's and Fisher's criteria(texp