Assessment of Oxidative Stress in Patients with an Isolated Traumatic Brain Injury Using Disposable Electrochemical Test Strips

Abstract

1IntroductionImbalances in oxidation-reduction potential (ORP), or redox status,o fh uman plasma are the result of an increasedp roduction of reactiveo xygen species (ROS)/reactive nitrogen species (RNS), ad ecrease in levels of endogenous non-enzymatic antioxidants,adecrease in antioxidante nzyme activity (such as superoxide dismutase (SOD),c atalase, and reduced nicotinamide adenined inucleotide( NADH) peroxidase), and/or ani nterference with mitochondrialo xidative phosphorylation [1,2].O xidative damage caused by an imbalance in redox status has been associated with the pathophysiology of acute clinicalc onditions including but not limited to traumatic brain injury (TBI), multiple trauma, sepsis,a nd stroke (Table 1) [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17].Reductive stress, whichc an result from an over-compensatory mechanism to oxidatives tress,m ay cause mitochondrial dysfunction and has deleterious effects on health [18][19][20].R OS generated by mitochondria can also result in both oxidative and reductive stress [18,19].T he criticalr ole of oxidative and reductive stress in disease is mainly due to damage to electron-rich biological targets such as lipids,p roteins,a nd DNA[ 1].C urrentm ethods for determiningr edox status therefore mainly utilize assays that allow assessment of damage caused to these individual biological targets.Unlike the assessment of as ingle biomarker of oxidative stress,a ssessing the ORP of ab iological sample provides ac omprehensive measureo fr edox status without lookingfor any particular molecule.ORP provides acomposite measurement of the balance between oxidants and antioxidants in as ample and thus does not rely on any single biomarker of redox stress.F urthermore,d etermining ORP does not require processing,p urification, or isolation of specific biomarkers,a nd reflects changes in redox status under conditions in which modificationso f individual targets are not detected. This important characteristic of measuring ORP makes it av ery valuable research tool readily applicable to ac linical lab setting. Despite the utility of measuring ORP over any single biomarker of redoxs tress,aplatform that allows for the fast Abstract:T he barriers to using plasma redoxp otential as am easure of oxidative stress in patients are the use of specialized equipment, necessity of sterilization between tests,a nd inconsistent electrodes urfaces and cell geometry.T hese problems are resolved using disposable test strips with built in electrochemicalc ells.M easuring the electrode potential at as mallc urrent yields as table value that is~50 mV higherf or isolated traumatic brain injury (ITBI) patients than for healthyi ndividuals.E ven with naturalv ariations within blood chemistry, this simple method may be clinically useful for assessing the degree of oxidative stress and injury severity in ITBI patients.

Optimization of a diagnostic platform for oxidation–reduction potential (ORP) measurement in human plasma

“…The data present a much more drastic decrease in ORP signal (43 and 60 mV for citrate and heparinized plasma at 10 mM ascorbic acid, respectively) in comparison to the decrease seen under basal conditions (9 and 1 mV for citrate and heparinized plasma at 10 mM ascorbic acid, respectively), as more proteins become oxidized through H 2 O 2 treatment leading to an overall greater potential for reduction after ascorbic acid treatment. One previous study also found decreased ORP signal by ascorbate despite this study used the phosphate-buffered saline solution (PBS) rather than plasma [17]. Our data further validate the ability of the device to detect decreases in ORP signal when plasma samples are exogenously treated with an antioxidant independently of the basal ORP measurement.…”

“…Freeze-thawing control human plasma samples led to a decrease in ORP of 10 mV for citrated plasma and 6 mV for heparinized plasma measured at day 6 ( Figure 2(A); two-way ANOVA, P < .05, n = 5). We also measured the stability of the ORP signal in oxidized samples by adding exogenous H 2 O 2 (1%) to mimic the ORP signal obtained in a severe disease state such a sepsis or trauma [10,11,17]. Freeze-thawing exogenously elevated plasma samples with 1% H 2 O 2 also led to a decrease in ORP signal of 25 mV and 22 mV for citrated and heparinized plasma, respectively (Figure 2(B); two-way ANOVA, P < .05, n = 5).…”

Semen quality and infertility status can be identified through measures of oxidation-reduction potential

“…Recently, the development of a novel technology has removed the limitations by creating a single‐use electrode sensor that requires only 30 μl of sample. This has allowed expansion into biomedical fields in which oxidative stress is suspected (Agarwal, Sharma, Roychoudhury, Du Plessis, & Sabanegh, ; Bjugstad, Rael, et al., ; Bjugstad, Fanale, ; Rael, Bar‐Or, Kelly, Carrick, & Bar‐Or, ).…”

Poor acute outcome in congestive heart failure is associated with increases in the plasma static oxidation–reduction potentials (sORP) in men but not in women

“…Therefore, measures of ORP provide a relative indicator of the balance between all pro-and anti-oxidants which, consistent with the recent definitions, is indicative of oxidative stress [3,26,27]. ORP has traditionally been used in water quality testing [28][29][30] but has also been applied to medical biologics for assessing relative change in oxidative stress [23,[31][32][33][34][35][36][37][38]. In the current study, we used ORP as an indicator of relative plasma oxidative stress to illuminate potential differences between men and women hospitalized for CHF.…”