A simple automated procedure for thiol measurement in human serum samples

Carolina M Da Costa,Emerson S Lima,Rita C C Dos Santos

doi:10.1590/s1676-24442006000500006

Carolina M Da Costa, Emerson S Lima + Show 1 more

Open Access

https://doi.org/10.1590/s1676-24442006000500006

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Abstract

Thiol groups have been described as the main responsible for antioxidative effects of plasmatic proteins. Also, thiol serum levels have shown a positive correlation with total antioxidant capacity (TAC) in many studies. Measurement of TAC by substract oxidation-based methods have been widely used as a reference to measure antioxidant status; however, in many cases these methods are inexact or imprecise, usually when performed by manual procedures. In this paper we describe a simple automated procedure for the determination of total thiols in serum, which was based on Ellman’s method. It was correlated with several markers of oxidative/antioxidative status, such as TAC and thiobarbituric acid reactive substance test (TBARs). Serum thiol levels were correlated positively with TAC (r = 0.298, p < 0.001) and negatively with TBARs levels (r = -0.330, p < 0.001). The novel automated procedure for thiol groups measurement can be a great tool in estimation of antioxidant status together with TAC assay. This procedure makes the determination of total thiol groups in large scale possible in clinical chemistry or research laboratories where this approach is necessary.

Highlights

Oxidative stress is a commonly used term to denote the imbalance between the concentrations of reactive oxygen and nitrogen species and the antioxidative defense mechanisms of the body[11, 13, 14, 21]
It shows that when separated by sex no variation was shown for the majority of the analyzed parameters, except for albumin, uric acid and iron, as was already believed (t test, p < 0.05)
The average levels were in accordance with those described in literature

Summary

Introduction

Oxidative stress is a commonly used term to denote the imbalance between the concentrations of reactive oxygen and nitrogen species and the antioxidative defense mechanisms of the body[11, 13, 14, 21]. The determination of the oxidative stress status of a person allows comparison with the average of a population, but can indicate the risk of suffering disorders and diseases that are product of oxidative stress[2] Thiols are those compounds which contain the sulfhydryl group (- SH) attached to a carbon atom. Thiols are extraordinarily efficient antioxidants protecting cells against consequences of damage induced by free radicals, due to their ability to react with the latter[3, 27]. Both intracellular and extracellular redox states of thiols play a critical role in the determination of protein structure and function, regulation of enzymatic activity of transcription factors and antioxidant protection[29]

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