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Determination of the total mass of antioxidant substances and antioxidant capacity per unit mass in serum using redox titration.

Zhang M, Liu N, Liu H - Bioinorg Chem Appl (2014)

Bottom Line: Results.Compared with the younger group, total antioxidant capacity in the over-75-year age group was found to be significantly reduced, along with a decrease in the mass of antioxidant substances and average activity levels in human serum.Conclusions.

View Article: PubMed Central - PubMed

Affiliation: College of Medical Laboratory, Dalian Medical University, Dalian 116044, China.

ABSTRACT
Objective. Total antioxidant capacity in serum is determined by the total mass of antioxidant substances and the antioxidant capacity per unit mass (average activity). The purpose of this study was to develop a method to determine the mass of antioxidant substances and average activity in human serum. Methods. Specimens of serum were collected from 100 subjects each from two different age groups: over 75 years old and 20-40 years old. The test serum was diluted into a series of concentrations, following which standard oxidation agents (KMnO4 for potassium permanganate method and I2 for iodimetry) were added to each concentration of serum, and the absorbance of the mixture (optical density, OD) was measured. The OD value and logarithm of dilution factor (lgT) at the end of the titration were obtained, from which the lgT could be considered as mass of antioxidant substances (M). Total antioxidant capacity (Ta) was calculated with the equation Ta = 100/(OD1 + 2 ∗ OD2 + 2 ∗ OD3 + 2 ∗ OD4 + OD5), and average activity (A) was calculated as A = Ta/M. Results. The potassium permanganate method generated similar results to the iodimetric method. Compared with the younger group, total antioxidant capacity in the over-75-year age group was found to be significantly reduced, along with a decrease in the mass of antioxidant substances and average activity levels in human serum. Conclusions. The approach described in this paper is suitable for determining the average activity and mass of antioxidant substances in human serum.

No MeSH data available.


Schematic diagram of total antioxidant capacity, calculated as the total area under the plotted line.
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fig1: Schematic diagram of total antioxidant capacity, calculated as the total area under the plotted line.

Mentions: A constant volume of standard oxidation agent (iodine or potassium permanganate) was added to a series of diluted test samples (double dilution), and measurements were performed in a point-by-point manner. Changes in OD values were arranged from the smallest to the largest. OD values changed as a result of oxidation agents reacting with reducing serum samples. The serum dilution factors (1 : 10; 1 : 20; 1 : 40; 1 : 80; and 1 : 160) were transformed into a logarithmic scale (1.0, 1.30, 1.6, 1.9, and 2.2) to simple calculations (Figure 1). The area under the plotted line inversely represented the total antioxidant capacity of the serum, as explained below.


Determination of the total mass of antioxidant substances and antioxidant capacity per unit mass in serum using redox titration.

Zhang M, Liu N, Liu H - Bioinorg Chem Appl (2014)

Schematic diagram of total antioxidant capacity, calculated as the total area under the plotted line.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4129143&req=5

fig1: Schematic diagram of total antioxidant capacity, calculated as the total area under the plotted line.
Mentions: A constant volume of standard oxidation agent (iodine or potassium permanganate) was added to a series of diluted test samples (double dilution), and measurements were performed in a point-by-point manner. Changes in OD values were arranged from the smallest to the largest. OD values changed as a result of oxidation agents reacting with reducing serum samples. The serum dilution factors (1 : 10; 1 : 20; 1 : 40; 1 : 80; and 1 : 160) were transformed into a logarithmic scale (1.0, 1.30, 1.6, 1.9, and 2.2) to simple calculations (Figure 1). The area under the plotted line inversely represented the total antioxidant capacity of the serum, as explained below.

Bottom Line: Results.Compared with the younger group, total antioxidant capacity in the over-75-year age group was found to be significantly reduced, along with a decrease in the mass of antioxidant substances and average activity levels in human serum.Conclusions.

View Article: PubMed Central - PubMed

Affiliation: College of Medical Laboratory, Dalian Medical University, Dalian 116044, China.

ABSTRACT
Objective. Total antioxidant capacity in serum is determined by the total mass of antioxidant substances and the antioxidant capacity per unit mass (average activity). The purpose of this study was to develop a method to determine the mass of antioxidant substances and average activity in human serum. Methods. Specimens of serum were collected from 100 subjects each from two different age groups: over 75 years old and 20-40 years old. The test serum was diluted into a series of concentrations, following which standard oxidation agents (KMnO4 for potassium permanganate method and I2 for iodimetry) were added to each concentration of serum, and the absorbance of the mixture (optical density, OD) was measured. The OD value and logarithm of dilution factor (lgT) at the end of the titration were obtained, from which the lgT could be considered as mass of antioxidant substances (M). Total antioxidant capacity (Ta) was calculated with the equation Ta = 100/(OD1 + 2 ∗ OD2 + 2 ∗ OD3 + 2 ∗ OD4 + OD5), and average activity (A) was calculated as A = Ta/M. Results. The potassium permanganate method generated similar results to the iodimetric method. Compared with the younger group, total antioxidant capacity in the over-75-year age group was found to be significantly reduced, along with a decrease in the mass of antioxidant substances and average activity levels in human serum. Conclusions. The approach described in this paper is suitable for determining the average activity and mass of antioxidant substances in human serum.

No MeSH data available.