The modification of the methodology for determining the antioxidant activity of saliva

Relevance. The state of antioxydant system is of great importance for the athlets whose activities are accompanied by oxidative stress development. Thus the use of saliva as an object of biochemical analysis is very promising because of the ease of taking biomaterial. Also there are a positive correlations between individual indicators of saliva and blood plasma antioxydant systems. The number of methods for assessing the antioxidant activity of saliva is known but there also remains the problem of development of simple techniques that do not require expensive reagents and equipment.

Objective. The objective of the work is to modify and adapt the method for determining the overall antioxidant activity of saliva according to the inhibition rate of oxidation of Tween-80 to TBA-active products. Modification's essence lies in the use of Fenton 's reaction (Н₂О₂ + ions Fe²⁺) to initialize an oxidation.

Material and methods. For the study used mixed saliva samples. In the experience I we used a method of determining the antioxidant activity proposed for blood plasma by Galactionova L.P. et al. (1998). According to this method Tween-80 oxidation was initiated by a mixture of Iron(II) sulfate and ascorbic acid, after which the saliva was added. In the experience II the same operations were carried out, but we added 0.1 ml of 2 % water solution of hydrogen peroxide. The samples were incubated in darkness at 40°С, in doing so, we used five parallel series, each with different incubation time: 1, 2, 4, 24, 48 hours. The overall antioxidant activity was determined by the degree of reduction of TBA-active products formation.

Results. It was found that the addition of hydrogen peroxide to the initiating mixture makes Tween-80 oxidation and TBA-active products formation more intense than when using only Iron(II) sulfate and ascorbic acid as oxidation initiators. The maximum of TBA-active products formation is observed after 2 hours in contrast to 48 hours in original method. The results of determining saliva overall antioxidant activity obtained by modified method also speak in favor of 2 hour samples incubation period.

Conclusions. The proposed modification of the methodology for determining overall antioxidant activity by Galactionova L.P. et al. makes it possible to reduce the duration of examining and is adapted for saliva analysis.