A Modified Chemiluminescent Method for Determination of the Antioxidant Capacity of Biological Fluids and Tissues

Resumo

Abstract—In this study we present a modified method for determination of the antioxidant capacity of biological fluids and tissues based on the use of a chemiluminescent model system in which oxidation of luminol was induced by 2,2'-azobis(2-amidinopropane) dihydrochloride. It was shown that the addition of EDTA as an extra component gives the system a number of advantages. The intensity of chemiluminescence at the stationary stage was increased substantially (by 6–7 times) and stationarity remained unchanged for a long period of time (more than 1 h). As well, it should be noted that no significant increase in the intensity of chemiluminescence occurred in the presence of biological fluids or individual antioxidants (human serum albumin and ascorbic acid) after the end of the latent period but it was observed in the absence of EDTA. Taking the fact into account that the values of the latent periods that were determined while introducing some low-molecular-weight antioxidants (trolox and uric acid) into our system, as well as human biological fluids (blood serum and tear fluid), were not significantly different from those obtained in the system without EDTA, we suppose that EDTA had no impact on luminol oxidation reactions. The proposed system can also be used to evaluate antioxidant capacity of various tissues. The obtained data are discussed in terms of prospects for the use of the proposed modified method for determination of the antioxidant capacity of biological material in clinical practice.