The Quantitative Determination of the Total Antioxidant Activity of Tears

In the present study, the authors developed a protocol for determining the total antioxidant activity of tears. For this purpose, a chemiluminescent model of free-radical oxidation of luminol initiated in the presence of hemoglobin and hydrogen peroxide was used. This approach allows for controlling the kinetics of inhibition of luminol oxidation by tears. Total antioxidant activity was evaluated by the induction period, which showed the delay time of the initiation of luminol oxidation. The calibration curve for tear fluid was linear within the range from 0.5 to 7 μL (r2 = 0.972). The advantages of the developed protocol are high sensitivity, reproducibility, and rapidity of the assay. This makes our protocol suitable for determining the total antioxidant activity of tears. Keywords: total antioxidant activity, tear fluid, antioxidants, chemiluminescence