Comparative investigation of antioxidant activity of human serum blood by amperometric, voltammetric and chemiluminescent methods

INTRODUCTION: A blood test can provide important information about the functional state of the antioxidant system. Malfunction of this system increases the concentration of free radicals and can cause oxidative stress. A difficulty in assessing oxidative stress is the lack of a universal method for determining the antioxidant activity (AOA) of blood components, because of their different nature. MATERIAL AND METHODS: The objects of investigation were sera of 30 male patients with a diagnosis of alcohol dependence syndrome and healthy donors. Comparative investigation of total antioxidant activity (TAA) of human serum blood was carried out by voltammetric (VA), amperometric (AM) and chemiluminescent (HL) methods. RESULTS: All applied methods revealed that serum TAA of the patients with alcoholism is lower than TAA of healthy donors (control group); according to amperometric method the average value of serum TAA was 850 ±210 nA × s, and 660 ±150 nA × s for healthy donors and alcoholics respectively (p < 0.05). Similar trend was revealed by chemiluminescence and voltammetry methods. The results confirm that thiol compounds make a significant contribution to the antioxidant activity of serum. The average thiol concentrations were 0.94 ±0.34 mmol/l and 1.21 ±0.36 mmol/l (p < 0.05) for alcoholics and healthy donors respectively. Decreasing thiol concentration in blood of alcoholics leads to depletion of antioxidant systems of blood. However, the differences between the results of AM, VA and HL methods were significant, because they reflected different aspects of antioxidant activity. CONCLUSIONS: For objective assessment of antioxidant activity of biological objects, we suggest using methods based on different model systems.